JP2005238331A - Composite material and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite material which exerts a high thermal conductivity and whose surface can be easily made precisely flat and smooth so that it can be attached tightly to a member to be attached and cannot be peeled off from the member to be attached even after repetitive use, and a manufacturing method therefor. <P>SOLUTION: The composite material 1 comprises 40-85 vol% of ceramic particles 4 with a comparatively large size, 15-60 vol% of aluminum 5, continual phase of aluminum 5 filling space between ceramic particles, and main bodies 2 having no gap in a boundary surface between the ceramic particle 4 and the aluminum 5. Both top and bottom surfaces in the thickness direction of the main body 2 are covered with covering parts 2A with a designated thickness subjected to non-electrolytic nickel plating treatment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a composite material composed of ceramic particles and aluminum or an aluminum alloy, and a method for producing the same.

  For example, since a power semiconductor element is driven by a large current, it generates heat, and a heat dissipation plate with excellent heat dissipation is required to maintain element characteristics. In recent years, especially with the progress of miniaturization and weight reduction due to high density integration and mixed mounting with control circuit, dissipation of high density heat flow has become an important issue, and a highly heat conductive heat dissipation substrate is required. . Further, since a high heat is generated when a pattern is deposited on a soaking plate for manufacturing a plasma television or a glass substrate for a liquid crystal panel in a vacuum, a highly heat-conductive heat dissipation substrate is required.

Furthermore, in the fields of small personal computers, measuring instruments, projectors, etc., as the density of semiconductor elements increases, the amount of heat generated by the semiconductor elements increases. There is a tendency. Thus, a heat dissipation board with high thermal conductivity is also required for the housing and the heat sink material.
In a vehicle, for example, a brake disk is required to have high heat dissipation in the field of braking, and a heat dissipation board with high thermal conductivity is required in a portion where a power transistor or the like is used.
As described above, materials having high thermal conductivity are demanded in various fields, and in response to this demand, conventionally, a SiC / A1 system, which is a composite material of SiC (silicon carbide) and A1 (aluminum). A composite material has been proposed (for example, Patent Document 1).

JP 2002-322524 A

However, when a metal plate is used, there is a problem that the coefficient of thermal expansion is large. On the other hand, the SiC / A1 composite material has a problem that the thermal conductivity is not sufficient.
In addition, in the conventional SiC / A1-based composite material, a method in which SiC powder is dispersed in molten aluminum, SiC particles and aluminum or aluminum alloy particles are formed by adding a binder or a sintering aid, and then sintered. There are methods. The reason why the thermal conductivity is not sufficient in these methods is considered to be as follows.
-The content of SiC is as low as about 20% volume.
-SiC has a very fine particle size of 10-100 μm, and the contact area with aluminum becomes very large.
-Residues of binder and sintering aid remain as foreign matter at the interface between SiC and aluminum.
This is because there is a void containing air at the interface between SiC and aluminum.

Furthermore, when the SiC / A1 composite material as described above is used as a heat dissipation substrate connected to a semiconductor such as an MPU or a power module, the SiC / A1 composite material and the semiconductor are often bonded. In some cases, it may be screwed.
However, since the shrinkage rates of SiC and A1 constituting the composite material are different, when the composite material is contracted, the tip 4A of SiC4 protrudes from the surface of the composite material 100 by a dimension S as shown in FIG. Thus, fine irregularities are generated on the surface of the composite material 100. The unevenness is, for example, about 0.05 mm, but the unevenness is not changed, and the surface of the composite material 100 is not smooth. Therefore, when the composite material 100 is used as it is and the SiC / A1-based composite material and a semiconductor such as a power module are bonded and fixed, there is an unevenness of about 0.05 mm between the opposing surfaces of both. Therefore, they are not sufficiently adhered to each other. As a result, heat from the semiconductor is not sufficiently transmitted to the SiC / A1-based composite material 100, and there is a problem that a sufficient function as a heat dissipation substrate cannot be performed.

Therefore, in order to obtain smoothness and improve adhesion, the surface of the SiC / A1-based composite material is ground or polished. However, many SiC tips protrude and the hardness of the SiC is large. Therefore, in the case of grinding, the tool is damaged quickly. Also, in the case of polishing, the work takes a long time, the efficiency is poor, and it is not possible to cope with a large amount of demand.
Furthermore, even if the attached member is attached to the attachment surface that has been smoothed by grinding and polishing, due to the difference in expansion coefficient between the SiC / A1 composite and the attached member, There is also a problem that they are separated from each other.

  It is an object of the present invention to obtain high thermal conductivity, to easily attach a surface to a member to be attached in a highly accurate and smooth surface, and to attach a member even when used repeatedly. It is to provide a composite material that does not peel between and a manufacturing method thereof.

  The composite material of the present invention comprises a ceramic particle having a relatively large particle size of 40 to 85% by volume, aluminum or an aluminum alloy of 15 to 60% by volume, and the aluminum or aluminum alloy is placed in a gap between the ceramic particles. In a composite material that forms a continuous phase and has no gap at the interface between the ceramic particles and aluminum or aluminum alloy, a plate-shaped main body portion made of the ceramic particles and aluminum or aluminum alloy; The body portion is formed of a covering portion that covers at least one surface in the thickness direction and is excellent in workability.

