JP2000313904A - Composite material, its manufacture and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite material having high thermal conductivity, a low coefficient of thermal expansion, and high plastic workability, and its manufacturing method. SOLUTION: The composite material contains a metal and particles of an inorganic compound having a smaller coefficient of thermal expansion than the metal. Plastic working is carried out simultaneously with sintering. Moreover, >=95% or <=50% of the whole compound particles are in an indefinate form where a plurality of particles are joined together. The composite material can be manufactured by feeding a powder mixture between heating rolls 2 and applying shaping and heating to it continuously or simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material having low thermal expansion and high thermal conductivity, its use, and a method for producing the same.

[0002]

2. Description of the Related Art Power electronics is a technology related to the conversion and control of power and energy by an electronic device, in particular, a power electronic device used in an on / off mode and a power conversion system as an application technology thereof.

[0003] For power conversion, power semiconductor devices having various on / off functions are used. This semiconductor device includes a rectifier diode having a built-in pn junction and having conductivity in only one direction, and a thyristor, a bipolar transistor,
MOSFETs and the like have been put to practical use, and furthermore, insulated gate bipolar transistors (IGBTs) and gate turn-off thyristors (GTOs) having a turn-off function by a gate signal have been developed.

[0004] These power semiconductor elements generate heat when energized, and the amount of heat generated tends to increase as their capacity and speed increase. In order to prevent the deterioration of the characteristics of the semiconductor element and the shortening of the service life due to the heat generation, it is necessary to provide a heat radiating section to suppress the temperature rise in the semiconductor element and its vicinity. Copper is generally used as a heat dissipating member because it has a large thermal conductivity of 393 W / m · K and is inexpensive. However, since the heat radiation member of the semiconductor device including the power semiconductor element is bonded to Si having a coefficient of thermal expansion of 4.2 × 10 ⁻⁶ / ° C., a heat radiation member having a coefficient of thermal expansion close to this is desired. Copper has a large coefficient of thermal expansion of 17 × 10 ⁻⁶ / ° C., and thus has poor solder jointability with a semiconductor element. It is provided between heat dissipating members.

On the other hand, integrated circuits (ICs) in which electronic circuits are integrated on one semiconductor chip are classified into memories, logics, microprocessors, and the like according to their functions.
Here, the power semiconductor element is called an electronic semiconductor element. The degree of integration and the operation speed of these semiconductor elements have been increasing year by year, and accordingly, the amount of heat generated has also increased. by the way,
In general, an electronic semiconductor element is housed in a package for the purpose of shutting it off from the outside air and preventing failure and deterioration.
Many of these are a ceramic package in which a semiconductor element is die-bonded to ceramics and sealed, and a plastic package in which the semiconductor element is sealed with resin.
Also, in order to support high reliability and high speed, a multi-chip module (MCM) in which a plurality of semiconductor devices are mounted on one substrate is also manufactured.

The plastic package has a structure in which a lead frame and terminals of a semiconductor element are connected by a bonding wire, and this is sealed with a resin. In recent years, with an increase in the amount of heat generated by a semiconductor element, a package in which a lead frame has heat dissipation properties and a package in which a heat dissipation plate for heat dissipation is mounted have appeared. For heat dissipation, a copper-based lead frame or a heat radiating plate having a large thermal conductivity is often used, but there is a concern about a problem due to a difference in thermal expansion from Si.

On the other hand, the ceramic package has a structure in which a semiconductor element is mounted on a ceramic substrate on which wiring is printed, and is sealed with a metal or ceramic cap. Furthermore, Cu-Mo or Cu
-W composite material or Kovar alloy is joined,
Although it is used as a heat radiating plate, each material is required to have low thermal expansion or high thermal conductivity as well as improved workability and low cost.

The MCM has a structure in which a plurality of semiconductor elements are mounted on a thin film wiring formed on a substrate made of Si, metal, or ceramics by a bare chip, placed in a ceramics package, and sealed with a lid. When heat dissipation is required, a heat sink or a heat dissipation fin is installed on the package. Copper or aluminum is used as a metal substrate material, which has the advantage of high thermal conductivity, but has a large coefficient of thermal expansion and poor compatibility with semiconductor elements. For this reason, Si or aluminum nitride (AlN) is used for the substrate of the highly reliable MCM. Further, since the heat radiating plate is bonded to the ceramic package, a material having good compatibility with the package material in terms of the coefficient of thermal expansion and having a large thermal conductivity is desired.

As described above, any semiconductor device on which a semiconductor element is mounted generates heat during its operation, and if the heat is stored, the function of the semiconductor element may be impaired. Therefore, a heat radiating plate having excellent thermal conductivity for dissipating generated heat to the outside is required. Since the heat sink is bonded to the semiconductor element directly or via an insulating layer, the heat sink needs to have not only thermal conductivity but also consistency with the semiconductor element in terms of thermal expansion.

[0010]

The semiconductor devices currently used are mainly Si and GaAs. The coefficients of thermal expansion of these are 2.6 × 10 ^{−6 to} 3.6 × 10 ⁻⁶ /
° C, 5.7 × 10 ^{-6 to} 6.9 × 10 ^-6 / ° C. A heat sink material having a thermal expansion coefficient close to these is conventionally made of Al
N, SiC, Mo, W, Cu-W, etc. are known,
Since these are a single material, it is difficult to arbitrarily control the heat transfer coefficient and the thermal conductivity, and there is a problem that workability is poor and cost is high. JP Hei 8
-78578 discloses a Cu-Mo sintered alloy,
No. 20 discloses a Cu-W-Ni sintered alloy,
No. 58 discloses a Cu-SiC sintered alloy,
In this publication, Al-SiC is proposed. These conventionally known composite materials can control the heat transfer coefficient and the thermal conductivity over a wide range by changing the ratio of both components, but have low plastic workability, it is difficult to manufacture a thin plate, and the number of production steps is large. It becomes.

An object of the present invention is to provide a composite material having low thermal expansion, high thermal conductivity, and excellent plastic workability, a use thereof, and a production method thereof.

