TWI880499B - In-mold electronic device and manufacturing method thereof - Google Patents

Abstract

An in-mold electronic device includes a substrate, a circuit layer, at least one electronic component, a protective layer and a plastic part. The substrate has a first surface and a second surface. The circuit layer is disposed on the first surface, the second surface, in the substrate, or a combination thereof, and comprises a plurality of conductive circuits. The at least one electronic component is disposed on the circuit layer and is electrically connected to the plurality of conductive circuits. The protective layer is disposed on the circuit layer; the protective layer is composed of paint, and the paint covers at least a part of the plurality of conductive circuits, at least a part of the at least one electronic component, or a combination thereof. The plastic part is disposed on the protective layer; the plastic part is formed by plastic injection and covers at least a part of the circuit layer and the at least one electronic component.

Description

In-mold electronic device and manufacturing method thereof

The present invention relates to an in-mold electronic device, in particular to a method for manufacturing an in-mold electronic device and the manufactured in-mold electronic device.

In-mold electronics (IME) technology combines electronic substrates with plastic parts through in-mold decoration (IMD), making products smaller, thinner, and giving them a shape that adds functionality and beauty. The use of IME technology can also shorten the assembly process, saving costs and time. However, despite the above advantages, it is now found that the IMD process will affect the product yield, so the IMD process needs to be adjusted and optimized.

The present invention provides an in-mold electronic device and a manufacturing method thereof. The present invention helps to simplify the manufacturing process, shorten the operation time, realize operation automation, and improve the yield rate of the finished in-mold electronic device.

The in-mold electronic device provided by the present invention includes a substrate, a circuit layer, at least one electronic component, a protective layer and a plastic part. The substrate has a first surface and a second surface. The circuit layer is arranged on the first surface, the second surface, inside the substrate or a combination thereof, and includes a plurality of conductive lines. At least one electronic component is arranged on the circuit layer and is electrically connected to the plurality of conductive lines. The protective layer is arranged on the circuit layer; the protective layer is composed of a coating, and the coating covers at least a portion of the plurality of conductive lines, at least a portion of at least one electronic component or a combination thereof. The plastic part is arranged on the protective layer; the plastic part is formed by plastic injection and covers at least a portion of the circuit layer and at least one electronic component.

The manufacturing method of the in-mold electronic device provided by the present invention includes the steps of: providing an electronic substrate having a first surface, and a circuit layer and at least one electronic component are arranged on the first surface, wherein the circuit layer includes a plurality of conductive lines electrically connected to the at least one electronic component; distributing a coating on the first surface to form a protective layer, which is located on the circuit layer and covers the plurality of conductive lines and at least one electronic component; providing a mold and placing the electronic substrate in the mold; injecting a plastic material into the cavity of the mold to form a plastic part covering the first surface and the circuit layer and at least one electronic component on the first surface.

The present invention uses a protective layer, and the protective layer is arranged on the circuit layer, so it can reduce the impact on the conductive circuit and electronic components during the in-mold injection molding process, and improve the yield of the finished product. The protective layer of the present invention is composed of a coating; because the coating is not distributed locally on the conductive circuit and electronic components, but distributed on the first surface in a large area and a large range, the process is more simplified, the operation time is shortened, and it can be realized by automated operations.

In order to make the above and other purposes, features and advantages of the present invention more clearly understood, the following is a detailed description of the embodiments with the accompanying drawings.

10: In-mold electronic devices

100: Substrate

101: First surface

102: Second surface

200, 200’: Circuit layer

210: Conductive lines

220: Transmission wire

300, 300’: electronic components

400, 400’: Pin connection

500, 500’: protective layer

600: Plastic parts

R1, R1’: first area

R2, R2’: The second area

Figure 1 is a schematic cross-sectional view of an in-mold electronic device of an embodiment of the present invention.

Figure 2 is a schematic top view of a portion of an in-mold electronic device of an embodiment of the present invention.

Figure 3 is a schematic top view of a portion of an in-mold electronic device of another embodiment of the present invention.

