JPH09181209A - Semiconductor device and fabrication thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the side face and upper surface of a semiconductor chip from being smeared with a paste material. SOLUTION: The semiconductor device 10 comprises a semiconductor chip 2 bonded in a recess, made in the center of major surface of a heat plate 1, through a paste material 4 wherein a paste reservoir 14 for storing the excess paste material 4 is made in the bottom of the recess 3 facing at least a part of edge of the semiconductor chip 2. The heat plate 1 comprises a planar heat dissipating body 11 having a major surface provided with the paste reservoir 14, and a planar heat dissipating frame 12 being pasted to the major surface of heat dissipating body 11 wherein the recess 3 is defined by the major surface of a heat dissipating body 11 and the inner circumferential wall of the recess 3. An insulating film 16, arranged with leads 21 and bump electrodes 22 through a tape-like elastomer 15, is then pasted onto the major surface of a heat plate 1 while connecting the lead 21, at the forward end thereof, with the electrode of the semiconductor chip 2 and projecting the bump electrode 22 to the outside thus constituting a ball grid array type semiconductor device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly to a technique effective when applied to a mounting technique of a semiconductor chip of a BGA (Ball Grid Array) type semiconductor device.

[0002]

2. Description of the Related Art A BGA type semiconductor device is known as one of package structures for semiconductor devices. The BGA type semiconductor device is described, for example, in "Electronic Materials", September 1995 issue, published by the Industrial Research Board, and P27 to P32, issued September 1, 1995.

In this document, "TCMT (Tessera Compl
A copper-polyimide two-layer tape called iant Mounting Tape) is attached to the chip via an elastomer, and the peripheral leads are bonded to the chip pads. Bumps are formed on the TCMT via via holes, and the bumps electrically connect to the mounting board.
Connected mechanically. "Is described.

Also, US Pat. No. 5,148,265 (September 1992)
Filed on March 15) and U.S. Pat. No. 5,148,266 (1992)
(September 15, application) GD (Face Down) -BGA
Is described.

[0005]

In the FD-BGA type semiconductor device, as shown in FIG.
1) A heat sink 1 is provided with a depression 3 slightly larger than the semiconductor chip 2 in the center of the main surface, and the semiconductor chip 2 is fixed to the bottom of the depression 3 with an adhesive (paste material) 4. .

However, in such a structure, it has been found that the surplus paste material 4 contaminates the side surface (peripheral surface) and the upper surface of the semiconductor chip 2.

That is, in the work, a proper amount of the paste material 4 is applied to the bottom of the recess 3 using a dispenser or the like, but the application amount of the paste material is liable to change depending on the temperature, and is often not constant. When the coating amount is large, the surplus paste material 4 creeps up between the side surface of the semiconductor chip 2 and the inner peripheral wall of the recess 3 and contaminates the upper side surface and the upper surface (main surface) of the semiconductor chip 2.

Contamination on the upper side surface of the semiconductor chip 2 is a target for defective appearance.

Contamination of the upper surface of the semiconductor chip 2 causes contamination of the electrode (bonding pad) 5 provided on the main surface of the semiconductor chip 2, and when a lead is subsequently connected to the bonding pad 5, the lead and the bonding are bonded. The electrical connection with the pad 5 becomes unstable, resulting in poor characteristics of the semiconductor device.

An object of the present invention is to provide a BGA type semiconductor device and a method of manufacturing the same which can prevent the occurrence of characteristic defects and appearance defects.

[0011] The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0012]

The following is a brief description of an outline of typical inventions disclosed in the present application.

