JPH05175378A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent deformation and breakage when members with different thermal expansion coefficients are bonded by arranging carbon fiber reinforced carbon compound at the specific part on the compound material and a semiconductor device. CONSTITUTION:Tungsten 1 and copper 2 are bonded by arranging CFRC 3 in between. The tungsten 1 is 5mm (thickness)X50mm (width), the copper plate is 20mm (thickness)X50mm (width), the CFRC 3 is 30mm (thickness)X50mm (width) and the orientation direction of the carbon fiber is arranged to be vertical to the bonding plane. A metallized layer 4 is previously formed of paste composition which is silver solder containing titanium of 2vol.% on the bonding plane of the CFRC 3 by being heated in a vacuum furnace. Thus, deformation and breakage of the compound material formed by bonding the members with different thermal expansion coefficients are prevented and the highly reliable compound material is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite composed of members having different thermal expansion coefficients, which are widely applied to industrial products such as aerospace equipment and nuclear fusion devices, and a member having different thermal expansion coefficients. The present invention relates to a semiconductor device obtained.

[0002]

2. Description of the Related Art In the case of joining members having different coefficients of thermal expansion by joining for the purpose of utilizing the characteristics of each member, the composite is deformed or destroyed by the thermal stress caused by the difference in thermal expansion between the members. However, there is a problem that a complex that sufficiently achieves the purpose of use cannot be obtained. This problem is more remarkable when a combination of members having a large difference in coefficient of thermal expansion is required.

Conventionally, the following methods have been disclosed as measures against this. That is, in JP-A-60-77181 and JP-A-60-155577, a soft metal having high ductility such as copper is arranged and bonded between a metal and a ceramic. Kohei
In 1-119571, the silicon nitride ceramics and the metal are joined together by interposing a member having an intermediate coefficient of thermal expansion such as nickel or tungsten alloy. In JP-A-62-132780, a wire-shaped metal is interposed between the non-oxide ceramics and the metal to bond them. In Japanese Unexamined Patent Publication No. 62-38319, ceramics and metal are bonded together via a composite material of fibers made of an inorganic material and a metal matrix. In JP-A 1-290569, in joining zirconia and metal,
Palladium and palladium alloys are used as stress relaxation materials.

However, the above-mentioned composite body joined by the conventional joining method could not completely prevent the composite body from being broken due to the difference in thermal expansion coefficient. Further, even when no breakage occurred, there were many problems in the strength and heat resistance of the composite. This problem is especially noticeable when the complex is large. on the other hand,
Recently, semiconductor elements for power or LSI have a high heat generation amount, and it is necessary to use an insulating material having a good heat dissipation characteristic in a module, a package or the like in which they are mounted. Ceramic materials suitable for this include high thermal conductivity silicon carbide ceramics and AIN ceramics. Since both of them have the same coefficient of thermal expansion as that of silicon, there are few problems in bonding with the semiconductor element. However, the difference in thermal expansion coefficient between the metal support and the metal support tends to increase, and destruction of the ceramics or thermal fatigue of the bonding layer when the ceramics substrate and the metal substrate are bonded poses a serious problem.
This problem also applies to a semiconductor device using alumina ceramics as an insulating substrate. Conventionally, as a countermeasure against this, in Japanese Patent Laid-Open No. 56-146261, in order to facilitate heat dissipation of a silicon chip that generates heat and to alleviate a difference in thermal expansion coefficient between the silicon chip and the alumina ceramics, the silicon chip and the alumina A thermal stress relaxation material such as molybdenum was inserted between the ceramics. But,
Even in this case, the thermal fatigue of the bonding layer due to the difference in thermal expansion coefficient between the silicon chip and molybdenum or between the alumina ceramics and molybdenum is a problem.

