WO2023058613A1 - Film formation method, electronic device production method, and film formation device - Google Patents

Abstract

Provided is a film formation method and an application thereof, the method comprising: a step for preparing a stepped substrate, which is a substrate having a step in the substrate thickness direction; and a film formation step for discharging an ink from an inkjet head to supply the ink onto at least the top surface of the step of the stepped substrate, blowing air on to the ink which has come into contact with the top surface of the step to form a film that covers at least the top surface and the side surfaces of the step,

Description

Film forming method, electronic device manufacturing method, and film forming apparatus

The present disclosure relates to a film forming method, an electronic device manufacturing method, and a film forming apparatus.

Various studies are being conducted on techniques for applying liquid to substrates with steps (e.g., uneven patterns, electronic components, etc.).

Patent Literature 1 discloses the following coating device as a solution coating device capable of preventing unevenness in a thin film formed by a solution coated on a substrate.
The coating device disclosed in Patent Document 1 is
A solution applicator for applying a solution to the recesses and protrusions of a substrate having an uneven pattern in which recesses and protrusions are regularly formed on the upper surface by inkjet method,
a coating head having a plurality of nozzles arranged along a predetermined direction and coating the substrate with the dot-shaped solution from the plurality of nozzles at a constant timing;
a driving means for relatively moving the substrate and the coating head;
When the substrate and the coating head are moved relative to each other by the driving means, each line of the dot-shaped solution discharged from each of the nozzles and coated on the substrate is arranged adjacent to the upper surface of the substrate. control means for controlling the direction of relative movement to be shifted by a predetermined angle with respect to the extending direction of the uneven pattern so as to straddle two or more of the protrusions extending in the extending direction of the uneven pattern;
It is a solution coating device comprising:

Patent Document 2 discloses a sealant supply control method capable of continuously applying a predetermined amount of sealant at a predetermined number of times while applying the sealant continuously without a waiting time for permeation of the sealant. The following supply control method is disclosed as a supply control method for the sealant to be provided.
The supply control method disclosed in Patent Document 2 is
While relatively moving the coating head that discharges the sealant and the circuit board on which the electronic component is mounted, the supply of the sealant that is repeatedly applied multiple times between each electronic component and the circuit board is controlled. in the method
The supply amount of the sealant to be applied to each electronic component is divided into the number of times of application corresponding to the viscosity of the sealant and the size of the electronic component, and the divided amount of the sealant is increased as the number of times of application increases. The amount of the sealant is set to alternately increase or decrease according to the above and is allocated for each application, and the amount of the sealant that is allocated for each application is changed from the application head by varying the discharge pressure of the application head. It was set and supplied by the control of
This is a method of controlling the supply of a sealant.

Patent Document 1: Japanese Patent No. 5244758 Patent Document 2: Japanese Patent Application Laid-Open No. 11-47657

In some cases, a film that covers at least the top surface (that is, the upper surface) and side surfaces of a step is formed by an inkjet method on a substrate with a step, which is a substrate having a step in the thickness direction of the substrate.
An example of a stepped board is an electronic board including a wiring board and electronic components arranged on the wiring board.

The inventors of the present invention have found that, in the formation of the film by the inkjet method, the thickness of the film from the top surface of the step (that is, the top surface) to the side surface of the step may vary greatly. .

Specifically, as a case where the thickness variation of the film becomes large, for example:
When the thickness of the film on the side surface of the step is too thin compared to the thickness of the film on the top surface of the step;
When the thickness of the film on the corner of the joint between the side surface and the top surface of the step is too thin compared to the thickness of the film on the top surface of the step;
etc.

An object of one aspect of the present disclosure is to form a film that covers at least the top surface of the step and the side surface of the step on a stepped substrate, which is a substrate having a step in the substrate thickness direction, by an inkjet method. To provide a film forming method and a film forming apparatus capable of suppressing variation in film thickness from the top surface of a step to the side surface of a step.
An object of another aspect of the present disclosure is to apply ink by an inkjet method to a region including at least the top surface of the electronic component and the side surface of the electronic component on the electronic substrate including the wiring board and the electronic component arranged on the wiring board. Manufacture of an electronic device capable of suppressing variations in the thickness of the insulating layer and/or conductive layer from the top surface of the electronic component to the side surface of the electronic component when the insulating layer and/or conductive layer are formed to form the electronic device. to provide a method.

Specific means for solving the above problems include the following aspects.
<1> Preparing a stepped substrate, which is a substrate having a step in the thickness direction of the substrate;
Ink is applied to at least the top surface of the steps in the substrate with steps by ejecting ink from an inkjet head, and by blowing air against the ink applied to the top surface of the steps, at least the top surface of the steps. and a film forming step of forming a film covering the side surface of the step;
including,
Membrane formation method.
<2> The method for forming a film according to <1>, wherein the wind speed is 1 m/s or more and less than 30 m/s.
<3> The method of forming a film according to <1> or <2>, wherein the film forming step includes collecting air.
<4> The film forming step further includes subjecting the ink blown by the wind to pinning exposure,
The time from the start of wind blowing to the start of pinning exposure is 1 second or less.
The method for forming a film according to any one of <1> to <3>.
<5> The film forming step further includes subjecting the ink applied on the top surface of the step to the ink before the wind is blown to a pinning exposure.
The method for forming a film according to any one of <1> to <4>.
<6> The wind is blown out from the wind blower,
The direction of the wind includes a component in the opposite direction to the side where the inkjet head is arranged when viewed from the wind blower,
The method for forming a film according to any one of <1> to <5>.
<7> Applying the ink in the film forming step is performed while relatively moving the stepped substrate and the inkjet head,
In the ink applied to the stepped substrate, the dot resolution in the direction of relative movement is higher than the dot resolution in the direction perpendicular to the direction of relative movement.
The method for forming a film according to any one of <1> to <6>.
<8> The wind is an inert gas stream,
the ink is an active energy ray-curable ink containing a polymerizable compound;
The method for forming a film according to any one of <1> to <7>.
<9> The stepped substrate includes a base substrate and components arranged on the base substrate, and a gap exists between the base substrate and the components.
The method for forming a film according to any one of <1> to <8>.
<10> Furthermore, before the film forming step, a partition wall forming step of forming partition walls surrounding the region where the film is formed by ejecting ink from an inkjet head,
The method for forming a film according to any one of <1> to <9>.
<11> Furthermore, before the film forming step, at least the region where the film is to be formed is subjected to a hydrophilic treatment,
The method for forming a film according to any one of <1> to <10>.
<12> A step of preparing an electronic substrate including a wiring substrate and electronic components arranged on the wiring substrate;
forming at least one of an insulating layer and a conductive layer on an electronic substrate to obtain an electronic device;
including
At least one of the insulating layer and the conductive layer is formed by the film forming method according to any one of <1> to <11>,
A method of manufacturing an electronic device.
<13> An inkjet head that applies ink to at least the top surface of the step in the stepped substrate, which is a substrate having a step in the thickness direction of the substrate;
A wind blower for blowing air against the ink applied on the top surface of the step;
with
The stepped substrate and the inkjet head move relative to each other,
A film forming apparatus, wherein an inkjet head and an air blower are arranged in a direction of relative movement.
<14> Furthermore, a wind collector for collecting wind is provided,
The film forming apparatus according to <13>.
<15> The component contains a component in which the direction of the wind blown from the wind blower is opposite to the side on which the inkjet head is arranged as viewed from the wind blower,
The film forming apparatus according to <13> or <14>.
<16> Equipped with two wind blowers,
An inkjet head is arranged between the two air blowers,
the relative movement is reciprocating movement,
The film forming apparatus according to any one of <13> to <15>.
<17> The wind blower has an on/off function for switching between an on state for blowing air and an off state for stopping the blowing of air.
The film forming apparatus according to any one of <13> to <16>.
<18> Further, it comprises a pinning exposure machine that performs pinning exposure on the ink blown by the wind.
The film forming apparatus according to any one of <13> to <17>.
<19> Further, a pinning exposure machine is provided for performing pinning exposure on the ink applied on the top surface of the step and before the wind is blown,
The film forming apparatus according to any one of <13> to <18>.

According to one aspect of the present disclosure, in forming a film that covers at least the top surface of the step and the side surface of the step on a stepped substrate, which is a substrate having a step in the thickness direction of the substrate, by an inkjet method, the step is Provided are a film forming method and a film forming apparatus capable of suppressing variations in film thickness from the top surface of the step to the side surface of the step.
According to another aspect of the present disclosure, a region including at least the top surface of the electronic component and the side surface of the electronic component on the electronic substrate including the wiring board and the electronic component arranged on the wiring board is coated by an inkjet method. Manufacture of an electronic device capable of suppressing variations in the thickness of the insulating layer and/or conductive layer from the top surface of the electronic component to the side surface of the electronic component when the insulating layer and/or conductive layer are formed to form the electronic device. A method is provided.

1 is a process flow chart conceptually showing a method of forming a film according to an embodiment of the present disclosure; FIG. 1 is a process flow chart conceptually showing a method of forming a film according to an embodiment of the present disclosure; FIG. 1 is a process flow chart conceptually showing a method of forming a film according to an embodiment of the present disclosure; FIG. 1 is a process flow chart conceptually showing a method of forming a film according to an embodiment of the present disclosure; FIG. FIG. 4 is a schematic side view showing an example of a stepped substrate in which a gap exists between the base substrate and the member; 4 is a schematic plan view conceptually showing an example of a mode in which the dot resolution in the direction of relative movement is higher than the dot resolution in the direction orthogonal to the direction of relative movement in the present disclosure; FIG. FIG. 4 is a schematic side view conceptually showing an example of how ink lands on a corner of a member in the present disclosure. FIG. 4 is a conceptual diagram showing an example of elevation angles in the present disclosure; FIG. 4 is a schematic side view showing an example after the partition forming step and before the film forming step in the case where the film forming method of the present disclosure includes the partition forming step. 1 is a schematic plan view showing an example of a film forming apparatus of the present disclosure; FIG. 7B is a side view of FIG. 7A; FIG. 7B is a schematic cross-sectional view showing a modification of the film forming apparatus shown in FIG. 7B; FIG. FIG. 4 is a schematic plan view showing another example of the film forming apparatus of the present disclosure; 8B is a side view of FIG. 8A; FIG. FIG. 4 is a schematic plan view showing still another example of the film forming apparatus of the present disclosure; Figure 9B is a side view of Figure 9A; FIG. 4 is a schematic plan view showing still another example of the film forming apparatus of the present disclosure; 10B is a side view of FIG. 10A; FIG. FIG. 4 is a schematic plan view showing still another example of the film forming apparatus of the present disclosure; FIG. 4 is a schematic plan view showing still another example of the film forming apparatus of the present disclosure; 1 is a schematic plan view showing an example of a film forming apparatus of the present disclosure in which two air blowers are provided; FIG. 13B is a side view of FIG. 13A; FIG. FIG. 13B is a side view of the case where the conveying direction of the stepped substrate is reversed with respect to FIG. 13B. 1 is a schematic plan view showing an example of a film forming apparatus of the present disclosure in which two air blowers are provided; FIG. 14B is a side view of FIG. 14A; FIG. FIG. 14B is a side view of a case in which the conveying direction of the stepped substrate is reversed with respect to FIG. 14B; FIG. 4 is a schematic plan view of an electronic substrate prepared in a preparation step in the method of manufacturing an electronic device according to the embodiment of the present disclosure; FIG. 15B is a cross-sectional view taken along the line XX of FIG. 15A; 1 is a schematic plan view of an electronic substrate on which an insulating protective layer is formed in a first step in a method of manufacturing an electronic device according to an embodiment of the present disclosure; FIG. FIG. 16B is a cross-sectional view taken along line XX of FIG. 16A; FIG. 4 is a schematic plan view of an electronic substrate (that is, an electronic device according to an embodiment of the present disclosure) on which an electromagnetic wave shield layer is formed in a second step in a method for manufacturing an electronic device according to an embodiment of the present disclosure; FIG. 17B is a cross-sectional view taken along the line XX of FIG. 17A;

In the present disclosure, a numerical range indicated using "to" means a range including the numerical values before and after "to" as the minimum and maximum values, respectively.
In the numerical ranges described step by step in the present disclosure, upper or lower limits described in a certain numerical range may be replaced with upper or lower limits of other numerical ranges described step by step. In addition, in the numerical ranges described in the present disclosure, upper or lower limits described in a certain numerical range may be replaced with values shown in Examples.

In the present disclosure, when there are multiple substances corresponding to each component in the composition, the amount of each component in the composition is the total amount of the multiple substances present in the composition unless otherwise specified. means.
In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.
In the present disclosure, the term "process" includes not only an independent process, but also if the intended purpose of the process is achieved, even if it cannot be clearly distinguished from other processes. .

[Method of Forming Film]
The method of forming the membrane of the present disclosure comprises:
a step of preparing a stepped substrate that is a substrate having a step in the thickness direction of the substrate (hereinafter also referred to as a “stepped substrate preparation step”);
Ink is applied to at least the top surface of the stepped substrate by ejecting ink from an inkjet head, and by blowing air against the ink that has landed on the top surface of the stepped surface, at least the top surface of the stepped portion and the top surface of the stepped portion. a film forming step of forming a film covering the side surface of the step;
including.
The film formation method of the present disclosure may include other steps as necessary.

According to the film forming method of the present disclosure, when forming a film covering at least the top surface of the step and the side surface of the step on the stepped substrate by the inkjet method, the top surface of the step and the side surface of the step are formed. It is possible to suppress variations in the thickness of the film over time.
The reason why such an effect can be obtained is that the air blowing against the ink that has landed on the top surface of the step can cause a part of the ink on the top surface to flow around the side surface, and as a result, the film on the side surface of the step and/or the thickness of the film on the corner located at the joint between the side surface and the top surface of the step can be suppressed.

There is no particular limitation on the apparatus for carrying out the film formation method of the present disclosure.
The film forming method of the present disclosure can be implemented, for example, by a film forming apparatus of the present disclosure, which will be described later.

<One Embodiment of Film Forming Method>
An embodiment of the film forming method of the present disclosure will be described below with reference to the drawings.
However, the film forming method of the present disclosure is not limited to the following embodiments.
In the following description, substantially the same elements (for example, parts or portions) may be denoted by the same reference numerals, and redundant description may be omitted.

1A-1D are process flow diagrams conceptually illustrating a method of forming a film according to an embodiment of the present disclosure.
In the method of forming a film according to this embodiment, a stepped substrate 10 shown in FIG. 1A is prepared.
The stepped substrate 10 includes a flat base substrate 12 and members 18 provided on the base substrate 12 .
In this embodiment, the end of the member 18 on the base substrate 12 corresponds to the “step” in the present disclosure, the side surface 18S of the end of the member 18 corresponds to the side of the step in the present disclosure, and the The top surface 18U corresponds to the top surface of the step in the present disclosure.

As shown in FIGS. 1A and 1B, in this embodiment, the inkjet head 24 is fixed, and ink is ejected from the inkjet head 24 while transporting (that is, moving) the stepped substrate 10 in the transport direction M1. 26 is discharged. As a result, the ink 26 is applied to the area including the top surface of the member 18 .
In the film forming process in this embodiment, the inkjet head is fixed and the stepped substrate is moved, but the stepped substrate may be fixed and the inkjet head may be moved, or both the inkjet head and the stepped substrate may be moved. may
In the film forming process in this embodiment, the ink is applied to the area extending over the top surface of the member 18 and the area outside the top surface (on the side surface of the member 18 and on the base substrate 12). However, the ink may be applied at least on the top surface of the member 18 and may be applied only on the top surface of the member 18 .

