JPH1098140A - Multiple-chip type semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat radiation effect and electric continuity by inserting an elastic multiple structure for absorbing the height dispersion between semiconductor chips which are different in height and heat radiating member and connecting the chips to the radiating member by a pressing force to contact them to one flat plate en bloc, without arranging their heights. SOLUTION: Semiconductor chips 1a, 1b, 1c, different in height are disposed on an Mo, W or Cu-C composite strain buffer board 2 having a thermal expansion coefficient equal to that of the semiconductor and mounted on a common collector electrode 3. On the semiconductor chips an Mo, W, or Cu-C composite strain buffer board 4, having a thermal expansion coefficient equal to that of the semiconductor, is disposed and covered with an elastic multiple structure 5 for absorbing steps. It is a double structure made of Cu pipes, such that the small-aperture pipe is inserted in the large-aperture one, made flat, with a center hollow space 6 formed in its contral part and connected to a common emitter electrode 7 thereon, allowing simultaneous connections to one common electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-chip type semiconductor device in which a plurality of semiconductor chips having different heights mounted on a substrate can be provided with a common electrode which also functions as a common radiating fin.

[0002]

2. Description of the Related Art In recent years, with the increase in the speed of computer systems, a multi-chip module capable of mounting a plurality of semiconductor chips from a single-chip type package structure in which only one semiconductor chip is mounted in an integrated circuit (IC) package. It is shifting to a semiconductor device having a structure. For this reason, various multi-chip module structures have been sought.
Although it has been developed, it is important to eliminate a step, that is, a so-called height difference between the plurality of semiconductor chips when the plurality of semiconductor chips are to be directly adhered to one heat radiating material and one electrode.

In a conventional multi-chip type semiconductor device, in order to dissipate heat by directly adhering a plurality of semiconductor chips to one radiating fin, if the package is a hermetic type, the semiconductor chip and the radiating fin must be connected to each other. The brazing material is melted between them to achieve heat conduction. If the package is a non-hermetic type, a sheet with good heat conductivity is sandwiched between the semiconductor chip and the radiating fins to reduce resistance. Was. However, when actually manufacturing a multi-chip type semiconductor package, the heights of all chips need to be uniform, but the heights of the chips are practically non-uniform. FIG. 10 is a schematic view of a conventional pressurized multi-chip semiconductor device. A plurality of semiconductor chips 21 a, 21 b, 21 c having different heights are arranged on a strain buffer 22, and they are mounted on a common electrode collector 23. A strain buffer 24 is disposed on the semiconductor chip 21. A multi-layered elastic body 25 serving as a conventional step absorber is disposed between the semiconductor chip 21 and the strain buffer 22. The multi-structure elastic body 25 serving as the step difference absorbing material uses a solder material. Then, the common electrode emitter 27 is connected from above.

A gate electrode 28 is disposed at an end of the semiconductor chip 21, and a gate wiring network 210 is disposed on an insulating plate 29 on the common electrode collector 23. The gate electrode 28 and the gate wiring network 210 are connected by a wire lead 211.
As described above, each member is mounted around the semiconductor chips 21a, 21b, and 21c, and the common electrode collector 23 and the common electrode emitter 27 are fixed by the insulating outer tube 212. The semiconductor chips are arranged by the insulating positioning plate 213. This is the shape of one unit module.

A plurality of semiconductor chips 21a, 21b, 21
Since c has different heights as shown in the figure, the softest solder material among the materials of this system is compressed as the multi-structure elastic body 25. The contact between the members due to the initial pressurization becomes good due to the deformation of the solder material. However, the semiconductor device is repeatedly used or stopped. That is, during use, the semiconductor chip generates heat and its temperature rises, and when stopped, the semiconductor chip is cooled and its temperature falls. That is, a semiconductor module in which heating and cooling are repeated repeats thermal expansion. In this case, the solder material of the step absorbing material repeats thermal expansion but does not have spring property. Since it does not have a spring property, a space is generated between the strain buffer plate 24 and the common electrode emitter 27 which are in pressure contact with each other, and there is a disadvantage that the electric and heat conduction is interrupted, which is a very serious problem. Was.

[0006] Japanese Patent Application Laid-Open No. H5-211259 discloses an IGB
It is shown that a ring spring made of steel made of a material having good electrical conductivity is provided to the emitter terminal plate in order to improve heat dissipation of the T module.