[0005]

SUMMARY OF THE INVENTION In the above-mentioned prior art, it is difficult to completely prevent deformation and breakage when members having different coefficients of thermal expansion are combined by joining, and therefore a composite having high quality reliability. Couldn't get Further, even when no deformation or breakage occurs, there is a problem in strength and heat resistance of the composite body, and this problem is more remarkable as the composite member is larger.

On the other hand, a semiconductor device is usually made of a silicon chip as a semiconductor element, a ceramic as an insulating substrate, and a member having a large coefficient of thermal expansion such as a metal plate that supports the ceramic and radiates heat from the semiconductor element. It is configured. Further, these members are assembled by joining with a solder material or a brazing material. Therefore, even in the semiconductor device, there are many problems due to the difference in the coefficient of thermal expansion between the constituent elements. For example, in any case, the ceramics described above are fixed to a metal support made of copper, iron, aluminum, or an alloy thereof by a bonding material in order to maintain mechanical strength of a semiconductor device and for heat dissipation. .. For purposes that do not require insulation,
It is customary to directly bond the semiconductor element and the metal support. However, since these semiconductor devices have a large difference in coefficient of thermal expansion between the metal support and the ceramics or semiconductor element, the ceramics, the semiconductor element, or the bonding layer may be broken due to thermal stress during the bonding process or thermal fatigue during use. There are many. As a result, the heat dissipation characteristic of the semiconductor device is deteriorated, and there is a problem that the function as a semiconductor device is impaired after a short period of use. Particularly in the case of a power semiconductor mounted with a semiconductor element that generates a large amount of heat, the temperature rise of the entire device and the temperature difference between the members also increase, and this problem is more pronounced.

Further, with the increase in output of semiconductor devices,
It is also required to improve the heat dissipation characteristics of semiconductor devices. That is,
An object of the present invention is to prevent deformation and breakage in the case where members having different thermal expansion coefficients are combined by joining to provide a composite having high reliability in quality, and a semiconductor device having excellent heat dissipation characteristics and high reliability in quality. To do.

[0008]

Means for Solving the Problems The present inventor has conducted extensive studies in view of the above-mentioned problems, and as a result, the carbon fiber reinforced carbon composite (C
It has been found that such problems can be solved by disposing arbon Fiber Reinforced Carbon (hereinafter referred to as “CFRC”) at a specific portion of the composite material and the semiconductor device.

That is, according to the present invention, firstly, a CFRC having a metallized layer formed on at least one side surface between members having different coefficients of thermal expansion is arranged and composited. Secondly, in a semiconductor device having a structure in which a ceramic substrate on which a semiconductor element is mounted and a metal supporting plate supporting the same are assembled via a bonding material, between the ceramic substrate and the metal supporting plate, or a semiconductor At least one of the element and the ceramics substrate, a semiconductor device characterized in that it is configured by disposing a CFRC,
And a semiconductor device characterized in that a CFRC is arranged between a semiconductor element and a metal supporting plate.

(1) Composite As a combination of members having different coefficients of thermal expansion used in the composite of the present invention, for example, the coefficient of thermal expansion of tungsten and copper, molybdenum and copper, tungsten and stainless steel, molybdenum and stainless steel, etc. Combinations of metals that are different from each other; combinations of metals and ceramics such as copper and silicon carbide ceramics, copper and alumina ceramics, stainless steel and silicon carbide ceramics, stainless steel and alumina ceramics; copper and isotropic graphite, stainless steel and isotropic Examples thereof include a combination of a metal such as graphite and graphite, or a combination of isotropic graphite and copper, a combination of isotropic graphite and stainless steel and the like, and graphite.

Next, the composite of the present invention is characterized in that CFRC having a metallized layer is disposed or interposed on at least one side surface between the members having different thermal expansion coefficients.
The orientation direction of the carbon fibers with respect to the joint surface of the CFRC to be arranged with other members is determined according to the specific application of the composite in the present invention. That is, when the composite of the present invention is used for applications requiring heat insulation, it is preferable that the orientation direction of such carbon fibers is arranged so as to be parallel to the joint surface with other members. When it is used for the purpose in which the property is required, it is preferable to arrange it at a right angle.