Figure 4 is a schematic diagram of the steps of the in-mold electronic device manufacturing method of an embodiment of the present invention.

Figure 5 is a schematic top view of a portion of an in-mold electronic device of another embodiment of the present invention.

Figures 1 and 2 show schematic cross-sectional views and top views of an in-mold electronic device of an embodiment of the present invention. As shown in Figures 1 and 2, the in-mold electronic device 10 includes a substrate 100, a circuit layer 200, at least one electronic component 300, a protective layer 500, and a plastic part 600. The substrate 100 may be a flexible or rigid plate having a first surface 101 and a second surface 102, and the circuit layer 200 is disposed on the first surface 101 or the second surface 102, or the circuit layer 200 is disposed on both the first surface 101 and the second surface 102. In some embodiments, the circuit layer 200 may also be disposed in the substrate 100.

The circuit layer 200 includes a plurality of conductive lines 210, or it can be said that the circuit layer 200 is mainly composed of the conductive lines 210. The electronic components 300 include active and passive components, such as resistors, capacitors, inductors, transistors, diodes, chips, light-emitting components or combinations thereof, and can be electrically connected to the conductive lines 210 by any means. For example, the electronic components 300 may be provided with pins 400, and are electrically connected to the conductive lines 210 by soldering the pins 400. In a preferred embodiment of the present invention, the conductive lines 210 also include transmission wires 220 for signal transmission between the in-mold electronic device 10 and an external device.

As shown in FIG. 2 , the first surface 101 has a first area A1, and the first surface 101 includes a first region R1 in a left dashed frame and a second region R2 in a right dashed frame (the dashed frame is used to circle the first region R1 and the second region R2, and its range is not equal to the first region R1 and the second region R2). The first region R1 is preferably larger than the second region R2 and has a second area A2. The circuit layer 200 is mainly located in the first region R1 of the first surface 101, but the circuit layer 200 may also be distributed in the second region R2. In a preferred embodiment of the present invention, the transmission wire 220 of the circuit layer 200 may be located in the second region R2 of the first surface 101.

As mentioned above, the circuit layer 200 is mainly composed of the conductive lines 210. That is, the area occupied by the conductive lines 210 is in principle equivalent to the area of the circuit layer 200. In some cases, when the number of conductive lines 210 is large, the area occupied is in principle larger than when the number is small; however, if the conductive lines 210 are distributed more densely and concentratedly, the area occupied by the dense conductive lines 210 may be smaller than that of the sparse and wide distribution type under the same number. In a preferred embodiment of the present invention, the circuit layer 200 has a third area A3 on the first surface 101 and a fourth area A4 in the first region R1. The first area A1 is larger than the second area A2 (A1>A2), and the first area A1 is larger than or equal to the third area A3 (A1≧A3), and the second area A2 is larger than or equal to the fourth area A4 (A2≧A4). In a preferred embodiment of the present invention, the first area A1 is larger than the third area A3 (A1>A3), and the second area A2 is larger than the fourth area A4 (A2>A4).

When a circuit layer 200' is disposed on the second surface 102 of the substrate 100, the relationship between the area of the circuit layer 200' and the area of the second surface 102 is substantially the same as that of the first surface 101. Specifically, taking FIG. 3 as an example, the second surface 102 has a first area A1', and its first region R1' has a second area A2', and the first area A1' is larger than the second area A2' (A1'>A2'). The circuit layer 200' has a third area A3' on the second surface 102 and a fourth area A4' in the first region R1', and the first area A1' is greater than or equal to the third area A3' (A1'≧A3'), and the second area A2' is greater than or equal to the fourth area A4' (A2'≧A4'). In addition, the areas of the second surface 102 and the first surface 101 are the same in principle, and the areas of the first region R1 and the first region R1' can be the same.

