JP2003253371A - Composite material with high thermal conductivity and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite material with high thermal conductivity, which can acquire the high thermal conductivity and a high-precision flat face, and to provide a manufacturing method therefor. <P>SOLUTION: The composite material with high thermal conductivity 1 comprises a main body 2 of the composite material consisting of 40-85 vol.% of ceramic particles and 15-60 vol.% of aluminum or an aluminum alloy, which has a continuous phase of aluminum or the aluminum alloy formed in gaps among the ceramic particles, and has no gap in interfaces between the ceramic particles 4 and the aluminum or the aluminum alloy, and a coating member 3 superior in workability, which is integrally provided on at least one side of the front or the back of the composite body 2. Thereby, the composite material can acquire very high thermal conductivity and an excellent dimensional stability. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high thermal conductivity composite material and a method for manufacturing the same, and more particularly, to a heat dissipation substrate that absorbs and dissipates heat generated from a semiconductor such as an MPU or a power module, and the surface of the substrate Vacuum deposition apparatus, sputtering apparatus, CVD as a film forming apparatus for forming a thin film on
(Chemical Vapor Deposition) Heat dissipation substrate or transport substrate used in devices, etc., soaking plate for plasma television production, small personal computer, housing used for electronic equipment such as measuring equipment, heat sink material, and vehicle The present invention relates to a highly heat-conductive composite material that absorbs and radiates heat generated in the control section or the like, or that is used in the brake section or the like and has good heat dissipation characteristics, and a manufacturing method thereof.

[0002]

2. Description of the Related Art For example, a power semiconductor element is driven by a large current and therefore generates heat. Therefore, a heat radiating plate having excellent heat radiating property for maintaining element characteristics is required. In particular, in recent years, since miniaturization and weight reduction have been promoted by high-density integration and mixed mounting with control circuits, dissipation of high-density heat flow has become an important issue.
There is a demand for a heat dissipation board having high thermal conductivity. Further, since a high heat is generated when a pattern is vapor-deposited on a glass plate for a liquid crystal panel or a soaking plate for manufacturing a plasma television in a vacuum, a heat dissipation substrate having a high thermal conductivity is required.

Further, in the fields of small personal computers, measuring instruments, projectors, etc., as the high density integration of semiconductor elements progresses, the amount of heat generated by the semiconductor elements increases, while the miniaturization of the equipment makes it difficult to dissipate heat. It tends to be structured. As described above, a heat dissipation board having high thermal conductivity is required for the housing and the heat sink material. Further, in vehicles, for example, in the field of braking, brake disks are required to have high heat dissipation, and in parts such as power transistors, a heat dissipation substrate having high heat conductivity is required. Furthermore, in order to effectively use heat such as gas and electricity at the time of cooking or the like, a device having high thermal conductivity is required so that cooking can be performed in a short time. Also,
For example, for a panel body of a panel heater, a heating surface of a far-infrared heater, an ironing surface, and the like, a material having high thermal conductivity that can transfer heat more efficiently is desired. As described above, materials with high thermal conductivity are required in various fields, and in response to this demand, SiC is conventionally used.
/ Al-based composite materials have been proposed.

[0004]

However, the metal plate has a problem that the coefficient of thermal expansion is large, while the SiC / Al-based composite material has a problem that the thermal conductivity is not sufficient. Also,
Conventional SiC / Al-based composite materials include a method of dispersing SiC powder in an aluminum melt, a method of molding SiC particles and aluminum or aluminum alloy particles with a binder or a sintering aid, and then sintering. is there.
The insufficient thermal conductivity in these methods is considered to be due to the following reasons. 1) Since the content rate of SiC is as low as about 20% by volume, 2) The particle size of SiC is very fine from 10 μ to 100 μ,
Since the contact area with aluminum becomes very large, 3) the residue of the binder and the sintering aid remains as foreign matter at the interface between SiC and aluminum, and 4) the void containing air at the interface between SiC and aluminum. And so on, and so on.

When such a SiC / Al-based composite material is used as a heat dissipation substrate by connecting to a semiconductor such as an MPU or a power module, it is bonded or screwed. However, the surface of the composite is
The finish is not always smooth due to the difference in shrinkage between SiC and Al. Therefore, when the SiC / Al-based composite material and the semiconductor such as the power module are bonded and fixed to each other, a gap is generated between the surfaces of the SiC / Al-based composite material and they are not sufficiently adhered to each other. There is a problem that it can not fulfill. Therefore, in order to obtain smoothness and improve adhesion, the surface of the SiC / Al-based composite material is ground, but since the hardness of SiC is large, the grinding process is difficult and the tool is damaged. early. In addition, SiC / Al
Even when trying to attach a composite material with screws, drilling is difficult and the tool is damaged quickly. In addition, even when a product whose grinding surface is finished to be smooth is attached to a member to be attached such as a semiconductor, due to the difference in expansion coefficient between the SiC / Al-based composite material and the member to be attached, it is repeatedly used. In addition, there is a problem that they are separated from each other.