The composite of the present invention is expected to be used mainly in applications requiring heat dissipation, such as the first wall of a nuclear reactor. In this sense, the above orientation direction is relative to the joint surface. It is preferable that they are at right angles. The CFRC
As the above, it is possible to use a commercially available product or a commonly known method.

The composite of the invention is characterized in that a metallization layer is formed on at least one side surface between the CFRC and the other member. By forming this metallized layer,
This facilitates brazing or soldering with other members using a general-purpose brazing material such as a silver brazing material or a nickel brazing material which has been generally applied to joining metals. The method of forming the metallization layer for bonding on the surface of this CFRC can be performed by the following method. (1) A method in which an element that reacts with carbon to form a carbide or an alloy containing the element is attached to the surface of CFRC by a physical method such as vapor deposition or a chemical method such as plating, and then heated. (2) Non-oxidizing after arranging or applying a composition containing copper, silver, nickel alone or an alloy containing one or more kinds of the metals, or a composition containing at least 50% by volume of titanium in the mixed powder on the surface of CFRC. A method of heating in the atmosphere above the melting point of the alloy foil or the mixed powder. In this case, in particular, a composition in which 1 to 10 wt% of titanium is added to an alloy of copper and silver is at a heating temperature of 800 to 900 ° C., and a composition in which 30 wt% of titanium is added to nickel or copper is 900 A metallization layer is formed at a heating temperature of up to 1000 ° C., and in the case of alloys based on nickel and chromium, at a heating temperature of about 1000 ° C.

Further, since a brazing material can be selected over a wide range by previously providing a metallizing layer for bonding on the CFRC surface, it is possible to form a composite with many kinds of members. For example, since a brazing material having a low melting point such as soft brazing can be applied to brazing with a member which is not suitable for high temperature heating, thermal stress generated in the joining process can be reduced and a composite having high quality reliability can be obtained.
Further, since it is possible to join in the atmosphere, it is possible to join with a member having a complicated shape or a large member. Further, mass production of the composite of the present invention is easy by the method of previously providing a metallization layer for bonding on the CFRC surface.

The metallized layer is preferably formed by using a paste containing a metal such as tungsten, titanium, zirconium, hafnium or niobium which reacts with carbon to form a carbide with respect to the silver brazing material. Metal is 0.1-
10% by volume, preferably 0.5-5% by volume, is contained in the paste. (2) Semiconductor Device The semiconductor device of the present invention is characterized in that the CFRC is arranged between the ceramic substrate and the metal supporting plate or between the semiconductor element and the ceramic substrate, or between the semiconductor element and the metal supporting plate. ..

In such a semiconductor device, the disposition direction of the CFRC with respect to the joint surface with other members can be originally determined freely, but considering the achievement of the intended purpose of improving the heat dissipation of the semiconductor device, It is preferable to arrange the carbon fibers of CFRC at right angles to the joint surface. The method of joining CFRC and other members of this semiconductor device is a method of directly joining with a brazing material containing an active metal such as titanium or the above-mentioned method.
A conventionally known method of joining a metallized layer on the surface of CFRC in advance and then bonding it with an ordinary brazing material, for example, a method using an inorganic or organic adhesive, can also be employed.

In the semiconductor device of the present invention, the CFRC
In order to prevent the carbon powder generated by the above from adhering to the electric circuit and causing a conductive failure in the circuit, it is preferable to coat the surface of the CFRC with a ceramic or glassy carbon film. CFRC with such ceramics and glassy carbon film
As a coating method of, for example, a method of coating the surface of CFRC with SiC by CVD and further coating these with ordinary glass can be exemplified.