[0012]

The present invention comprises a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, and is plastically worked at the same time as sintering. % Or more and 50% or less, a plurality of particles are dispersed as a continuous mass, the compound particles are present alone, and 100 or less within 100 μm square, and the remaining compound particles are plural. And the compound particles are dispersed in the form of a mass of a complex shape connected to each other, and the compound particles include 10 or less masses in which a plurality of particles are connected within a 100 μm square, and the rest are dispersed as single particles. The compound particles have a Vickers hardness of 300.
The thermal expansion coefficient at 20 ° C. to 300 ° C. is 5 × 10 ^{−6 to} 17 × 10 ⁻⁶ / ° C., and the thermal conductivity is 270.
３375 W / m · K and conductivity of 60-85%
It is characterized in that the compound particles are IACS, and that at least 10% of the compound particles are connected to each other and dispersed as a lump, and the lump is plastically processed and extends in the processing direction. Composite materials.

According to the present invention, there is provided a complex mass comprising copper and copper oxide particles, wherein the copper oxide particles are subjected to plastic working at the same time as sintering, and 95% or more or 10% or less of the whole of the particles are connected to each other. And is dispersed.

According to the present invention, copper (I) oxide (Cu ₂ O)
Of copper (Cu) alloy containing 80% by volume, the Cu ₂ O
Phase and Cu phase each have a dispersed structure, from room temperature
The coefficient of thermal expansion at 300 ° C. is 5 × 10 ^{-6 to} 14 × 10 ^-6
/ C and a thermal conductivity of 30 to 325 W / mK.

The present invention preferably has a density of 93% or more of the true density.

The present invention is a method for producing a composite material having a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, characterized in that molding and heating are performed continuously or simultaneously.

The present invention is a method for producing a composite material having a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, wherein a mixture of the metal particles and the inorganic compound particles is heated to a predetermined temperature. It is supplied to a rolling roll and is continuously or simultaneously formed and heated.

According to the present invention, the surface temperature of the rolling roll is set to 800
℃ or more, molding and heating are performed continuously or simultaneously, and the produced composite material of copper and copper oxide has a true density of 93%.
% Is a method for producing a composite material having a density of not less than%.

According to the present invention, in the above-described method for producing a composite material, at least a region to be formed and heated is a reduced-pressure atmosphere or an inert gas atmosphere.

In the composite material according to the present invention, Au, Ag, Cu, Al having high electric conductivity is used as a metal.
u is most excellent in that it has a high melting point and high strength. An inorganic compound as a stable conventional SiC with different extreme hardness relative to the base of the metal as described above, after sintering at a relatively soft particles rather than compounds such as Al ₂ O _3, 20 to 150
The average coefficient of thermal expansion in the range of ° C. is preferably 5.0 × 10
^-6 / ° C. or lower, more preferably 3.5 × 10 ^-6 / ° C. or lower, and a Vickers hardness of 300 or lower are preferable.
By using soft inorganic compound particles in this way, high plastic workability by hot and cold after sintering can be obtained. A very thin plate can be obtained. And since the composite material has the inorganic particles dispersed therein, high strength can be obtained. Copper oxide, tin oxide, lead oxide, nickel oxide and the like can be considered as the inorganic compound particles. However, soft copper oxide having the smallest coefficient of thermal expansion is particularly preferable.

Further, the composite material of the present invention is made of SiC, Al ₂
It is preferable to contain 5% by volume or less of fine ceramic particles having a Vickers hardness of 1000 or more and a hard average particle size of 3 μm or less, such as O ₃ , to further strengthen them.

Particularly, as the composite material according to the present invention, copper (Cu) containing 20 to 80% by volume of cuprous oxide (Cu ₂ O) is used.
The alloy has a structure in which the Cu ₂ O phase and the Cu phase are respectively dispersed, and has a coefficient of thermal expansion from room temperature to 300 ° C. of 5 × 10 ^{−6 to} 14 × 10 ⁻⁶ / ° C. and a thermal conductivity of 30 to 30 ° C.
It is preferably 325 W / m · K.

The copper-copper oxide composite material contains 5 to 80% by volume of cuprous oxide (Cu ₂ O), and the remainder is copper (C
u), having a structure in which the Cu ₂ O phase and the Cu phase are oriented, and having a coefficient of thermal expansion from room temperature to 300 ° C. of 5 × 10 ^−6.
１４14 × 10 ⁻⁶ / ° C. and a thermal conductivity of 30 to 32.
It is preferable that the thermal conductivity is 5 W / m · K and the thermal conductivity in the orientation direction is twice or more that in the direction perpendicular to the orientation direction.

As a method for producing a composite material according to the present invention,
Press molding a mixed powder having copper dioxide (CuO) as an example of the above-mentioned inorganic compound particles and copper (Cu) powder as an example of a metal;
C. and a step of cold or hot plastic working are considered. In the present invention, in order to further improve the thermal conductivity of the composite material, copper dioxide (CuO) is used. ) Is characterized in that the molding and heating of a mixed powder containing powder and copper (Cu) powder are performed continuously or simultaneously. According to this method, a better copper network is formed as compared with a composite material manufactured by a general powder metallurgy method, and the thermal conductivity can be improved while maintaining the thermal expansion coefficient. Further, it is preferable to further include a step of performing plastic working by cold or hot pressing and a subsequent annealing step.

The copper composite material according to the present invention is 17.6 × 1
Cu having a thermal expansion coefficient of 0 ^-6 / ° C and a high thermal conductivity of 391 W / m · K, a thermal conductivity of 12 W / m · K and 2.7
This is a composite material of Cu ₂ O having a low coefficient of thermal expansion of × 10 ⁻⁶ / ° C., and has a sintered body composition of Cu-20 to 80% by volume Cu ₂ O applied to a heat sink of a semiconductor device. It is selected in the composition range, has a coefficient of thermal expansion from room temperature to 300 ° C. of 5 × 10 ^{−6 to} 14 × 10 ⁻⁶ / ° C., and has a thermal conductivity of 3
0 to 325 W / m · K.

When the content of Cu ₂ O is 20% or more, the thermal expansion coefficient required for the heat sink is obtained, and when the content is 80% by volume or less, sufficient thermal conductivity and strength as a structure are obtained.

The mixing of the raw material powder is performed by a V mixer, a pot mill, a mechanical alloying or the like.
Since the particle size of the raw material powder affects the press formability and the dispersibility of Cu ₂ O after sintering, the particle size of Cu powder is 100 μm or less, and the particle size of Cu ₂ O and CuO powder is 10 μm or less, particularly 1-2 μm. Is preferred. The inside of the container for continuously supplying the powder is preferably kept in a reduced pressure atmosphere or a vacuum for the purpose of enhancing the sinterability thereafter.