As shown in FIG. 1B, in this embodiment, after applying the ink 26, the thickness of the ink 26 on the side surface 18S of the member 18 and the thickness of the ink 26 on the corner 18C located at the joint between the side surface 18S and the top surface 18U The thickness of the ink 26 on the top surface 18U is thinner than the thickness of the film on the top surface 18U.
As a result, variations in the thickness of the film from the side surface 18S to the top surface 18U of the member 18 are increased.
The problem of the film forming method of the present disclosure is to suppress this thickness variation.

As shown in FIG. 1C, in this embodiment, after applying the ink 26, a wind W1 is blown to the ink 26 on the top surface 18U. A portion of the ink 26 on the central portion of the top surface 18U moves onto the peripheral edge portion of the top surface 18U and further moves onto the corner portions 18C and the side surfaces 18S due to the force of the wind W1.
As a result, as shown in FIG. 1D, the phenomenon that the thickness of the ink on the corner 18C and the side surface 18S becomes thin is suppressed, and the variation in the thickness of the film from the side surface 18S to the top surface 18U is suppressed. be.

Next, each step in the film formation method of the present disclosure will be described.

<Stepped substrate preparation process>
The film formation method of the present disclosure includes a stepped substrate preparation step.
A stepped substrate is a substrate having a step in the thickness direction of the substrate.
The stepped substrate preparation step may be a step of simply preparing a previously manufactured stepped substrate, or may be a step of manufacturing a stepped substrate.

An example of the stepped substrate is the stepped substrate 10 including the base substrate 12 and the member 18 arranged on the base substrate 12 described above.
The member 18 may be a component (e.g., electronic component) attached to the base substrate 12 (e.g., wiring board), or a pattern film (e.g., metal pattern film, insulating film, resist pattern film, etc.).

The stepped substrate 10 may be an electronic substrate including a wiring substrate and electronic components arranged on the wiring substrate.
As the wiring board, a board on which wiring is formed, for example, a printed wiring board can be used.
Examples of electronic components include semiconductor chips such as integrated circuits (ICs), capacitors, and transistors.
The wiring board may include a ground electrode, ground wiring, a solder resist layer, and the like.

The substrate with a step is not limited to a substrate with a step formed by attaching a member to the base substrate. including), through holes, etc.) may be formed.

The material of the base substrate in the stepped substrate is not particularly limited, but examples include glass, ceramics, metal, resin, and the like.

The stepped substrate includes a base substrate and a member arranged on the base substrate, and a gap may exist between the base substrate and the member.
In the conventional film formation method without air blowing, if there is a gap between the base substrate and the member, when the ink is applied to the region including the member, the gap between the base substrate and the member The thickness of the ink on the side surface of the member tends to be thinner because the ink enters the gap between the members.
However, in the method of forming a film according to the present disclosure, by blowing air against the ink on the top surface of the member, the ink on the top surface can be made to flow onto the side surface.
Thus, when there is a gap between the base substrate and the member, the effect of the present disclosure is more likely to be exhibited by blowing air against the ink on the top surface of the step.

FIG. 2 is a schematic side view showing an example of a stepped substrate in which a gap exists between the base substrate and the member.
The structure of the stepped substrate 13 according to the example shown in FIG. It is a structure in which a gap 17 is provided between it and the member 18 .
The connection member 16 includes a connection material (for example, a solder ball, an adhesive, etc.) for connecting the base substrate 12 and the member 18, and the like.

<Film forming process>
A method of forming a film of the present disclosure includes a film forming step.
In the film forming step, ink is applied to at least the top surface of the stepped substrate by ejecting ink from an inkjet head, and by blowing air against the ink that has landed on the top surface of the stepped surface, at least This is a step of forming a film covering the top surface of the step and the side surface of the step.

(Applying ink)
The ink is not particularly limited, but examples thereof include conductive inks and insulating inks described later in the section of the electronic device manufacturing method.

As a method for applying ink, a known method in inkjet recording can be appropriately applied. As a method for ejecting ink from an inkjet head, a charge control method that ejects ink using electrostatic attraction, and a vibration pressure of a piezoelectric element can be used. The drop-on-demand method (pressure pulse method) used, the acoustic inkjet method that converts an electrical signal into an acoustic beam and irradiates it on the ink and uses radiation pressure to eject the ink, and the ink that is heated to form bubbles and generate Any thermal ink jet (bubble jet (registered trademark)) system that utilizes pressure may be used.
As a method for ejecting ink from an inkjet head, in particular, the method described in Japanese Patent Laid-Open No. 59936/1989, the volume of the ink undergoes abrupt changes due to the action of thermal energy. , an ink jet recording method in which ink is ejected from nozzles can be effectively used.
As for the method of ejecting ink from an inkjet head, the method described in paragraphs 0093 to 0105 of JP-A-2003-306623 can also be referred to.

It is preferable to apply the ink in the film forming step while relatively moving the stepped substrate and the inkjet head. As a result, the ink can be efficiently applied to a desired area on the stepped substrate.
In this case, the inkjet head may be fixed and the stepped substrate may be moved, the stepped substrate may be fixed and the inkjet head may be moved, or both the inkjet head and the stepped substrate may be moved.

When the ink is applied in the film forming process while the stepped substrate and the inkjet head are relatively moved, the dot resolution in the direction of the relative movement in the ink applied to the stepped substrate is different from the direction of the relative movement. It is preferably higher than the dot resolution in the orthogonal direction.
This makes it easier for the ink to land on the corners of the steps in the direction that intersects (for example, perpendicularly) the direction of relative movement, and as a result, secures the amount of ink adhering to the side surfaces of the steps in the intersecting direction. easier to do. As a result, since the thickness of the ink on the side surface of the step is ensured, variations in the thickness of the film from the side surface to the top surface of the step are further suppressed.

FIG. 3 is a schematic plan view conceptually showing an example of a mode in which the dot resolution in the direction of relative movement is higher than the dot resolution in the direction orthogonal to the direction of relative movement.
FIG. 4 is a schematic side view conceptually showing an example of how ink lands on a corner of a member.

In the example shown in FIG. 3, the stepped substrate 10 is moved in the transport direction M1, and a large number of ink dots D1 are formed over the member 18 and its surroundings on the stepped substrate 10 . In this example, the density (ie, dot resolution) of the ink dots D1 in the direction parallel to the transport direction M1 (ie, the direction of relative movement) is the same as the density of the ink dots D1 in the direction perpendicular to the direction of relative movement. higher than the density (ie dot resolution). More specifically, FIG. 3 illustrates a state in which the dot resolution in the direction of relative movement is about twice the dot resolution in the direction orthogonal to the direction of relative movement.

When the dot resolution in the direction of relative movement is higher than the dot resolution in the direction orthogonal to the direction of relative movement, as shown in FIG. easier to do. As a result, it is possible to ensure the amount of ink adhering to the side surface 18S below the corner 18C. to the top surface 18U is further suppressed.

(Blowing wind)
In the film forming process, by blowing air against the ink that has landed on the top surface of the step,
A film covering at least the top surface of the step and the side surface of the step is formed.
Specifically, as described above, due to the force of this wind, part of the ink that has landed on the top surface moves onto the corners and sides, and as a result, the thickness of the ink on the corners and sides becomes thin. phenomenon is suppressed.

When the film forming step includes blowing air against the ink that has landed on the top surface of the steps on the substrate with steps, the speed of the wind is not particularly limited.
From the viewpoint of exerting the above effects more effectively, the wind speed of the wind is preferably 1 m / s to 30 m / s, more preferably 1 m / s or more and less than 30 m / s, and 1 m / s to 25 m / s. /s, more preferably 2 m/s to 20 m/s, even more preferably 5 m/s to 15 m/s.

When the film forming step includes blowing air against the ink that has landed on the top surface of the steps on the substrate with steps, the direction in which the air blows against the ink that has landed on the top surface of the steps is particularly limited. no.
From the viewpoint of exhibiting the above effect more effectively, the direction in which the wind blows against the ink that has landed on the top surface of the step is preferably a direction in which the elevation angle is 10° to 90°, and the elevation angle is 20° to 90°. is more preferable, and a direction in which the elevation angle is 30° to 90° is even more preferable.

In the present disclosure, "the direction in which the wind B is blown against the ink that has landed on the top surface of the step is the direction in which the elevation angle is X degrees." It means that the angle from the horizontal plane when looking up is X° (here, X° is an angle in the range of 0° to 90°).
FIG. 5 is a conceptual diagram showing an example of elevation angles.
The elevation angle in this example is the angle X° from the horizontal plane when looking up at the position P1 where the wind blows represented by symbol W1 and the direction from which the wind comes.

Moreover, it is preferable that the wind is the wind blown from the wind blower.
As the air blower, for example, a dryer, hot air generator, compressed air generator, fan, blower, etc. can be used. Further, as the air blower, a pipe for circulating compressed air in the factory may be drawn into the film forming apparatus and used.

The direction of the air blown from the air blower preferably includes a component in the direction opposite to the side on which the inkjet head is arranged as viewed from the air blower (for example, see FIG. 7B described later). As a result, since the wind does not blow in the direction of the inkjet head, it is possible to further suppress the deterioration of the ink ejection accuracy due to the influence of the wind.

In the film forming method of the present disclosure, the wind is not particularly limited, and any gas stream can be used.
In the film forming method of the present disclosure, when the ink is an active energy ray-curable ink containing a polymerizable compound, the wind is preferably an inert gas stream. As a result, inhibition of polymerization by oxygen (specifically, a phenomenon in which oxygen inhibits the polymerization of a polymerizable compound in the active energy ray-curable ink) can be suppressed, so that the curability of the active energy ray-curable ink is excellent.
Examples of inert gas include nitrogen gas, argon gas, helium gas, and the like.

Moreover, it is preferable that the film forming step includes recovering the air blown against the ink.
As a result, it is possible to further suppress the pressure increase in the device (for example, the inkjet recording device) in which the film forming process is performed. Also, satellite droplets and/or mist droplets ejected from the inkjet head and not adhered to the substrate can be recovered.
The wind can be collected, for example, by using a wind collector, an exhaust device, or the like, which is a combination of a fan and a pipe connected to the outside of the film forming apparatus.
For example, in the wind collector, a replaceable filter is placed in front of the fan and replaced periodically to prevent satellite droplets and/or mist droplets from diffusing into the factory.

(pinning exposure)
The film forming step may further include subjecting the ink blown by the wind to pinning exposure (hereinafter also referred to as “pinning exposure A”).
Although the integrated exposure amount of the pinning exposure A is not particularly limited, it is, for example, 0.1 J/cm ² to 1000 J/cm ² .
Since the fluidity of the ink can be suppressed by this pinning exposure A, it is possible to suppress the ink adhering to the side surface of the step from flowing down due to gravity. Therefore, variations in the thickness of the film from the side surface to the top surface of the step can be further suppressed.
Although the integrated exposure amount of the pinning exposure A is not particularly limited, it is, for example, 0.1 J/cm ² to 1000 J/cm ² .
When the ink in the film forming step is the conductive layer forming ink described later, the integrated exposure amount of the pinning exposure A for the conductive layer forming ink is preferably 0.1 J/cm ² to 1000 J/cm ² , It is more preferably 1 J/cm ² to 100 J/cm ² .
When the ink in the film forming step is an insulating layer forming ink described later, the integrated exposure amount of the pinning exposure A for this insulating layer forming ink is preferably 0.1 J/cm ² to 100 J/cm ² , It is more preferably 0.1 J/cm ² to 10 J/cm ² .

The time from the start of blowing air to the start of pinning exposure A is preferably 1 second or less. As a result, variations in the thickness of the film from the side surface to the top surface of the step can be further suppressed.

The film forming step may further include applying pinning exposure (hereinafter also referred to as “pinning exposure B”) to the ink that has been applied to the top surface of the step and has not yet been blown with air. . As a result, the viscosity of the ink on the top surface can be increased appropriately, so that the ink on the top surface can be suppressed from excessively flowing down due to the blowing of the wind, and the ink on the top surface after the blowing of the wind can be prevented. It becomes easy to make it remain moderately on the top surface. As a result, the effect of suppressing variations in the thickness of the film from the side surface to the top surface of the step is exhibited more effectively.
The preferred range of the integrated exposure amount of the pinning exposure B is the same as the preferred range of the integrated exposure amount of the pinning exposure A.

Note that both the pinning exposure A (that is, the pinning exposure before wind is blown against the ink) and the above pinning exposure B (that is, the pinning exposure after the wind is blown against the ink) are arbitrary operations. be.
Therefore, in the film forming process, either one of the pinning exposure A and the pinning exposure B may be performed, both of them may be performed, or neither of them may be performed.

(heating)
The film forming step may include heating the stepped substrate to which the ink is applied to a temperature of 100° C. or higher.
As a result, the fluidity of the ink can be suppressed by heating and drying the ink, so that the ink adhering to the side surface of the step can be suppressed from flowing down due to gravity. Therefore, variations in the thickness of the film from the side surface to the top surface of the step can be further suppressed.

The heating temperature of the stepped substrate to which the ink is applied is preferably 250°C or less, more preferably 50°C to 200°C, and even more preferably 60°C to 180°C.

<Partition forming process>
The method of forming a film of the present disclosure includes, before the film forming step, a partition forming step of forming partitions surrounding a region where the film is formed by ejecting ink from an inkjet head.
In this aspect, due to the partition wall formed before the film forming step, the ink in the film forming step flows out of the originally intended region, and/or the ink in the film forming step does not form the film on the stepped substrate. A phenomenon that wraps around the surface is suppressed.

FIG. 6 is a schematic side view showing an example after the partition forming step and before the film forming step in the case where the film forming method of the present disclosure includes the partition forming step.
The example shown in FIG. 6 is the same as the example shown in FIG. 2 except that partition walls 19 are formed.
By previously providing the partition wall 19 surrounding the region where the film is formed before the film forming step (that is, before applying the ink), the outflow and wraparound described above are suppressed.

The method of forming the partition is not particularly limited, but from the viewpoint of productivity, it is preferable to form the partition by an inkjet method, as in the film forming process.

<Step of applying hydrophilic treatment>
The film forming method of the present disclosure may include a step of subjecting at least the region where the film is to be formed to a hydrophilic treatment prior to the film forming step.
As a result, the adhesion of ink to the side surfaces and corners of the steps is improved, so that variations in the thickness of the film from the side surfaces to the top surface of the steps can be further suppressed.

Examples of hydrophilic treatment include corona discharge treatment, ozone treatment, argon plasma treatment, oxygen plasma treatment, and the like.

<Preheating step>
The film forming method of the present disclosure preferably includes a step of heating the stepped substrate (also referred to as a “preheating step” in the present disclosure) prior to the film forming step.
In this case, the film forming step applies ink to the stepped substrate heated to the above temperature.

Because the fluidity of the ink can be suppressed by heating and drying the ink according to the aspect including the preheating step, it is possible to suppress the ink adhering to the side surface of the step from flowing down due to gravity. Therefore, variations in film thickness from the top surface to the side surface of the step can be further suppressed.

The heating temperature in the preheating step is more preferably 20°C to 120°C, still more preferably 28°C to 80°C.

<Film Formation on End Face of Stepped Substrate>
In the method of forming a film of the present disclosure, as described above, ink is applied to at least the top surface of the step of the stepped substrate, and air is blown onto the applied ink, thereby covering the top surface from the side surface of the step. To form a film in which thickness variation is suppressed.
At this time, the ink is also applied to the vicinity of the edge of the substrate with the step, and the ink in the vicinity of the edge is blown with air to flow the ink around the edge of the substrate with the step, thereby forming a film on the edge of the substrate with the step. may be formed. As a result, it is possible to form a film having excellent coverage over the end face of the stepped substrate.