[0018]

Next, the CF in the composite and semiconductor device of the present invention
The function of RC will be described. CF to achieve this objective
RC is made by impregnating a carbon fiber woven fabric with phenolic resin, pitch, etc. and firing it many times to carbonize the matrix. The carbon fiber can achieve this object whether it is pitch-based or bread-based. Further, the composite is obtained by laminating methods such as a feather-like laminating method, a paper making method, an isotropic casting method, a spray laminating method and a cloth laminating method. The carbon fibers may be woven by any one-dimensional, two-dimensional or three-dimensional method.

The CFRC manufactured by the above method can control the thermal expansion coefficient, the thermal conductivity and the elastic modulus over a wide range by controlling the type and the orientation direction of the carbon fiber. That is, CFRC has the following characteristics, and by making the best use of these characteristics, the intended purpose of the present invention can be achieved. (1) CFRC can control the coefficient of thermal expansion to an intermediate value between metals and ceramics or semiconductor elements depending on the orientation direction of carbon fibers. In particular, the coefficient of thermal expansion in the direction perpendicular to the fiber orientation direction can be changed within the range of 1 to 10 × 10 ^-6 / ° C. For this reason, it is possible to reduce the thermal stress on the joint surface when joined to a member having a different coefficient of thermal expansion such as ceramics, a semiconductor element, or a metal. Carbon fibers having a diameter of 10 μm or less, preferably 0.1 to 10 μm in length are used, and those oriented in one direction are preferable, and the content thereof is 10 to 80% by volume, preferably 20 to 60% by volume. Is. In addition, the strength is a 3-point bending strength of 10 kg / mm ² or more, preferably 20 to 60 kg, with respect to the orientation direction of the carbon fiber.
It is about / mm ² . (2) CFRC can also control the elastic modulus depending on the fiber orientation direction. Especially, the elastic modulus in the direction perpendicular to the fiber orientation direction is 3
Can be as small as GPa. For this reason, it is possible to reduce the thermal stress on the joint surface when joined to members having different coefficients of thermal expansion such as ceramics and metals.

Therefore, the effects of the above (1) and (2) of CFRC can prevent the destruction of ceramics when the ceramics and the metal are joined. (3) One of the greatest features of CFRC is that by controlling the fiber orientation direction, even if a crack occurs in CFRC, it is possible to suppress the progress of the crack. In particular, by arranging and joining the joint surface so as to be perpendicular to the orientation direction of the fibers, the progress of cracks generated in the parallel direction to the joint surfaces of the members having different thermal expansion coefficients is It can be prevented by the effect of pinning at the interface. That is, with respect to thermal stress, a large thermal stress or strain can be accommodated between the layers of carbon fibers. Therefore, due to the carbon fibers oriented in the plate thickness direction, the development of cracks is easily prevented, and a composite having no defect in quality can be obtained.

By applying the characteristics of CFRC which can prevent the development of cracks to the semiconductor device, it is possible to prevent the destruction of the ceramics and the bonding layer during the process of manufacturing the semiconductor device and during the operation, and to improve its quality. Therefore, a highly reliable semiconductor device can be obtained. (4) CFRC can increase the thermal conductivity in the fiber orientation direction to be equal to or higher than that of copper. Therefore, by arranging the CFRC so that the orientation direction of the fibers is at right angles to the joint surface with the ceramic or metal, a composite having excellent cooling characteristics can be obtained. On the contrary, by arranging the CFRC so that the orientation direction of the fibers is parallel to the joint surface, it is possible to obtain a composite that shields heat.

On the other hand, by arranging the above-mentioned features of CFRC in the semiconductor device, it is possible to obtain a semiconductor device having excellent heat dissipation characteristics. That is, as described above, the CFRC is placed between the semiconductor element and the ceramic substrate, or between the ceramic substrate and the metal substrate, or between the semiconductor element and the metal substrate, in which the fiber orientation direction is perpendicular to the bonding surface. By arranging the CFRC so that, the heat from the semiconductor element can be efficiently dissipated. As a result, even when the semiconductor device is used for a long time, the heat dissipation characteristics are not deteriorated,
High quality reliability can be maintained. (5) Since the density of CFRC is as small as 2 g / cm ³ (2 × 10 ³ kg / m ³ ) or less, it can be made lighter in weight than conventional composites and semiconductor devices using Mo or the like.

