JP3015709B2 - Film carrier, semiconductor device using the same, and semiconductor element mounting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film carrier, a semiconductor device using the same, and a method for mounting a semiconductor element.

[0002]

2. Description of the Related Art Conventionally, a film carrier method has been adopted as a method for mounting a semiconductor element. A conductive projection (hereinafter referred to as a bump) for connection is used for inner lead bonding between a lead on the film carrier and an electrode of the semiconductor element. ) Is used.

In the above-mentioned film carrier method, bumps are usually formed on the electrode surface of a semiconductor element by using gold or the like. At this time, before forming the bumps, a bonding metal layer such as titanium or chromium is formed. In addition, it is necessary to form a barrier metal layer such as copper, platinum, palladium or the like on the electrode surface for preventing the diffusion of the bump metal. Therefore, there is a problem that the process is extremely complicated. Further, in a process of forming a bump on an electrode surface of a semiconductor element, the semiconductor element and the electrode surface may be contaminated or damaged.

For this reason, instead of the electrode surface of the semiconductor element,
It has also been proposed to form bumps on the lead side of the film carrier, but in this method, when the wiring of the semiconductor element becomes fine pitch or high density, the corresponding circuit or bump is formed. It becomes difficult to form on a film carrier.

[0005] Therefore, it has been proposed to use an anisotropic conductive film having conductivity in the thickness direction of the film instead of the bump as described above. Specifically, the anisotropic conductive film is obtained by dispersing conductive particles such as carbon black and metal particles in a film thickness direction in an insulating film. However, in this anisotropic conductive film, if the orientation of the conductive particles is insufficient, the electrical connection between the lead on the film carrier and the electrode of the semiconductor element becomes uncertain, resulting in poor connection reliability. There is a problem that the electrical resistance of the connection part is large.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the conventional film carrier system, to cope with fine pitch and high density wiring of a semiconductor element, and to improve the electrode and the electrode of the semiconductor element. The purpose of the present invention is to provide a film carrier that can easily and surely make electrical connection of the film carrier. Another object of the present invention is to provide a semiconductor device which is miniaturized in response to fine pitch and high density, and in which electrical connection between an electrode of a semiconductor element and a film carrier is ensured. . Still another object of the present invention is to mount a semiconductor element which can cope with fine pitch and high density wiring of the semiconductor element and can easily and surely make an electrical connection between an electrode of the semiconductor element and a film carrier. Is to provide a way.

[0007]

Means for Solving the Problems The present inventors have found that the above objects can be achieved by the following present invention. That is, in the film carrier of the present invention, a conductive circuit is laminated on the insulator layer, and the laminated body is provided with a conduction portion for connection with an external substrate and an energy supply portion for connection with a semiconductor element. It is characterized by the following. Further, a semiconductor device of the present invention is obtained by mounting a semiconductor element on the above-mentioned film carrier. Still further, the method of mounting a semiconductor element according to the present invention includes contacting an electrode of the semiconductor element with the conductive circuit of the film carrier, and applying energy to the contact portion via an energy supply section of the film carrier. And connecting the conductive circuit to an electrode of a semiconductor element.

In the present invention, the term "semiconductor device" refers to a semiconductor element assembly (for example, a silicon chip after dicing), a circuit board for mounting a semiconductor device, a circuit board for LCD, a fine pitch circuit board such as a hybrid IC. , MCM substrate, etc., and the “conductive circuit” is a broad concept including not only wiring patterns but also electrodes, leads, and the like.

[0009]

According to the present invention, the film carrier is provided with an energy supply portion for connection with the semiconductor element, and energy for connection is applied to a portion intended for the connection via the energy supply portion. The connection between the film carrier and the semiconductor element is made.

Hereinafter, the film carrier of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a schematic sectional view showing one embodiment of the film carrier of the present invention. In the figure, F is a film carrier, and a conductive circuit 5 is laminated on an insulator layer 6, and a conductive part 8 (conductive path 81) for connection with an external substrate (not shown) is provided on the laminated body. ) And an energy supply unit 7 (conduction path 71) for connection to the semiconductor element 3.