Although there is no particular limitation on the apparatus for carrying out the film forming method of the present disclosure described above, the following film forming apparatus of the present disclosure is suitable.

[Film forming device]
The film forming apparatus of the present disclosure is
an inkjet head that applies ink to at least the top surface of the stepped substrate, which is a substrate having a stepped portion in the thickness direction of the substrate;
A wind blower for blowing air against the ink applied on the top surface of the step;
with
The stepped substrate and the inkjet head move relative to each other,
The inkjet head and the air blower are arranged in the direction of relative movement,
It is a film forming apparatus.

According to the film forming apparatus of the present disclosure, similarly to the film forming method of the present disclosure, for a stepped substrate that is a substrate having a step in the substrate thickness direction, the thickness from the top surface to the side surface of the step is A film with suppressed variation can be formed.
The reason why such an effect is obtained is as explained in the section of the film forming method of the present disclosure.

Preferred embodiments of the film forming apparatus of the present disclosure will be described below.
Each of the following aspects may be applied in combination as appropriate.

It is preferable that the film forming apparatus of the present disclosure further includes a wind collector that collects the wind.
The effect of recovering wind and an example of the wind collector are as described in the section of the membrane formation method of the present disclosure.

The direction of the air blown from the air blower preferably includes a component in the direction opposite to the side on which the inkjet head is arranged as viewed from the air blower (for example, see FIG. 7B described later). As a result, since the wind does not blow in the direction of the inkjet head, it is possible to further suppress the deterioration of the ink ejection accuracy due to the influence of the wind.

7A is a schematic plan view showing an example of the film forming apparatus of the present disclosure, and FIG. 7B is a side view of FIG. 7A.
As shown in FIGS. 7A and 7B, the film forming apparatus 300 according to this example includes a substrate transport stage 212 for transporting the stepped substrate 10, transport rails 210 on which the substrate transport stage 212 moves, and an inkjet head 24. , an air blower 28 , an air collector 30 , and a pinning exposure machine 32 .
The inkjet head 24, the wind blower 28, the wind recovery device 30, and the pinning exposure device 32 are arranged in this order from the upstream side in the transport direction M1 (that is, the movement direction of the substrate transport stage 212).

In the formation of the film using the film forming apparatus 300, ink is applied from the inkjet head 24 and air is applied from the air blower 28 to the area including the top surface of the stepped substrate 10 transported in the transporting direction M1. Wind blowing and pinning exposure by the pinning exposure device 32 are performed in this order. At this time, the wind is collected by the wind collector 30 as appropriate.
By blowing air from the air blower 28 against the ink applied on the top surface of the step, as described above, variations in the thickness of the film from the side surface to the top surface of the step are suppressed.
The pinning exposure by the pinning exposure unit 32 further suppresses variations in the thickness of the film, as described above.
As described above, the recovery of the wind by the wind recovery device 30 makes it possible to further suppress the pressure rise in the apparatus and to recover ink satellite droplets and/or mist droplets.

As shown in FIG. 7B, in this example, the direction W1 of the wind blown from the wind blower 28 includes a component W1X in the direction opposite to the side where the inkjet head 24 is arranged when viewed from the wind blower 28. .
As a result, since the wind is not directed toward the inkjet head 24, it is possible to further suppress the deterioration of the ink ejection accuracy due to the influence of the wind.

As shown in FIG. 7B , in this example, the reflection angle (hereinafter also simply referred to as “reflection angle”) with respect to the top surface of the step in the direction in which the wind is collected by the wind collector 30 is blown out from the wind blower 28. The angle of incidence of the direction W1 of the wind with respect to the top surface of the step (hereinafter also simply referred to as "incident angle") is adjusted to be substantially equal.

Here, the angle of incidence of the direction W1 of the wind blown from the wind blower 28 with respect to the top surface of the step corresponds to the elevation angle described above (see FIG. 5, for example).
The preferred range of the incident angle is the same as the preferred range of the elevation angle described above.

Since the angle of incidence (that is, the angle of elevation) is defined by the direction W1 of the wind blown out from the wind blower 28, the traveling direction of the wind inside the wind blower may be any direction. Therefore, for example, the modification (film forming apparatus 300X) shown in FIG. 7C below also has the same effect as the film forming apparatus 300 in FIG. 7B.
FIG. 7C is a schematic cross-sectional view showing a modification (film forming apparatus 300X) of the film forming apparatus 300 shown in FIG. 7B.
As shown in FIG. 7C, inside the wind blower 28X (that is, the flow path) in the film forming apparatus 300X, the wind first travels downward in the direction of gravity, then bends halfway and is blown out from the wind blower 28X. The angle of incidence of the direction W1 of the wind blown out from the wind blower 28X (FIG. 7C) is approximately the same as the angle of incidence of the direction W1 of the wind blown out from the wind blower 28 (FIG. 7B).
As shown in FIG. 7C, the wind is collected by the wind collector 30X in the film forming device 300X. The reflection angle of the wind (FIG. 7C) at this time is approximately the same as the reflection angle of the wind (FIG. 7B) when the wind is collected by the wind collector 30 . The wind collected by the wind collector 30X bends in its traveling direction inside the wind collector 30X (that is, the flow path), and then travels upward in the direction of gravity.
The configuration of the film forming apparatus 300X shown in FIG. 7C is the same as that of the film forming apparatus 300 shown in FIG. 7B except for the points described above.
The film forming apparatus 300X shown in FIG. 7C also has the same effect as the film forming apparatus 300 shown in FIG. 7B.

The air blower 28 and the air blower 28X preferably have an on/off function for switching between an on state for blowing air and an off state for stopping the blowing of air.
Thereby, it is possible to selectively blow the air onto the ink on the area including the top surface of the step.
The on/off function can be realized, for example, by providing a shutter at the air outlet of the air blower.

The film forming apparatus of the present disclosure is not limited to the example shown in FIGS. 7A-7C.
From the point of view of the effect of forming a film in which the thickness variation from the top surface to the side surface of the step is suppressed, the direction W1 of the wind blown from the wind blower 28 and the wind recovery device 30 recover the wind. The orientation is not limited to the above example. For example, the direction W1 of the wind blown from the wind blower 28 may be downward in the direction of gravity, and the direction in which the wind is recovered by the wind collector 30 may be upward in the direction of gravity.
Moreover, from the viewpoint of the effect of forming a film in which the thickness variation from the top surface to the side surface of the step is suppressed, the arrangement of the wind blower and the wind recovery device may be exchanged. Moreover, from the point of view of the above effect, the wind collecting device and the pinning exposure device may be omitted.

FIG. 8A is a schematic plan view showing another example (film forming apparatus 300A) of the film forming apparatus of the present disclosure, and FIG. 8B is a side view of FIG. 8A.
A film forming apparatus 300A shown in FIGS. 8A and 8B is different from the film forming apparatus 300 shown in FIGS. This is an example in which the direction of collecting wind is changed upward in the direction of gravity by means of 30 . In the film forming apparatus 300A shown in FIGS. 8A and 8B, similarly to the film forming apparatus 300 shown in FIGS. They are arranged in this order from the upstream side in the transport direction M1 (that is, the movement direction of the substrate transport stage 212).

FIG. 9A is a schematic plan view showing still another example (film forming apparatus 300B) of the film forming apparatus of the present disclosure, and FIG. 9B is a side view of FIG. 9A.
A film forming apparatus 300B shown in FIGS. 9A and 9B is an example in which the positions of the wind blowing device 28 and the wind collecting device 30 are exchanged with respect to the film forming device 300A shown in FIGS. 8A and 8B. That is, in this modification, the inkjet head 24, the wind recovery device 30, the wind blower 28, and the pinning exposure device 32 are arranged in this order from the upstream side in the transport direction M1 (that is, the movement direction of the substrate transport stage 212). ing.
According to this film forming apparatus 300B, the wind recovery device 30 not only recovers the wind from the wind blowing device 28, but also collects minute particles that do not reach the stepped substrate 10 and are carried together with the stepped substrate 10. Ink droplets (ink mist) can also be recovered. 8A and 8B, the air blower 28 can form a film in which the thickness variation from the side surface to the top surface of the step is suppressed. Further, since minute ink droplets can be collected by the wind collector 30, it is possible to suppress the diffusion of the minute ink droplets due to the wind from the wind blower 28. FIG.

FIG. 10A is a schematic plan view showing still another example (film forming apparatus 300C) of the film forming apparatus of the present disclosure, and FIG. 10B is a side view of FIG. 10A.
A film forming apparatus 300C shown in FIGS. 10A and 10B is an example in which a pinning exposure device 34 is added between the inkjet head 24 and the wind blower 28 to the film forming apparatus 300A shown in FIGS. 8A and 8B. . In the film forming apparatus 300C, the inkjet head 24, the pinning exposure device 34, the air blowing device 28, the air recovery device 30, and the pinning exposure device 32 are arranged from the upstream side in the transport direction M1 (that is, the movement direction of the substrate transport stage 212). arranged in this order.
According to the film forming apparatus 300C shown in FIGS. 10A and 10B, the pinning exposure can be performed by the pinning exposure device 34 on the ink applied on the top surface and before the wind blows. As a result, the viscosity of the ink on the top surface can be increased appropriately, so that the ink on the top surface can be suppressed from excessively flowing down due to the blowing of the wind, and the ink on the top surface after the blowing of the wind can be prevented. It becomes easy to make it remain moderately on the top surface. As a result, the effect of suppressing variations in the thickness of the film from the side surface to the top surface of the step is exhibited more effectively.

In addition, the pinning exposure for the ink applied on the top surface and before the air is blown can be performed by using the film forming apparatus 300C, or by reciprocating the stepped substrate. A film forming apparatus 300A shown in FIG. 8B can also be used.

In addition, from the viewpoint of the effect of suppressing the ink on the top surface from excessively flowing down due to the blowing of the wind, the pinning exposure is performed for the ink before the wind is blown, and the ink after the wind is blown. It is also possible to omit the pinning exposure.

Also, as exemplified below, in the example shown in FIGS. 8A and 8B, the wind recovery can be implemented even if the wind recovery machine is omitted.

FIG. 11 is a schematic plan view showing another example of the film forming apparatus of the present disclosure.
A film forming apparatus 301 shown in FIG. 11 is based on the film forming apparatus 300, omits the wind collector 30, and has a through hole 214 in the substrate transfer stage 213 instead. The through hole 214 in this example is provided outside the area of the substrate transfer stage 213 that contacts the stepped substrate 10 .
In the film forming apparatus 301, air can be recovered by exhausting the space in which the stepped substrate 10 is arranged through the through holes 214. FIG.

FIG. 12 is a schematic plan view showing still another example of the film forming apparatus of the present disclosure.
A film forming apparatus 302 shown in FIG. 12 is based on the film forming apparatus 300, omits the wind collector 30, and instead has a through hole 216 provided in the substrate transfer stage 215, and a stepped substrate 10A having a through hole. This device uses a stepped substrate in which holes 11 are formed. The through-hole 216 in this example is a through-hole extending from the outside of the area in contact with the substrate 10 with a step to the inside of the area in contact with the substrate 10 with a step in the substrate transfer stage 215 . This through-hole 216 has a function of collecting wind and a function of causing the substrate 10 with a step to be attracted to the substrate transfer stage 215 .
In the film forming apparatus 302, air can be recovered by exhausting the space in which the stepped substrate 10A is arranged through the through holes 11 of the stepped substrate 10A itself and the through holes 216 of the substrate transfer stage 215. FIG.

The film forming apparatus of the present disclosure includes two of the air blowers,
An inkjet head is arranged between the two air blowers,
It is preferable that the relative movement between the stepped substrate and the inkjet head is reciprocating movement.
According to this aspect, the application of ink and the blowing of air can be performed in both the forward movement and the backward movement, so the productivity of film formation is excellent.

13A is a schematic plan view showing an example of a film forming apparatus of the present disclosure in which two air blowers are provided, FIG. 13B is a side view of FIG. 13A, and FIG. FIG. 10 is a side view of the stepped substrate when the conveying direction is reversed;

As shown in FIGS. 13A to 13C, the film forming apparatus 400 according to this example includes, with respect to the film forming apparatus 300, an air blower 28B, an air collector 30B, and a pinning exposure machine 32B are added in this order.
The substrate transfer stage 212 in the film forming apparatus 400 is movable in both the transfer direction M11 (outward path) and the transfer direction M11B (return path) (that is, reciprocating movement is possible).

In the film formation using the film forming apparatus 400, similarly to the film formation using the film forming apparatus 300, in the region including the top surface of the step in the stepped substrate 10 transported in the transport direction M11 (outward path) On the other hand, application of ink from the inkjet head 24, blowing of air from the air blower 28, and pinning exposure by the pinning exposure device 32 are performed in this order. At this time, the wind is collected by the wind collector 30 as appropriate. During this time, none of the wind blower 28B, the wind collector 30B, and the pinning exposure device 32B are operated and turned off.
Further, the substrate transport stage 212 in the film forming apparatus 400 applies ink from the inkjet head 24 to the area including the top surface of the stepped substrate 10 transported in the transport direction M11B (return path), and blows air. The blowing of air from the machine 28B and the pinning exposure by the pinning exposure machine 32B are performed in this order. At this time, the wind is collected by the wind collector 30B as appropriate. During this time, none of the wind blower 28, the wind recovery device 30, and the pinning exposure device 32 are operated and turned off.

Another example different from the example shown in FIGS. 13A to 13C is an example in which at least one of the positions of the wind blower 28 and the wind collector 30 and the positions of the wind blower 28B and the wind collector 30B are exchanged. .
14A is a schematic plan view showing another example of the film forming apparatus of the present disclosure in which two air blowers are provided, FIG. 14B is a side view of FIG. 14A, and FIG. On the other hand, it is a side view in the case where the conveying direction of the stepped substrate is reversed.
According to the film forming apparatus 400A shown in FIGS. 14A to 14C, in the transport direction M11 (outward path), the wind collector 30 not only collects the wind from the wind blower 28, but also makes it reach the stepped substrate 10. It is also possible to collect minute ink droplets (ink mist) carried together with the stepped substrate 10 without removing. 13A to 13C, the air blower 28 can be used to form a film in which the thickness variation from the side surface to the top surface of the step is suppressed. . Further, since minute ink droplets can be collected by the wind collector 30, it is possible to suppress the diffusion of the minute ink droplets due to the wind from the wind blower 28. FIG.
Further, according to the modified example (film forming apparatus 400A), in the conveying direction M11B (return trip), the wind recovery device 30B not only recovers the wind from the wind blower 28B, but also makes it reach the stepped substrate 10. It is also possible to collect minute ink droplets (ink mist) carried together with the stepped substrate 10 without removing. 11A to 11C, the air blower 28B can form a film in which the thickness variation from the side surface to the top surface of the step is suppressed. Further, since minute ink droplets can be collected by the wind collector 30B, it is possible to suppress the diffusion of minute ink droplets due to the wind from the wind blower 28B.

The film forming method and the film forming apparatus of the present disclosure described above can be applied to all uses as a method and apparatus for forming a film on a stepped substrate by an inkjet method.
The film forming method of the present disclosure and the film forming apparatus of the present disclosure are applicable, for example, to the method of manufacturing an electronic device of the present disclosure, which will be described later.

[Method for producing electronic device]
The manufacturing method of the electronic device of the present disclosure includes:
preparing an electronic substrate comprising a wiring substrate and electronic components arranged on the wiring substrate;
forming at least one of an insulating layer and a conductive layer on an electronic substrate to obtain an electronic device;
including
At least one of the insulating layer and the conductive layer is formed by the film forming method of the present disclosure described above;
A method for manufacturing an electronic device.
The method of manufacturing an electronic device of the present disclosure may include other steps as necessary.