Next, the mixed powder is press-formed between the rolling rolls and fired at the same time. At this time, the pressing must be performed under the condition that the density of the composite material is 93% or more of the true density, and the condition varies depending on the roll temperature and the roll rotation speed. It is also desirable to increase the inter-roll pressure as the Cu ₂ O content increases.

The heating of the mixed powder compact is preferably performed in a reduced pressure atmosphere or an inert gas atmosphere, and particularly preferably in a vacuum of 1 Torr or less from the viewpoint of gas generation. Heating is performed using a roll whose surface temperature is maintained at 800 ° C. or higher. The surface temperature is preferably from 800 ° C. to 1100 ° C., and the temperature increases as the Cu ₂ O content increases.
Although the surface temperature varies depending on the base metal, in particular, Cu
At 800 ° C. or lower, a sintered body having a high density cannot be obtained. At 1100 ° C. or higher, there is a risk of partial melting due to the eutectic reaction between Cu and Cu ₂ O.
00 ° C to 1000 ° C is preferred.

The copper composite material of the present invention has a low hardness of Cu and Cu ₂ O, and has a high ductility, so that it can be subjected to cold or hot working such as rolling and forging, and becomes necessary after sintering. Will be applied accordingly. By imparting the processing, the material exhibits heat conduction anisotropy, but it is effective for applications requiring strength improvement and heat transfer in a certain direction.

In the present invention, CuO is used as a raw material powder, mixed with Cu powder and press-molded, and then sintered in a sintering process.
By internally oxidizing u, a sintered body having a structure in which a Cu phase and a Cu ₂ O phase are dispersed can be finally obtained. That is, when CuO coexists with Cu, it utilizes the fact that it is more thermally stable to transform to Cu ₂ O at high temperature according to the equation (1).

2Cu + CuO → Cu + Cu ₂ O (1) The particle size of Cu ₂ O in the sintered body is preferably fine because it affects density, strength or plastic workability. However, the particle size is strongly affected by the method of mixing the powders, and the larger the mixing energy, the less the agglomeration between the powders, and a fine Cu ₂ O phase is obtained after sintering.

In the present invention, in a V mixer having a small mixing energy, the Cu ₂ O phase has a particle size of 50 to 200 μm in 50% by volume or less of the Cu ₂ O phase and the remaining 50 μm or less,
50 μm or less in a pot mill containing steel balls,
For mechanical alloying having the largest mixing energy, the diameter is specified to be 10 μm or less. Particle size 200μm
Above, the porosity greatly increases, and plastic working becomes difficult. When the porosity is 50% by volume or more of the Cu ₂ O phase, the thermal conductivity decreases and the variation in characteristics increases, and the heat dissipation of the semiconductor device is caused. Unsuitable for board. More preferred tissue is 50 μm
This is a structure in which the following Cu ₂ O phase is uniformly dispersed with the Cu phase.
Although the particle size of Cu ₂ O is extremely irregular, since the particles before sintering are continuous, the particle size before sintering can be seen by looking at a higher magnification. The Cu ₂ O phase is preferably 10 μm or less.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Example 1) As a raw material powder, 75
An electrolytic Cu powder of μm or less and a Cu ₂ O powder having a purity of 3N and a particle size of 1 to ₂ μm were used. Table 1 shows Cu powder and Cu ₂ O powder.
After mixing 5 kg in the ratio shown in the above, the mixture was mixed in a dry pot mill containing steel balls for 10 hours or more. FIG. 1 schematically shows a rolling sintering apparatus. The powder is put in a powder container 1 and supplied to a heating roll 2. Heating roll 2 is power supply 3
The surface temperature is continuously measured by the non-contact type temperature measuring device 4. Also, a roll 5 is provided downstream of the heating roll. These are housed in the chamber 6 and the atmosphere can be controlled. The rolling heating conditions used in this example were as follows: roll diameter: 300 mm, roll width: 200 mm, degree of vacuum: 0.005 To.
rr. The roll rotation peripheral speed, load, and roll surface temperature are each 3 to 0.5 mm depending on the Cu ₂ O content.
/ S, 100 to 500 kN, and a predetermined value in the range of 900 to 1050 ° C. Then, it was subjected to chemical analysis, microstructure observation, measurement of thermal expansion coefficient, thermal conductivity and Vickers hardness. The coefficient of thermal expansion is TMA in the temperature range from room temperature to 300 ° C.
(Thermal Mechanical Analysis) The thermal conductivity was measured by a laser flash method. The results are shown in Table 1. As a result of chemical analysis, the composition of the sintered body was consistent with the composition. Further, as is clear from Table 1, the thermal expansion coefficient and the thermal conductivity are varied over a wide range by adjusting the composition ratio of Cu and Cu ₂ O. I found that I could control it.

On the other hand, Cu ₂ O aggregates in the mixing step,
Although it grew and grew in the heating step, it had a dense structure in which the Cu phase and the Cu ₂ O phase were uniformly dispersed. In addition, in the composite materials of any mixing ratio, the Cu phase had an irregular shape in which 50% or more of the entire area thereof was continuous in cross-sectional area ratio.

As a result of the hardness measurement, the Cu phase was Hv75-8.
0, Cu ₂ O had a hardness of Hv 210 to 230. In addition, as a result of evaluating the machinability by lathe and drill processing,
It was found that the workability was very good, and that the shape was easily imparted.

[0037]

[Table 1]

The microstructure was 95% for all samples.
% Or more of Cu ₂ O particles were formed as an unexpectedly complicated mass formed by connecting a plurality of Cu ₂ O particles, and were arranged in the direction extended by the roll.

Comparative Example 1 As raw material powder, electrolytic Cu powder having a particle size of 75 μm or less and Cu ₂ O having a purity of 3N and a particle size of 1 to ₂ μm were used.
Powder was used. After mixing 1400 g of Cu powder and Cu ₂ O powder in the ratio shown in Table 2, they were mixed for 10 hours or more in a dry pot mill containing steel balls. The mixed powder was poured into a mold having a diameter of 150 mm and cold-pressed at a pressure of 400 to 1000 kg / cm ² depending on the content of Cu ₂ O to obtain a preform having a diameter of 150 mm and a height of 17 to 19 mm. Thereafter, the preform was sintered in an argon gas atmosphere and subjected to chemical analysis, structure observation, measurement of thermal expansion coefficient, and measurement of thermal conductivity. The sintering temperature is 9 depending on the Cu ₂ O content.
The temperature was changed between 00 ° C. and 1000 ° C., and each temperature was maintained for 3 hours. The coefficient of thermal expansion is T at room temperature to 300 ° C.
The measurement was performed using a MA (Thermal Mechanical Analysis) device, and the thermal conductivity was measured by a laser flash method.
The results are shown in Table 2.