(1) A semiconductor device in which a semiconductor chip is fixed to a recess provided in the center of the main surface of a heat dissipation plate via a paste material, the bottom of the recess facing at least part of the edge of the semiconductor chip. A recessed paste reservoir for accumulating the excess paste material is provided in the portion. The heat dissipation plate is composed of a flat heat dissipation main body having the paste reservoir on the main surface, and a frame-shaped flat heat dissipation frame body attached to the main surface of the heat dissipation main body, and the recess is the main surface of the heat dissipation main body. It is formed by the inner peripheral wall of the recess. An insulating film having a plurality of leads and bump electrodes is attached to the main surface of the heat dissipation plate via a tape-shaped elastomer, the tips of the leads are connected to the electrodes of the semiconductor chip, and the bump electrodes project to the outside. Form a ball grid array type semiconductor device.

(2) After the semiconductor chip is fixed to the depression provided in the center of the main surface of the heat dissipation plate with a paste material, a plurality of leads and bump electrodes are provided on the main surface of the heat dissipation plate with a tape-shaped elastomer interposed. A method for manufacturing a ball grid array type semiconductor device by attaching an insulating film, then connecting the tip of the lead and an electrode of the semiconductor chip, and arranging the bump electrode so as to project outward, the method comprising: In the recess bottom portion facing at least part of the edge of the semiconductor chip, a recessed paste reservoir for accumulating an excess amount of the paste material is provided, and then the semiconductor chip is fixed to the recess bottom via the paste material. .
The heat dissipation plate is formed by preparing a flat heat dissipation main body having the paste reservoir on the main surface and a frame-shaped flat heat dissipation frame, and then bonding the main surface heat dissipation frame of the heat dissipation main body to form a heat dissipation plate. . Further, the depression of the heat dissipation plate is formed by the main surface of the heat dissipation main body and the inner peripheral wall of the heat dissipation frame.

According to the above-mentioned means (1), since the paste reservoir is provided in the depression of the heat dissipation plate, when the semiconductor chip is fixed, the excess paste material enters the paste reservoir. It does not creep up the side surface of the semiconductor chip as in the above, and the side surface and the upper surface of the semiconductor chip are not contaminated by the paste material.

Accordingly, the upper side surface and the upper surface (main surface) of the semiconductor chip are not contaminated with the paste material, and the appearance defect does not occur, and the upper surface of the semiconductor chip is not contaminated. It is also possible to prevent the connection from becoming defective due to the presence of the paste material. As a result,
It is possible to provide a BGA type semiconductor device that does not have a defective appearance or defective characteristics.

According to the above-mentioned means (2), since the semiconductor chip is fixed to the heat dissipation plate having the paste reservoir at the bottom of the recess via the paste material, when the paste material becomes an excess, the excess paste material is made. Since the paste enters the paste reservoir, the paste material does not crawl on the side surface of the semiconductor chip as in the conventional case, and the upper side surface and the upper surface of the semiconductor chip are not contaminated by the paste material.

Therefore, the appearance of the upper surface and the upper surface of the semiconductor chip, which are contaminated by the paste material, is eliminated, and the upper surface of the semiconductor chip is not contaminated.
It is also possible to prevent the connection between the electrodes of the semiconductor chip and the leads from becoming defective due to the presence of the paste material. As a result, it is possible to manufacture a BGA type semiconductor device without a defect in appearance or a characteristic with high yield.

The heat dissipation plate is formed by preparing a flat heat dissipation main body having the paste reservoir on the main surface and a frame-shaped flat heat dissipation frame, and then bonding the main surface heat dissipation frame of the heat dissipation main body together. Use as a heat sink. Further, the depression of the heat dissipation plate is formed by the main surface of the heat dissipation main body and the inner peripheral wall of the heat dissipation frame. Therefore, since the depth of the depression becomes constant, the positional relationship between the height of the semiconductor chip and the height of the main surface of the heat sink becomes constant, the beam lead bonding becomes accurate and reliable, and the yield can be improved.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In all the drawings for explaining the embodiments of the invention, components having the same function are designated by the same reference numeral, and the repeated description thereof will be omitted.