Since the electronic device manufacturing method of the present disclosure includes the film forming method of the present disclosure described above, according to the electronic device manufacturing method of the present disclosure, effects similar to those of the film forming method of the present disclosure described above are obtained. is played.
At least one of the insulating layer and the conductive layer in the electronic device manufacturing method of the present disclosure may be formed by the film forming apparatus of the present disclosure described above.

As mentioned above,
In the electronic device manufacturing method of the present disclosure, the electronic substrate (that is, the electronic substrate including the wiring substrate and the electronic components arranged on the wiring substrate) is the above-described "step difference" in the film forming method of the present disclosure. It corresponds to the board with
In the method for manufacturing an electronic device of the present disclosure, the end of the electronic component on the wiring board, the side surface of the end of the electronic component, and the top surface of the electronic component are each ""Step","Side of Step", and "Top of Step".

<An example of a method for manufacturing an electronic device>
An example of a method for manufacturing an electronic device according to the present disclosure will be described below with reference to the drawings.
However, the manufacturing method of the electronic device of the present disclosure is not limited to the following example.
The method for manufacturing an electronic device according to this example includes:
A wiring board having a mounting surface, a plurality of electronic components mounted on the mounting surface of the wiring board, and a ground electrode arranged to surround at least one electronic component among the plurality of electronic components in plan view. and an electronic board preparation step of preparing an electronic board comprising
a first step of forming an insulating protective layer covering at least one electronic component in a ground area surrounded by a ground electrode;
a second step of forming, as a solidified ink for forming an electromagnetic wave shield layer, an electromagnetic wave shield layer that straddles the insulating protective layer and the ground electrode, covers the insulating protective layer, and is electrically connected to the ground electrode; ,
including
At least one of the insulating protective layer and the electromagnetic wave shielding layer is formed by the film forming method of the present disclosure described above.

Here, the insulating protective layer is an example of an insulating layer, and the electromagnetic wave shielding layer is an example of a conductive layer.

15A is a schematic plan view of an electronic substrate prepared in the electronic substrate preparation step, and FIG. 15B is a cross-sectional view taken along line XX of FIG. 15A.
16A is a schematic plan view of an electronic substrate on which an insulating protective layer, which is an example of an insulating layer, is formed, and FIG. 16B is a cross-sectional view taken along line XX of FIG. 16A.
FIG. 17A is a schematic plan view of an electronic substrate (that is, the electronic device of the present embodiment) on which an electromagnetic wave shield layer, which is an example of a conductive layer, is formed, and FIG. 17B is a cross-sectional view taken along line XX of FIG. 17A. be.

-Electronic board preparation process-
As shown in FIGS. 15A and 15B, in the electronic board preparation step in this example, a wiring board 112 having a mounting surface, a plurality of electronic components 118 mounted on the mounting surface of the wiring board 112, and and a ground electrode 116 arranged to surround a plurality of electronic components 118. An electronic substrate 110 is prepared.
Although illustration is omitted, each of the plurality of electronic components 118 is mounted on the mounting surface of the wiring board 112 via solder balls. A minute gap exists between the wiring board 112 and each of the plurality of electronic components 118 (see FIG. 2 described above).

The electronic substrate preparation step may be a step of simply preparing the electronic substrate 110 manufactured in advance, or may be a step of manufacturing the electronic substrate 110 .
As a method for manufacturing the electronic board 110, for example, a known method for manufacturing an electronic board in which electronic components are mounted on a printed wiring board can be appropriately referred to.

As the wiring board 112, a board on which wiring is formed, for example, a printed wiring board can be used.
The wiring board 112 may include electrodes other than the ground electrode 116, a solder resist layer, and the like.

The ground electrode 116 is an electrode to which a ground (GND) potential is applied.
In this example, the ground electrode 116 is arranged to surround a plurality of electronic components (electronic components 118).
In other words, a plurality of electronic components (electronic components 118) are mounted within the ground area 114A surrounded by the ground electrode 116. FIG.

As shown in FIG. 15A, the ground electrode 116 in this example is formed as a discontinuous pattern (more specifically, a segmented line pattern), but the ground electrode in the present disclosure is not limited to this example. . For example, the ground electrode in the present disclosure may be formed as a continuous pattern (ie, an unbroken line pattern).

Also, the ground electrode 116 in this example is formed as an annular pattern that completely circles around the plurality of electronic components (electronic components 118).
However, the ground electrode 116 in the present disclosure is not limited to this annular pattern, and may be, for example, a pattern in which at least a portion of the annular pattern is missing.
From the viewpoint of further reducing the influence of external electromagnetic waves on the plurality of electronic components (electronic component 118), the ground electrode 116 preferably surrounds the region where the plurality of electronic components are arranged by more than half the circumference. It is more preferable to enclose more than the perimeter.

Further, as shown in FIG. 15B , the ground electrode 116 in this example is formed such that a portion of the ground electrode 116 in the thickness direction is embedded in the wiring substrate 112, but the ground electrode in the present disclosure is , but not limited to this example. For example, the ground electrode in the present disclosure may be formed so as to be completely embedded in the thickness direction of the ground electrode. Also, the ground electrode in the present disclosure may be formed on the surface of the wiring board 112 instead of being embedded in the wiring board 112 . Also, the ground electrode in the present disclosure may be formed as a pattern penetrating the wiring board 112 .

The plurality of electronic components 118 mounted in the ground area 114A may be electronic components of the same design or electronic components of different designs. Also, the number of electronic components mounted in the ground area is not limited to a plurality, and may be only one.
Examples of the electronic component 118 include a semiconductor chip such as an integrated circuit (IC), a capacitor, a transistor, and the like.

The height of the electronic component (eg, electronic component 118) in the present disclosure is preferably 100 μm or more, more preferably 200 μm or more, and even more preferably 300 μm or more.
The height of the electronic component is preferably 2000 μm or less, more preferably 1000 μm or less.

The height of the ground electrode (eg, ground electrode 116) in the present disclosure is preferably −10 μm or more, more preferably 0 μm or more, and even more preferably 5 μm or more.
The height of the ground electrode is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less.

-First step-
As shown in FIGS. 16A and 16B, in the first step, an insulating protective layer 122 is formed to cover the plurality of electronic components 118 mounted within the ground area 114A.

The insulating protective layer 122 is formed within the ground area 114</b>A in a region extending over the plurality of electronic components 118 and around the plurality of electronic components 118 .
The function of the insulating protective layer is, for example, the function of protecting electronic components and the function of suppressing short circuits between electronic components and other conductive members (for example, electromagnetic shielding layers).

In the first step of this example, the insulating protective layer 122 can be formed using, for example, an insulating layer forming ink. The insulating layer forming ink is, for example, an active energy ray-curable ink.
The film manufacturing method of the present disclosure described above can be applied to the formation of the insulating protective layer 122 .
Thereby, it is possible to form the insulating protective layer 122 in which the thickness variation from the side surface to the top surface of the electronic component 118 is suppressed.

-Second step-
As shown in FIGS. 17A and 17B, in the second step, an electromagnetic wave shielding layer forming ink is used as the conductive layer forming ink, and the ink extends over the insulating protective layer 122 and at least a portion of the ground electrode 116, An electromagnetic wave shielding layer 130 (that is, a conductive layer), which is a solidified ink for forming an electromagnetic wave shielding layer and which covers the insulating protective layer 122 and is electrically connected to the ground electrode 116, is formed. Thus, the electronic device 100 is obtained.
The electromagnetic wave shield layer 130 is formed by applying an electromagnetic wave shield layer forming ink to the ground area 114A and solidifying the ink.
A preferred range of the ink for forming the electromagnetic shield layer and the method for forming the electromagnetic shield layer will be described later.

The electromagnetic wave shield layer is a layer for reducing the influence of electromagnetic waves on electronic components by shielding the electromagnetic waves irradiated to the electronic components.
The performance of such an electromagnetic wave shielding layer is also referred to as "electromagnetic wave shielding property" in the present disclosure.
The electromagnetic wave shielding property of the electromagnetic wave shield layer is exhibited by placing the electromagnetic wave shield layer on the electronic component via an insulating protective layer.
Further, the electromagnetic shielding property of the electromagnetic shielding layer is exhibited by applying a ground (GND) potential to the electromagnetic shielding layer. For this reason, the electromagnetic wave shield layer has conductivity as a premise of the electromagnetic wave shield layer.

The film manufacturing method of the present disclosure described above can also be applied to the formation of the electromagnetic wave shield layer 130 .
As a result, the electromagnetic wave shield layer 130 can be formed with the insulating protective layer 122 interposed therebetween, in which variations in thickness from the side surface to the top surface of the electronic component 118 are suppressed.

Next, ink for forming a conductive layer (e.g. ink for forming an electromagnetic wave shield layer), method for forming an electromagnetic wave shield layer, ink for forming an insulating layer (e.g. ink for forming an insulating protective layer), and method for forming an insulating protective layer A preferred embodiment of is described.

<Ink for forming conductive layer>
Examples of conductive layer-forming inks (for example, electromagnetic wave shielding layer-forming inks) include inks containing metal particles (hereinafter also referred to as "metal particle ink") and inks containing metal complexes (hereinafter also referred to as "metal complex ink"). Alternatively, an ink containing a metal salt (hereinafter also referred to as “metal salt ink”) is preferred, and a metal salt ink or metal complex ink is more preferred.

(metal particle ink)
Metal particle ink is, for example, an ink composition in which metal particles are dispersed in a dispersion medium.

-metal particles-
Examples of the metal that constitutes the metal particles include particles of base metals and noble metals. Base metals include, for example, nickel, titanium, cobalt, copper, chromium, manganese, iron, zirconium, tin, tungsten, molybdenum, and vanadium. Noble metals include, for example, gold, silver, platinum, palladium, iridium, osmium, ruthenium, rhodium, rhenium, and alloys containing these metals. Among them, from the viewpoint of electromagnetic wave shielding properties, the metal constituting the metal particles preferably contains at least one selected from the group consisting of silver, gold, platinum, nickel, palladium and copper, and more preferably contains silver. preferable.

Although the average particle size of the metal particles is not particularly limited, it is preferably 10 nm to 500 nm, more preferably 10 nm to 200 nm. When the average particle size is within the above range, the firing temperature of the metal particles is lowered, and the process suitability for forming the electromagnetic wave shielding layer is enhanced. In particular, when the metal particle ink is applied using a spray method or an inkjet recording method, there is a tendency that the ejection property is improved, and the pattern formability and the uniformity of the film thickness of the electromagnetic wave shield layer are improved. The average particle diameter here means the average value of the primary particle diameters of the metal particles (average primary particle diameter).

The average particle size of metal particles is measured by a laser diffraction/scattering method. The average particle size of the metal particles is, for example, a value calculated as the average value of the values obtained by measuring the 50% volume cumulative diameter (D50) three times and using a laser diffraction/scattering particle size distribution analyzer. (product name “LA-960”, manufactured by HORIBA, Ltd.).

In addition, the metal particle ink may contain metal particles having an average particle size of 500 nm or more, if necessary. When metal particles having an average particle size of 500 nm or more are contained, the electromagnetic wave shielding layer can be bonded by melting point depression of the nanometer-sized metal particles around the micrometer-sized metal particles.

The content of the metal particles in the metal particle ink is preferably 10% by mass to 90% by mass, more preferably 20% by mass to 50% by mass, relative to the total amount of the metal particle ink. When the content of the metal particles is 10% by mass or more, the surface resistivity is further lowered. When the content of the metal particles is 90% by mass or less, the jettability is improved when the metal particle ink is applied using an inkjet recording method.

In addition to the metal particles, the metal particle ink may contain, for example, a dispersant, a resin, a dispersion medium, a thickener, and a surface tension adjuster.

- Dispersant -
The metal particle ink may contain a dispersant adhering to at least part of the surface of the metal particles. The dispersant, together with the metal particles, substantially constitutes the metal colloid particles. The dispersant has the effect of coating the metal particles to improve the dispersibility of the metal particles and to prevent aggregation. The dispersant is preferably an organic compound capable of forming colloidal metal particles. The dispersant is preferably an amine, carboxylic acid, alcohol, or resin dispersant from the viewpoint of electromagnetic wave shielding properties and dispersion stability.

The number of dispersants contained in the metal particle ink may be one, or two or more.

Amines include, for example, saturated or unsaturated aliphatic amines. Among them, the amine is preferably an aliphatic amine having 4 to 8 carbon atoms. The aliphatic amine having 4 to 8 carbon atoms may be linear or branched, and may have a ring structure.

Examples of aliphatic amines include butylamine, n-pentylamine, isopentylamine, hexylamine, 2-ethylhexylamine, and octylamine.

Amines having an alicyclic structure include cycloalkylamines such as cyclopentylamine and cyclohexylamine.

Aniline can be mentioned as an aromatic amine.

The amine may have functional groups other than amino groups. Functional groups other than amino groups include, for example, hydroxy groups, carboxy groups, alkoxy groups, carbonyl groups, ester groups, and mercapto groups.

Carboxylic acids include, for example, formic acid, oxalic acid, acetic acid, hexanoic acid, acrylic acid, octylic acid, oleic acid, thianoic acid, ricinoleic acid, gallic acid, and salicylic acid. A carboxy group that is part of a carboxylic acid may form a salt with a metal ion. The number of metal ions that form a salt may be one, or two or more.

The carboxylic acid may have functional groups other than the carboxy group. Functional groups other than carboxy groups include, for example, amino groups, hydroxy groups, alkoxy groups, carbonyl groups, ester groups, and mercapto groups.

Examples of alcohol include terpene alcohol, allyl alcohol, and oleyl alcohol. Alcohol is easily coordinated to the surface of the metal particles and can suppress aggregation of the metal particles.

The resin dispersant includes, for example, a dispersant that has a nonionic group as a hydrophilic group and is uniformly soluble in a solvent. Examples of resin dispersants include polyvinylpyrrolidone, polyethylene glycol, polyethylene glycol-polypropylene glycol copolymer, polyvinyl alcohol, polyallylamine, and polyvinyl alcohol-polyvinyl acetate copolymer. The weight-average molecular weight of the resin dispersant is preferably 1,000 to 50,000, more preferably 1,000 to 30,000.

The content of the dispersant in the metal particle ink is preferably 0.5% by mass to 50% by mass, more preferably 1% by mass to 30% by mass, relative to the total amount of the metal particle ink. .

-dispersion medium-
The metal particle ink preferably contains a dispersion medium. The type of dispersion medium is not particularly limited, and examples thereof include hydrocarbons, alcohols, and water.

The dispersion medium contained in the metal particle ink may be of one type or two or more types.
The dispersion medium contained in the metal particle ink is preferably volatile. The boiling point of the dispersion medium is preferably 50°C to 250°C, more preferably 70°C to 220°C, even more preferably 80°C to 200°C. When the boiling point of the dispersion medium is 50° C. to 250° C., there is a tendency that both the stability and the sinterability of the metal particle ink can be achieved.

Hydrocarbons include aliphatic hydrocarbons and aromatic hydrocarbons.

Examples of aliphatic hydrocarbons include saturated aliphatic hydrocarbons such as tetradecane, octadecane, heptamethylnonane, tetramethylpentadecane, hexane, heptane, octane, nonane, decane, tridecane, methylpentane, normal paraffin and isoparaffin, or unsaturated hydrocarbons. Aliphatic hydrocarbons are mentioned.

Aromatic hydrocarbons include, for example, toluene and xylene.

Alcohols include aliphatic alcohols and alicyclic alcohols. When alcohol is used as the dispersing medium, the dispersing agent is preferably an amine or carboxylic acid.