As a result of chemical analysis, the composition of the sintered body was consistent with the composition. Table 2 shows the thermal expansion coefficient and thermal conductivity.
As is clear, it was found that by adjusting the composition ratio of Cu and Cu ₂ O, the composition varied over a wide range, and it was possible to control the thermal characteristics required for the heat sink.

[0041]

[Table 2]

On the other hand, Cu ₂ O aggregates in the mixing step,
It grows enlarged in the sintering process, but has a particle size of 50 μm or less, and has a dense structure in which a Cu phase and a Cu ₂ O phase are uniformly dispersed. It is apparent that Cu ₂ O particles are dispersed as irregularly shaped masses in which 99% or more of the entire cross-sectional area ratio is continuous. As a result of evaluating the machinability with a lathe and a drill, it was found that the machinability was very good and the shape was easily imparted.

From the comparison between Table 1 and Table 2, even if the copper-copper oxide composite material has the same composition, the composite material manufactured in Example 1 of the present invention is more suitable for the powder metallurgy method in Comparative Example 1. Thermal conductivity was better than composite material.

(Example 2) Electrolytic Cu powder having a particle size of 74 µm or less and CuO powder having a purity of 3N and a particle size of 1 to 2 µm were used as raw material powders. After mixing 1400 g of Cu powder and CuO powder at the ratio shown in Table 3, they were mixed in a dry pot mill containing steel balls for 10 hours or more. Using a rolling sintering apparatus shown in FIG. 1, a roll diameter: 300 mm and a roll width: 2
The rolling was carried out under the conditions of 00 mm and a degree of vacuum of 0.005 Torr. Roll rotation speed, load and roll surface temperature are C
3 to 0.5 mm / s, 100 depending on the uO content.
５００500 kN, and a predetermined value in the range of 900 to 1050 ° C. Then, it was subjected to X-ray diffraction, structure observation, measurement of thermal expansion coefficient, and measurement of thermal conductivity. Thermal expansion coefficient from room temperature to 30
In the temperature range of 0 ° C, TMA (Thermal Mechanical Analysi
s) Using a device, the thermal conductivity was measured by a laser flash method. The results are shown in Table 3.

[0045] The sintered body, the result of the identification of the oxide by X-ray diffraction, diffraction peaks of the detected cuprates are only Cu ₂ O, transformation from CuO during sintering to Cu ₂ O Was confirmed to have been completed.

The composite material manufactured in this embodiment is the same as that in the first embodiment.
Of the same composition as that of Cu ₂ O
Phase consists of Cu ₂ O to Cu ₂ O and CuO produced by the oxidation reaction of Cu and CuO is produced by decomposition. C
The u ₂ O particles and Cu network are the same as in Example 1.

On the other hand, as is apparent from Table 3, the coefficient of thermal expansion is not significantly different from that of Example 1 in which Cu ₂ O powder is used as the raw material, but the thermal conductivity is CuO as the raw material. Is better when the content of CuO, that is, the content of Cu ₂ O is 50% by volume.
Above, there is a tendency to increase. This is because the density of the sintered body is higher when CuO is used as the raw powder.

[0048]

[Table 3]

Example 3 Electrolytic Cu powder having a particle size of 75 μm or less and Cu ₂ O powder having a particle size of 1 to ₂ μm were used as raw material powders. Cu powder and Cu ₂ O powder were mixed in a ratio of 140 as shown in Table 4.
After mixing 0 g, the mixture was mixed in a dry pot mill containing steel balls for 10 hours or more. The mixed powder was placed in the powder container 1 in the same manner as in Example 1, and was rolled at a high temperature simultaneously with sintering by a heated roll. Thermal expansion coefficient is TMA (Thermal Mechanic) in the temperature range from room temperature to 300 ° C.
al Analysis) device, the thermal conductivity was measured using a laser flash method, and the conductivity was measured using a sigma tester.
The results are shown in Table 4. As a result of chemical analysis, the composition of the sintered body was consistent with the composition. The thermal expansion coefficient, thermal conductivity, and electrical conductivity are, as apparent from Table 4, Cu and C
By adjusting the composition ratio of u ₂ O, the composition changed over a wide range, and it was found that the thermal characteristics required for the heat sink could be controlled.

[0050]

[Table 4]

On the other hand, the microstructure of No. 23 is Cu ₂ O
Are grown in the aggregating and sintering steps in the mixing step, but have a particle size of 50 μm or less, and have a dense structure in which Cu phase and Cu ₂ O phase are uniformly dispersed. The white part in the photograph is the Cu phase, and the black part is the Cu ₂ O phase.
Most of the Cu ₂ O particles have a particle size of 10 μm or less,
More than that, a plurality of Cu ₂ O particles are connected,
% By volume. The Cu ₂ O was oriented in the rolling direction. As a result of the hardness measurement, the Cu phase was Hv 75 to 80,
Cu ₂ O had a hardness of Hv 210 to 230. Also,
As a result of evaluating the machinability with a lathe and a drill, it was found that the machinability was very good and the shape was easily imparted.

[0052] The copper composite material (Example 4) The present invention, among the power semiconductor element, IGBT (I nsulated G ate B ipolar
T ransistor; hereinafter abbreviated as IGBT) described an embodiment applied to the heat radiating plate (base plate) of the modules.

FIG. 2 is a plan view of the inside of the module in the case of 24 IGBT elements, and FIG. 3 is a sectional view of the module in the case of one IGBT. Four IGBT elements 101 and two diode elements 102 are connected by solder 201 to an AlN substrate 103 in which copper foils 202 and 203 are joined to an AlN plate 204 with a silver brazing material (not shown). AlN substrate 1
03, an emitter wiring 104 and a collector wiring 105,
The region of the gate wiring 106 is formed, and the IGBT element 101 and the diode element 102
Soldered to five areas. From each element, a metal wire 1
07 is connected to the emitter wiring 104. Also,
A resistance element 108 is arranged on the gate wiring 106 region, and is connected to the resistance element 108 by a metal wire 107 from a gate pad of the IGBT element 101 which is a semiconductor element. Six AlN substrates 103 on which semiconductor elements are mounted
Is connected to the heat radiating plate 109 made of a Cu—Cu ₂ O composite material whose entire surface is plated with Ni according to the present invention described in the first and second embodiments by the solder 205. The terminals 206 and the AlN substrate 103 of the case block 208 in which the terminals 206 and the resin case 207 are integrated
09 for wiring. Also, the case 207 and the heat sink 1
09 are connected by a silicone rubber adhesive 210. The terminals from the case block 208 have the main terminals
On the 1N substrate 103, the emitter terminal connection position 110, the emitter sense terminal connection position 111, and the collector connection terminal position 1
12 are connected at two locations and the gate terminal connection position 113 is connected at one location. Next, a case lid 21 having a resin injection port is provided.
1 to cover the entire surface of the terminal.
Is injected, and then a thermosetting epoxy resin 213 is injected over the entire surface to complete the module.