The semiconductor device according to the present invention is a power semiconductor device in which a plurality of combination composite plates of a business card size ceramic plate and a CFRC plate are mounted on an A4 size metal heat dissipation plate, and a plurality of semiconductor elements are mounted on each of them. Applicable to Such a semiconductor element is preferably mounted on the ceramic side.

[0024]

According to the present invention, firstly, it is possible to prevent deformation and breakage when members having different thermal expansion coefficients are combined by joining to obtain a composite having high reliability in quality. Secondly, it is possible to obtain a semiconductor device which is stable at high temperature and has excellent heat dissipation characteristics.

[0025]

EXAMPLES Examples of the present invention will be described below.

[0026]

Example 1 FIG. 1 is an exploded cross-sectional view of a composite body in which CFRC is arranged and joined between tungsten and copper. In FIG. 1, 1 is tungsten, 2 is a copper plate, 3 is CFRC, 4 is a metallized layer, and 5a and 5b are brazing materials.

The tungsten 1 has a thickness of 5 mm and 50 mm square, the copper plate 2 has a thickness of 20 mm and 50 mm square, and the CFRC 3 has a thickness of 3.
It is a square of 50 mm and is arranged so that the orientation direction of the carbon fiber is perpendicular to the joint surface. The characteristics of CFRC3 used in this example are shown in Table 1.

[0028]

[Table 1]

In the table, X, Y, Z indicate the orientation directions of the carbon fibers in FIG. 2 below. The CF in Table 1
RC was manufactured by laminating carbon fibers with a diameter of 7 μm in a felt shape. And, FIG. 2 shows CF showing the orientation direction of carbon fiber.
It is a schematic diagram of RC. In FIG. 2, arrows indicate the orientation directions of CFRC carbon fibers. The metallized layer 4 was formed on the bonding surface of the CFRC 3 with a thickness of 100 μm in advance by a method of heating in a vacuum furnace at 850 ° C. for 3 minutes, using a paste-like composition in which 2% by volume of titanium was added to silver braze. Has been formed. The brazing materials 5a and 5b are silver brazing foils having a thickness of 100 μm.

The respective members are joined together in a vacuum furnace.
Heating was carried out at 0 ° C. for 3 minutes. As a result of performing a shear test on the composite of tungsten-copper-CFRC joined by this method, it was found that the composite had a strength equivalent to that of CFRC. In this example,
Similar results were obtained in the above shear test for the composite using molybdenum instead of tungsten.

[0031]

Example 2 FIG. 3 is an exploded cross-sectional view of a composite body in which CFRC is arranged and bonded between isotropic graphite and copper. In FIG. 3, 1 is an isotropic graphite, 2 is a copper plate, 3 is CFRC, 4 is a metallized layer, 5a and 5b are brazing materials.

The isotropic graphite 1 has a thickness of 5 mm and 50 mm square,
The copper plate 2 has a thickness of 20 mm and 50 mm square, and the CFRC 3 has a thickness of 3 mm and
The carbon fibers are 50 mm square and arranged so that the orientation direction of the carbon fibers is perpendicular to the joint surface. The characteristics and the like of this CFRC3 are the same as those in the first embodiment. The metallized layer 4 is formed by printing a paste-like composition in which titanium powder is mixed with an organic solution material on the bonding surface of the CFRC 3 in advance to a thickness of 100 μm. The brazing materials 5a and 5b are silver brazing foils having a thickness of 100 μm.

The joining of the members is carried out in a vacuum furnace.
Heating was carried out at 0 ° C. for 3 minutes. As a result of a shear test on a composite joined by this method, it was found that this composite had a strength equivalent to that of CFRC. In addition, in this example, the same result was obtained in the above shear test for the composite body using the silicon carbide ceramics instead of the copper plate 2.