Examples of aliphatic alcohols include heptanol, octanol (eg, 1-octanol, 2-octanol, 3-octanol, etc.), decanol (eg, 1-decanol, etc.), lauryl alcohol, tetradecyl alcohol, cetyl alcohol, 2- C6-20 aliphatic alcohols which may contain an ether bond in the saturated or unsaturated chain, such as ethyl-1-hexanol, octadecyl alcohol, hexadecenol and oleyl alcohol.

Alicyclic alcohols include, for example, cycloalkanols such as cyclohexanol; terpineol (including α, β, γ isomers, or any mixture thereof), terpene alcohols such as dihydroterpineol; dihydroterpineol, myrtenol, Sobrerol, menthol, carveol, perillyl alcohol, pinocarveol, sobrerol, and verbenol.

The dispersion medium may be water. From the viewpoint of adjusting physical properties such as viscosity, surface tension and volatility, the dispersion medium may be a mixed solvent of water and other solvents. Another solvent that is mixed with water is preferably an alcohol. The alcohol used in combination with water is preferably an alcohol miscible with water and having a boiling point of 130° C. or less. Alcohols include, for example, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and propylene. Glycol monomethyl ether is mentioned.

The content of the dispersion medium in the metal particle ink is preferably 1% by mass to 50% by mass with respect to the total amount of the metal particle ink. If the content of the dispersion medium is 1% by mass to 50% by mass, sufficient electrical conductivity can be obtained as the ink for forming the electromagnetic wave shielding layer. The content of the dispersion medium is more preferably 10% by mass to 45% by mass, and even more preferably 20% by mass to 40% by mass.

-resin-
The metal particle ink may contain resin. Examples of resins include polyesters, polyurethanes, melamine resins, acrylic resins, styrenic resins, polyethers, and terpene resins.

The number of resins contained in the metal particle ink may be one, or two or more.

The content of the resin in the metal particle ink is preferably 0.1% by mass to 5% by mass with respect to the total amount of the metal particle ink.

- Thickener -
The metal particle ink may contain a thickening agent. Examples of thickeners include clay minerals such as clay, bentonite and hectorite; cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose; and polysaccharides such as xanthan gum and guar gum. be done.

The number of thickeners contained in the metal particle ink may be one, or two or more.

The content of the thickener in the metal particle ink is preferably 0.1% by mass to 5% by mass with respect to the total amount of the metal particle ink.

-Surfactant-
The metal particle ink may contain a surfactant. When the metal particle ink contains a surfactant, a uniform electromagnetic wave shielding layer is easily formed.

The surfactant may be an anionic surfactant, a cationic surfactant, or a nonionic surfactant. Among them, the surfactant is preferably a fluorosurfactant from the viewpoint that the surface tension can be adjusted with a small content. Further, the surfactant is preferably a compound having a boiling point of over 250°C.

The viscosity of the metal particle ink is not particularly limited, and may be from 0.01 Pa·s to 5000 Pa·s, preferably from 0.1 Pa·s to 100 Pa·s. When the metal particle ink is applied using a spray method or an inkjet recording method, the viscosity of the metal particle ink is preferably 1 mPa·s to 100 mPa·s, more preferably 2 mPa·s to 50 mPa·s. More preferably, it is 3 mPa·s to 30 mPa·s.

The viscosity of the metal particle ink is a value measured at 25°C using a viscometer. Viscosity is measured using, for example, a VISCOMETER TV-22 viscometer (manufactured by Toki Sangyo Co., Ltd.).

The surface tension of the metal particle ink is not particularly limited, and is preferably 20 mN/m to 45 mN/m, more preferably 25 mN/m to 40 mN/m.
Surface tension is a value measured at 25°C using a surface tensiometer.

　The surface tension of the metal particle ink is measured using, for example, DY-700 (manufactured by Kyowa Interface Science Co., Ltd.).

-Method for producing metal particles-
The metal particles may be commercially available products or may be produced by known methods. Methods for producing metal particles include, for example, a wet reduction method, a vapor phase method, and a plasma method. As a preferred method for producing metal particles, there is a wet reduction method capable of producing metal particles having an average particle size of 200 nm or less with a narrow particle size distribution. A method for producing metal particles by a wet reduction method, for example, JP 2017-37761, International Publication No. 2014-5763
A step of mixing the metal salt and a reducing agent described in No. 3 and the like to obtain a complexing reaction solution, and heating the complexing reaction solution to reduce the metal ions in the complexing reaction solution to obtain a slurry of metal nanoparticles. and obtaining

In the production of the metal particle ink, heat treatment may be performed in order to adjust the content of each component contained in the metal particle ink within a predetermined range. The heat treatment may be performed under reduced pressure or under normal pressure. Moreover, when performing under a normal pressure, you may carry out in air|atmosphere, and you may carry out in inert gas atmosphere.

(metal complex ink)
A metal complex ink is, for example, an ink composition in which a metal complex is dissolved in a solvent.

-Metal complex-
Examples of metals constituting metal complexes include silver, copper, gold, aluminum, magnesium, tungsten, molybdenum, zinc, nickel, iron, platinum, tin, copper, and lead. Among them, from the viewpoint of electromagnetic wave shielding properties, the metal constituting the metal complex preferably contains at least one selected from the group consisting of silver, gold, platinum, nickel, palladium and copper, and more preferably contains silver. preferable.

The content of the metal contained in the metal complex ink is preferably 1% by mass to 40% by mass, more preferably 5% by mass to 30% by mass, in terms of metal element, with respect to the total amount of the metal complex ink. Preferably, it is more preferably 7% by mass to 20% by mass.

A metal complex is obtained, for example, by reacting a metal salt with a complexing agent. A method for producing a metal complex includes, for example, a method in which a metal salt and a complexing agent are added to an organic solvent and the mixture is stirred for a predetermined period of time. The stirring method is not particularly limited, and can be appropriately selected from known methods such as a method of stirring using a stirrer, a stirring blade or a mixer, and a method of applying ultrasonic waves.

Metal salts include metal oxides, thiocyanates, sulfides, chlorides, cyanides, cyanates, carbonates, acetates, nitrates, nitrites, sulfates, phosphates, perchlorates, Tetrafluoroborates, acetylacetonate complexes, and carboxylates.

Complexing agents include amines, ammonium carbamate compounds, ammonium carbonate compounds, ammonium bicarbonate compounds, and carboxylic acids. Among them, from the viewpoint of electromagnetic wave shielding properties and stability of the metal complex, the complexing agent is at least selected from the group consisting of ammonium carbamate compounds, ammonium carbonate compounds, amines, and carboxylic acids having 8 to 20 carbon atoms. It is preferred that one species is included.

The metal complex has a structure derived from a complexing agent, and contains at least one selected from the group consisting of ammonium carbamate compounds, ammonium carbonate compounds, amines, and carboxylic acids having 8 to 20 carbon atoms. A metal complex having a derived structure is preferred.

Amines that are complexing agents include, for example, ammonia, primary amines, secondary amines, tertiary amines, and polyamines.

Examples of primary amines having linear alkyl groups include methylamine, ethylamine, 1-propylamine, n-butylamine, n-pentylamine, n-hexylamine, heptylamine, octylamine, nonylamine, n - decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine,
Hexadecylamine, heptadecylamine, and octadecylamine are included.

Examples of primary amines having branched alkyl groups include isopropylamine, sec-butylamine, tert-butylamine, isopentylamine, 2-ethylhexylamine, and tert-octylamine.

Examples of primary amines having an alicyclic structure include cyclohexylamine and dicyclohexylamine.

Examples of primary amines having a hydroxyalkyl group include ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, propanolamine, isopropanolamine, dipropanolamine, diisopropanolamine, tripropanolamine, and triisopropanol. Amines are mentioned.

Examples of primary amines having an aromatic ring include benzylamine, N,N-dimethylbenzylamine, phenylamine, diphenylamine, triphenylamine, aniline, N,N-dimethylaniline, N,N-dimethyl-p- Toluidine, 4-aminopyridine, and 4-dimethylaminopyridine.

Examples of secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, diphenylamine, dicyclopentylamine, and methylbutylamine.

Tertiary amines include, for example, trimethylamine, triethylamine, tripropylamine, and triphenylamine.

Polyamines include, for example, ethylenediamine, 1,3-diaminopropane, diethylenetriamine, triethylenetetramine, tetramethylenepentamine, hexamethylenediamine, tetraethylenepentamine, and combinations thereof.

The amine is preferably an alkylamine, preferably an alkylamine having 3 to 10 carbon atoms, more preferably a primary alkylamine having 4 to 10 carbon atoms.

The number of amines constituting the metal complex may be one, or two or more.

When the metal salt and the amine are reacted, the molar ratio of the amine to the metal salt is preferably 1 to 15 times, more preferably 1.5 to 6 times. When the above ratio is within the above range, the complex formation reaction is completed and a transparent solution is obtained.

Ammonium carbamate compounds as complexing agents include ammonium carbamate, methylammonium methylcarbamate, ethylammonium ethylcarbamate, 1-propylammonium 1-propylcarbamate, isopropylammonium isopropylcarbamate, butylammonium butylcarbamate, isobutylammonium isobutylcarbamate, amyl ammonium amyl carbamate, hexylammonium hexyl carbamate, heptylammonium heptyl carbamate, octylammonium octyl carbamate, 2-ethylhexylammonium 2-ethylhexyl carbamate, nonyl ammonium nonyl carbamate, and decyl ammonium decyl carbamate.

Ammonium carbonate-based compounds as complexing agents include ammonium carbonate, methylammonium carbonate, ethylammonium carbonate, 1-propylammonium carbonate, isopropylammonium carbonate, butylammonium carbonate, isobutylammonium carbonate, amylammonium carbonate, hexylammonium carbonate, and heptyl. Ammonium carbonate, octylammonium carbonate, 2-ethylhexylammonium carbonate, nonyl ammonium carbonate, and decylammonium carbonate.

Ammonium bicarbonate-based compounds as complexing agents include ammonium bicarbonate, methylammonium bicarbonate, ethylammonium bicarbonate, 1-propylammonium bicarbonate, isopropylammonium bicarbonate, butylammonium bicarbonate, isobutylammonium bicarbonate, amyl Ammonium bicarbonate, hexylammonium bicarbonate, heptyl ammonium bicarbonate, octylammonium bicarbonate, 2-ethylhexylammonium bicarbonate, nonyl ammonium bicarbonate, and decylammonium bicarbonate.

When reacting a metal salt with an ammonium carbamate-based compound, an ammonium carbonate-based compound, or an ammonium bicarbonate-based compound, the amount of the ammonium carbamate-based compound, the ammonium carbonate-based compound, or the ammonium bicarbonate-based compound relative to the molar amount of the metal salt. The molar ratio is preferably 0.01 to 1, more preferably 0.05 to 0.6.

Carboxylic acid as a complexing agent includes, for example, caproic acid, caprylic acid, pelargonic acid, 2-ethylhexanoic acid, capric acid, neodecanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and palmitoleic acid. , oleic acid, linoleic acid, and linolenic acid. Among them, the carboxylic acid is preferably a carboxylic acid having 8 to 20 carbon atoms, more preferably a carboxylic acid having 10 to 16 carbon atoms.

The content of the metal complex in the metal complex ink is preferably 10% by mass to 90% by mass, more preferably 10% by mass to 40% by mass, relative to the total amount of the metal complex ink. When the content of the metal complex is 10% by mass or more, the surface resistivity is further lowered. When the content of the metal complex is 90% by mass or less, the jettability is improved when the metal particle ink is applied using an inkjet recording method.

-solvent-
The metal complex ink preferably contains a solvent. The solvent is not particularly limited as long as it can dissolve the components contained in the metal complex ink such as the metal complex. From the viewpoint of ease of production, the solvent preferably has a boiling point of 30°C to 300°C, more preferably 50°C to 200°C, and more preferably 50°C to 150°C.

The content of the solvent in the metal complex ink is such that the concentration of the metal ion relative to the metal complex (the amount of metal present as free ions per 1 g of the metal complex) is 0.01 mmol/g to 3.6 mmol/g. is preferred, and 0.05 mmol/g to 2 mmol/g is more preferred. When the metal ion concentration is within the above range, the metal complex ink has excellent fluidity and can obtain electromagnetic wave shielding properties.

Solvents include, for example, hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons, carbamates, alkenes, amides, ethers, esters, alcohols, thiols, thioethers, phosphines, and water. Only one solvent may be contained in the metal complex ink,
Two or more types may be used.

The hydrocarbon is preferably a linear or branched hydrocarbon having 6 to 20 carbon atoms. Hydrocarbons include, for example, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane and icosane.

The cyclic hydrocarbon is preferably a cyclic hydrocarbon having 6 to 20 carbon atoms. Cyclic hydrocarbons can include, for example, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, and decalin.

Aromatic hydrocarbons include, for example, benzene, toluene, xylene, and tetralin.

The ether may be any of straight-chain ether, branched-chain ether, and cyclic ether. Ethers include, for example, diethyl ether, dipropyl ether, dibutyl ether, methyl-t-butyl ether, tetrahydrofuran, tetrahydropyran, dihydropyran, and 1,4-dioxane.

The alcohol may be any of primary alcohol, secondary alcohol, and tertiary alcohol.

Examples of alcohols include ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol and 1-hexanol. , 2-hexanol, 3-hexanol, 1-octanol, 2-octanol, 3-octanol, tetrahydrofurfuryl alcohol, cyclopentanol, terpineol, decanol, isodecyl alcohol, lauryl alcohol, isolauryl alcohol, myristyl alcohol, isomyristyl alcohol, cetyl alcohol (cetanol), isocetyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, isoleyl alcohol, linolyl alcohol, isolinolyl alcohol, palmityl alcohol, isopalmityl alcohol, eicosyl alcohol, and iso Aicosyl alcohols can be mentioned.

Ketones include, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of esters include methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol. monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monoethyl ether acetate, Propylene glycol monobutyl ether acetate, and 3-methoxybutyl acetate.

-Reducing agent-
The metal complex ink may contain a reducing agent. When the metal complex ink contains a reducing agent, the reduction of the metal complex to the metal is promoted.

Examples of reducing agents include metal borohydride salts, aluminum hydride salts, amines, alcohols, organic acids, reducing sugars, sugar alcohols, sodium sulfite, hydrazine compounds, dextrin, hydroquinone, hydroxylamine, ethylene glycol, glutathione, and oxime compounds.

The reducing agent may be an oxime compound described in JP 2014-516463. Examples of oxime compounds include acetone oxime, cyclohexanone oxime, 2-butanone oxime, 2,3-butanedione monoxime, dimethylglyoxime, methylacetoacetate monoxime, methylpyruvate monoxime, benzaldehyde oxime, and 1-indanone. oximes, 2-adamantanone oxime, 2-methylbenzamide oxime, 3-methylbenzamide oxime, 4-methylbenzamide oxime, 3-aminobenzamide oxime, 4-aminobenzamide oxime, acetophenone oxime, benzamide oxime, and pinacolone oxime .

The number of reducing agents contained in the metal complex ink may be one, or two or more.

The content of the reducing agent in the metal complex ink is not particularly limited. more preferably 1% by mass to 5% by mass.

-resin-
The metal complex ink may contain resin. When the metal complex ink contains a resin, the adhesion of the metal complex ink to the substrate is improved.

Examples of resins include polyester, polyethylene, polypropylene, polyacetal, polyolefin, polycarbonate, polyamide, fluorine resin, silicone resin, ethyl cellulose, hydroxyethyl cellulose, rosin, acrylic resin, polyvinyl chloride, polysulfone, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl-based Resins, polyacrylonitrile, polysulfides, polyamideimides, polyethers, polyarylates, polyetheretherketones, polyurethanes, epoxy resins, vinyl ester resins, phenolic resins, melamine resins, and urea resins.