The heat radiating plate 109 is supported by eight supporting holes made of Al through eight bolt holes 114. The bolt holes 114 are drilled by machining. Furthermore, the case
Reference numeral 207 denotes the other two bolts which are connected by the adhesive 210, and is connected through the bolt holes 115.

[0055] Table a base material generally used in 5, Cu-30% by volume Cu-Cu ₂ O alloy material of the present invention Cu ₂
The thermal expansion coefficient and thermal conductivity of O 2 are shown. A semiconductor device using a Cu—Cu ₂ O-based material is a commonly used C element.
lower thermal expansion coefficient than u-based module,
The reliability of the solder 209 connecting the 1N substrate 103 and the heat sink 109 can be improved. On the other hand, Mo or Al—SiC base used for improving the reliability of the solder 106 under severe use environment is Cu—Cu ₂ O
Although the coefficient of thermal expansion is smaller than that of the semiconductor element using the base, the thermal conductivity is small, and there is a problem that the thermal resistance of the module increases. The module with Cu-Cu ₂ O base of the present embodiment, reliability (thermal fatigue test life) 5 times compared with the Cu-based, thermal resistance at the module of the same base thickness, as compared with Mo-based 0.8 It can be less than double.

[0056]

[Table 5]

With these effects, it is possible to expand the range of selection of the module structure and other members. For example, in the embodiment shown in FIG. 2, the Cu—Cu ₂ O alloy base material has a higher thermal conductivity than the Mo base material, in other words, the heat spreadability is improved. This has the effect of suppressing the temperature difference of the semiconductor module to a small value, and the semiconductor element is about 1.2 times larger than the conventional module. As a result, in order to secure the same amount of current in the conventional device, the structure using 30 IGBTs can be designed with 24, and the module size can be reduced. Further, it becomes possible to use an alumina substrate having a thermal conductivity smaller than that of AlN by about 20% as the insulating substrate. Alumina has higher bending strength than AlN, and can increase the substrate size. Further, since the alumina plate has a larger thermal expansion coefficient than the AlN plate and can reduce the difference in thermal expansion from the base material, the warpage of the module itself can be reduced. By using an alumina substrate, the allowable size of the substrate can be increased, so that the number of semiconductor elements that can be mounted on one substrate can be increased. That is, it is possible to reduce an area for securing insulation and an area between substrates, which are indispensable for each insulating plate, and it is possible to reduce a module size.

FIG. 4 is a schematic diagram showing a module manufacturing process according to this embodiment. (a) The heat radiating plate 109 made of Cu—Cu ₂ O is received with its surface plated with Ni and almost flat. (B) shows an AlN substrate 103 in which an IGBT element 101 composed of a semiconductor element is joined by soldering,
05. At this time, since the thermal expansion coefficient of the heat radiating plate 109 is larger than the composite of the semiconductor element and the AlN substrate, the back surface of the module warps in a concave shape during the cooling of the solder.
(C) In the process of assembling the case block 208 with a thermosetting adhesive, the coefficient of thermal expansion of the case is larger than that of the composite body 301 after the soldering is completed, so that the module back surface becomes almost flat during the cooling of the adhesive. (D) When the inside of the module is filled with the silicone gel 212 and the thermosetting epoxy resin 213, the resin has a large coefficient of thermal expansion, and the back surface of the module is warped in a convex shape.

FIG. 5 shows the measured results of the amount of back surface warpage in each step. When the deformation amount is positive, the back surface is concave, and when the deformation amount is negative, the back surface is convex. When the Cu—Cu ₂ O base of the present invention is used, the amount of warpage can be suppressed to about ３ as compared with a module using a conventional Mo base. Although the results for the Cu base are not shown, the difference in expansion coefficient from the AlN substrate is large, and in the step (b), the amount of warpage is large in the direction in which the back surface is concave.
Warpage of 00 μm or more occurs. Cu-Cu _{2 of the} present invention
With the O base, the amount of warpage of the module can be reduced, so that the module can be made larger. Also, since the amount of change in the warpage due to the temperature change during the actual operation of the module is small, as in the amount of warpage in the assembly process, it is possible to suppress the grease applied to the space between the module and the cooling fins.

FIG. 6 shows an embodiment of a power converter to which the module of the present invention is applied. Power semiconductor device 501
Is a heat dissipating grease 51 on an aluminum heat sink 511.
0 is mounted by tightening bolts 512
The example which comprised the level inverter is shown. In general, a power semiconductor device 501 composed of a module has an intermediate point (B
(Point) is mounted by inverting left and right so that it can be wired with one intermediate point wiring 503. The collector-side wiring 502 and the emitter-side wiring 504 supply the power supply voltage 509 by wiring the U, V, and W phases, respectively. The signal line is composed of a power semiconductor device 501 including each IGBT module to a gate wiring 505, an auxiliary emitter wiring 506, and a collector auxiliary wiring 507. 508 is a load.