[0007]

As described above, when the heights of the semiconductor chips are different from each other, the tallest chip fills the gap between the semiconductor chip and the radiating fins. There is a gap between the fin and
There is a problem that the thermal resistance is significantly increased only in the gap. Further, in the above-mentioned publication, high thermal conductivity cannot be obtained.

It is an object of the present invention to improve the heat radiation effect and electric conduction by making sure that the chips having different heights are collectively brought into close contact with a heat radiating member of one flat plate without adjusting the height of all the semiconductor chips. Another object of the present invention is to provide a multi-chip type semiconductor device capable of easily performing chip repair for mechanical pressure welding.

[0009]

According to the present invention, there is provided a multi-chip type semiconductor device having a structure in which heat of a semiconductor chip is radiated through a heat radiating member, wherein the plurality of semiconductor chips having different heights are provided. A multi-chip type wherein a semiconductor chip and a heat radiating member are connected by a pressing force with a multi-structure elastic body interposed between the semiconductor chip and a heat radiating member to absorb variations in the height of the semiconductor chip. In semiconductor devices.

Further, in a multi-chip type semiconductor device in which upper and lower surfaces of a plurality of semiconductor chips provided between common electrode members are formed via a strain buffer plate, in addition to the plurality of semiconductor chips having different heights, For a plurality of these semiconductor chips, such as the variation of the thickness of the strain buffer plate and the variation of the solder layer thickness when the semiconductor chip and the buffer plate are soldered, and the variation of the thickness of the strain buffer plate and the solder layer. And a heat dissipating member connected to the common electrode member by a pressurizing force with a multi-structure elastic body absorbing these variations interposed therebetween.

In a multi-chip type semiconductor device having a plurality of semiconductor chips having different heights provided between common electrode members, a variation in height of the semiconductor chips is reduced between the plurality of semiconductor chips and the common electrode member. There is provided a multi-chip type semiconductor device in which a semiconductor chip and an electrode member are connected by a pressing force through a multi-structure elastic body that absorbs. Further, the present invention provides a multi-chip semiconductor device formed through a strain buffer plate soldered to upper and lower surfaces of a plurality of semiconductor chips provided between common electrode members,
In addition to the plurality of semiconductor chips having different heights, one of the common electrode members may be distorted due to variations in the thickness of the strain buffer plate and variations in the thickness of the solder layer when the semiconductor chip and the buffer plate are soldered. It is characterized in that a multi-structure elastic body for absorbing these variations is interposed between the buffer member and the electrode member by a pressing force.

Further, the present invention is also a multi-chip type semiconductor device in which a plurality of semiconductor chips are applied to a power switching device, an insulated gate type element and the like.

Investigation of the height of the semiconductor chip after manufacture reveals that the height differs by about 30 to 60 μm.
In addition, the substrate also has a deformation.
A step of about 100 μm was observed. As described above, the step difference as a semiconductor module is about 30 μm at the minimum and about 160 μm at the maximum, and 30 to 160 μm as the elastic body.
It must be able to absorb the difference in level.

Therefore, as a result of investigating various kinds of metals, a pipe is preferable to have elasticity. Considering the thermal conductivity and electric conductivity of the heat radiating action, Cu, A
g, Au or their alloys were found to be good. It is important that the center of the multi-layer structure is hollow. Especially,
A pure Cu pipe is effective, having a double or triple pipe structure in a concentric circle, a multiple pipe structure in which a plurality of small diameter pipes are inserted in parallel in a large diameter pipe, and Ni and Ni are used for Cu.
It is preferable to provide a coating such as plating of a material having excellent oxidation resistance and corrosion resistance such as Au and Ag.

In particular, the multi-structure elastic body according to the present invention is capable of absorbing a step of 50 μm by the elastic body, and has a step of 1 to 1.5 kg / m.
Having spring property by pressing m ² , spring area is 50 μm
It is preferable that there is the above.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a cross-sectional view showing a multi-chip type semiconductor device according to the present invention, showing a pressure-type package.
A plurality of semiconductor chips 1a, 1b, 1c having different heights are made of Mo, W, Cu- having the same thermal expansion coefficient as the semiconductor chips.
They are arranged on a strain buffer plate 2 made of a C composite material or the like, and they are mounted on a collector 3 of a common electrode plate. Semiconductor chip 1
On top of that, Mo, whose thermal expansion coefficient is equivalent to that of a semiconductor chip,
A strain buffer plate 4 made of W, Cu-C composite material or the like is arranged,
The step-absorbing multi-structure elastic body 5 is mounted thereon. Here, the multi-structure elastic body has a double structure of a Cu pipe,
A small-diameter pipe is inserted into a large-diameter pipe and then flattened. It is important to form a hollow portion 6 at the center of the multi-structure elastic body 5. Then, the common electrode emitter 7 is connected above.

