JPH09148370A - Semiconductor element mounting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect the surface of an IC against a pressing force of conductive grains in an anisotropic conductive adhesive agent by forming a protective layer round electrodes of a semiconductor element electrically isolated from the electrodes and connecting these electrodes with those of a substrate by said adhesive agent. SOLUTION: Electrodes 12 are formed on a semiconductor element 11 and protective layer 13 are formed round and electrically isolated from the electrodes 12 connected to electrodes 2 of a substrate 1 by an anisotropically conductive adhesive agent 3. For example, Al electrodes 12 are formed on the IC 11, protective layer 13 made from the same conductor film as the electrode 12 is formed round and electrically isolated from the electrodes 12, and passivation film 14 is formed thereon. In case the layer 13 uses the conductor film, the electrically isolated region 15 is 1.5 times or more as wide as the grain size of conductive grains 3b composing the adhesive agent 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor element mounting structure using an anisotropic conductive adhesive.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
Reference "COG mounting using anisotropic conductive resin", IEICE technical report CPM91-77, p.
p. Some were disclosed in 19-22 and 1991. FIG. 3 is a sectional view showing such a conventional semiconductor element mounting structure, and FIG. 4 is a sectional view of the semiconductor element mounting process.

In FIG. 3, reference numeral 21 is a substrate, and 22 is an electrode formed on the substrate. An anisotropic conductive adhesive 23 is composed of an insulating resin 23a for adhesion and conductive particles 23b. Reference numeral 24 denotes an IC, on which an Au bump-shaped electrode 25 is formed. In this mounting structure, the electrodes 22 of the substrate 21 and the IC 24 are connected through the conductive particles 23b dispersed in the insulating resin 23a of the anisotropic conductive adhesive 23.
Of the electrode 25 are electrically connected to each other, and the insulating resin 23a of the anisotropic conductive adhesive 23 is used to connect the IC 24 to the substrate 21.
And the conductive particles 23b between the electrodes 22 and 25 are stressed to obtain the above electrical connection.

The process of mounting the semiconductor element will be described below with reference to FIG. (1) First, as shown in FIG. 4A, the electrode 22 is formed on the substrate 21. (2) Next, as shown in FIG. 4B, the anisotropic conductive adhesive 23 is placed in the mounting area of the IC (integrated circuit device) as the semiconductor element. (3) Next, as shown in FIG. 4C, an IC 24 having an electrode 25 is prepared, and the electrode 25 of the IC 24 and the electrode 22 of the substrate 21 are aligned with each other.

(4) Next, as shown in FIG.
A load is applied to C24 to press it against the substrate 21 to heat the anisotropic conductive adhesive 23 or cure the insulating resin forming the anisotropic conductive adhesive 23 by means such as light. As described above, the IC 24 can be mounted on the substrate 21 by a simple method.

[0006]

However, in the conventional semiconductor element mounting process described above, a load is applied to the IC 24 in the process (4). In order to avoid damage to the circuit portion formed on the surface portion of the IC 24 (not shown) due to this load, the electrode 25 of the IC 24 is formed into an Au bump shape thicker than the particle diameter of the conductive particles 23b. Does not press the surface of the IC 24.

As described above, in the conventional semiconductor element mounting using the anisotropic adhesive, the Au bump electrode must be formed as the IC electrode in order to avoid the damage on the IC surface due to the conductive particles. For the formation process of
There is a problem that the price of IC becomes high. SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above problems and provide a semiconductor element mounting structure capable of protecting the surface of an IC from being pressed by conductive particles of an anisotropic conductive adhesive.

[0008]

In order to achieve the above object, the present invention provides: (1) In a semiconductor element mounting structure using an anisotropic conductive adhesive, an electrode formed on the semiconductor element, and A protective layer electrically separated from the electrode is formed around the electrode, and the electrode of the semiconductor element and the electrode of the substrate are connected by an anisotropic conductive adhesive.

Therefore, the surface of the IC can be protected from being pressed by the conductive particles of the anisotropic conductive adhesive. (2) In the mounting structure for a semiconductor element according to (1) above, the electrodes and the protective layer are made of an Al conductor film, and the width of the electrical isolation region is the diameter of the conductive particles contained in the anisotropic conductive adhesive. 1.5 times or more.

Therefore, it becomes possible to mount the IC on the substrate by the anisotropic conductive adhesive in a simple process without using Au bump electrodes that raise the price of the IC, and it is possible to mount an extremely inexpensive semiconductor element. Become. Further, since Al is used for the protective layer of the semiconductor element, Al itself causes plastic deformation due to the pressing of the conductive particles, and the stress of the conductive particles can be dispersed.

Further, the electrodes of the semiconductor element and the protective layer can be formed of the same conductive material in the same step, so that the cost can be further reduced.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a mounting structure of a semiconductor element using an anisotropic conductive adhesive showing an embodiment of the present invention, and FIG. 2 is a sectional view of a mounting step of the semiconductor element. In FIG. 1, 1 is a substrate, 2 is an electrode of the substrate, 3 is an anisotropic conductive adhesive, and is composed of an insulating resin 3a for adhesion and conductive particles 3b. These are shown in FIG. It is similar to the conventional one. Further, an Al electrode 12 is formed on the IC 11 used here, and a protective layer 13 formed of the same conductive film as the electrically separated Al electrode is formed around the Al electrode 12. Further, a passivation film 14 is formed on this.