FIG. 7 shows the amount of warpage of the module and FIG. 8 shows the amount of warpage (grease thickness) on the back surface of the module before and after fastening when the module is mounted.
(b) is a conventional method. Conventionally known Al-S
In the case of an iC-based module, the amount of protrusion on the back surface is about 100
μm, but when the module is coated with grease and tightened, the module is pressed by the grease during tightening and deforms, and conversely, the back side of the module deforms into a concave state, the grease thickness at the center increases, Resistance increases. On the other hand, in the case of the Cu—Cu ₂ O base of the present invention, the initial back surface warpage amount is about 50 μm, but the rigidity of the base material is large. Grease thickness was suppressed to about 50 μm, which was halved compared to the conventional Al-SiC base. Further, the variation of the grease thickness in the module can be reduced. Implementation of grease pushed deformation problem, a problem which naturally also occurs when implementing the rigidity of small Cu base module than Cu-Cu ₂ O alloy, measures in Cu-Cu ₂ O alloy of the present invention. As shown in the figure, the Cu—Cu ₂ O alloy base of the present invention can reduce the thermal resistance and the contact thermal resistance as compared with the base material such as Mo or Al—SiC used in the conventional high reliability module. Explained what you can do. Thereby,
As shown in FIG. 6, the module could be mounted in a fine state. Furthermore, since the cooling efficiency of the cooling fins can be reduced, the mounting area and volume of the power converter can be reduced. Also, because the grease thickness can be reduced,
Since the allowable range of the flatness of the cooling fins can be set large, it is also possible to assemble the power converter with large fins. Further, an auxiliary cooling function such as forced air cooling can be eliminated, and in this respect, the size and noise can be reduced.

(Example 5) The copper composite material of the present invention described in Examples 1 and 2 was used as a radiator plate for the IC shown in FIGS.
Was applied to a plastic package equipped with. FIG. 9 shows a heat sink built-in type, and FIG. 10 shows a heat sink exposed type.

The heat radiation plate has a thermal expansion coefficient of 9 × 1 from room temperature to 300 ° C. in consideration of the thermal expansion coefficient of the mold resin.
Cu-2 so as to be in the range of 0 ^{-6 to} 14 × 10 ^-6 / ° C.
It was prepared by changing the composition within the range of 0 to 55% by volume Cu ₂ O, and subjected to machining and Ni plating.

FIG. 9 illustrates the package structure. The lead frame 31 is provided with a Ni-plated heat sink 3 made of the copper composite material of the present invention via an insulating polyimide tape 32.
3 is adhered. The IC 34 is joined to the heat sink 33 by soldering. Also, the Al wire on the IC is connected to the Au wire 35.
The electrode and the lead frame are connected. These are, except for a part of the lead frame, a molding resin 36 mainly composed of an epoxy resin, a silica filler, and a curing agent.
It is sealed with. The heatsink-exposed package shown in FIG. 10 differs from FIG. 9 in that the heatsink 33 is exposed outside the mold resin.

With respect to the package mounted as described above, the presence or absence of warping and cracks at the joint between the heat sink and the mold resin was observed. As a result, if the difference in thermal expansion between the mold resin and the heat radiating plate is 0.5 × 10 ⁻⁶ / ° C. or less, there is no problem, and the composition is Cu-5 to 40% by volume Cu ₂ O.
However, the thermal conductivity was as high as 200 W / m · K, which was suitable.

(Embodiment 6) FIGS. 11 and 12 are sectional views of a ceramic package on which an IC is mounted using the copper composite material of the present invention described in Embodiments 1 and 2 as a heat sink. First, FIG. 11 will be described. The IC 41 is joined to a radiator plate 42 plated with Ni using a polyimide resin. Further, the heat sink 42 and the package 43 made of Al ₂ O ₃ are joined by solder. C in the package
u, and a pin 44 is provided for connection to a wiring board. The Al electrode on the IC and the wiring of the package are connected by an Al wire 45. To seal them, a weld ring 46 made of Kovar was joined to the package with Ag solder, and the weld ring and a lid 47 made of Kovar were welded using a roller electrode. FIG. 12 shows a package in which a radiation fin 48 is connected to the ceramic package of FIG. (Embodiment 7) FIGS. 13 and 14 show TAB (Tape Automated).
(ated bonding) technology and a package using the copper composite material of the present invention described in Examples 1 and 2 for a heat sink will be described.

First, the package shown in FIG. 13 will be described. The IC 51 is joined to a heat-radiating plate 53 according to the present invention, which is plated with Ni, via a heat conductive resin 52. Au bumps 54 are formed on the terminals of the IC and are connected to the TAB 55. The TAB is connected to the lead frame 57 via the thin film wiring 56. The IC is formed by inserting a silicon rubber 58 into a ceramic substrate 59 made of Al ₂ O ₃ .
It is sealed with a frame 60 and a sealing glass 61.

FIG. 14 shows a package sealed with a resin. The IC 65 is joined with the Ni-plated heat radiating plate 67 of the present invention by the Au-Si alloy 66, and further, the copper ground plate 69 and the Ni-plated heat radiating plate of the present invention are plated with the heat conductive resin 68. 70.
On the other hand, the terminals of the IC are connected to the TAB 72 by the Au bumps 71 and are sealed by the resin 73. Here, the lead frame 57 and a part of the heat sink are exposed outside the sealing resin. TAB is an epoxy-based Ag paste 7
4 is fixed to the copper ground plate.

(Embodiment 8) FIG. 15 shows an embodiment of an MCM in which the copper composite material of the present invention described in Embodiments 1 and 2 is applied to a heat sink. The radiator plate 83 is a sintered body or one obtained by rolling the sintered body and pressing it into a predetermined shape.

The IC 81 uses an Au wire 82 to
The thin film wiring 84 formed on the plated heat sink 83 according to the present invention is connected to the thin film wiring 84, and further, the AlN is connected with an Au wire.
Are connected to the wiring formed on a package 85 made of the same and are taken out as external terminals 86. The IC section
A preform 88 made of Au-Sn is inserted between the lid 87 made of 42 alloy and the W metallized layer of the package to be joined and sealed.

(Embodiment 9) FIG. 16 is a sectional view of an electrostatic chuck using the composite material of the present invention for an electrode plate.

As shown in FIG.
It can be used as a chuck of a sputtering apparatus for processing a workpiece 90 made of a conductor or a semiconductor in a reduced-pressure atmosphere inside a vacuum processing chamber 95. When a voltage (approximately 500 V) from the DC power supply 91 is applied to the electrode 94 of the present electrostatic attraction device, an electrostatic attraction force is generated between the dielectric plate 92 and the workpiece 90, so that the dielectric plate 92 Workpiece 90 on the surface
Can be adsorbed. The composite material described in Examples 1 to 5 was used for the electrode plate used in this example.

Now, in actual sputtering,
After attaching the workpiece 90 to the electrostatic chuck, the exhaust pump connected to the gas exhaust port 97 is driven,
Evacuation is performed until the internal pressure of the vacuum processing chamber 95 becomes about 1 × 10 ⁻³ Pa. Thereafter, by opening a valve attached to the gas inlet 96, the vacuum processing chamber 95 is opened.
A reaction gas (argon gas or the like) is introduced at about 10 SCCM. At this time, the internal pressure of the vacuum processing chamber 95 is 2
It is about × 10 ^-2 Pa.