The protective layer 500 is made of coating and is disposed on the circuit layer 200. The coating can be a fluid curable material such as ink, gel, adhesive and/or other compositions that can be used in electronic substrates, and is distributed on the circuit layer 200 and cured to form the protective layer 500. The coating is heat-resistant and can be well attached to the circuit layer 200 and cover at least a portion of the conductive line 210, at least a portion of the electronic component 300, and at least a portion of the pin 400. Good adhesion means that the coating can still adhere to the circuit layer 200 without obviously detaching from the circuit layer 200, or even completely remain on the circuit layer 200, under the impact, pressure, or shear force caused by the flowing liquid (described later). The protective layer 500 can completely cover the conductive line 210, the electronic components 300, and the pins 400 without being affected by the flowing liquid. In the embodiment of the present invention, the shape of the protective layer 500 on the surface of the substrate 100 is preferably a closed pattern such as a rectangle, trapezoid, triangle, circle, or other irregular pattern. The shape of the protective layer 500 can be substantially the same as the shape of the surface of the substrate 100. In a preferred embodiment of the present invention, the protective layer 500 has a fifth area A5. The fifth area A5 is preferably larger than the fourth area A4, and the range of the circuit layer 200 in the first region R1 is preferably included in the range of the protective layer 500 having the fifth area A5.

When a protective layer 500' is disposed on the second surface 102 of the substrate 100, the relationship between the area of the protective layer 500' and the area of the circuit layer 200' is basically the same as that of the first surface 101. Taking FIG. 3 as an example, the protective layer 500' has a fifth area A5'; the fifth area A5' is preferably larger than the fourth area A4', and the range of the circuit layer 200' in the first region R1' is preferably included in the range of the fifth area A5' of the protective layer 500'.

The plastic part 600 is an injection molded part, which is disposed on the protective layer 500 and covers at least a portion of the circuit layer 200 and the electronic components 300. The plastic part 600 has the functions of protection, support, identification and beautification. In the embodiment of the present invention, the plastic part 600 also covers at least a portion of the first surface 101 of the substrate 100. In some embodiments, the first area R1 of the first surface 101 can be completely covered by the plastic part 600. The second area R2 can also be covered by the plastic part 600 except for the range where the transmission wire 220 is located, but it is not limited to this.

Injection molding is a process for manufacturing parts made of thermoplastic plastic or thermosetting plastic. The process may include heating and melting plastic pellets, and quickly injecting the molten liquid plastic into a mold with a lower temperature. Therefore, the injection molding of the plastic part 600 will cause the electronic components 300 and the conductive lines 210 on the substrate 100 to be heated and impacted. However, because the coating is heat-resistant and can be well attached to the circuit layer 200, it helps to prevent the conductive lines 210 and the electronic components 300 of the circuit layer 200 under the protective layer 500 from being damaged, deformed or displaced due to impact. For example, the pin 400 can be protected from displacement due to injection molding impact under the coverage of the protective layer 500, thereby improving the poor contact situation and increasing the yield of the in-mold electronic device. It should be noted that even if the protective layer 500 may have a coating partly detached under the injection molding impact, this does not affect the scope of the protective layer 500 defined in this article, and the circuit layer 200 is included in the scope of the first region R1 in principle within the scope of the fifth area A5 of the protective layer 500.

The fifth area A5 of the protective layer 500 may be equal to or less than the first area A1 of the first surface 101 of the substrate 100, wherein when the fifth area A5 is less than the first area A1, the fifth area A5 may be greater than, equal to, or less than the second area A2 of the first region R1. For example, in the embodiment shown in FIG. 2 , the protective layer 500 may be disposed on the circuit layer 200 and cover the second region R2 of the entire first region R1 and a portion thereof, and the fifth area A5 is greater than the second area A2. In addition, in some embodiments of the present invention, the protective layer 500 may be further disposed on the circuit layer 200 located in the first region R1, and the protective layer 500 covers the entire first region R1 or a portion thereof. When the protective layer 500 covers the entire first area R1, the fifth area A5 may be equal to the second area A2, and when the protective layer 500 does not completely cover the first area R1, the fifth area A5 may be less than the second area A2. In the embodiment of the present invention, when the fifth area A5 is less than or equal to the second area A2, the fifth area A5 is preferably 70% to 100% of the second area A2.