The material of the insulator layer 6 is not particularly limited as long as it can stably support the conductive circuit 5, the conductive path 71 and the like, and has substantially electric insulation. Specifically, polyester resin, epoxy resin, urethane resin, polystyrene resin, polyamide resin, polyimide resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polycarbonate resin, silicone resin Examples include, but are not limited to, various thermosetting resins or thermoplastic resins such as fluororesins, among others,
A polyimide resin excellent in heat resistance, dimensional stability during heating, mechanical strength, and the like is particularly suitable.

The thickness of the insulator layer 6 is not particularly limited, but is preferably 2 to 500 mm so that the mechanical strength and the flexibility are sufficient.
It is appropriate that the thickness is about μm, preferably about 5 to 150 μm.

The material for forming the conductive circuit 5 is not particularly limited as long as it has conductivity. For example, various metals such as gold, silver, copper, nickel and cobalt or various materials containing these as a main component are used. Alloys and the like can be used.

Although the thickness of the conductive circuit 5 is not particularly limited, it is usually about 1 to 200 μm, preferably 5 to 80 μm.
Suitably, it is about μm.

The laminate of the insulator layer 6 and the conductive circuit 5 is formed, for example, by forming a conductor layer on the insulator layer 6 and then forming the conductor layer into a desired circuit pattern ( (Subtractive method). As a method for forming a conductor layer on the insulator layer 6, for example, a conductive powder such as metal powder or carbon black made of various metals or alloys as described above and a binder such as polyester are contained. A method of applying a conductive paint on the insulator layer 6, or a method of forming a conductive thin film made of the same metal as described above on the insulator layer 6 by sputtering, CVD, vacuum deposition, or the like, and then by plating or the like, A method of growing to a thickness is exemplified. Alternatively, a foil made of the same metal as described above is used as a conductor layer, and various kinds of resins as described above or a precursor solution thereof are coated on the foil, and a solvent removal treatment or the like is performed to form an insulator layer 6. Alternatively, a method of bonding a film made of the same various resins as described above is also possible. Note that the laminate can also be manufactured by a method in which a conductive material is directly formed into a circuit pattern without a step of forming a conductive layer (an additive method, a semi-additive method, or the like).

Preferably, the conductive circuit 5 is coated with a metal such as gold having a high connection reliability so that the connection with the electrode 10 of the semiconductor element 3 can be surely made. Depending on the type of metal of the conductive circuit 5, it is desirable to interpose a barrier metal such as nickel between them in a layered manner. Examples of the method of forming the metal coating and the barrier metal layer include plating methods such as electrolytic plating and electroless plating, sputtering, ion plating, and vacuum deposition.

The energy supply unit 7 includes a conductive circuit 5
This is a portion to which energy for connecting the semiconductor device and the electrode of the semiconductor element is supplied. The energy supply unit 7 receives the energy for the connection from the outside,
What is necessary is just to be able to transmit this to the portion of the conductive circuit 5 intended to be connected to the electrode of the semiconductor element.
In the embodiment shown in FIG. 1, a conduction path 71 is provided as the energy supply unit 7.

In the embodiment shown in FIG. 1, a conduction path 81 is provided as the conduction section 8 for connection to an external substrate.

The material for forming the conductive paths 71 and 81 is not particularly limited as long as it has conductivity, and known metal materials can be used. For example, gold, silver, copper, platinum, lead, tin, Single metal such as nickel, cobalt, indium, rhodium, chromium, tungsten, ruthenium or various alloys containing these (eg, solder, nickel-tin alloy, gold-cobalt alloy, etc.) Examples include a conductive paste in which conductive particles such as carbon black are dispersed.

Although the conductive paths 71 and 81 are formed to protrude from the surface of the insulator layer 6 in FIG.
This facilitates positioning at the time of contact (or connection) with an object to be connected such as an energy applying means (not shown) or an electrode of an external substrate, and this contact (or connection) can be reliably performed. The height of the protruding portion from the surface of the insulator layer 6 is not particularly limited. However, in terms of the reliability of contact (or connection) with the object to be connected and the reliability after connection, the height is 5%.
It is appropriate that the thickness is about 200 μm.