Thereafter, a high-frequency power of about 4 kW (13.56 MHz) is supplied from the high-frequency power supply 13 of the electrode 94 of the present electrostatic chuck.
z), the electrodes 9 of the electrostatic chuck
A plasma is generated between the electrode 4 and another electrode (not shown). The VDC and VPP of the high frequency applied voltage in this case are
2 kV and 4 kV. In addition, the electrode 9 of the present electrostatic suction device
A matching box 98 inserted between the power supply 4 and the high frequency power supply 93 is for impedance matching with the vacuum processing chamber 95 so that high frequency power is efficiently supplied to the plasma.

As a result of actually using this sputtering apparatus, the temperature of the workpiece 90 reached about 450 ° C. during the processing. No cracks were found.
This means that the use of the present electrostatic suction device is useful for improving the reliability of processing.

In addition to the sputtering apparatus, a processing apparatus for processing a workpiece made of a conductor or a semiconductor (for example, a silicon substrate) in a reduced-pressure atmosphere (a so-called processing apparatus under reduced pressure), for example, a chemical vapor deposition apparatus, Physical vapor deposition equipment,
It goes without saying that the same effect of improving the processing reliability can be achieved by using the present electrostatic chucking device as a chuck for a milling device, an etching device, an ion implantation device and the like.

According to the present embodiment, the thermal expansion of the dielectric plate and the electrodes can be adjusted, and the heat resistance thereof can be improved. Therefore, if the electrostatic suction device according to the present invention is used as a chuck of a processing device under reduced pressure, it is possible to reduce the incidence of foreign matter due to cracks in the dielectric plate. Further, even when a heater for heating is incorporated in the electrode plate or a lower portion of the electrode plate, a similar effect of improving the reliability of processing can be achieved by adjusting the coefficient of thermal expansion.

[0078]

Since the composite material of the present invention has low thermal expansion and high thermal conductivity and high plastic workability, it has a remarkable effect of shortening the manufacturing process and enabling mass production.

Further, the composite material of the present invention has both properties because it has a mixed structure composed of a Cu phase having high thermal conductivity and a Cu ₂ O phase having low thermal expansion.
In addition, the composite material of the present invention can obtain a high thermal conductivity with a low coefficient of thermal expansion by adjusting the contents of both Cu and Cu ₂ O. The present invention can be applied over a wide range as a heat sink mounted on a semiconductor device or an electrode plate of an electrostatic attraction device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a rolling sintering apparatus of the present invention.

FIG. 2 is a plan view of an IGBT module according to Embodiment 6 of the present invention.

FIG. 3 is a sectional view of an IGBT module according to a sixth embodiment of the present invention.

FIG. 4 is a schematic view of a manufacturing process of an IGBT module according to Embodiment 6 of the present invention.

FIG. 5 is a diagram showing the amount of base warpage in each step of the IGBT module according to Embodiment 6 of the present invention.

FIG. 6 is a plan view and a cross-sectional view of a power converter in which an IGBT module according to a sixth embodiment of the present invention is mounted.

FIG. 7 is a diagram showing the amount of warpage of a power converter in which an IGBT module according to a sixth embodiment of the present invention is mounted before mounting the module.

FIG. 8 is a diagram showing the amount of warpage after mounting.

FIG. 9 is a sectional view of a plastic package with a built-in heat sink according to a seventh embodiment of the present invention.

FIG. 10 is a sectional view of a heatsink-exposed plastic package according to a seventh embodiment of the present invention.

FIG. 11 is a sectional view of a ceramic package according to Example 8 of the present invention.

FIG. 12 is a cross-sectional view of a ceramic package with heat radiation fins according to Embodiment 8 of the present invention.

FIG. 13 is a sectional view of a semiconductor device according to a ninth embodiment of the present invention.

FIG. 14 is a sectional view of a semiconductor device according to a ninth embodiment of the present invention.

FIG. 15 is a sectional view of an MCM according to Embodiment 10 of the present invention.

FIG. 16 is a cross-sectional view of the electrostatic suction device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Powder container, 2 ... Heating roll, 3 ... Power supply, 4 ... Non-contact type temperature measuring device, 5 ... Roll, 6 ... Chamber, 7 ... Powder, 8 ... Composite material, 31, 57 ... Lead frame, 32
... insulating polyimide tape, 33, 42, 53, 67,
70, 83, 109 ... heat sink, 34, 41, 51, 65,
81: IC, 35, 82: Au wire, 36: Mold resin, 43, 85: Package, 44: Pin, 45: A
1 wire, 46 ... weld ring, 47, 87 ... lid, 48 ... radiation fins, 52, 68 ... thermal conductive resin, 5
4,71 ... Au bump, 55,72 ... TAB, 56,8
4: Thin film wiring, 58: Silicon rubber, 59: Ceramic substrate, 60: Frame, 61: Sealing glass, 6
6 ... Au-Si alloy, 69 ... Copper ground plate, 73 ... Resin, 7
4: Epoxy Ag paste, 86: external terminal, 88:
Preform, 95: vacuum processing chamber, 90: workpiece, 94
... electrodes, 91 ... DC power supply, 92 ... dielectric plate, 97 ...
Gas outlet, 96 ... Gas inlet, 93 ... High frequency power supply, 9
8 ... matching box, 101 ... IGBT element, 10
2: Diode element, 103: AlN substrate, 104: Emitter wiring, 105: Collector wiring, 106, 505 ...
Gate wiring, 107: metal wire, 108: resistance element,
110: emitter terminal connection position, 111: emitter sense terminal connection position, 112: collector connection terminal position, 113
... Gate terminal connection positions, 114, 115 ... bolt holes, 2
01, 205, 209: solder, 202, 203: copper foil,
204: AlN plate, 206: terminal, 207: case, 2
08: case block, 210: silicone rubber adhesive, 211: lid, 212: silicone gel, 213: post-thermosetting epoxy resin, 501: power semiconductor device, 5
02: collector side wiring, 504: emitter side wiring, 50
6: Emitter auxiliary wiring, 507: Collector auxiliary wiring, 5
08: load, 509: power supply voltage, 511: heat sink made of Al, 510: heat-dissipating grease, 512: fastening bolt, 503: midpoint wiring.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazutaka Okamoto 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Teruyoshi Abe 7, Omika-cho, Hitachi City, Ibaraki No. 1-1 Inside Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Yasuhisa Aono 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi, Ltd. Hitachi Research Laboratory F-term (reference) 4K018 AA02 AA03 AA14 AB01 AC01 BA02 EA29 KA32 KA62 5F036 AA01 BB01 BB08 BD01 BD11