A gate electrode 8 is disposed at an end of a part of the semiconductor chips 1a and 1c like a plurality of semiconductor chips 1a and 1c, and a gate wiring network 10 is disposed on an insulating plate 9 on the common electrode collector 3. The gate electrode 8 and the gate wiring network 10 are connected by wire leads 11.

As described above, each member is mounted around the semiconductor chip 1, and the common electrode collector 3 and the common electrode emitter 7 are fixed by the insulating outer tube 12. The arrangement of each semiconductor chip is performed by the insulating positioning plate 13. This is the shape of one unit module.

Next, the material of each member will be described. The semiconductor chip 1 is made of Si, and the strain buffer plates 2 and 4 are made of S
Mo, W, or the like having a thermal expansion coefficient close to that of the i-chip is applied.
The common electrode collector 3 and the emitter 7 use Cu which is excellent in electric and thermal conductivity. Gate electrode 8, gate wiring network 1
0 is Cu, which has excellent electrical properties,
Al, Cu, Au and the like are applied. The step-absorbing multi-structure elastic body 5 has excellent electrical and thermal conductivity.
u is used.

The multi-structure elastic body 5 uses two types of Cu pipes. One is a combination of a Cu pipe having an outer diameter of φ8 mm and an inner diameter of 6.8 mm and the other is a Cu pipe having an outer diameter of φ4 mm and an inner diameter of 2.4 mm, and flattened by pressing. The height can be determined in advance by the size of the step of the semiconductor chip. An important point of the flat processed pipe is that the hollow portion 6 is present at the center of the double structure pipe. That is, this hollow portion has an action of absorbing a step of a semiconductor chip or the like.

In addition to the above-described variation in the thickness of the semiconductor chip, the variation in the thickness of the strain buffer plate and the variation in the thickness of the solder layer when the semiconductor chip and the collector-side buffer plate are joined by soldering are employed. Can be absorbed, so that it is brought into contact with the common electrode emitter 7.

Further, when the semiconductor chips 1a, 1b, 1c generate heat, the heat is transmitted to the multi-structure elastic body 5 and is transmitted to the common electrode emitter 7, so that a low thermal resistance can be realized.

(Embodiment 2) FIG. 2 shows a multi-chip type semiconductor device according to another embodiment of the present invention. The difference from the embodiment of FIG. 1 is that the structure of the multi-structure elastic body 5 is changed. The multi-structure elastic body 5 uses two types of Cu pipes. One is a combination of a Cu pipe having an outer diameter of φ8 mm and an inner diameter of 6.0 mm and the other is a combination of three Cu pipes having an outer diameter of 2.2 mm and an inner diameter of 1.6 mm. In this case, a small diameter Cu
Since there are three pipes, the amount of deformation may be reduced. Actually, it is desirable to process all three small diameter Cu pipes so as to be flat. There are three hollow portions 6 in the small diameter, which play one part in the action of expansion and contraction.

This multi-structure elastic body has a thickness variation of the semiconductor chip, a variation of the thickness of the strain buffer plate, and a variation of the thickness of the solder layer when the semiconductor chip and the collector side buffer plate are soldered. Since the step can also be absorbed, it comes into contact with the common electrode emitter 7.

Further, when the semiconductor chips 1a, 1b, 1c generate heat, the heat is transmitted to the multi-structure elastic body 5 and is transmitted to the common electrode emitter 7, so that a low thermal resistance can be realized.

That is, heat is first transmitted to the large-diameter Cu pipe, and the heat is transmitted to the common electrode emitter 7 through the bypass of the three small-diameter Cu pipes. That is, heat conductivity is improved by the amount of Cu bypass.