[0034]

[Embodiment 3] FIG. 4 is an exploded cross-sectional view showing respective parts of a semiconductor device when CFRC is arranged between a silicon chip and a ceramic substrate before joining. In FIG.
3 is CFRC, 11 is a silicon chip, 12 is alumina ceramics, 13 is a metal support plate, 14a to 14c are bonding materials, and 15 is a metallized layer.

The CFRC 3 has a thickness of 2 mm and has metallization layers 15 for bonding formed on both side surfaces thereof in advance. The method for forming the metallized layer 15 is the same as in the first embodiment. CFRC3 is the first embodiment
A copper plate was used as the metal supporting plate 13, which had the same characteristics as the above, and was arranged so that the orientation direction of the carbon fibers was perpendicular to the joint surface. The bonding material 14a has a melting point of 310.
95 ℃ Lead-5tin (wt%) solder, bonding materials 14b and 14c
Is a 63 tin-37 lead (wt%) solder with a melting point of 183 ° C. Therefore, the order of joining is silicon chip 11 and CFRC3.
Are first bonded by the bonding material 14a, and then the bonding material 14b
CFRC3-alumina ceramics 12-
The copper support plate 13 is simultaneously joined.

The semiconductor device having the above structure was subjected to a power cycle test, and as a result, no change in thermal resistance was observed up to 50000 cycles or more, and about 5 times or more quality reliability was secured as compared with the conventional structure. It was In this example, silver brazing was used as the brazing material 14b, and the CFRC3
14a and 14 after brazing aluminum and alumina ceramics 12
It was also proved that the quality reliability of about 5 times or more as compared with the conventional product is secured when c is joined by the solder material.

[0037]

[Embodiment 4] FIG. 5 is an exploded cross-sectional view showing respective parts of a semiconductor device in which a CFRC is arranged between a silicon chip and an alumina ceramics substrate and between an alumina ceramics substrate and a metal supporting plate before joining. .. In FIG.
3a and 3b are CFRC, 11 is a silicon chip, 12 is an alumina ceramics, 13 is a metal support plate, 14a to 14d are bonding materials, and 15 is a metallized layer.

The CFRCs 3a and 3b have a thickness of 3 mm, and a metallization layer 15 for bonding is previously formed on one side surface thereof. The method for forming the metallized layer 15 is the same as in the first embodiment. Further, CFRCs 3a and 3b having the same characteristics as in Example 1 were used, and the carbon fibers were arranged so that the orientation direction thereof was perpendicular to the joint surface. A copper plate was used as the metal supporting plate 13. The bonding material 14a in this embodiment has a melting point of 280
C. 1.5 silver-5 tin-93.5 lead (wt%) solder, 14b and
14c is a silver solder with a melting point of 780 ° C, and 3d is 63 with a melting point of 183 ° C.
Tin-37 Lead (wt%) solder. Therefore, as for the order of joining, CFRCs 3a and 3b are brazed to both surfaces of the alumina ceramic 12 by the joining materials 14b and 14c. Then, the silicon chip 11 is bonded to the CFRC 3a by the bonding material 14a.
Is soldered in place. Finally, the CFRC 3b is soldered to the metal supporting plate 13 by the joining material 14d.

The semiconductor device having the above structure was subjected to a power cycle test, and as a result, no change in electric resistance was observed up to 50,000 cycles or more, which was about 5 times that of the conventional structure.
The quality reliability is more than doubled. In this embodiment, the same result can be obtained by using silver solder for the joining material 14d, brazing the CFRC 3b and the metal support plate 13 in advance, and then joining the joining materials 14a, 14b, and 14c with solder. Was given.