An object of the present invention is to provide a high thermal conductivity composite material which can obtain high thermal conductivity and a method for producing the same. Another object of the present invention is, in addition to the above object, that a smooth surface can be easily obtained, and that the device can be mounted while ensuring sufficient adhesion with the member to be mounted, and can also be mounted to the member to be mounted. It is an object of the present invention to provide a high thermal conductivity composite material that does not peel off even if it is repeatedly used and a method for producing the same.

[0007]

In order to achieve the above-mentioned object, the high thermal conductive composite material of the present invention comprises 4 ceramic particles.
0 to 85% by volume and 15 to 60% by volume of aluminum or aluminum alloy, the aluminum or aluminum alloy forms a continuous phase in the gap between the ceramic particles, and the ceramic particles and aluminum or aluminum alloy. The composite material main body is made so that there is no gap at the interface, and at least one of the front and back surfaces of the composite material main body is integrally provided with a coating member having excellent workability. is there.

According to the present invention as described above, the composite material main body containing aluminum as the continuous phase contains as much ceramic particles as possible having a relatively large particle size, and the adhesion between the ceramic particles and the aluminum continuous phase is improved. Since it has been increased, it is possible to obtain a material having very high thermal conductivity and excellent dimensional stability. Further, since the coating member excellent in workability is integrally provided on at least one surface of the front and back surfaces of the composite body of the high thermal conductive composite material, a smooth surface can be easily obtained by grinding the coating member, Drilling is also facilitated, and attachment with a member to be attached can be performed while maintaining highly accurate adhesion, and a sufficient function as a heat dissipation substrate can be exhibited. Further, since a relatively large amount of ceramic particles having a relatively large particle size is contained, the thermal conductivity can be improved, and the linear expansion coefficient can be reduced to suppress the expansion, so that it can be connected to the connected member. At this time, it is possible to prevent peeling due to repeated use due to the difference in expansion coefficient between each other, and it is possible to prolong the service life.

Another high thermal conductivity composite material of the present invention comprises ceramic particles of 40 to 85% by volume and aluminum or aluminum alloy of 15 to 60% by volume, and the aluminum or aluminum is provided in the gaps between the ceramic particles. The alloy forms a continuous phase, and there is no gap at the interface between the ceramic particles and aluminum or an aluminum alloy, and the ceramic particles are not exposed on the surface to form a composite material body. At least one of the front and back surfaces of the main body is integrally provided with a coating member having excellent workability.

In the above high thermal conductive composite material, it is preferable that the thermal conductivity of the high thermal conductive composite material can be expected to be 200 W / mK or more. And, as the ceramic particles in the above-mentioned high thermal conductive composite material, in addition to SiC, AlN,
It is preferable to use particles such as BN and carbon. As the covering member, it is preferable to use any one of aluminum, an aluminum alloy, and an alloy of aluminum and zinc, and the thickness thereof is, for example, 0.5 mm.
It is preferably in the range of ˜2 mm, but it is not limited as long as the amount of the material is small and the dimension is such that a highly accurate smooth surface can be easily obtained.

In order to produce the above high thermal conductivity composite material,
In the present invention, the ceramic particles having good thermal conductivity are filled in the cavity of the mold, and the molten aluminum or aluminum alloy is impregnated therein. When the molten metal is in the anti-solidification state in the solidification process of the composite material body, sufficient pressure may be applied to solidify it. Alternatively, the molten aluminum is injected while vacuuming the inside of the cavity. At the same time, the molten aluminum may be pressurized at the same time.
Then, the molten metal is solidified to manufacture a composite body having high thermal conductivity. Then, a coating member having excellent workability is integrally provided on at least one of the front and back surfaces of the composite material body to manufacture a high thermal conductivity composite material.