(Embodiment 3) FIG. 3 shows a multi-type semiconductor device assembled by stacking one unit semiconductor module. The number of semiconductor chips and the number of stacks are determined according to the electric capacity. In the multi-type semiconductor device, the water-cooled electrode 14 is provided for each unit semiconductor module. The whole of the stacked semiconductor modules is caulked by pressurization 15. As can be seen from the figure, similarly to the first embodiment, a multi-structure elastic body is arranged for each semiconductor chip of one unit semiconductor module, and expands and contracts according to various steps. It applies a pressure 15 to the member with the largest step, and absorbs all the steps with the multi-structure elastic body. That is, the electric conduction with the semiconductor chip and the conduction of the heat generated from the semiconductor chip are favorably performed by the caulking by the pressurization 15 and the action of the multi-structure elastic body.

In the above embodiment, the steps such as the height of the semiconductor chip and the thickness of the strain buffer plate were 50 μm at the minimum and 250 μm at the maximum. In a fatigue test in which the use and shutdown of a multi-chip type semiconductor device were repeated, the use of a double-structured elastic body maintained the soundness for a long time without cracks in the pipe, and maintained electrical and thermal performance. It also had good properties in conductivity.

(Embodiment 4) FIG. 4 is a sectional view of an IGBT module. In the figure, I made of silicon (Si)
An emitter collector electrode 31 is provided on the upper surface of the GBT semiconductor chip 1 so as to avoid the upper part of the gate structure, and a collector electrode 32 is provided on the lower surface. Collector electrode 32
Is molybdenum (Mo) whose thermal expansion coefficient is almost equal to that of Si
A support plate 2 for reducing thermal expansion is brazed or fused. The support plate 2 is provided with a common electrode collector made of copper, one surface of which is exposed to the outer surface of the container, and is attached by a solder 30. On the other hand, the upper surface of the emitter collector electrode 31 is also provided with M
A support 35 made of o is provided. A ring 2 is provided between the support plate 35 and the common electrode emitter 7 exposed on the outer surface of the container.
A heavy spring 36 is interposed. The springs 36 are each made of a pure copper pipe having a thickness of 0.6 mm. The outer pure copper pipe has an outer diameter of 8.0 mm and the inner pure copper pipe has an outer diameter of 6.0 mm, and the two are not integrally joined. Also,
Between the semiconductor chip 1 and the common electrode emitter 7, an electric current and heat path composed of the emitter collecting electrode 31, the support plate 35 and the spring 36 is formed. In this structure, pressure contact occurs between the Mo support plate 35 and the emitter collector electrode 31, but the Mo support plate 35 is made of, for example, aluminum (Al).
May be fused to the electrode made of. Also in that case, the spring 36
Helps to improve the reliability of the connection between the semiconductor chip 1 and the Mo support plate 35 or the Mo support plate 32. The gate electrode is connected to the gate terminal exposed on the outer surface of the container by bonding an Al conductor.

FIG. 5 shows a comparison between a pure copper single pipe (Cu double pipe) and a pure copper single pipe (Cu single pipe) and a stainless steel 304 stainless steel pipe according to the present invention.
It is a diagram which shows the relationship between the amount of deformation of the heavy pipe (SUS single pipe) in the radial direction at room temperature and the pressing force. As shown in the figure, when the pressing force exceeds 50 kgf, the Cu single pipe is rapidly deformed and has low spring characteristics. SUS single pipe has sufficient spring properties. The Cu double pipe in the present invention has the same spring characteristics as the SUS single pipe.

FIG. 6 is a diagram showing the relationship between the same spring region and the pressing force. As shown in FIG.
Although it is clear from the fact that the spring property cannot be obtained when the weight exceeds kgf, a high spring property can be obtained by using the Cu double pipe of the present invention. In this embodiment, the pressure of 50 kgf is 0.72 kg / mm ² , and the pressure of 122 kg is 1.76 kgf / mm ² .
² , and the applied pressure of 70 to 105 kgf is 1 to 1.5 kgf / m
Since corresponding to m ^2, the spring region in the pressure 5
Preferably, it has a thickness of 0 μm or more. The Cu double pipe of the present invention is sufficiently satisfactory.

The following experiment was conducted on a Cu double pipe.

The Cu pipe is cut so as to conform to the shape of the semiconductor chip, pressed to be flattened, and a thermal and electrical contact area with the electrode plate and the strain buffer plate is secured. First C
The pressing force and deformation amount of a single pipe made of u were processed flat. As a result, when a pressing force of 50 kg is applied, 20
0 μm and 1100 μm when 120 kg was applied. After applying the pressing force, the spring area was examined.
It was 40 μm, and showed 10 μm when 120 kg was applied. It was found that this result can be used at a low pressing force, but cannot be used at a high pressing force because of its low spring property.