[0040]

[Embodiment 5] FIG. 6 is an exploded cross-sectional view showing respective parts of a semiconductor device in which a CFRC is arranged between a ceramic substrate and a metal supporting plate before joining. In FIG. 6, 3 is
CFRC, 11 is a silicon chip, 12 is AIN ceramics, 13
Is a metal support plate, 14a to 14c are brazing filler metals, and 15 is a metallized layer.

The CFRC 3 has a thickness of 5 mm and has metallization layers 15 for bonding formed on both side surfaces thereof in advance. The metallized layer 15 has a thickness of 1 μm and is formed by a vapor deposition method from the CFRC3 side to titanium-lead-
It was formed in the order of nickel. Further, CFRC3 having the characteristics shown in Table 2 was used, and the CFRC3 was arranged so that the orientation direction of the carbon fibers was perpendicular to the joint surface.

[0042]

[Table 2]

In Table 2, X, Y and Z are the same as in Table 1 above. The CFRC is manufactured by orienting carbon fibers having a diameter of 10 μm in one direction and impregnating them with a pitch-based thermoplastic resin to carbonize them. AIN ceramics 12 has a thermal conductivity of 400 W / m · K. A copper plate was used as the metal supporting plate 13. The bonding material 14a has a melting point of 31.
95 ° C-5 tin (wt%) solder at 0 ° C, 14b has a melting point of 183
63-37 Lead (wt%) solder at 3 ° C, 3c has a melting point of 780 ° C
It is silver wax. Therefore, the order of bonding is that the silicon chip 1 is bonded to the AIN ceramics 12 by the bonding material 14a, the CFRC
3 are separately bonded to the metal supporting plate 13 by a bonding material 14c. Finally, the AIN ceramics 12 and CFR are bonded by the bonding material 14b.
C3 joins.

The semiconductor device having the above structure was subjected to a power cycle test, and as a result, no change in electric resistance was observed up to 50,000 cycles or more, which was about 5 times that of the conventional structure.
The quality reliability is more than doubled. In this embodiment, the same result was obtained when the AIN ceramics 12 and the bonding material 14b were omitted and the bonding was carried out by the bonding materials 14a and 14c through the silicon chip 11, the metal supporting plate 13 and the CFRC3. ..

[Brief description of drawings]

FIG. 1 is an exploded cross-sectional view of a composite body shown in Example 1.

FIG. 2 is a schematic diagram of CFRC showing the orientation direction of carbon fibers.

FIG. 3 is an exploded cross-sectional view of the complex shown in Example 2.

FIG. 4 is an exploded sectional view of a semiconductor device shown in a third embodiment.

FIG. 5 is an exploded sectional view of a semiconductor device shown in a fourth embodiment.

FIG. 6 is an exploded sectional view of a semiconductor device shown in a fifth embodiment.

Claims (5)

[Claims] 1. A semiconductor device having a ceramic substrate on which a semiconductor element is mounted and a metal supporting plate supporting the ceramic substrate, wherein the ceramic substrate and the metal supporting plate are disposed between the semiconductor device and the ceramic substrate. A semiconductor device comprising a carbon fiber reinforced carbon composite material disposed on at least one of them. 2. A semiconductor device comprising a carbon fiber reinforced composite material disposed between a semiconductor element and a metal support plate. 3. A semiconductor device, wherein a metallization layer for bonding is formed on the surface of the carbon fiber reinforced composite material according to claim 1 or 2. 4. A semiconductor device having a ceramic substrate on which a semiconductor device is mounted and a metal supporting plate for supporting the semiconductor substrate, wherein the ceramic substrate and the metal supporting plate are disposed between the semiconductor element and the ceramic substrate. A semiconductor device, characterized in that the carbon fibers of the carbon fiber reinforced carbon composite material arranged in at least one of them are arranged so that the orientation direction of the carbon fibers is perpendicular to the joint surface. 5. The carbon fiber reinforced carbon composite material as claimed in claim 1, wherein the surface of the carbon fiber reinforced carbon composite material is covered with a glassy carbon film or a metal film. Semiconductor device.