The shape of the protruding portions of the above-mentioned conductive paths 71 and 81 is not limited to a mushroom shape (or hemisphere) as shown in FIG. , A trapezoidal shape, etc., and the planar shape of the protruding portion may be a square shape, a triangular shape, a trapezoidal shape, other polygonal shapes, a circular shape, an oval shape, or the like.

The form of the ends of the conductive paths 71 and 81 may be changed as appropriate according to the layout and shape of the connected object. That is, for example, when the object to be connected is planar, it is preferable that the end of the conductive path be in a form in which the tip is point-like, such as the above-mentioned mushroom shape, cone shape, or the like. When the body has a protruding shape, it is preferable that the end of the conduction path has a shape such that the tip is planar, such as the above-mentioned prismatic or cylindrical shape. Further, when the tip is planar as in the latter case, the end of the conduction path may be flush with the surface of the insulator layer 6.

The conductive paths 71 and 81 are formed, for example, by forming through holes 72 and 82 in the insulator layer 6.
And 82 are formed by exposing the conductive circuit 5 at the bottom, and then filling the through holes 72 and 82 with a conductive material.

Examples of the method of forming the through holes 72 and 82 include mechanical processing methods such as punching, photolithography processing, plasma processing, chemical etching processing, and laser processing. In this case, laser processing capable of fine processing is preferable, and it is particularly preferable to use an ultraviolet laser having an oscillation wavelength in ultraviolet light.

The diameter of the through holes 72 and 82 is 5 to 5
It is appropriate that the thickness is about 00 μm.
In the case of the through hole 72 for forming one, about 10 to 100 μm,
10 to 300 μm in the case of the through hole 82 for forming the conduction path 81
It is appropriate to be about m.

The method for filling the through holes 72 and 82 with a conductive substance is not limited to a physical filling method such as a method of injecting a conductive substance into the through holes under pressure. , Plating methods such as electroless plating, CVD
And a chemical filling method such as a method in which a conductive material is deposited by immersing a through-hole formation site in a molten metal bath. Particularly, when electroplating is performed using the conductive circuit 5 as an electrode, The substance can be easily filled.

In the present invention, for example, as shown in FIG. 2, the conductive circuit 5 is exposed without filling the through-hole 72 with a conductive substance, and the exposed portion of the conductive circuit 5 is supplied with energy. It is also possible to use the unit 7. in this case,
The exposed portion of the conductive circuit 5 is desirably coated with a metal such as gold, silver, copper, or solder that can improve the reliability of contact with the energy applying means. In addition, the through hole 82 may be filled with a conductive substance (for example, solder, conductive paste, or the like) immediately before connection with an external substrate. Thus, when the film carrier is manufactured, when the conductive material is not filled in the through holes,
The structure of the film carrier is simplified, and the manufacturing cost is reduced. If necessary, the through holes 72 and 8
Only one of the two may be filled with a conductive material.

In FIG. 1, the conductive portion 8 for connection to the external substrate is formed inside a region A where the semiconductor element 3 is to be mounted in the laminate of the insulator layer 6 and the conductive circuit 5. However, according to this, the size (area) of the semiconductor device can be reduced to, for example, the size (area) of the semiconductor element 3, and the electrode 10 of the semiconductor element 3 and the lead of the external substrate are connected. Since the connection can be performed over a short distance, a semiconductor device having excellent electric characteristics can be obtained. Needless to say, the conductive portion 8 may be formed so as to be located outside the region A where the semiconductor element 3 is to be mounted.
Further, it may be formed so as to be located both inside and outside the area A. As described above, the formation position of the conductive portion 8 can be appropriately determined. According to this, even if the arrangement of the electrodes 10 of the individual semiconductor elements 3 is different, the connection position with the external substrate can be unified. This is desirable in standardizing electronic components.