FIG. 1 is a cross-sectional view of a semiconductor device according to an embodiment of the present invention, and FIGS. 2 to 5 are views showing respective steps of a method of manufacturing a BGA type semiconductor device according to the present embodiment. Two
5 is a cross-sectional view showing a heat-dissipating main body and a heat-dissipating frame used to manufacture a BGA type semiconductor device, FIG. 3 is a perspective view of the same, and FIG. 4 is a cross-sectional view showing a state in which an adhesive paste material is applied to a heat-dissipating plate. FIG. 6 is a cross-sectional view showing a state in which a semiconductor chip is fixed to a heat sink.

The BGA type semiconductor device 10 of this embodiment is
As shown in FIG. 1, the semiconductor chip 2 is fixed via an adhesive (paste material) 4 to the bottom of a recess 3 provided in the center of the main surface (lower surface) of a radiator plate 1 made of a rectangular aluminum plate. There is.

The heat dissipation plate 1 is a heat dissipation main body 11 made of a rectangular aluminum plate, and a frame-shaped flat heat dissipation frame made of an aluminum plate bonded to the main surface (lower surface) of the heat dissipation main body 11 with an adhesive 13. It is formed by the body 12. The heat dissipating body 11 and the heat dissipating frame 12 have the same outer dimensions, and each has a thickness of 0.3 mm, for example. The recess 3 slightly larger than the semiconductor chip 2 is formed by the main surface of the heat dissipation main body 11 and the inner peripheral wall of the heat dissipation frame 12.

The thickness of the semiconductor chip 2 is, for example, 0.28 mm. The thickness of the adhesive 13 for bonding the heat dissipation body 11 and the heat dissipation frame 12 is several tens μ
Since the thickness of the heat dissipation main body 11 is approximately the depth of the recess 3, the height of the surface of the semiconductor chip 2 fixed to the bottom of the recess 3 and the main surface of the heat dissipation main body 11 is It is about the same.

In addition, on the bottom of the heat dissipating body 11, a paste reservoir 1 is formed which is recessed substantially corresponding to the edge of the semiconductor chip 2.
4 are provided. This paste reservoir 14 is shown in FIG.
As shown in, when the semiconductor chip 2 is fixed to the main surface of the heat dissipating body 11 via the paste material 4, the semiconductor chip 2 is formed corresponding to the remaining side portions except the vertex portions of the semiconductor chip 2.
It is a recess into which the surplus paste material 4 enters.

As a result, the surplus paste material 4 does not crawl along the peripheral surface of the semiconductor chip 2 and the peripheral surface of the semiconductor chip 2, the main surface of the semiconductor chip 2 and the electrodes 5 are prevented from becoming dirty.

On the other hand, in the heat dissipation frame 12 of the heat dissipation plate 1,
The insulating film 16 is fixed via the elastomer 15. The elastomer 15 is a frame having the same size as the heat dissipation frame 12, and is fixed to the heat dissipation frame 12 with an adhesive 17.

The insulating film 16 is also the heat dissipation frame 12
The size is approximately the same as that of and is fixed to the elastomer 15 via an insulating adhesive 18.

The insulating film 16 has a conductor layer 20 patterned on one surface. A part of the conductor layer 20 becomes a lead (beam lead) 21 protruding into the frame, and the tip end is fixed to the electrode 5 of the semiconductor chip 2.

On the lower surface of the insulating film 16,
A hole is provided at a predetermined position, and a bump electrode 22 that protrudes is provided in this hole portion. The bump electrode 22 is connected to the conductor layer 20 located at the bottom of the hole.

Next, a method of manufacturing (assembling) the BGA type semiconductor device 10 of this embodiment will be described.

First, as shown in FIGS. 2 and 3, a heat dissipation body 11 and a heat dissipation frame 12 for forming the heat dissipation plate 1 are prepared. The heat dissipation main body 11 and the heat dissipation frame 12 are made of, for example, a rectangular aluminum plate having a thickness of 0.3 mm.