The following method is effective as a method for removing the voids in the case where voids are formed at the interface between the ceramic particles and aluminum by performing ordinary solidification. 1) A method of heating the composite material body of the high thermal conductivity composite material to a temperature at which aluminum or an aluminum alloy is in a semi-molten state and applying pressure to fill the voids. 2) A method of extruding a composite body of a high thermal conductivity composite at a temperature at which aluminum or an aluminum alloy softens. 3) A method of hot rolling the composite material body of the high thermal conductivity composite material at a temperature at which aluminum or an aluminum alloy softens. 4) A method of hot forging the composite material body of the high thermal conductivity composite material at a temperature at which aluminum or an aluminum alloy softens.

Regarding the molten metal used in all of the above-mentioned methods, the fine ceramic particles are mixed with molten aluminum or aluminum alloy and used for stirring the molten metal to further increase the content of the ceramic fine particles. be able to. Further, nickel plating may be applied to the ceramic particles in order to improve the wetting of the ceramic particles and aluminum or aluminum alloy.

Then, a coating member having excellent workability is integrally provided on at least one of the front and back surfaces of the composite material body in the high thermal conductive composite material manufactured in this manner. At this time, the mold is a movable mold, and the composite material body formed in the mold cavity is supported by predetermined supporting means, and at least one of the front and back surfaces of the mold is opened. Alternatively, a predetermined gap may be formed, and a coating member made of molten aluminum, an aluminum alloy, or an alloy of aluminum and zinc may be injected into the gap and integrated. In this case, since the covering member is formed of aluminum, an aluminum alloy, or an alloy of aluminum and zinc, the covering member is fused with the surface of the aluminum or the aluminum alloy of the composite body, resulting in good integration. A state is formed.

When a movable die is used, a large number of fine irregularities (for example, irregularities such as graining) may be formed on the surface of the die. By doing so, fine irregularities are formed on the surface of the composite material main body, and the molten coating member enters the fine irregularities, and is more firmly integrated.

In addition, aluminum is preliminarily attached to the surface of the mold.
In order to form a composite material body by attaching a covering member formed of an aluminum alloy or an alloy of aluminum and zinc and setting a mold at a predetermined interval,
Alternatively, a method of injecting molten aluminum or aluminum alloy and integrating the composite material main body and the covering member may be performed. In this case, a partition made of aluminum or an aluminum alloy may be set up between the covering member and the gap for forming the composite material body, and the molten aluminum or aluminum alloy may be injected into the gap.
At this time, if the outer surface of the mold is configured to be rapidly cooled with water, for example, the molten aluminum or aluminum alloy and the covering member are prevented from completely fusing to the outside, and the ceramic particles of the composite material main body are prevented. Does not appear on the surface.

Alternatively, the composite material main body is momentarily immersed in any of molten aluminum, aluminum alloy and aluminum-zinc alloy constituting the coating material to adhere the coating material to the surface of the composite material main body. The composite material main body and the covering member may be integrally provided. Furthermore, the surface of the composite body is sprinkled with powder of aluminum, an aluminum alloy, or an alloy of aluminum and zinc,
It may be performed by a method of integrating the covering member and the composite material main body by hot pressing in which a pressure device gradually pressurizes while applying heat. Alternatively, a method may be used in which the covering member is melted and integrated on either surface of the composite material body by induction heating.

Furthermore, after the composite material main body and the covering member having a predetermined thickness are separately formed, the opposing surfaces of the composite material main body and the composite material main body and the covering member are pressure-bonded to each other, for example. The aluminum of the composite material main body and the aluminum of the covering member are chemically reacted to be fused,
It may be performed by a method of integrally forming the composite material main body and the covering member. Further, for example, the composite material main body and the covering member material may be bonded to each other with a soda-based inorganic adhesive resistant to high temperature to integrally form both. In addition, any method may be used as long as the composite material main body and the covering member can be integrally formed.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, the high thermal conductive composite material 1 of the present invention includes a composite material main body 2 and a covering member 3 covering the front and back surfaces of the composite material main body 2. The composite material main body 2 has a continuous phase formed by mixing aluminum or aluminum alloy between the dispersed ceramic particles 4 without a gap, and the thickness T thereof is formed to, for example, 3 mm. . However, this thickness T may be 3 mm or more, or 3 mm or less. The covering member 3 is made of aluminum or an aluminum alloy, and the thickness T thereof is in the range of 0.5 mm to 2.0 mm, for example. However, the thickness T is not limited to the above size range.