It is preferable that a conductor portion 11 for connection to an external substrate be provided on the conductive path 81, as shown in FIG. As a material for forming the conductor portion 11, the same material as the material for forming the conductive path 81 or another material may be used, but usually the same material is used. In this case, it is preferable that the conductor portion 11 and the conduction path 81 are formed integrally.

The conductive paths 71 and 81 may be formed using two or more kinds of forming materials. FIG.
Is a conduction path 8 composed of a plurality of types of forming materials as described above.
FIG. 2 is a schematic diagram showing one example of the first embodiment. In the conduction path 81 shown in the figure, a portion 811 in contact with the conductive circuit 5 is made of an inexpensive metal such as copper, and a portion 812 connected to a connected body is made of a metal having high connection reliability such as gold. Further, a barrier metal such as nickel capable of preventing an interaction between the two metals is used in an intermediate portion 813 between the two portions 811 and 812.

FIG. 4 is a schematic sectional view showing one embodiment of the semiconductor device of the present invention. In the same figure, the electrode 10 of the semiconductor element 3 is connected to the conductive circuit 5 of the film carrier F of the present invention similar to that shown in FIG. 1, and the semiconductor element 3 is mounted on the film carrier F. .

In the semiconductor device 1 shown in FIG. 4, the conductive portion 8 for connecting the film carrier F to the external substrate is provided.
However, since the semiconductor device 3 is provided inside the region where the semiconductor element 3 is mounted, the size (area) of the semiconductor device 1 is substantially the same as the size (area) of the semiconductor element 3.

FIG. 5 is a schematic sectional view showing one embodiment of a method for mounting a semiconductor device according to the present invention. In FIG. 5, as shown in FIG. 5A, the electrode 10 of the semiconductor element 3 is brought into contact with the conductive circuit 5 of the film carrier F of the present invention similar to that shown in FIG. As shown in (b), energy is applied to the contact portion via the energy supply portion 7 of the film carrier F, and the conductive circuit 5
And the electrode 10 are connected, thereby obtaining the same semiconductor device 1 as shown in FIG. 4 as shown in FIG. 5C.

The conductive circuit 5 and the electrode 1 of the semiconductor element 3
5, as shown in FIG. 5B, an energy applying means 9 is applied to the energy supply unit 7 (the conducting path 71 in the figure), and the energy applying means 9 transfers the energy to the conductive circuit 5. Energy for connecting the electrode and the electrode 10 may be supplied. Examples of the energy for the connection include heat, ultrasonic waves, pressure, or a combination of two or more of these, and can be appropriately selected according to the materials constituting the semiconductor element 3 and the film carrier F. it can. In the case where a film carrier F similar to that shown in FIG. 2 is used, the energy applying means 9 is applied to the exposed portion of the conductive circuit 5 at the bottom of the through-hole 72, and the conductive circuit 5 Energy for connection with the electrode 10 may be supplied.

[0035]

The present invention will be described more specifically with reference to the following examples. Note that the present invention is not limited to these examples.

Example 1 (Preparation of Film Carrier) On a copper foil having a thickness of 18 μm,
A polyimide resin layer having a thickness of 25 μm was formed, and the copper foil was formed into a circuit pattern by etching to obtain a laminate of an insulator layer and a conductive circuit. In this conductive circuit,
Gold was coated by electroplating to a thickness of 1 μm. Then, laser processing was performed on portions of the insulator layer where a conductive portion for connection to an external substrate and an energy supply portion for connection to a semiconductor element were to be formed, and through holes each having a diameter of 60 μm were formed. . Then, these through holes are filled with copper by performing electroplating using the conductive circuit as an electrode, and thereafter plated with gold to a thickness of 1 μm for the purpose of preventing oxidation of copper, and A conductive path for connection with the substrate and a conductive path for connection with the semiconductor element were formed. These conductive paths are formed so as to protrude in a mushroom shape from the surface of the insulator by 10 μm, and a ball-shaped portion having a diameter of about 120 μm is formed on the upper end of the conductive path for connection with an external substrate using solder. Formed. Thus, a film carrier similar to that shown in FIG. 1 was obtained.