The reason why Al is used for the protective layer 13 is that Al itself has a plastic deformation due to the pressing of the conductive particles 3b, and has the effect of dispersing the stress of the conductive particles 3b. The material of the protective layer is not limited to Al as long as it has the above-mentioned effects. Further, as long as it has a film structure that does not deform when pressed by the conductive particles 3b, it can be used as the protective layer 13, and if the above-mentioned requirements are satisfied, there is no distinction between a conductor and an insulator. . If it is a conductor, it is possible to use the protective layer 13 as a ground electrode, a shield, etc., and if it is an insulator,
The electrical separation from the Al electrode 12 described above is not necessary, and each feature can be utilized. However, so that the conductive particles 3b can sufficiently press the Al electrode 12, the protective layer 1
It is desirable that the position of the surface of No. 3 is approximately the same as the surface of the electrode 12 of the IC 11 or does not protrude.

When the conductor film is used as the protective layer 13, the width of the isolation region 15 for electrical isolation is
It is necessary to form the particle size larger than the particle diameter of the conductive particles 3b forming the anisotropic conductive adhesive 3 to prevent an electrical short circuit due to the conductive particles 3b. However, since there is a possibility that the conductive particles 3b may press the separation region 15, it is desirable to avoid disposing an element forming a circuit of the IC in the separation region 15. Therefore, it is not a good idea to widen the width of the isolation region 15 from the viewpoint of the degree of integration of the IC 11.

As a result, the width of the separation region 15 is preferably about 1.5 times or more the particle diameter, although it depends on the diameter of the conductive particles 3b. With this configuration, the circuit region formed on the surface of the IC 11 can be protected by the protective layer 13. Therefore, even if the Al electrode is used without using the Au bump electrode, the anisotropic conductive adhesive 3 can be used to form the substrate 1. It becomes possible to mount the IC 11 on the upper part by a simple process.

The steps of mounting the semiconductor device of the present invention will be described below with reference to FIG. (1) First, as shown in FIG. 2A, the electrode 2 is formed on the substrate 1. (2) Next, as shown in FIG. 2B, the anisotropic conductive adhesive 3 is placed in the mounting area of an IC (integrated circuit device) as a semiconductor element. (3) Next, as shown in FIG. 2C, the IC 11 on which the electrode 12, the protective layer 13, and the passivation film 14 are formed.
The electrode 12 of the IC 11 and the electrode 2 of the substrate 1
Align.

(4) Next, as shown in FIG.
A load is applied to C11 and pressed against the substrate 1, and the insulating resin forming the anisotropic conductive adhesive 3 is cured by means such as heating or light. (5) Other mounting steps can be performed by the same method as the conventional method. It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0018]

As described above in detail,
According to the present invention, the following effects can be achieved. (1) According to the invention described in claim 1, the surface of the IC can be protected from being pressed by the conductive particles of the anisotropic conductive adhesive.

(2) According to the invention of claim 2, an IC
It is possible to mount an IC on a substrate by a simple process using an anisotropic conductive adhesive without using an Au bump electrode that raises the temperature, and it is possible to mount an extremely inexpensive semiconductor element. Further, since Al is used for the protective layer of the semiconductor element, Al itself causes plastic deformation due to the pressing of the conductive particles, and the stress of the conductive particles can be dispersed.

Furthermore, since the electrodes of the semiconductor element and the protective layer can be formed of the same conductive material in the same step,
Further cost reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a mounting structure of a semiconductor element using an anisotropic conductive adhesive according to an embodiment of the present invention.

FIG. 2 is a sectional view of a semiconductor element mounting process showing an embodiment of the present invention.

FIG. 3 is a sectional view showing a mounting structure of a semiconductor element using a conventional anisotropic conductive adhesive.

FIG. 4 is a sectional view of a conventional semiconductor element mounting process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 substrate 2 substrate electrode 3 anisotropic conductive adhesive 3a insulating resin for adhesion 3b conductive particles 11 IC (integrated circuit device: semiconductor element) 12 Al electrode 13 protective layer 14 passivation film 15 isolation region

Front page continued (72) Inventor Yuko Kitayama 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (2)

[Claims] 1. In a mounting structure of a semiconductor element using an anisotropic conductive adhesive, (a) an electrode formed on the semiconductor element and (b) the electrode is electrically separated from the electrode around the electrode. A mounting structure for a semiconductor device, comprising: forming a protective layer; and (c) connecting the electrodes of the semiconductor device and the electrodes of the substrate with an anisotropic conductive adhesive. 2. The mounting structure for a semiconductor element according to claim 1, wherein the electrodes and the protective layer are Al conductor films,
A mounting structure for a semiconductor device, wherein the width of the electrically isolated region is 1.5 times or more the diameter of the conductive particles contained in the anisotropic conductive adhesive.