The relationship between the area of the protective layer 500' on the second surface 102 and the second surface 102 is basically the same as the situation of the first surface 101 described above. Further, the fifth area A5' of the protective layer 500' may be equal to or less than the first area A1' of the second surface 102 of the substrate 100, wherein when the fifth area A5' is less than the first area A1', the fifth area A5' may be greater than, equal to, or less than the second area A2' of the first region R1'. When the fifth area A5' is less than or equal to the second area A2', the fifth area A5' is preferably 70% to 100% of the second area A2'.

The present invention also provides a method for manufacturing an in-mold electronic device. As shown in FIG. 4 , the manufacturing method of an embodiment of the present invention includes steps S910 to S940: S910 includes providing an electronic substrate; the electronic substrate has a first surface, and a circuit layer and at least one electronic component are arranged on the first surface, wherein the circuit layer includes a plurality of conductive lines electrically connected to at least one electronic component; step S920 includes distributing a coating on the first surface and forming a protective layer; the protective layer is located on the circuit layer and covers a plurality of conductive lines and at least one electronic component; step S930 includes providing a mold and placing the electronic substrate in the mold; step S940 includes injecting a plastic material into the cavity of the mold to form a plastic part covering the first surface and the circuit layer and at least one electronic component on the first surface.

The electronic substrate of step S910 may substantially include the aforementioned substrate 100, conductive circuit 210 and electronic component 300. The conductive circuit 210 mainly constitutes the circuit layer 200, and the electronic component 300 is electrically connected to the conductive circuit 210. The coating of step S920 is a fluid curable material, which can be distributed on the first surface 101 by methods such as brushing, spraying, printing, etc., and then cured by methods such as light curing, baking, natural air drying or any other means that can cure or dry the coating to form a protective layer 500 on the first surface 101. The thickness of the distribution and the thickness of the protective layer 500 may vary depending on the coating.

Step S920 may further include applying a coating on the circuit layer 200 so that the coating covers the conductive lines 210 and the electronic components 300, so that after curing, a protective layer 500 is formed on the circuit layer 200 and covers the conductive lines 210 and the electronic components 300. One of the purposes of distributing the coating is to protect the conductive lines 210, the electronic components 300 and their pins 400 from damage, deformation or displacement in subsequent steps due to, for example, injection molding impact. In the embodiment of the present invention, even if the conductive line 210 and the electronic component 300 may be dispersed on the substrate 100, step S920 preferably distributes the coating on the first surface 101 in a large area and a large range, instead of only locally coating the conductive line 210 and the electronic component 300. In addition, the coating may not be limited to the first surface 101. For example, the coating may exceed the first surface 101 when brushing. In some embodiments of the present invention, the distribution range of the coating may be equivalent to the first surface 101. The protective layer 500 formed by the coating has a fifth area A5, which is equal to or less than the first area A1.

In some embodiments of the present invention, step S920 further includes distributing the coating on the first area R1 of the first surface 101. The area not subjected to injection molding, such as the second area R2, may not be provided with the protective layer 500. For example, as shown in FIG5 , the transmission wire 220 located in the second area R2 may be designed to be exposed outside the plastic part 600 and used for signal transmission between the in-mold electronic device 10 and the external device. In this case, the coating may not be distributed in the second area R2, but the present invention is not limited thereto. The area not subjected to injection molding may also be provided with the protective layer 500. The embodiment of the present invention distributes the coating in a large area and a wide range. Therefore, when the distribution range does not completely cover the first area R1, the area of the coating range is preferably not less than 70% to 100% of the area of the first area R1 (i.e., the second area A2).