(Semiconductor Device Mounting) An electrode of a semiconductor device is brought into contact with the conductive circuit of the film carrier, and then a bonding tool is applied to a conductive path for connecting the film carrier to the semiconductor device to apply ultrasonic energy. While supplying, the conductive circuit and the electrode of the semiconductor element were crimped to obtain a semiconductor device similar to that shown in FIG.

Example 2 (Preparation of Film Carrier) In Example 1 described above, copper was not filled in the through-hole, and no conductive path for connection to the external substrate and no conductive path for connection to the semiconductor element were formed. Except for the above, a film carrier was prepared in the same manner.

(Mounting of Semiconductor Element) An electrode of a semiconductor element is brought into contact with the conductive circuit of the film carrier, and then a bonding tool is inserted into a through hole in an energy supply portion for connecting the film carrier to the semiconductor element. While supplying heat and ultrasonic energy to the conductive circuit exposed at the bottom of the through-hole, the conductive circuit and the electrode of the semiconductor element were crimped to obtain a semiconductor device.

Each of the semiconductor devices obtained in Examples 1 and 2 has substantially the same size as a semiconductor element. Further, in these semiconductor devices, when the conduction between the conductive circuit of the film carrier and the electrode of the semiconductor element was inspected, all the conduction states were good.

[0041]

As described above in detail, in the present invention, the film carrier is provided with an energy supply for connection to the semiconductor element, and the energy for connection is intended to be connected via the energy supply. The connection between the film carrier and the semiconductor element is made by providing the film carrier with the semiconductor element, so that it is possible to cope with a finer pitch and a higher density of the wiring of the semiconductor element and to electrically connect the film carrier with the semiconductor element. Connection can be made easily and reliably.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a film carrier of the present invention.

FIG. 2 is a schematic sectional view showing another embodiment of the film carrier of the present invention.

FIG. 3 is a schematic diagram illustrating an example of a conductive path formed of a plurality of types of forming materials.

FIG. 4 is a schematic sectional view showing one embodiment of the semiconductor device of the present invention.

FIG. 5 is a schematic sectional view showing one embodiment of a method for mounting a semiconductor device according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 5 conductive circuit 6 insulator layer 7 energy supply section 71 for connection with semiconductor element 71 conduction path 72 through hole 8 conduction section 81 for connection to external substrate 81 conduction path 82 through hole 11 conductor section F film carrier 3 semiconductor Element 10 electrode

Claims (5)

(57) [Claims] A conductive circuit is laminated on one surface of an insulator layer, and the conductive circuit is formed by directly connecting electrodes of a semiconductor element.
A shall, energy supply unit for connection to the conductive portion and the semiconductor element for connection with an external substrate laminate is provided with, the conductive portion and the semiconductor element for connection with these external substrate The connection energy supply unit includes a conductive path formed by filling a hole reaching the conductive circuit through the insulator layer from the other surface of the insulator layer in the thickness direction and filling with a conductive metal. And a film carrier. 2. The film according to claim 1, wherein the conductive portion for connection to the external substrate is provided inside a region where the semiconductor element is intended to be mounted in the laminate of the insulator layer and the conductive circuit. Career. 3. A conductive circuit is laminated on one surface of the insulator layer, and the conductive circuit is directly connected to an electrode of a semiconductor element.
A shall, energy supply unit is set for connection to the conductive portion and the semiconductor element for connection with an external substrate to laminate
Al is and the energy supply unit for connection to the semiconductor element is made of a conductive circuit exposed at the bottom of the holes through the insulator layer in the thickness direction from the other surface of the insulator layer, the external substrate The conductive portion for connection with the conductive layer can be formed by filling a hole reaching the conductive circuit through the insulator layer in the thickness direction from the other surface of the insulator layer with a conductive metal. And a film carrier. 4. A semiconductor device comprising a semiconductor element mounted on the film carrier according to claim 1. 5. An electrode of a semiconductor element is brought into contact with the conductive circuit of the film carrier according to claim 1, and energy is applied to the contact portion via an energy supply section of the film carrier. Thereby connecting the conductive circuit to an electrode of the semiconductor element.