The number of resins contained in the metal complex ink may be one, or two or more.

-Additive-
The metal complex ink further contains an inorganic salt, an organic salt, an inorganic oxide such as silica; Additives such as agents, surfactants, plasticizers, curing agents, thickeners, and silane coupling agents may be contained. The total content of additives in the metal complex ink is preferably 20% by mass or less with respect to the total amount of the metal complex ink.

The viscosity of the metal complex ink is not particularly limited, and may be 0.01 Pa·s to 5000 Pa·s, preferably 0.1 Pa·s to 100 Pa·s. When the metal complex ink is applied using a spray method or an inkjet recording method, the viscosity of the metal complex ink is preferably 1 mPa·s to 100 mPa·s, more preferably 2 mPa·s to 50 mPa·s. More preferably, it is 3 mPa·s to 30 mPa·s.

The viscosity of the metal complex ink is a value measured at 25°C using a viscometer. Viscosity is measured using, for example, a VISCOMETER TV-22 viscometer (manufactured by Toki Sangyo Co., Ltd.).

The surface tension of the metal complex ink is not particularly limited, and is preferably 20 mN/m to 45 mN/m, more preferably 25 mN/m to 35 mN/m. Surface tension is a value measured at 25°C using a surface tensiometer.

　The surface tension of the metal complex ink is measured using, for example, DY-700 (manufactured by Kyowa Interface Science Co., Ltd.).

(metal salt ink)
A metal salt ink is, for example, an ink composition in which a metal salt is dissolved in a solvent.

-metal salt-
Examples of metals constituting metal salts include silver, copper, gold, aluminum, magnesium, tungsten, molybdenum, zinc, nickel, iron, platinum, tin, copper, and lead. Among them, from the viewpoint of electromagnetic wave shielding properties, the metal constituting the metal salt preferably contains at least one selected from the group consisting of silver, gold, platinum, nickel, palladium and copper, and more preferably contains silver. preferable.

The content of the metal contained in the metal salt ink is preferably 1% by mass to 40% by mass, more preferably 5% by mass to 30% by mass, in terms of metal element, relative to the total amount of the metal salt ink. Preferably, it is more preferably 7% by mass to 20% by mass.

The content of the metal salt in the metal salt ink is preferably 10% by mass to 90% by mass, more preferably 10% by mass to 40% by mass, relative to the total amount of the metal salt ink. When the content of the metal salt is 10% by mass or more, the surface resistivity is further lowered. When the content of the metal salt is 90% by mass or less, the jettability is improved when the metal particle ink is applied using a spray method or an inkjet recording method.

Examples of metal salts include metal benzoates, halides, carbonates, citrates, iodates, nitrites, nitrates, acetates, phosphates, sulfates, sulfides, trifluoroacetates, and carboxylates. In addition, salt may combine 2 or more types.

The metal salt is preferably a metal carboxylate from the viewpoint of electromagnetic wave shielding properties and storage stability. The carboxylic acid forming the carboxylic acid salt is preferably at least one selected from the group consisting of formic acid and a carboxylic acid having 1 to 30 carbon atoms, more preferably a carboxylic acid having 8 to 20 carbon atoms. , and fatty acids having 8 to 20 carbon atoms are more preferred. The fatty acid may be linear or branched, and may have a substituent.

Linear fatty acids include, for example, acetic acid, propionic acid, butyric acid, valeric acid, pentanoic acid, hexanoic acid, heptanoic acid, behenic acid, oleic acid, octanoic acid, nonanoic acid, decanoic acid, caproic acid, enanthic acid, and caprylic acid. , pelargonic acid, capric acid, and undecanoic acid.

Examples of branched fatty acids include isobutyric acid, isovaleric acid, ethylhexanoic acid, neodecanoic acid, pivalic acid, 2-methylpentanoic acid, 3-methylpentanoic acid, 4-methylpentanoic acid, 2,2-dimethylbutanoic acid, 2,3-dimethylbutanoic acid, 3,3-dimethylbutanoic acid, and 2-ethylbutanoic acid.

Examples of substituted carboxylic acids include hexafluoroacetylacetone acid, hydroangelic acid, 3-hydroxybutyric acid, 2-methyl-3-hydroxybutyric acid, 3-methoxybutyric acid, acetonedicarboxylic acid, 3-hydroxyglutaric acid, 2 -methyl-3-hydroxyglutarate, and 2,2,4,4-hydroxyglutarate.

The metal salt may be a commercially available product or may be produced by a known method. A silver salt is manufactured by the following method, for example.

First, in an organic solvent such as ethanol, add a silver compound (for example, silver acetate) as a source of silver, and formic acid or a fatty acid having 1 to 30 carbon atoms in an amount equivalent to the molar equivalent of the silver compound. The mixture is stirred for a predetermined time using an ultrasonic stirrer, and the precipitate formed is washed with ethanol and decanted. All these steps can be performed at room temperature (25°C). The mixing ratio of the silver compound to the formic acid or the fatty acid having 1 to 30 carbon atoms is preferably 1:2 to 2:1, more preferably 1:1 in terms of molar ratio.

-solvent-
The metal salt ink preferably contains a solvent.
The type of solvent is not particularly limited as long as it can dissolve the metal salt contained in the metal salt ink.
The boiling point of the solvent is preferably 30°C to 300°C, more preferably 50°C to 300°C, and even more preferably 50°C to 250°C, from the viewpoint of ease of production.

The content of the solvent in the metal salt ink is such that the concentration of metal ions relative to the metal salt (amount of metal present as free ions per 1 g of metal salt) is 0.01 mmol/g to 3.6 mmol/g. is preferred, and 0.05 mmol/g to 2.6 mmol/g is more preferred. When the metal ion concentration is within the above range, the metal salt ink has excellent fluidity and electromagnetic wave shielding properties can be obtained.

Solvents include, for example, hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons, carbamates, alkenes, amides, ethers, esters, alcohols, thiols, thioethers, phosphines, and water.
The number of solvents contained in the metal salt ink may be one, or two or more.

The solvent preferably contains an aromatic hydrocarbon.
Examples of aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, propylbenzene, isopropylbenzene, butylbenzene, isobutylbenzene, t-butylbenzene, trimethylbenzene, pentylbenzene, hexylbenzene, tetralin, benzyl alcohol, phenol, Cresol, methyl benzoate, ethyl benzoate, propyl benzoate, and butyl benzoate.
From the viewpoint of compatibility with other components, the number of aromatic rings in the aromatic hydrocarbon is preferably one or two, more preferably one.
The boiling point of the aromatic hydrocarbon is preferably 50°C to 300°C, more preferably 60°C to 250°C, even more preferably 80°C to 200°C, from the viewpoint of ease of production.

The solvent may contain aromatic hydrocarbons and hydrocarbons other than aromatic hydrocarbons.
Hydrocarbons other than aromatic hydrocarbons include linear hydrocarbons having 6 to 20 carbon atoms, branched hydrocarbons having 6 to 20 carbon atoms, and alicyclic hydrocarbons having 6 to 20 carbon atoms.
Examples of hydrocarbons other than aromatic hydrocarbons include pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane, decalin, cyclohexane, cycloheptane, and cyclooctane. , cyclononane, cyclodecane, decene, terpene compounds and icosane.
Hydrocarbons other than aromatic hydrocarbons preferably contain unsaturated bonds.
Hydrocarbons other than aromatic hydrocarbons containing unsaturated bonds include terpene compounds.
Terpene compounds are classified into, for example, hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, triterpenes, sesqualterpenes, and tetraterpenes, depending on the number of isoprene units that constitute the terpene compounds.
The terpene compound as the solvent may be any of the above, but monoterpene is preferred.
Examples of monoterpenes include pinene (α-pinene, β-pinene), terpineol (α-terpineol, β-terpineol, γ-terpineol), myrcene, camphene, limonene (d-limonene, l-limonene, dipentene), Ocimene (α-Ocimene, β-Ocimene), Alloocimene, Phellandrene (α-Phellandrene, β-Phellandrene), Terpinene (α-Terpinene, γ-Terpinene), Terpinolene (α-Terpinolene, β-Terpinolene, γ- terpinolene, δ-terpinolene), 1,8-cineole, 1,4-cineol, sabinene, paramentadiene, carene (δ-3-carene).
The monoterpene is preferably a cyclic monoterpene, more preferably pinene, terpineol, or carene.

The ether may be any of straight-chain ether, branched-chain ether, and cyclic ether. Ethers include, for example, diethyl ether, dipropyl ether, dibutyl ether, methyl-t-butyl ether, tetrahydrofuran, tetrahydropyran, dihydropyran, and 1,4-dioxane.

The alcohol may be any of primary alcohol, secondary alcohol, and tertiary alcohol.

Examples of alcohols include ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol and 1-hexanol. , 2-hexanol, 3-hexanol, 1-octanol, 2-octanol, 3-octanol, tetrahydrofurfuryl alcohol, cyclopentanol, terpineol, decanol, isodecyl alcohol, lauryl alcohol, isolauryl alcohol, myristyl alcohol, isomyristyl alcohol, cetyl alcohol (cetanol), isocetyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, isoleyl alcohol, linolyl alcohol, isolinolyl alcohol, palmityl alcohol, isopalmityl alcohol, eicosyl alcohol, and iso Aicosyl alcohols can be mentioned.

Ketones include, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of esters include methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol. monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monoethyl ether acetate, Propylene glycol monobutyl ether acetate, and 3-methoxybutyl acetate.

The viscosity of the metal salt ink is not particularly limited, and may be from 0.01 Pa·s to 5000 Pa·s, preferably from 0.1 Pa·s to 100 Pa·s. When the metal salt ink is applied using a spray method or an inkjet recording method, the viscosity of the metal salt ink is preferably 1 mPa·s to 100 mPa·s, more preferably 2 mPa·s to 50 mPa·s. More preferably, it is 3 mPa·s to 30 mPa·s.

The viscosity of the metal salt ink is a value measured at 25°C using a viscometer. Viscosity is measured using, for example, a VISCOMETER TV-22 viscometer (manufactured by Toki Sangyo Co., Ltd.).

The surface tension of the metal salt ink is not particularly limited, and is preferably 20 mN/m to 45 mN/m, more preferably 25 mN/m to 35 mN/m. Surface tension is a value measured at 25°C using a surface tensiometer.

　The surface tension of the metal salt ink is measured using, for example, DY-700 (manufactured by Kyowa Interface Science Co., Ltd.).

The ink for forming an electromagnetic wave shielding layer preferably contains a metal complex or a metal salt.
The metal complex is preferably a metal complex having a structure derived from at least one selected from the group consisting of ammonium carbamate compounds, ammonium carbonate compounds, amines and carboxylic acids having 8 to 20 carbon atoms.
Preferably, the metal salt is a metal carboxylate.

<Method for Forming Electromagnetic Shield Layer>
In the second step, the ink for forming the electromagnetic wave shielding layer is applied to the ground area on the electronic substrate, the wind is blown against the ink for forming the electromagnetic wave shielding layer applied to the top surface of the electronic component, and the wind is blown. It is preferable to form the electromagnetic wave shield layer by solidifying the electromagnetic wave shield layer forming ink by heating (for example, baking described later) and/or ultraviolet irradiation.

The ultraviolet irradiation for solidifying the ink referred to here is sometimes referred to as "main exposure" in the present disclosure.

In the second step, apart from the solidification by heating and/or main exposure, the above-described pinning exposure may be performed at least one of before and after blowing air onto the ink on the top surface of the electronic component.

(Applying method of ink for forming electromagnetic wave shield layer)
As a method for applying the ink for forming the electromagnetic wave shielding layer, an inkjet recording method, a dispenser method, or a spray method is preferable, and an inkjet recording method is particularly preferable.
Preferred aspects of the inkjet recording method are as described in the section "Film Forming Process".

The temperature of the electronic substrate when applying the electromagnetic wave shielding layer forming ink is preferably 20°C to 120°C, more preferably 28°C to 80°C.

The thickness of the entire electromagnetic shield layer is preferably 0.1 μm to 30 μm, more preferably 0.3 μm to 15 μm, from the viewpoint of electromagnetic shielding properties.

The thickness of the entire electromagnetic shield layer is measured using a laser microscope (product name "VK-X1000", manufactured by Keyence Corporation).

The average thickness per electromagnetic shield layer is obtained by dividing the thickness of the entire electromagnetic shield layer by the number of times the electromagnetic shield layer is formed (that is, the number of times the ink for forming the electromagnetic shield layer is applied).

In the second step, the average thickness per electromagnetic wave shield layer is preferably 1.5 μm or less, more preferably 1.2 μm or less.

When the average thickness of each electromagnetic shielding layer is 1.5 μm or less, the electromagnetic shielding properties are further improved.

(Baking process)
The second step may include a baking step of baking the electromagnetic shielding layer forming ink applied on the electronic substrate to solidify the electromagnetic shielding layer forming ink to form the electromagnetic shielding layer.

The firing temperature is preferably 250°C or less, more preferably 50°C to 200°C, and even more preferably 60°C to 180°C.
The firing time is preferably 1 minute to 120 minutes, more preferably 1 minute to 40 minutes.
When the firing temperature and the firing time are within the above ranges, it is possible to reduce the influence of thermal deformation of the base material.

<Insulation layer forming ink>
The insulating layer-forming ink (for example, the insulating protective layer-forming ink) is preferably active energy ray-curable ink.
The insulating layer-forming ink, which is active energy ray-curable ink, preferably contains a polymerizable monomer and a polymerization initiator.

(Polymerizable monomer)
A polymerizable monomer refers to a monomer having at least one polymerizable group in one molecule. The polymerizable group in the polymerizable monomer may be a cationically polymerizable group or a radically polymerizable group, but is preferably a radically polymerizable group from the viewpoint of curability. Moreover, the radically polymerizable group is preferably an ethylenically unsaturated group from the viewpoint of curability.

In the present disclosure, a monomer refers to a compound having a molecular weight of 1000 or less. The molecular weight can be calculated from the type and number of atoms that constitute the compound.

The polymerizable monomer may be a monofunctional polymerizable monomer having one polymerizable group, or may be a polyfunctional polymerizable monomer having two or more polymerizable groups.

The monofunctional polymerizable monomer is not particularly limited as long as it is a monomer having one polymerizable group.
From the viewpoint of curability, the monofunctional polymerizable monomer is preferably a monofunctional radically polymerizable monomer, more preferably a monofunctional ethylenically unsaturated monomer.

Examples of monofunctional ethylenically unsaturated monomers include monofunctional (meth)acrylates, monofunctional (meth)acrylamides, monofunctional aromatic vinyl compounds, monofunctional vinyl ethers and monofunctional N-vinyl compounds.

Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, hexyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. , tert-octyl (meth)acrylate, isoamyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate acrylate, 4-n-butylcyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, 2-ethylhexyl diglycol (meth)acrylate, butoxyethyl (meth)acrylate ) acrylate, 2-chloroethyl (meth) acrylate, 4-bromobutyl (meth) acrylate, cyanoethyl (meth) acrylate, benzyl (meth) acrylate, butoxymethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-( 2-Methoxyethoxy)ethyl (meth)acrylate, 2-(2-butoxyethoxy)ethyl (meth)acrylate, 2,2,2-tetrafluoroethyl (meth)acrylate, 1H,1H,2H,2H-perfluorodecyl (meth)acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, 2,4,5-tetramethylphenyl (meth)acrylate, 4-chlorophenyl (meth)acrylate, 2-phenoxymethyl (meth)acrylate , 2-phenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, glycidyloxybutyl (meth) acrylate, glycidyloxyethyl (meth) acrylate, glycidyloxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2- Hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylates, cyclic trimethylolpropane formal (meth)acrylate, phenylglycidyl ether (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminopropyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, trimethylsilylpropyl (meth)acrylate, polyethylene oxide monomethyl ether (meth)acrylate, polyethylene oxide (meth)acrylate, polyethylene oxide monoalkyl ether (meth)acrylate, dipropylene glycol (meth)acrylate, polypropylene oxide monoalkyl ether (meth)acrylate, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyhexahydrophthalic acid, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, ethoxydiethylene glycol (meth) acrylate, butoxydiethylene glycol (meth) ) acrylate, trifluoroethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, ethylene oxide (EO)-modified phenol (meth) acrylate, EO-modified cresol (meth) Acrylate, EO-modified nonylphenol (meth)acrylate, propylene oxide (PO)-modified nonylphenol (meth)acrylate, EO-modified 2-ethylhexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate , dicyclopentanyl (meth)acrylate, (3-ethyl-3-oxetanylmethyl) (meth)acrylate, phenoxyethylene glycol (meth)acrylate, 2-carboxyethyl (meth)acrylate, and 2-(meth)acryloyloxy Ethyl succinate can be mentioned.

Among them, from the viewpoint of improving heat resistance, the monofunctional (meth)acrylate is preferably a monofunctional (meth)acrylate having an aromatic ring or an aliphatic ring, such as isobornyl (meth)acrylate, 4-tert-butylcyclohexyl (Meth)acrylate, dicyclopentenyl (meth)acrylate, or dicyclopentanyl (meth)acrylate is more preferable.

Examples of monofunctional (meth)acrylamides include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, Nn-butyl(meth)acrylamide, Nt-butyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-methylol (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide and (meth)acryloylmorpholine.

Examples of monofunctional aromatic vinyl compounds include styrene, dimethylstyrene, trimethylstyrene, isopropylstyrene, chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, vinylbenzoic acid methyl ester, 3-methyl Styrene, 4-methylstyrene, 3-ethylstyrene, 4-ethylstyrene, 3-propylstyrene, 4-propylstyrene, 3-butylstyrene, 4-butylstyrene, 3-hexylstyrene, 4-hexylstyrene, 3-octyl Styrene, 4-octylstyrene, 3-(2-ethylhexyl)styrene, 4-(2-ethylhexyl)styrene, allylstyrene, isopropenylstyrene, butenylstyrene, octenylstyrene, 4-t-butoxycarbonylstyrene and 4- t-butoxystyrene can be mentioned.

Monofunctional vinyl ethers include, for example, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexylmethyl vinyl ether, 4-methyl Cyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, tetrahydro Furfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexylmethyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloroethoxyethyl vinyl ether , phenylethyl vinyl ether and phenoxypolyethylene glycol vinyl ether.

Examples of monofunctional N-vinyl compounds include N-vinyl-ε-caprolactam and N-vinylpyrrolidone.

The polyfunctional polymerizable monomer is not particularly limited as long as it has two or more polymerizable groups. From the viewpoint of curability, the polyfunctional polymerizable monomer is preferably a polyfunctional radically polymerizable monomer, more preferably a polyfunctional ethylenically unsaturated monomer.

Examples of polyfunctional ethylenically unsaturated monomers include polyfunctional (meth)acrylate compounds and polyfunctional vinyl ethers.

Examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and propylene glycol di(meth)acrylate. , dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate ) acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, heptanediol di(meth)acrylate , EO-modified neopentyl glycol di(meth)acrylate, PO-modified neopentyl glycol di(meth)acrylate, EO-modified hexanediol di(meth)acrylate, PO-modified hexanediol di(meth)acrylate, octanediol di(meth)acrylate , nonanediol di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate , diethylene glycol diglycidyl ether di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane EO addition tri(meth)acrylate , pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acryloyloxy ethoxytrimethylolpropane, glycerin polyglycidyl ether poly(meth)acrylate and tris(2-acryloyloxyethyl)isocyanurate.

Polyfunctional vinyl ethers include, for example, 1,4-butanediol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, Vinyl ether, 1,4-cyclohexanedimethanol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol Tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, EO-added trimethylolpropane trivinyl ether, PO-added trimethylolpropane trivinyl ether, EO-added ditrimethylolpropane tetravinyl ether, PO-added ditrimethylolpropane tetravinyl ether, EO-added penta Erythritol tetravinyl ether, PO-added pentaerythritol tetravinyl ether, EO-added dipentaerythritol hexavinyl ether and PO-added dipentaerythritol hexavinyl ether can be mentioned.

Among them, from the viewpoint of curability, the polyfunctional polymerizable monomer is preferably a monomer having 3 to 11 carbon atoms in the part other than the (meth)acryloyl group. Specific examples of the monomer having 3 to 11 carbon atoms in the portion other than the (meth)acryloyl group include 1,6-hexanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, and PO-modified neopentyl glycol. di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate (EO chain n=4), or 1,10-Decanediol di(meth)acrylate is more preferred.

The content of the polymerizable monomer is preferably 10% by mass to 98% by mass, more preferably 50% by mass to 98% by mass, relative to the total amount of the ink for forming the insulating protective layer.

(Polymerization initiator)
Examples of the polymerization initiator contained in the insulating layer forming ink include oxime compounds, alkylphenone compounds, acylphosphine compounds, aromatic onium salt compounds, organic peroxides, thio compounds, hexaarylbisimidazole compounds, borate compounds, Examples include azinium compounds, titanocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamines.

Among them, from the viewpoint of further improving conductivity, the polymerization initiator contained in the insulating layer forming ink is preferably at least one selected from the group consisting of oxime compounds, alkylphenone compounds, and titanocene compounds. It is more preferably an alkylphenone compound, and more preferably at least one selected from the group consisting of α-aminoalkylphenone compounds and benzylketal alkylphenones.

The content of the polymerization initiator is preferably 0.5% by mass to 20% by mass, more preferably 2% by mass to 10% by mass, relative to the total amount of the insulating layer forming ink.

The ink for forming the insulating protective layer may contain components other than the polymerization initiator and the polymerizable monomer. Other ingredients include chain transfer agents, polymerization inhibitors, sensitizers, surfactants and additives.

(chain transfer agent)
The insulating layer forming ink may contain at least one chain transfer agent.
From the viewpoint of improving the reactivity of the photopolymerization reaction, the chain transfer agent is preferably a polyfunctional thiol.

Examples of polyfunctional thiols include aliphatic thiols such as hexane-1,6-dithiol, decane-1,10-dithiol, dimercaptodiethyl ether, dimercaptodiethyl sulfide, xylylene dimercaptan, 4,4'- Aromatic thiols such as dimercaptodiphenyl sulfide and 1,4-benzenedithiol;
Ethylene Glycol Bis (Mercaptoacetate), Polyethylene Glycol Bis (Mercaptoacetate), Propylene Glycol Bis (Mercaptoacetate), Glycerin Tris (Mercaptoacetate), Trimethylolethane Tris (Mercaptoacetate), Trimethylolpropane Tris (Mercaptoacetate), Penta poly(mercaptoacetate) of polyhydric alcohols such as erythritol tetrakis (mercaptoacetate), dipentaerythritol hexakis (mercaptoacetate);
Ethylene glycol bis(3-mercaptopropionate), polyethylene glycol bis(3-mercaptopropionate), propylene glycol bis(3-mercaptopropionate), glycerol bis(3-mercaptopropionate), trimethylolethane Polyvalent tris (mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), etc. alcohol poly(3-mercaptopropionate); and
1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H )-trione, and poly(mercaptobutyrate) such as pentaerythritol tetrakis(3-mercaptobutyrate).

(Polymerization inhibitor)
The insulating layer forming ink may contain at least one polymerization inhibitor.
Polymerization inhibitors include p-methoxyphenol, quinones (e.g., hydroquinone, benzoquinone, methoxybenzoquinone, etc.), phenothiazine, catechols, alkylphenols (e.g., dibutylhydroxytoluene (BHT), etc.), alkylbisphenols, dimethyldithiocarbamine. zinc acid, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionates, mercaptobenzimidazole, phosphites, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl (TEMPOL), and tris(N-nitroso-N-phenylhydroxylamine) aluminum salt (also known as Cupferron Al).

Among them, the polymerization inhibitor is preferably at least one selected from p-methoxyphenol, catechols, quinones, alkylphenols, TEMPO, TEMPOL, and tris(N-nitroso-N-phenylhydroxylamine) aluminum salt, and p -Methoxyphenol, hydroquinone, benzoquinone, BHT, TEMPO, TEMPOL, and tris(N-nitroso-N-phenylhydroxylamine) aluminum salt is more preferred.

When the insulating layer-forming ink contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.01% by mass to 2.0% by mass, and 0.01% by mass to 2.0% by mass, based on the total amount of the insulating protective layer-forming ink. 02% by mass to 1.0% by mass is more preferred, and 0.03% by mass to 0.5% by mass is particularly preferred.

(sensitizer)
The insulating layer forming ink may contain at least one sensitizer.

Examples of sensitizers include polynuclear aromatic compounds (e.g., pyrene, perylene, triphenylene, and 2-ethyl-9,10-dimethoxyanthracene), xanthene compounds (e.g., fluorescein, eosin, erythrosine, rhodamine B, and Rose Bengal), cyanine compounds (e.g., thiacarbocyanine and oxacarbocyanine), merocyanine compounds (e.g., merocyanine and carbomerocyanine), thiazine compounds (e.g., thionine, methylene blue, and toluidine blue), acridine compounds compounds (e.g., acridine orange, chloroflavin, and acriflavin), anthraquinones (e.g., anthraquinone), squalium compounds (e.g., squalium), coumarin compounds (e.g., 7-diethylamino-4-methylcoumarin), thioxanthone compounds (eg, isopropylthioxanthone), and thiochromanone-based compounds (eg, thiochromanone). Among them, the sensitizer is preferably a thioxanthone compound.

When the insulating layer-forming ink contains a sensitizer, the content of the sensitizer is not particularly limited, but is 1.0% by mass to 15.0% by mass with respect to the total amount of the insulating protective layer-forming ink. and more preferably 1.5% by mass to 5.0% by mass.

(Surfactant)
The insulating layer forming ink may contain at least one surfactant.

Examples of surfactants include those described in JP-A-62-173463 and JP-A-62-183457. Examples of surfactants include anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, and fatty acid salts; polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycol, polyoxyethylene • Nonionic surfactants such as polyoxypropylene block copolymers; and cationic surfactants such as alkylamine salts and quaternary ammonium salts. Further, the surfactant may be a fluorosurfactant or a silicone surfactant.

When the insulating layer forming ink contains a surfactant, the content of the surfactant is preferably 0.5% by mass or less, more preferably 0.1% by mass, based on the total amount of the insulating layer forming ink. The following are more preferable. The lower limit of the surfactant content is not particularly limited.

When the content of the surfactant is 0.5% by mass or less, the insulating layer forming ink is less likely to spread after the insulating layer forming ink is applied. Therefore, the outflow of the ink for forming the insulating layer is suppressed, and the electromagnetic wave shielding property is improved.

(Organic solvent)
The insulating layer forming ink may contain at least one organic solvent.

Examples of organic solvents include (poly)alkylene glycols such as ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME), dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl ether. monoalkyl ethers;
(poly)alkylene glycol dialkyl ethers such as ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol diethyl ether, tetraethylene glycol dimethyl ether;
(poly)alkylene glycol acetates such as diethylene glycol acetate;
(poly)alkylene glycol diacetates such as ethylene glycol diacetate and propylene glycol diacetate;
(poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monobutyl ether acetate and propylene glycol monomethyl ether acetate; ketones such as methyl ethyl ketone and cyclohexanone;
Lactones such as γ-butyrolactone;
Esters such as ethyl acetate, propyl acetate, butyl acetate, 3-methoxybutyl acetate (MBA), methyl propionate, ethyl propionate;
cyclic ethers such as tetrahydrofuran and dioxane; and amides such as dimethylformamide and dimethylacetamide.

When the insulating layer forming ink contains an organic solvent, the content of the organic solvent is preferably 70% by mass or less, more preferably 50% by mass or less, relative to the total amount of the insulating layer forming ink. preferable. The lower limit of the content of the organic solvent is not particularly limited.

(Additive)
The insulating layer-forming ink may contain additives such as a co-sensitizer, an ultraviolet absorber, an antioxidant, an anti-fading agent, and a basic compound, if necessary.

(physical properties)
The pH of the insulating layer-forming ink is preferably 7 to 10, more preferably 7.5 to 9.5, from the viewpoint of improving ejection stability when applied using an inkjet recording method. . The pH is measured at 25° C. using a pH meter, for example, using a pH meter manufactured by DKK Toa (model number “HM-31”).

The viscosity of the insulating layer forming ink is preferably 0.5 mPa·s to 60 mPa·s, more preferably 2 mPa·s to 40 mPa·s. Viscosity is measured at 25° C. using a viscometer, for example, using a TV-22 viscometer manufactured by Toki Sangyo Co., Ltd.

The surface tension of the insulating layer forming ink is preferably 60 mN/m or less, more preferably 20 mN/m to 50 mN/m, even more preferably 25 mN/m to 45 mN/m. The surface tension is measured at 25° C. using a surface tensiometer, for example, by a plate method using an automatic surface tensiometer manufactured by Kyowa Interface Science Co., Ltd. (product name “CBVP-Z”).

<Method for forming insulating protective layer>
In the first step, preferably, an ink for forming an insulating layer is applied to the electronic base material using an inkjet recording method, a dispenser coating method, or a spray coating method, and the insulating layer provided on the top surface of the electronic component. Air is blown onto the forming ink, and then the blown insulating layer forming ink is cured to form an insulating protective layer.

The method of applying the ink for forming the insulating layer is preferably an inkjet recording method from the viewpoint of reducing the thickness of the ink film formed by applying a small amount of droplets in one application. The details of the inkjet recording method are as described above.

The method of curing the insulating layer forming ink is not particularly limited, but for example, a method of irradiating the insulating layer forming ink applied on the substrate with an active energy ray (for example, main exposure) can be used.

Examples of active energy rays include ultraviolet rays, visible rays, and electron beams, and among them, ultraviolet rays (hereinafter also referred to as "UV") are preferred.

The peak wavelength of ultraviolet rays is preferably 200 nm to 405 nm, more preferably 250 nm to 400 nm, even more preferably 300 nm to 400 nm.

The exposure dose in the irradiation of active energy rays is preferably 100 mJ/cm ² to 5000 mJ/cm ² and more preferably 300 mJ/cm ² to 1500 mJ/cm ² .

Mercury lamps, gas lasers, and solid-state lasers are mainly used as light sources for ultraviolet irradiation, and mercury lamps, metal halide lamps, and ultraviolet fluorescent lamps are widely known. UV-LEDs (light-emitting diodes) and UV-LDs (laser diodes) are small, have a long life, are highly efficient, and are low-cost, and are expected to serve as light sources for ultraviolet irradiation. Among them, the light source for ultraviolet irradiation is preferably a metal halide lamp, a high-pressure mercury lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, or a UV-LED.

In the step of obtaining the insulating protective layer, it is preferable to repeat the steps of applying the insulating ink and irradiating the active energy ray two or more times in order to obtain the insulating protective layer with a desired thickness.

The thickness of the insulating protective layer is preferably 5 μm to 5000 μm, more preferably 10 μm to 2000 μm.