As the ceramic particles 4, not only SiC but also particles of AlN, BN, carbon, etc. are used, and the particle size may be 0.15 mm (on a 100 mesh sieve) or more, but the thickness of the product, etc. Considering that, 0.3
A particle size range of about mm to 2.0 mm (48 to 9 mesh) is preferable. If the particle size is less than 0.15 mm, the spacing between the ceramic particles 4 becomes too small, and the molten metal of aluminum or aluminum alloy (hereinafter, simply referred to as aluminum in the embodiment) described later does not enter, resulting in impregnation failure. The ceramics may be used not only in the form of particles but also in the form of fibers, and as the carbon, for example, carbon black, carbon balloons or the like can be used.

An appropriate amount of ceramic particles 4 is 40 to 85% by volume. If it is less than 40% by volume, the thermal conductivity of the composite material body 2 in the high thermal conductivity composite material 1 will not be high, and if it exceeds 85% by volume, the strength of the composite material body 2 will be insufficient. On the other hand, the amount of aluminum is 4
Corresponding to the above, it is set to 15-60% by volume.

As described above, since the composite material main body 2 contained a relatively large amount of the ceramic particles 4 having a relatively large particle size, the thermal conductivity was 200 W / mK or more, and the linear expansion coefficient was 9 to 12 ×. It can be about 10 ⁻⁶ . As a result, expansion of the high thermal conductivity composite material 1 can be suppressed.
It is preferable that the ceramic particles 4 are not exposed on the surface of the composite body 2. For that purpose, grooves smaller than the ceramic particles 4 are provided in the cavity inner wall of the molding die of the composite material main body 2 which will be described later so that only the molten aluminum flows in, and the surface of the composite material main body 2 is made of aluminum. There are methods such as covering with.

The composite material body 2 can be manufactured by the manufacturing apparatus 20 as shown in FIG. That is, the manufacturing apparatus 20 is configured to include the movable mold 30, the pouring unit 40, and the suction unit 50. The mold 30 is a plate-shaped body 31 m
Has a cavity 30a sandwiched between 32,
Has a runner 41 communicating with the upper end of the cavity 30a, and the lower end of the cavity 30a communicates with a vacuum box 51 sucked by a vacuum pump P.

Now, the ceramic particles 4 having a particle size of 0.15 mm or more are filled in the cavity 30a of the mold 30 in an amount of 40% by volume or more of the cavity space.
0a is vacuumed by a pump P to remove the air in the gaps between the ceramic particles 4, the molten aluminum is poured into the gaps from the runner 41, and the gaps between the ceramic particles 4 are impregnated with the molten metal. Solidify. If solidified normally during this solidification, a vacuum void will be formed at the interface between the ceramic particles 4 and aluminum because the solidification shrinkage of the molten aluminum is large. This vacuum void significantly reduces the thermal conductivity. Therefore, this vacuum void must be removed. One method for that purpose is to apply sufficient pressure to solidify the molten metal when it is in a semi-solidified state during the solidification process. Alternatively, the molten aluminum may be pressurized at the same time while the molten aluminum is being injected while the inside of the cavity 30a is being vacuumed.

The following method is effective as a method for removing the vacuum voids in the case where the vacuum voids are formed at the interface between the ceramic particles 4 and aluminum after the normal solidification. 1) A method in which the composite material body 2 is heated to a temperature at which aluminum, which is a constituent element of the composite material body 2, is in a semi-molten state, and pressure is applied to form a vacuum void in the aluminum. 2) A method of extruding the composite material body 2 at a temperature at which the aluminum of its constituent elements softens. In this method, the aluminum in the softened state creates a vacuum void during extrusion. 3) A method of hot rolling the composite material main body 2 at a temperature at which the aluminum of its constituent elements softens. 4) A method of hot forging the composite material main body 2 at a temperature at which the aluminum of its constituent elements softens.

In any of the above methods, the particle size of the ceramic particles 4 can be increased to 0.15 mm or more. Further, the content thereof can be 40% by volume or more. Further, nothing may be used except for the ceramic particles 4 and aluminum. Then, finally, it becomes possible to remove voids formed at the interface between the ceramic particles 4 and aluminum. As a result, it is possible to manufacture the composite material body 2 having high thermal conductivity.

The content of the ceramic fine particles can be further increased by using, as the molten aluminum used in each of the above methods, ceramic fine particles mixed in molten aluminum and stirred. As a result, the thermal conductivity is improved. Further, in order to improve the wettability of the ceramic particles 4 and aluminum, the ceramic particles may be plated with nickel or the like.