The heat dissipation body 11 has a groove-shaped paste reservoir 14 on its main surface. Four paste reservoirs 14 are provided corresponding to the periphery of the semiconductor chip 2. That is, it is provided in a portion excluding the respective apexes (4 apexes) of the semiconductor chip 2 which is a rectangular body. The paste reservoir 14 may be provided in a rectangular shape along the entire periphery of the semiconductor chip 2.

The heat dissipation frame 12 is a frame so that the semiconductor chip 2 can be inserted into the inner part thereof.

Then, as shown in FIG. 4, the heat dissipation plate 1 is formed by adhering the heat dissipation frame 12 to the heat dissipation main body 11 with the adhesive 13.

By attaching the heat dissipation frame 12 to the heat dissipation body 11, a recess 3 into which the semiconductor chip 2 is attached is formed in the center of the main surface of the heat dissipation plate 1. That is, in the recess 3, the bottom of the recess 3 is formed by the main surface of the heat dissipation main body 11, and the peripheral wall of the recess 3 is formed by the inner peripheral surface of the heat dissipation frame 12.

In the heat dissipation plate 1 of the present embodiment, the recess 3 is formed by attaching the heat dissipation frame 12 to the heat dissipation main body 11, so that the depth of the recess 3 becomes constant, so that the height of the semiconductor chip 2 is The positional relationship of the height of the main surface of the heat sink becomes constant, and the lead bonding performed thereafter becomes accurate and reliable, and the yield can be improved.

Next, as shown in FIG. 4, after the paste material 4 is applied to the bottom surface of the depression 3 with a dispenser or the like, the depression 3 is formed.
The semiconductor chip 2 is fixed to the bottom of the. At this time, the excess paste material 4 is removed from the paste pool 14 provided at the bottom of the depression 3.
Since the paste material 4 does not creep up on the peripheral surface of the semiconductor chip 2, the paste material 4 does not contaminate the upper peripheral surface and the main surface of the semiconductor chip 2.

Therefore, the electrode (bonding pad) 5 located on the upper surface (main surface) of the semiconductor chip 2 is not contaminated with the paste material 4.

Next, as shown in FIG. 5, an elastomer 15 having substantially the same shape as the heat dissipation frame 12 is attached to the heat dissipation frame 12 with an adhesive (not shown), and the conductor layer 2 is formed.
An insulating film 16 having 0 or bump electrodes 22 is attached to the elastomer 15 via an insulating adhesive agent not shown.

The insulating film 16 serves as the heat dissipation frame 1.
The film is approximately the same size as 2, and has a conductor layer 20 patterned on one surface. A part of the conductor layer 20 serves as a lead (beam lead) 21 protruding into the frame. The tips of the leads 21 are designed to overlap the electrodes 5 of the semiconductor chip 2 fixed to the heat sink 1.

A hole is formed at a predetermined position on the lower surface of the insulating film 16, and a protruding bump electrode 22 is provided in this hole portion. The bump electrode 22 is connected to the conductor layer 20 located at the bottom of the hole. A ball grid array is formed by these bump electrodes 22.

Next, the tips of the leads 21 are fixed to the electrodes 5 of the semiconductor chip 2. In this lead bonding, as described above, the height of the electrode 5 of the semiconductor chip 2 and the height of the main surface of the heat sink 1 are constant, so that the leads 21 of the insulating film 16 attached to the heat sink 1 are formed.
The connection with and becomes easy and reliable, and the bonding yield is improved.

Since the paste material does not adhere to the surface of the electrode 5 as described above, the electrode 5 and the lead 21 are not attached.
Are electrically connected securely, and the reliability of the connection is high.

The heat sink 1 is turned upside down to manufacture the BGA type semiconductor device 10 as shown in FIG.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

[0048]

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

(1) Since the paste reservoir is provided in the depression of the heat dissipation plate, when the semiconductor chip is fixed, the excess paste material enters the paste reservoir. It does not crawl up the side surface, and the upper side surface and the upper surface of the semiconductor chip are not contaminated by the paste material.