The mold of step S930 has a cavity. When the electronic substrate is placed in the mold, the first surface 101 of the substrate 100, the first region R1 of the first surface 101 and/or the portion of the substrate 100 to be covered with the plastic part can be further oriented toward the cavity. In some embodiments of the present invention, for example, the area not to be molded, such as the second region R2, can be placed outside the cavity. In step S940, a molten liquid plastic material at a high temperature is injected into the cavity of the mold, and after cooling, a plastic part 600 is formed to cover the circuit layer 200 and the electronic components 300 on the first surface 101 or its first region R1. After demolding, the in-mold electronic device 10 can be obtained.

Steps S910 to S940 are also applicable to the second surface 102 of the electronic substrate. The embodiment of the present invention uses coating to form a protective layer 500 on the substrate 100, so that the conductive circuit 210 of the circuit layer 200 and the electronic components 300 can be protected from damage, deformation or displacement caused by injection molding impact. And because the coating is distributed on the substrate 100 in a large area and a wide range, it can simplify the process, shorten the operation time, and facilitate the automation of the coating operation.

Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention belongs may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of the patent application attached hereto.

10: In-mold electronic devices

100: Substrate

101: First surface

102: Second surface

200, 200’: Circuit layer

300, 300’: electronic components

400, 400’: Pin connection

500, 500’: protective layer

600: Plastic parts

Claims (9)

An in-mold electronic device comprises: A substrate having a first surface and a second surface, wherein the first surface has a first area, and the first surface includes a first region and a second region, and the first region has a second area; A circuit layer disposed on the first surface, the second surface, in the substrate, or a combination thereof, and the circuit layer includes a plurality of conductive lines; the circuit layer has a third area, and the third area is less than or equal to the first area; and the circuit layer has a fourth area in the first region of the first surface; At least one electronic component disposed on the circuit layer and electrically connected to the conductive lines; A protective layer is disposed on the circuit layer and has a fifth area; the protective layer is composed of a coating, and the coating covers at least a portion of the conductive lines, at least a portion of the at least one electronic component, or a combination thereof, wherein the fifth area is larger than the fourth area; and A plastic part is disposed on the protective layer; the plastic part is formed by plastic injection and covers at least a portion of the circuit layer and the at least one electronic component. The in-mold electronic device as described in claim 1 further includes a plurality of pins, and the at least one electronic component is connected to the conductive lines through the pins, wherein the coating further covers at least a portion of the pins. An in-mold electronic device as described in claim 1, wherein the fifth area is greater than, equal to, or less than the second area; when the fifth area is less than or equal to the second area, the fifth area is 70% to 100% of the second area. An in-mold electronic device as described in claim 1, wherein the protective layer is further disposed on the circuit layer located in the first area. An in-mold electronic device as described in claim 1, wherein the conductive circuits further include a transmission wire, and the transmission wire is arranged in the second area of the first surface. An in-mold electronic device as described in claim 1, wherein the second surface includes a first region and a second region; the second surface has a first area, and the first region has a second area; the circuit layer has a third area that is less than or equal to the first area; the circuit layer further has a fourth area in the first region, and the protective layer has a fifth area that is larger than the fourth area. A method for manufacturing an in-mold electronic device comprises the following steps: Providing an electronic substrate having a first surface, wherein the first surface includes a first area and a second area; a circuit layer and at least one electronic component are disposed on the first surface, wherein the circuit layer includes a plurality of conductive lines electrically connected to the at least one electronic component; Distributing a coating on the first surface and forming a protective layer, including distributing the coating on the first area of the first surface; the formed protective layer is located on the circuit layer and covers the conductive lines and the at least one electronic component, and the area of the protective layer is 70% to 100% of the area of the first area; Providing a mold, placing the electronic substrate in the mold; and Inject a plastic material into a cavity of the mold to form a plastic part covering the first surface and the circuit layer and the at least one electronic component on the first surface. The method for manufacturing an in-mold electronic device as described in claim 7, wherein the step of distributing the coating on the first surface further includes distributing the coating on the circuit layer and allowing the coating to cover the conductive circuits and the at least one electronic component. A method for manufacturing an in-mold electronic device as described in claim 8, wherein the step of forming the plastic part to cover the first surface further includes covering the first area of the first surface.

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