In the first step, apart from the irradiation of the active energy ray (for example, the main exposure), the above-described pinning exposure may be performed at least one of before and after the air blows to the ink on the top surface of the electronic component. good.

Examples of the present disclosure are shown below, but the present disclosure is not limited to the following examples.

[Example 1]
<Preparation of Ink for Forming Conductive Layer>
40 g of silver neodecanoate was added to a 200 mL three-necked flask. Next, 30.0 g of trimethylbenzene and 30.0 g of terpineol were added and stirred to obtain a solution containing silver salt. This solution was filtered using a PTFE (polytetrafluoroethylene) membrane filter with a pore size of 0.45 μm to obtain an ink for forming a conductive layer.

<Preparation of electronic board>
A wiring board with electronic components was prepared.
In a wiring board with an electronic component, the wiring board and the electronic component are connected by a plurality of solder balls, and minute gaps exist between the electronic component and the wiring board and between the plurality of solder balls.
This gap was filled with an underfill material from Zymet using a dispenser from Musashi Engineering, and then left to stand in a constant temperature oven for 20 minutes to fill the gap.
As described above, an electronic substrate having the same structure as the electronic substrate 110 shown in FIGS. 15A and 15B (that is, an electronic substrate as a stepped substrate) was prepared.
Each size in the prepared electronic substrate is as follows.

Width of ground electrode: 600 μm
Height of ground electrode (height of portion protruding above wiring board): 25 μm
Area surrounded by ground electrodes (ground area): 10.65 mm x 10.65 mm
Electronic component size and shape: 10.00 mm x 10.00 mm rectangular Height of electronic component (height from the surface of the wiring board to the top surface of the electronic component): 500 μm
Distance between electronic component and ground electrode: 50 μm

<Formation of conductive layer>
a stage on which a substrate (for example, the electronic substrate) is placed;
a transporter for transporting the stage;
a 1200 dpi (dot per inch) inkjet head arranged so that the nozzle rows are orthogonal to the transport direction of the stage;
a dryer and
a 385 nm LED light source (13 W/cm ² , manufactured by Kyocera) as a pinning light source;
A single-pass inkjet recording apparatus was prepared.
Here, the inkjet, the dryer, and the pinning light source are arranged in this order from the upstream side in the transport direction of the stage.

An electronic substrate was fixed on the stage of the inkjet recording apparatus with an adhesive tape. At this time, the electronic board was fixed on the stage so that one of the four sides of the electronic component on the electronic board was parallel to the nozzle row of the inkjet head.
The ink for forming a conductive layer was mounted on the inkjet recording apparatus, and the ink for forming a conductive layer was applied onto the electronic substrate while the electronic substrate was being conveyed. In the application of the conductive layer forming ink, the resolution (dpi) in the direction perpendicular to the direction of relative movement and the resolution (dpi) in the direction of relative movement were adjusted to the values shown in Table 1, respectively.
The application area of the ink for forming the conductive layer is 10.40 mm x 10, including the electronic component (rectangular area of 10.00 mm x 10.00 mm) and protruding from each of the four sides of the electronic component by 0.20 mm. A rectangular area of 0.40 mm.
The application of the conductive layer forming ink described above was repeated three times.

A drier was used to blow air at a temperature of 23° C. and a wind speed of 3 m/s in the following directions to the conductive layer forming ink applied on the top surface of the electronic component of the electronic substrate.
The direction in which the air was blown was such that the elevation angle was 90° from above the center of the top surface of the electronic component.
The time from the end of application of the ink for forming the conductive layer to the start of air blowing was adjusted to be 0.44 seconds.
Then, pinning exposure was applied to the blown ink with a 385 nm LED light source (13 W/cm ² , manufactured by Kyocera). The exposure amount of the pinning exposure was set to 5 J/cm ² .
The time from the end of air blowing to the conductive layer forming ink to the start of pinning exposure was adjusted to 0.44 seconds.

After the pinning exposure, the conductive layer forming ink applied to the electronic substrate was heated (that is, baked) at 150° C. for 20 minutes to obtain a conductive layer as an electromagnetic wave shield layer.
As described above, an electronic device of Example 1 was obtained.

<Evaluation>
The following evaluations were carried out on the obtained electronic devices.
Table 1 shows the results.

(thickness of conductive layer)
The thickness of the conductive layer was measured based on an optical micrograph taken of a cross section of the electronic device.
As the thickness of the conductive layer,
thickness of the conductive layer on the top surface of the electronic member,
The thickness of the conductive layer on the side surface of the electronic member, and
The thickness of the conductive layer on the corner between the top surface and the side surface of the electronic member was measured.
Based on the measurement results, the average thickness and thickness variation were obtained.

(Ink splattering to conductive layer non-formation area)
Ink splattering to the conductive layer non-formed region was evaluated as follows.
Using an optical microscope (200x magnification), three locations on each side at a predetermined distance from the edge of the electronic component were observed to confirm the presence or absence of scattering of the conductive ink.
Based on the obtained results, ink splattering to the conductive layer non-formed region was evaluated according to the following evaluation criteria.
In the following evaluation criteria, "5" is the most excellent rank for suppressing ink splattering to the conductive layer non-formed region.

-Evaluation Criteria for Ink Spattering to Conductive Layer Non-Formed Area-
5: No splattering was observed in a region of 300 μm or more and less than 500 μm from the edge, and no splattering was observed in a region of 500 μm or more from the edge.
4: Splattering was observed in a region of 300 μm or more and less than 500 μm from the edge, but no splattering was observed in a region of 500 μm or more from the edge.
3: Splattering was observed in a region of 500 μm or more and less than 600 μm from the edge, but no splattering was observed in a region of 600 μm or more from the edge.
2: Splattering was observed at a distance of 600 μm or more and less than 1000 μm from the edge, but no scattering was observed at a region of 1000 μm or more from the edge.
1: Scattering was observed in a region of 1000 μm or more from the edge.

(Electromagnetic shielding performance)
Using WM7400 (manufactured by Morita Tech Co., Ltd.), leaked electromagnetic waves were measured in the range up to 3 GHz, and the electromagnetic shielding performance of the conductive layer (electromagnetic shielding layer) was evaluated according to the following evaluation criteria. In the following evaluation criteria, "5" is the most excellent rank for electromagnetic wave shielding performance.

－Evaluation Criteria for Electromagnetic Shielding Performance－
5: Less than 20 dB 4: 20 dB or more and less than 30 dB 3: 30 dB or more and less than 50 dB 2: 50 dB or more and less than 70 dB 1: 70 dB or more

(Amount of ink flowing out to conductive layer non-formed region (μm ³ ))
The amount (μm ³ ) of the ink flowed into the conductive layer non-formed region was measured.

[Example 2]
The same operation as in Example 1 was performed except that the resolution (dpi) in the direction of relative movement was changed as shown in Table 1 in the application of the ink for forming the conductive layer (three times).
Table 1 shows the results.

[Examples 3 to 7]
The same operation as in Example 2 was performed, except that the speed of the wind blown against the conductive layer forming ink was changed as shown in Table 1.
Table 1 shows the results.

[Example 8]
The same operation as in Example 2 was performed except that the wind was collected using an exhaust duct and a fan.
Table 1 shows the results.

[Example 9]
The same operation as in Example 8 was performed except that the direction in which the wind was blown was changed to a direction in which the elevation angle was 30° (see FIGS. 5 and 7B).
Table 1 shows the results.
Regarding the direction of blowing air, more specifically, the direction of air blown from the dryer is different from the side where the inkjet head is arranged as viewed from the dryer, similar to the example shown in FIG. It was made to contain components in opposite directions.

[Example 10]
By changing the arrangement of the pinning light source and the dryer, the timing of performing the pinning exposure on the ink applied to the electronic substrate was changed from after blowing the wind against the ink to before blowing the wind against the ink. The same procedure as in Example 8 was carried out.

[Example 11]
The same operation as in Example 10 was performed, except that the wind speed for blowing against the conductive layer forming ink was changed as shown in Table 1.
Table 1 shows the results.

[Comparative Example 1]
The same operation as in Example 2 was performed, except that the air for forming the conductive layer was not blown.
Table 1 shows the results.

 

 

As shown in Table 1, in Examples 1 to 11 in which wind was blown against the conductive layer forming ink that landed on the top surface of the electronic component, compared to Comparative Example 1 in which the wind was not blown , the variation in the thickness of the conductive layer (that is, film) from the side surface to the top surface of the electronic component could be suppressed.

From the comparison between Example 2 and Example 8, it can be seen that when the wind is collected (Example 8), the scattering of the ink to the conductive layer non-formed region is further suppressed.

From the comparison between Example 1 and Example 2, when the dot resolution in the direction of relative movement is higher than the dot resolution in the direction perpendicular to the direction of relative movement (Example 2), from the side of the electronic component It can be seen that variations in the thickness of the conductive layer (that is, film) over the top surface can be further suppressed.

[Examples 101 to 111, Comparative Example 101]
Electronic devices of Examples 101 to 111 and Comparative Example 101 were obtained in the same manner as in Examples 1 to 11 and Comparative Example 1 except for the following points.
Regarding the obtained electronic device, the thickness of the insulating layer and the scattering of the insulating layer-forming ink were evaluated in the same manner as the evaluation of the thickness of the conductive layer and the scattering of the conductive layer-forming ink in Example 1.
Table 2 shows the results.

-Changes from Examples 1 to 11 and Comparative Example 1-
- Instead of applying the conductive layer forming ink (three times), the following insulating layer forming ink was applied (once) to form an insulating layer instead of the conductive layer.
・Baking after blowing wind was changed to UV (ultraviolet) irradiation as main exposure.
The ultraviolet irradiation as the main exposure was performed using an ultraviolet irradiation apparatus (product name: 385 nm LED light source (13 W/cm ² , manufactured by Kyocera). The exposure amount as the main exposure was 0.8 J/cm ² .
The time from the start of air blowing to the insulating layer ink to the start of active energy ray irradiation was adjusted to 0.44 seconds.
- In Examples 101 to 111, the main exposure was performed without performing the pinning exposure after blowing air.

-Preparation of ink for insulating layer-
In a 300 mL resin beaker,
2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)-butan-1-one (product name "Omnirad 379", IGM
Resins B. V. company) 4.0 g,
2-Isopropylthioxanthone as a sensitizer (product name “SPEEDCURE ITX
”, manufactured by LAMBSON; hereinafter also referred to as “ITX”) 2.0 g,
30.0 g of isobornyl acrylate (manufactured by Fujifilm Wako Pure Chemical Industries; hereinafter also referred to as "IBOA") as monofunctional acrylate X1 (that is, monofunctional acrylate having a molecular weight of 200 or more and a ring structure);
15.0 g of cyclic trimethylolpropane formal monoacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat #200, hereinafter also referred to as “CTFA”) as monofunctional acrylate X2;
20.0 g of N-vinylcaprolactam (hereinafter also referred to as "NVC") as a monofunctional monomer,
10.0 g of 1,6-hexanediol diacrylate (hereinafter also referred to as "1,6-HDDA") as a bifunctional monomer;
10.0 g of alkoxylated hexanediol diacrylate (manufactured by Sartomer, CD561) as a bifunctional monomer, and
9.0 g of trimethylolpropane triacrylate (manufactured by Fujifilm Wako Pure Chemical Industries; hereinafter also referred to as "TMPTA") as a trifunctional monomer
and
Using a mixer (product name “L4R”, manufactured by Silverson), the mixture was stirred at 25° C. and 5000 rpm for 20 minutes to obtain an insulating layer ink.

 

 

As shown in Table 2, in Examples 101 to 111 in which air blowing was performed on the insulating layer forming ink that landed on the top surface of the electronic component, compared with Comparative Example 101 in which this air blowing was not performed, Variation in the thickness of the insulating layer (that is, film) from the side surface to the top surface of the electronic component could be suppressed.

The disclosures of Japanese Patent Application No. 2021-165574 filed on October 7, 2021 and Japanese Patent Application No. 2022-003362 filed on January 12, 2022 are herein incorporated by reference in their entirety. It is captured.
All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.

Claims (19)

preparing a stepped substrate, which is a substrate having a step in the thickness direction of the substrate;
By ejecting ink from an inkjet head to apply the ink onto at least the top surface of the step in the stepped substrate, and blowing air against the ink applied on the top surface of the step, a film forming step of forming a film covering at least the top surface of the step and the side surface of the step;
including,
Membrane formation method. The method of forming a film according to claim 1, wherein the wind speed of the wind is 1 m/s or more and less than 30 m/s. The method of forming a film according to claim 1 or 2, wherein the film forming step includes recovering the wind. The film forming step further includes subjecting the ink blown by the wind to a pinning exposure,
The time from the start of blowing of the wind to the start of the pinning exposure is 1 second or less.
The method for forming a film according to any one of claims 1 to 3. The film forming step further includes subjecting the ink applied on the top surface of the step to the ink before the wind is blown to a pinning exposure,
The method for forming a film according to any one of claims 1 to 4. The wind is blown out from a wind blower,
The direction of the wind includes a component opposite to the side on which the inkjet head is arranged as viewed from the wind blower,
A method for forming a film according to any one of claims 1 to 5. The application of the ink in the film forming step is performed while relatively moving the stepped substrate and the inkjet head,
In the ink applied to the stepped substrate, the dot resolution in the direction of the relative movement is higher than the dot resolution in the direction perpendicular to the direction of the relative movement.
A method for forming a film according to any one of claims 1 to 6. The wind is an inert gas stream,
wherein the ink is an active energy ray-curable ink containing a polymerizable compound;
A method for forming a film according to any one of claims 1 to 7. The stepped substrate includes a base substrate and components arranged on the base substrate, and a gap exists between the base substrate and the components.
A method for forming a film according to any one of claims 1 to 8. Furthermore, before the film forming step, a partition wall forming step of forming partition walls surrounding the region where the film is formed by ejecting ink from an inkjet head,
A method for forming a film according to any one of claims 1 to 9. Furthermore, before the film forming step, at least the region where the film is formed is subjected to a hydrophilic treatment.
A method for forming a film according to any one of claims 1 to 10. preparing an electronic substrate comprising a wiring substrate and electronic components arranged on the wiring substrate;
forming at least one of an insulating layer and a conductive layer on the electronic substrate to obtain an electronic device;
including
At least one of the insulating layer and the conductive layer is formed by the film forming method according to any one of claims 1 to 11,
A method of manufacturing an electronic device. an inkjet head that applies ink to at least the top surface of the stepped substrate, which is a substrate having a stepped portion in the thickness direction of the substrate;
an air blower for blowing air against the ink applied on the top surface of the step;
with
relative movement between the stepped substrate and the inkjet head,
A film forming apparatus, wherein the inkjet head and the air blower are arranged in the direction of the relative movement. Furthermore, comprising a wind collector for collecting the wind,
The film forming apparatus according to claim 13. The direction of the wind blown from the wind blower includes a component in the opposite direction to the side on which the inkjet head is arranged as viewed from the wind blower,
15. The film forming apparatus according to claim 13 or 14. Equipped with two wind blowers,
The inkjet head is arranged between the two air blowers,
wherein the relative movement is reciprocating movement;
The film forming apparatus according to any one of claims 13 to 15. The wind blower has an on/off function for switching between an on state for blowing the wind and an off state for stopping the blowing of the wind.
The film forming apparatus according to any one of claims 13 to 16. Furthermore, a pinning exposure machine is provided for performing pinning exposure on the ink blown by the wind.
The film forming apparatus according to any one of claims 13 to 17. Furthermore, a pinning exposure device is provided for performing pinning exposure on the ink applied on the top surface of the step and before the wind is blown,
The film forming apparatus according to any one of claims 13 to 18.

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