Claims (25)

[Claims] 1. A metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, which are plastically worked at the same time as sintering, wherein the compound particles are 50% or less of the whole particles and a plurality of particles are connected to each other. A composite material characterized by being dispersed as a mass of complicated shape. 2. A compound having a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, and plastically processed at the same time as sintering. Wherein the number of the compound particles is 10 or less, and the remaining compound particles are present alone and dispersed. 3. A composite comprising a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, wherein the compound particles are plastically processed at the same time as sintering, and the compound particles have a Vickers hardness of 300 or less. material. 4. It has a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, and is plastically worked at the same time as sintering.
Coefficient of thermal expansion from 0 ° C to 300 ° C is 5 × 10 ^-6 to 1
7 × 10 ^-6 / ° C, thermal conductivity 270-375 W / m · K
And a conductivity of 60 to 85% IACS. 5. A composite material comprising a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, and subjected to plastic working at the same time as sintering. A composite material, wherein the composite material is dispersed, and the lump extends in a direction elongated by plastic working. 6. Copper and copper oxide particles, which are plastically worked at the same time as sintering, said copper oxide particles being 10% of the total of said particles.
A composite material, wherein a plurality of particles are dispersed in the form of a complex shaped mass connected to each other below. 7. A composite material comprising a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, and subjected to plastic working at the same time as sintering. A composite material characterized by being dispersed as a series of complicated shaped blocks. 8. A composite material comprising a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, which is plastically processed at the same time as sintering.
A composite material, wherein the number of particles is 100 or less in a square of μm, and the remaining compound particles are dispersed as a complex-shaped mass in which a plurality of particles are connected to each other. 9. A composite material comprising a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, wherein the compound particles have a Vickers hardness of 300 or less. 10. A semiconductor device comprising: a metal; and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, wherein the compound particles have a plurality of particles connected to each other and are dispersed in a lump, and the lump is formed simultaneously with sintering. A composite material which is plastically processed and extends in a processing direction. 11. Copper and copper oxide particles, which are plastically worked at the same time as sintering, wherein said copper oxide particles have a cross-sectional area ratio of 95% or more of the whole particles, and a plurality of particles are connected to each other. A composite material characterized by being dispersed as a complex shaped mass. 12. The method according to claim 1, wherein a coefficient of thermal expansion from room temperature to 300 ° C. is 5 × 10 ^{−6 to} 14
A composite material characterized by having a thermal conductivity of 30 to 325 W / m · K at × 10 ^-6 / ° C. 13. Copper (Cu) according to any one of claims 1 to 12, containing 20 to 80% by volume of cuprous oxide (Cu ₂ O).
A composite material comprising an alloy and having a density of 93% or more of the true density. 14. A method for producing a composite material comprising a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal,
A method of manufacturing a composite material, comprising supplying a mixed powder containing a powder of a metal and an inorganic compound powder between heated rolls and performing plastic working simultaneously with sintering. 15. A heat sink for a semiconductor device comprising the composite material according to claim 1. Description: 16. A heat sink for a semiconductor device according to claim 15, wherein the heat sink has a Ni plating layer on the surface. 17. A semiconductor device having an insulating substrate mounted on a radiator plate and a semiconductor element mounted on the insulating substrate, wherein the radiator plate comprises the radiator plate according to claim 15. Semiconductor device. 18. A semiconductor device, comprising: a semiconductor element mounted on a heat sink; a lead frame connected to the heat sink; and a metal wire for electrically connecting the lead frame and the semiconductor element. 17. A semiconductor device in a resin-sealed semiconductor device, wherein the heat radiating plate comprises the heat radiating plate according to claim 15 or 16. 19. A semiconductor device comprising: a semiconductor element mounted on a heat sink; a lead frame connected to the heat sink; and a metal wire for electrically connecting the lead frame and the semiconductor element. 17. A semiconductor device which is resin-sealed and has at least a surface of the heat radiating plate opposite to the element bonding surface being open, wherein the heat radiating plate is made of the heat radiating plate according to claim 15 or 16. Semiconductor device. 20. A ceramic multilayer wiring board having a semiconductor element mounted on a heat sink, an external wiring connecting pin, and an open space for accommodating the element in the center, and a terminal of the element and the substrate. A metal wire that electrically connects the heat sink and the substrate so as to place the element in the space, and joins the substrate with a lid to shield the element from the atmosphere. 17. A semiconductor device comprising the heat radiating plate according to claim 15 or 16. 21. A ceramic multilayer wiring board having a semiconductor element mounted on a heat sink, a terminal for external wiring connection, and a concave portion for accommodating the element in the center, and a terminal of the element and the substrate. And a metal wire for electrical connection,
In a semiconductor device in which the heat sink and the recess of the substrate are joined so that the element is installed in the recess and the substrate is joined by a lid and the element is shielded from the atmosphere, the heat sink is the claim 15 or A semiconductor device comprising the heat sink according to claim 16. 22. A semiconductor device comprising: a semiconductor element joined to a heat sink by a thermally conductive resin; a lead frame joined to a ceramic insulating substrate; and a TAB for electrically connecting the element to the lead frame. In a semiconductor device in which a heat radiating plate and an insulating substrate are connected to block the element from the atmosphere and a heat conductive resin elastic body is interposed between the element and the insulating substrate, the heat radiating plate according to claim 15 or 16 A semiconductor device comprising the heat sink according to any one of the preceding claims. 23. A semiconductor device joined by metal on a first radiator plate, and the first radiator plate is mounted on the ground plate of a second radiator plate joined to a ground plate, 16. A semiconductor device comprising: a TAB electrically connected to a terminal of
A semiconductor device comprising the heat radiating plate according to claim 16. 24. A dielectric plate for an electrostatic attraction device, comprising a composite material according to any one of claims 1 to 12. 25. An object is fixed to a surface of the dielectric plate by applying a voltage to the electrode layer to generate an electrostatic attraction force between the dielectric plate and the object bonded on the electrode layer. 25. An electrostatic attraction device according to claim 24, wherein said dielectric plate is made of claim 24.