Therefore, it is possible to prevent the occurrence of a defective appearance in which the side surface or the upper surface of the semiconductor chip is contaminated with the paste material, and the electrode material on the upper surface of the semiconductor chip is not contaminated with the paste material. It will not occur.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a heat dissipation main body and a heat dissipation frame used in the method for manufacturing a semiconductor device of the present embodiment.

FIG. 3 is a perspective view showing a heat dissipation main body and a heat dissipation frame used in the method for manufacturing a semiconductor device of the present embodiment.

FIG. 4 is a cross-sectional view showing a state in which an adhesive paste material is applied to a heat dissipation plate in the method of manufacturing a semiconductor device of this embodiment.

FIG. 5 is a cross-sectional view showing a state in which a semiconductor chip is fixed to a heat dissipation plate in the method for manufacturing a semiconductor device of this embodiment.

FIG. 6 is a cross-sectional view showing a state in which a semiconductor chip is fixed to a heat sink in a conventional semiconductor device.

[Explanation of symbols]

1 ... Heat sink, 2 ... Semiconductor chip, 3 ... Dimple, 4 ... Paste material, 5 ... Electrode (bonding pad), 10 ... BGA
Type semiconductor device, 11 ... Heat dissipation main body, 12 ... Heat dissipation frame, 13
... Adhesive, 14 ... Paste pool, 15 ... Elastomer, 16 ... Insulating film, 17, 18 ... Adhesive, 20 ...
Conductor layer, 21 ... Lead, 22 ... Bump electrode.

Claims (5)

[Claims] 1. A semiconductor device in which a semiconductor chip is fixed to a recess provided in the center of the main surface of a heat dissipation plate via a paste material, the bottom portion of the recess facing at least part of the edge of the semiconductor chip. The semiconductor device is characterized in that a recessed paste reservoir for accumulating an excess amount of the paste material is provided in the semiconductor device. 2. The heat dissipation plate comprises a flat heat dissipation main body having the paste reservoir on a main surface thereof, and a frame-shaped flat heat dissipation frame body bonded to the main surface of the heat dissipation main body, and the recess has the heat dissipation function. The semiconductor device according to claim 1, wherein the semiconductor device is formed by the main surface of the main body and the inner peripheral wall of the recess. 3. An insulating film having a plurality of leads and bump electrodes is attached to the main surface of the heat dissipation plate via a tape-shaped elastomer, and the tips of the leads are connected to the electrodes of the semiconductor chip, 3. The semiconductor device according to claim 1, wherein the electrodes protrude outward to form a ball grid array type semiconductor device. 4. An insulation having a plurality of leads and bump electrodes on the main surface of the heat dissipation plate via a tape-shaped elastomer after fixing a semiconductor chip to a recess provided in the center of the main surface of the heat dissipation plate via a paste material. Stick a film, then connect the tip of the lead and the electrode of the semiconductor chip,
A method for manufacturing a ball grid array type semiconductor device by arranging the bump electrodes so as to project outward, wherein the paste is provided on the bottom of the recess facing the edge of at least a part of the semiconductor chip in the heat dissipation plate. A method for manufacturing a semiconductor device, characterized in that a recessed paste reservoir for accumulating a surplus material is provided, and then a semiconductor chip is fixed to the bottom of the recess via a paste material. 5. A flat heat dissipation body having the paste reservoir on the main surface and a frame-shaped flat heat dissipation frame body are prepared, and then the main surface heat dissipation frame body of the heat dissipation body is bonded to form a heat dissipation plate. The method of manufacturing a semiconductor device according to claim 4, wherein the recess of the plate is formed by the main surface of the heat dissipation main body and the inner peripheral wall of the heat dissipation frame.