Both sides of the composite body 2 thus manufactured are covered with a covering member 3 made of any one of aluminum, an aluminum alloy and an alloy of aluminum and zinc. To cover the composite material body 2 with this covering member 3,
For example, in the cavity 30a of the mold 30,
After the composite material main body 2 is formed, its both surfaces and the plate-like bodies 31, 3 are formed.
A predetermined gap is formed between the two and the molten metal, for example, aluminum, an aluminum alloy, or an alloy of aluminum and zinc is injected. here,
The thickness t of the covering member 3 is, for example, 0.5 as described above.
It is set to mm to 2 mm. However, it is not limited to this range.

The usage state of the high thermal conductive composite material 1 as described above is shown in FIG. For example, the power semiconductor element 10 for MPU is fixed to an AlN chip 11, and this AlN chip 11 is fixed to a highly accurate smooth surface 3A obtained by grinding one surface of the covering member 3 with a tool such as an end mill. There is. A wire 12 is connected to the AlN chip 11 by a conductor circuit wiring 13.

According to this embodiment as described above, the following effects can be obtained. (1) In the composite material body 2, 40 to 85% by volume of ceramic particles and 15 to 6 of aluminum or aluminum alloy are used.
0% by volume, the aluminum or aluminum alloy forms a continuous phase in the gaps between the ceramic particles, and
Since it is formed so that there is no gap at the interface between the ceramic particles and aluminum or aluminum alloy, the thermal conductivity can be 200 W / mK or more, and the composite material main body 2 having high thermal conductivity can be obtained. As a result, MP
Vacuum vapor deposition equipment, sputtering equipment, CVD (chemical vapor deposition) as a heat dissipation substrate that absorbs and radiates heat generated from semiconductors such as U and power modules, and as a film formation device that forms a thin film on the surface of the substrate Occurred in heat dissipation boards or transfer boards used in devices, etc., heat equalizers for plasma TV manufacturing, small personal computers, housings used in electronic devices such as measuring instruments, heat sink materials, and vehicle control units. It can rapidly absorb and radiate heat, or can be used as an excellent heat dissipation substrate for a brake part or the like.

(2) Since the covering members integrally provided on both surfaces of the composite material body 2 are made of any one of aluminum, aluminum alloy and aluminum-zinc alloy, grinding is easy. Surface grinding can be easily performed with a tool such as an end mill, and a highly accurate smooth surface can be obtained. In addition, drilling is easy. Therefore, the highly heat-conductive composite material 1 having a thermal conductivity of 200 W / mK or more can be attached to the connected members such as the power transistor, the glass substrate for the liquid crystal panel and the heat equalizing plate for manufacturing the plasma TV with high accuracy. Since they can be maintained and connected, heat can be dissipated on the entire surface of the high thermal conductive composite material 1, high heat generated on the connected member side can be rapidly released, and the function as a heat dissipation substrate can be sufficiently achieved. .

(3) Composite body 2 of high thermal conductivity composite 1
However, as described above, the linear expansion coefficient can be suppressed to about 9 to 12 × 10 ^−6, and it is difficult to expand. Therefore, when connected to the connected member, peeling due to repeated use due to difference in expansion coefficient between each other. Etc. can be prevented and the service life can be extended.

(4) Since the high thermal conductivity composite material 1 has a high thermal conductivity of 200 W / mK or more as described above, the high thermal conductivity composite material 1 is
It can be used as a product requiring high thermal conductivity, for example, a panel body of a panel heater, a heating surface of a far-infrared heater, or an ironing surface. If the high thermal conductive composite material 1 is used for such a material, the effect can be obtained in a short time.

(5) Since the high thermal conductivity composite material 1 has excellent thermal conductivity as described above, for example, a frying pan,
It can also be used in cooking utensils such as a rice cooker pot and a cooking pot. If the high thermal conductive composite material 1 is used for such a thing, it becomes possible to cook in a short time, and as a result, electricity,
It requires less fuel such as gas and can save fuel costs. Here, for example, if the coating material on the surface of the frying pan is subjected to a fluorine treatment, it is possible to prevent charring, and if a deep groove is formed in the periphery, for example, meat juice can be easily released and the breadth of cooking is widened. be able to.