Therefore, the pressing force and the deformation amount of the Cu double pipe were similarly examined. As a result, the applied pressure was 90 μm when applied with 50 kg and 190 μm when applied with 120 kg. After the application of the pressing force, the spring region (also referred to as the elastic region) was examined, and found to be 80 μm when 50 kg was applied and 140 μm when 120 kg was applied.

This result indicates that the step of the semiconductor chip is, for example, 1
Assuming that the thickness is 90 μm, the semiconductor chip and the heat radiating member uniformly adhere to each other when 120 kg of the heat radiating member is applied.
It shows that the spring property in the 140 μm range is maintained. That is, it has been found that the pressing force can be determined according to the step of the semiconductor chip, and that the spring force is maintained by the pressing force. In other words, it has been found that by working a Cu double pipe in a flat shape, the effect as an elastic body can be sufficiently exhibited.

In the double pipe, the respective pipes restrain each other,
Withstands pressure and has spring properties. In addition, triple pipe, 2
Various shapes of the heavy pipe will be described in detail in the application section of the present invention. In addition, as a result of conducting an experiment in which a single-layer and a double-layer semiconductor module of a Cu pipe were manufactured and electrical on and off were repeated, a crack was generated from the end of the Cu pipe in the Cu single pipe by repeating 1000 times. From that point on, the spring has disappeared.

On the other hand, a Cu double pipe is 10,000
No cracks were observed even after the repetition, and it was confirmed that good elastic properties were maintained thereafter.

In other words, it is clear that the pipe with the step difference absorbing material has a very good result, and that the multi-layered elastic body can cope with various steps in the pipe and has excellent reliability even for long-term use. Became.

The semiconductor device according to the present invention is effective for all semiconductor chips in which heat generation is a problem, and in particular, a power switching device including an insulated gate element such as an IGBT having the first and second main surfaces of the semiconductor chip as main electrodes. It is suitable for.

FIG. 7 is a perspective view showing the appearance of the IGBT module.

As shown in FIG. 4, since the module can be cooled on both sides, it is possible to manufacture an IGBT module whose volume is reduced to about half that of the conventional IGBT module. Furthermore, if the interior space of the module is filled with a gel having high thermal conductivity such as a gel resin containing alumina, the heat dissipation to the common electrode emitter 7 side is further improved. As shown in FIG.
The appearance of the BT module is such that the common electrode emitter 7 is exposed on the upper surface of the container surrounded by the insulating side wall 40, and the gate terminal 33 protrudes on the side surface. The common electrode emitter 7 has a cooling body mounting hole 72 formed therein.

FIG. 8 is a sectional view of a multi-chip type semiconductor device having ten semiconductor chips mounted thereon. The basic structure of this embodiment is exactly the same except for the multi-structure elastic body shown in FIG.

(Comparative Example) As a comparison, a multi-chip type semiconductor device was tested in the same manner as in the example using an elastic body of a single Cu pipe. Initially, when the step was as small as 50 μm, good step absorption was exhibited, but the step was 250 μm.
When it was large, it was not in contact when the pressure was removed.
That is, the space is created when the deformation is caused by the initial pressurization but the pressurization is removed thereafter. In other words, it was found that the elastic body intended by the present invention cannot be exerted at a certain level difference, and that a single Cu pipe cannot be applied.

Further, when the step was small, an experiment of long-term use revealed that cracks occurred from the end of the pipe, and there was a problem in reliability.

(Embodiment 5) FIG. 9 shows another application example other than the embodiment of the multi-structure elastic body 5 and the hollow portion 6.
(A) is a double structure in which two small diameter pipes are inserted in a large diameter, (b) is a triple structure in which one small diameter pipe is inserted in a double pipe, and (c) is a double structure in which two small pipes are inserted. 2 small diameter pipes
(D) shows a triple structure in which a number of small diameter pipes are inserted in a double pipe.

In any case, it is necessary to select the thickness and structure of the Cu pipe in accordance with the size of the step of the semiconductor chip or the like. Characteristically, in any of the multiple structures, a gap exists on the center of the pipe.