(6) Since the high thermal conductivity composite material 1 is excellent in thermal conductivity, it may be formed in a tray shape for natural thawing of frozen food or the like. In this case, for example, by opening holes in the four corners, the melted ice flows out, so that it can be thawed more quickly and its utility value is great. Generally, thawing is performed on a daily basis in a microwave oven or the like, but it is thought that the thawing is uneven and the taste is adversely affected. However, when the high thermal conductive composite material 1 is used, it is uniformly and quickly. Can be unzipped. Here, as a result of actually thawing using ice in the refrigerator, it was possible to thaw in a much shorter time as compared with the case of placing it on a normal glass plate. That is, 50 mm x 70 mm
× On the high thermal conductive composite material 1 formed to have a thickness of 3 mm, the bottom surface is 40 mm × 40 mm, the upper surface is 25 mm × 25 mm,
Place ice with a height of about 30 mm, while 150 mm x 9
Place on a glass dish with 0 mm x 10 mm depth, room temperature 20
I tried to measure the time until it completely melted in the room. As a result, the ice placed on the high thermal conductive composite material 1 was completely melted in about 50 minutes, while the ice placed on the glass dish was
It took about 100 minutes to completely melt. That is, when the high thermal conductive composite material 1 was used, it could be thawed in half the time.

(7) Since the high thermal conductivity composite material 1 is excellent in thermal conductivity, the high thermal conductivity composite material 1 is, for example, 20 to
It is also possible to prepare a plurality of sheets having a width of 30 mm, form each of them into a gently curved shape so as to be recessed on the lower surface side, and arrange each of them side by side to cover the base to form a pillow. It has long been called cold head and foot fever, and it is said that cooling the head is good for health. Therefore, by using the high thermal conductive composite material 1 for the pillow, the heat of the head can be removed and comfortable sleep can be obtained.

[0037]

Example 1 In order to manufacture the composite material main body 2 of the high thermal conductive composite material 1, a mold having a cavity with a thickness of 3 mm was used, and a particle size of 0.35 to 0.85 mm (42 to 20 mes).
58% of the volume of the cavity was filled with SiC particles having a grain size of h), and at the same time, the inside of the cavity was vacuumed by a vacuum pump from the lower end of the mold. While continuing suction, from the upper part of the mold, cast aluminum AC3A at 690 ° C to 7 ° C.
A molten metal of 00 ° C. was injected to impregnate the gap between the SiC particles with the molten aluminum. Up to this point, the mold temperature is 550
C., then the mold temperature was set to 530.degree. C. for solidification and held for 3 minutes. As a result, the mold is cooled to such an extent that aluminum does not flow, so the mold was opened and the plate-shaped molded body, that is, the composite material main body 2 was taken out and completely solidified at room temperature.

The composite material body 2 was observed by an electron microscope and the thermal conductivity was measured by the laser flash method.
As a result, it was found that voids 6 were present at the interface between the SiC particles 4 and aluminum, as shown in FIG.
On the other hand, the thermal conductivity was 138 W / mK. The following treatment was performed in order to eliminate the voids 6 at the interface between the SiC particles 4 and aluminum and further improve the thermal conductivity. 1) Aluminum AC3A was treated at a temperature of 450 ° C., 500 ° C. and 550 ° C. at which it becomes a semi-molten state or a softened state, and a pressure of 2 ton / cm 2 was applied for 5 minutes. As a result, as shown in FIG. 6, it can be seen that the voids at the interface between the SiC particles 4 and aluminum have almost disappeared. On the other hand, the thermal conductivity was 212 W / mK at 450 ° C., 280 W / mK at 500 ° C., and 280 W / mK at 550 ° C., and extremely high thermal conductivity was obtained. 2) After being heated to 450 ° C. in the furnace, it was taken out of the furnace and rolled to 1.3 mm at a rolling rate of 10%. Also in this case, the voids at the interface between the SiC particles 4 and aluminum were almost eliminated. The thermal conductivity was 205 W / mK, and a high value was obtained in this case as well. 3) The plate-shaped molded body, that is, the composite material main body 2 was subjected to a forging treatment at a forging temperature of 460 ° C. As a result, SiC particles 4
The void at the interface between aluminum and aluminum was almost gone. The thermal conductivity was 240 W / mK, and good results were obtained in this case as well.

Further, after covering both surfaces of the composite material main body 2 with the covering member 3, a predetermined portion or the whole surface of the high thermal conductive composite material 1 is made so that the surface of the covering member 3 becomes a highly accurate smooth surface. For example, grinding was performed with an end mill. Since the covering member was made of aluminum, it was very easy to grind, and a highly accurate smooth surface could be obtained very easily. Also,
Even in the drilling process, the tip of the drill was likely to bite into the covering member 3, and the drilling was extremely easy.