Although the Cu pipe has been described as the multi-structure elastic body, even if a material having good electric and thermal conductivity, for example, Ag, Au, Al or an alloy thereof is applied, the characteristics as the elastic body can be sufficiently exhibited. I do. Further, surface treatment for protecting the oxidation of the Cu pipe and maintaining the characteristics, for example, N 2
It has been confirmed that the electrical and thermal conductivity of the present invention and the properties as an elastic body can be obtained even when plated with i, Ag, Au or the like and used.

[0048]

As described above, according to the present invention, a plurality of semiconductor chips having different heights and variations in thickness of a strain buffer plate are connected to one common electrode at the same time. However, it has become difficult to connect the semiconductor device to the semiconductor device using the multi-structure elastic body of the present invention.

As a result, when designing a multi-chip module or the like, the layout and thermal design of the semiconductor chip can be easily performed, and the effect that the semiconductor device can be easily manufactured in a pressurized type can be exhibited.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a pressure-type package, which is a multi-chip type semiconductor device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a multi-chip type semiconductor device according to an embodiment of the present invention, which is a pressurized type package.

FIG. 3 is a cross-sectional view of a multi-chip type semiconductor device according to an embodiment of the present invention, in which a pressure-type package is assembled.

FIG. 4 shows a multi-chip type semiconductor device according to another embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between a deformation amount and a pressing force.

FIG. 6 is a diagram showing a relationship between a spring region and a pressing force.

FIG. 7 is an overall perspective view of a multi-chip semiconductor device according to the present invention.

FIG. 8 shows a multi-chip semiconductor device according to another embodiment of the present invention.

FIG. 9 is a perspective view showing another example of the multi-structure elastic body applied to the multi-chip semiconductor device of the present invention.

FIG. 10 is a cross-sectional view of a conventional multichip semiconductor device.

[Explanation of symbols]

1a, 1b, 1c, 21a, 21b, 21c: semiconductor chip, 2, 4, 22, 24: strain buffer plate, 3, 23: common electrode collector, 5, 25: multi-structure elastic body, 6: hollow portion, 7 27, common electrode emitter, 8, 28 gate electrode, 9, 29 insulating plate, 10, 210 gate wiring network,
11, 211: wire lead, 12, 212: insulating outer cylinder, 13, 213: insulating positioning plate, 14: water-cooled electrode,
15 ... Pressure.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hironori Kodama 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Koichi Inoue 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Hitachi Research Laboratory, Hitachi, Ltd.

Claims (9)

[Claims] 1. A multi-chip type semiconductor device having a structure for radiating heat of a semiconductor chip through a heat radiating member.
A multi-chip type semiconductor device, wherein the semiconductor chip and the heat radiating member are connected between the semiconductor chip and the heat radiating member with a multi-structure elastic body interposed therebetween. 2. A multi-chip type semiconductor device wherein upper and lower surfaces of a plurality of semiconductor chips provided between common electrode members are formed with a strain buffer interposed therebetween. A multi-chip type semiconductor device characterized by being connected under pressure with a multi-structure elastic body interposed therebetween. 3. A multi-chip type semiconductor device in which a plurality of semiconductor chips having different heights are provided between common electrode members, wherein a multi-structure elastic body is interposed between the semiconductor chip and the common electrode members. A multi-chip semiconductor device, wherein the semiconductor chip and the common electrode member are electrically connected by pressure. 4. A multi-chip type semiconductor device formed through a strain buffer plate solder-bonded to upper and lower surfaces of a plurality of semiconductor chips provided between common electrode members. A multi-chip type semiconductor device characterized in that a multi-structure elastic body is interposed between a buffer plate and an electrode member connected by a pressing force. 5. The multi-layer structure according to claim 1, wherein said multi-layer structure elastic body is made of Cu, Ag, Au or an alloy material mainly composed of Cu, Ag and Au, and at least the center of said multi-layer structure is hollow. Chip type semiconductor device. 6. The multi-structure elastic body has at least a double pipe structure or a pipe structure of two or more layers.
The multi-chip semiconductor device according to claim 1, wherein a central portion of the structure having more than one layer is hollow. 7. The multi-chip semiconductor according to claim 5, wherein said multi-structure elastic body is made of pure Cu, and the surface thereof is covered with a material having high oxidation resistance selected from Ni, Ag, and Au. apparatus. 8. The multi-chip semiconductor device according to claim 1, wherein said semiconductor chip includes a power switching device. 9. The multi-chip semiconductor device according to claim 1, wherein said semiconductor chip includes an insulated gate element.