[0040]

Example 2 In order to manufacture the composite body 2, a diameter of 10
For a mold having a 0 mm cylindrical cavity, 0.7 to 7
SiC particles having a particle size of 24 mm (particle size of 24 to 10 mesh) were filled in an amount of 52% of the cavity volume, and at the same time, the inside of the cavity was vacuumed by a vacuum pump from the lower end of the mold. While continuing the suction, the molten metal of casting aluminum AC3A at 690 ° C to 700 ° C is injected from the upper part of the mold, and S
The gap between the iC particles was impregnated with molten aluminum. Up to this point, the temperature of the mold was 550 ° C., and then the mold temperature was set to 530 ° C. for solidification and held for 3 minutes. As a result, the mold was cooled to such an extent that aluminum did not flow, so the mold was opened and the cylindrical composite material body was taken out and completely solidified at room temperature.

The columnar composite material body having a diameter of 100 mm was extruded at a temperature of 600 ° C. into a plate having a thickness of 6 mm and a width of 50 mm. When this plate-shaped composite material body was evaluated in the same manner as in Example 1, almost no voids were observed at the interface between the SiC particles 4 and aluminum. The thermal conductivity was 265 W / mK, which was a very high value.

[0042]

Example 3 In order to manufacture the composite material main body 2, a thickness of 3 m
0.35 to 0.85 m in a mold with m cavity
SiC particles having a particle size of m (particle size of 42 to 20 mesh) were filled in an amount of 58% of the cavity volume, and at the same time, the inside of the cavity was sucked into a vacuum by a vacuum pump from the lower end of the mold. While continuing the suction, from the upper part of the die, inject the molten aluminum AC3A for casting at 690 ° C to 700 ° C, and
The gap between the iC particles was impregnated with molten aluminum. Up to this point, the temperature of the mold was 550 ° C., and then the mold temperature was set to 530 ° C. for solidification and held for 3 minutes. As a result, the mold was cooled to such an extent that aluminum did not flow, so the mold was opened and the pressure-formed body, that is, the composite material body was taken out. 55 out of the mold
Put the composite body into a hot press set at 0 ° C and
It was pressed with a pressure of 00 Kg / cm ² . Cooling and solidification were performed while applying this pressure. The resulting composite material main body was evaluated in the same manner as in the first and second examples. As a result, SiC
Almost no voids were observed at the interface between the particles and aluminum, and the thermal conductivity was 250 W / mK. In this case also, very good results were obtained.

[0043]

Comparative Example 1 Similar to the example, a mold having a cavity with a thickness of 3 mm was charged with Si having a grain size of 0.35 to 0.85 mm.
The C particles were filled in an amount of 58% of the cavity volume. However, vacuum suction is not performed from below the mold, and from the upper part of the mold, 690 ° C. to 70 ° C. of aluminum AC3A for casting.
A molten metal of 0 ° C. was poured to try to impregnate the gap between the SiC particles with the molten aluminum. After cooling and solidifying, when the mold was opened, aluminum was not sufficiently impregnated.

[0044]

As described above, according to the high thermal conductivity composite material of the present invention and the method for producing the same, the composite material main body containing aluminum as the continuous phase should contain as many ceramic particles having a relatively large particle size as possible. Moreover, since the adhesion between the ceramic particles and the aluminum continuous phase is improved, a material having a very high thermal conductivity and an extremely excellent dimensional stability can be obtained.

Further, since the covering member excellent in workability is integrally provided on at least one surface of the front and back surfaces of the composite body of the high thermal conductive composite material, the processing accuracy is improved and it is easy to grind the covering member. A smooth surface can be obtained and drilling becomes easy. Therefore, the attachment to the member to be attached can be performed while maintaining the close contact with high accuracy, and the sufficient function as the heat dissipation substrate can be exhibited.

Further, since a relatively large amount of ceramic particles having a relatively large particle size is contained, the thermal conductivity can be improved, and the linear expansion coefficient can be reduced to suppress the expansion. When connected to a member, due to the difference in expansion coefficient between them, peeling due to repeated use can be prevented, and the service life can be extended.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a high thermal conductive composite material of the present invention.

FIG. 2 is a schematic sectional view showing an example of the high thermal conductivity composite material of the present invention.

FIG. 3 is a schematic vertical sectional view showing an example of an apparatus for producing a high thermal conductive composite material of the present invention.

FIG. 4 is a vertical sectional view showing a usage state of the high thermal conductive composite material of the present invention.

5 is a schematic cross-sectional view showing a high thermal conductive composite material manufactured according to Example 1. FIG.

FIG. 6 is a schematic sectional view showing a high thermal conductive composite material manufactured according to Example 1.

[Explanation of symbols]

1 High thermal conductivity composite material 2 Composite material body 3 Cover member 4 Ceramic particles 5 continuous phase 10 Power semiconductor element 11 AlN chip 13 conductor circuit 20 Manufacturing equipment 30 molds 30a cavity 31, 32 plate-shaped member 40 pouring part 41 Runway 50 suction unit 51 vacuum box P vacuum pump

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C22C 29/16 C22C 29/16 H 32/00 32/00 Q H01L 23/36 H01L 23/36 C 23 / 373 MF term (reference) 4K020 AA26 AB01 AB02 AC01 AC07 BB29 5F036 AA01 BA23 BB08 BD03 BD14

Claims (14)

[Claims] 1. Ceramic particles in an amount of 40 to 85% by volume and aluminum or an aluminum alloy in an amount of 15 to 60% by volume.
And a composite material body in which the aluminum or aluminum alloy forms a continuous phase in the gaps between the ceramic particles, and there is no gap at the interface between the ceramic particles and the aluminum or aluminum alloy, A high thermal conductive composite material, characterized in that a covering member excellent in workability is integrally provided on at least one of the front and back surfaces of the composite material main body. 2. Ceramic particles of 40 to 85% by volume and aluminum or aluminum alloy of 15 to 60% by volume.
And the aluminum or aluminum alloy forms a continuous phase in the gaps between the ceramic particles, and there is no gap at the interface between the ceramic particles and aluminum or aluminum alloy, further, the ceramic particles on the surface. A high thermal conductivity composite material, characterized in that a composite material body is formed so as not to be exposed, and at least one of front and back surfaces of the composite material body is integrally provided with a coating member having excellent workability. . 3. The high thermal conductivity composite material according to claim 1 or 2, wherein the composite material main body has a thermal conductivity of 2 or less.
A highly heat-conductive composite material characterized by having a power of at least 00 W / mK. 4. The high thermal conductive composite material according to claim 1, wherein the ceramic particles are at least one selected from SiC, AlN, BN and carbon. High thermal conductivity composite material. 5. The high thermal conductivity composite material according to claim 1, wherein the composite material body is formed of aluminum, an aluminum alloy, or an alloy of aluminum and zinc. High thermal conductivity composite material characterized by being 6. A method for producing the high thermal conductivity composite material according to claim 1, wherein the ceramic particles having good thermal conductivity and aluminum or aluminum alloy are compounded. After filling the cavity of the mold with the ceramic particles and impregnating the gap between the ceramic particles with the molten aluminum or aluminum alloy and solidifying the composite material body, the front and back surfaces of the composite material body are manufactured. A method for producing a highly heat-conductive composite material, characterized in that the coating member having excellent workability is integrally provided on at least one surface of. 7. The method for manufacturing a high thermal conductive composite material according to claim 6, wherein the molten metal is charged while vacuuming the inside of the cavity containing the ceramic particles at the time of impregnating the molten metal. Manufacturing method of high thermal conductive composite material. 8. A method for producing the high thermal conductivity composite material according to claim 1, wherein fine particles of ceramic are mixed into molten aluminum or aluminum alloy and stirred, After the molten metal obtained by stirring is molded into a predetermined shape, solidification is performed to manufacture a composite material main body, and then at least one of the front and back surfaces of the composite material main body is integrally formed with the coating member having excellent workability. A method for producing a high thermal conductive composite material, comprising: 9. The method for producing a highly heat-conductive composite material according to claim 6 or 8, wherein in the solidifying step, the solidification is completed while pressure is applied. Production method. 10. The method for producing a highly heat-conductive composite material according to claim 6, 8 or 9, wherein the solidified composite material body is heated to a temperature at which aluminum or an aluminum alloy is semi-melted, and at the same time, pressure is applied. A method for producing a highly heat-conductive composite material, which comprises applying heat. 11. The method for producing a highly heat-conductive composite material according to claim 6, 8 or 9, wherein the composite material body after solidification is extruded. Manufacturing method of composite material. 12. The method for producing a highly heat-conductive composite material according to claim 6, 8 or 9, wherein the composite material body after solidification is hot-rolled. Manufacturing method of composite material. 13. The method for producing a highly heat-conductive composite material according to claim 6, 8, or 9, wherein the solidified composite material body is hot forged or pressed. And a method for producing a high thermal conductive composite material. 14. The method for producing a highly heat-conductive composite material according to claim 6, wherein a surface of the ceramic particles is coated on the surface of the ceramic particles in order to improve wettability with the aluminum or aluminum alloy. A method for producing a high thermal conductive composite material, which comprises subjecting nickel to a plating treatment in advance.