  According to the present invention, since the main body portion of the composite material contains as many ceramic particles having a relatively large particle size as possible, and the ceramic particles and aluminum or aluminum alloy are in a continuous phase, It is formed with increased mutual adhesion. Both ceramic particles and aluminum are superior in thermal conductivity compared to other metals such as iron, and as a result, a composite material having high thermal conductivity can be obtained.

  In addition, when the composite material is attached to the member to be attached, it is only necessary to process the covering portion with excellent workability, and the surface of the covering portion can be easily made a highly accurate smooth surface. As a result, it can be mounted in close contact with the mounted member, and the heat of the mounted member is sufficiently transmitted to the main body to be dissipated, so that it exhibits a sufficient function as a heat dissipation substrate. Can do.

  Furthermore, since the main body contains a large number of ceramic particles having a relatively large particle size, the linear expansion coefficient of the main body can be kept small. Therefore, it becomes a main body part with extremely excellent dimensional accuracy, and when such a main body part is attached to a member to be attached, it can be prevented from being separated from each other due to a difference in expansion coefficient from the member to be attached. This makes it possible to extend the life of the composite material.

  In the above composite material, the particle size of the ceramic particles refers to the size of the maximum circumscribed circle in the width direction and the thickness direction, and the relatively large particle size may be 0.15 mm (above 100 mesh sieve) or more. And about 0.3 mm to 2.0 mm (48 to 49 mesh) is preferable.

  In the composite material of the present invention, it is preferable that the covering portion according to claim 1 is formed of an electroless nickel plating layer made of electroless nickel plating applied to the surface of the main body portion.

According to the present invention, even if subtle irregularities due to the difference in shrinkage between ceramic and aluminum are formed on the surface of the main body, according to the electroless nickel plating process that does not require an external power supply, Since the object can be applied even if it is ceramic, the above unevenness can be eliminated.
In addition, in order to form an electroless nickel plating layer, for example, a main body manufactured with a mold may be pretreated and then accommodated in an electroless nickel plating apparatus to perform the plating process. The part can be formed.
Furthermore, the surface of the electroless nickel plating layer becomes a smooth surface having a predetermined smoothness. Therefore, depending on the type of the member to be attached, it can be used as it is without performing a new planar process, and in that case, the labor of the process can be saved.

In the present invention described above, it is preferable to use an autocatalytic chemical reduction plating type as the electroless nickel plating.
Electroless nickel plating is a plating method that does not require an external power source, and corresponds to electroplating that requires an external power source. Two well-known metal deposition methods that do not use an external power source are displacement (dipping) plating caused by a difference in standard oxidation-reduction potential (ionization tendency) of metal and scientific reduction plating using a reducing agent.

Scientific reduction plating is one in which metal ions are reduced and deposited by a reducing agent, and the greatest feature is that the deposited metal has a catalytic action on the reaction of the reducing agent. That is, by this autocatalytic action, the metal deposition reaction proceeds continuously, and the plating film grows.
Electroless nickel plating and electroless copper plating, which are currently widely used industrially, are the above-described self-catalytic scientific reduction plating.
An electroless nickel plating layer may be formed by displacement (immersion) plating. Moreover, it may replace with electroless nickel plating and may perform an electroless copper plating process to a main-body part, and may form a coating | coated part.

  In the composite material of the present invention, it is preferable that an electroplated layer subjected to electroplating is formed on the surface of the electroless nickel plated layer in the composite material according to claim 2.

According to the present invention, even if the ceramic is exposed on the surface of the main body due to the difference in shrinkage between the ceramic and aluminum, first, the electroless nickel plating is applied to shrink the ceramic and aluminum. Unevenness due to the difference in rate can be eliminated. Then, by applying electroplating on the surface of the electroless nickel plating, which requires less cost than electroless nickel plating, the overall cost can be reduced.
Further, the surface of the electroplating layer is a smooth surface having a predetermined smoothness. Therefore, depending on the type of the member to be attached, it can be used as it is without performing a new planar process, and in that case, the labor of the process can be saved.

  In order to manufacture the composite material, the manufacturing method of the present invention is a method of manufacturing the composite material according to claim 2, wherein the ceramic particles and aluminum or aluminum alloy are combined using a mold. Further, after accommodating the ceramic particles in the cavity of the mold, the gap between the ceramic particles is impregnated with the molten aluminum or aluminum alloy while vacuuming the inside of the cavity of the mold. An electroless nickel plating formed by forming a main body, and after the main body is cooled in the mold, taken out from the mold, and then subjected to electroless nickel plating on the front and back surfaces of the main body. A covering portion is formed by a layer.

The following method is effective as a method for removing the voids in the solidified state where voids are formed at the interface between the ceramic particles and aluminum or between the aluminum and the shielding member.
A method in which the body of the composite material is heated to a temperature at which aluminum or an aluminum alloy is in a semi-molten state, and pressure is applied to fill the gap.
A method of extruding the main body of the composite material at a temperature at which aluminum or aluminum alloy softens.
A method of hot rolling the main body of the composite material at a temperature at which aluminum or aluminum alloy softens.
A method of hot forging the main body of the composite material at a temperature at which aluminum or aluminum alloy is softened.

Regarding the molten metal used in all the methods described above, in addition to coating the ceramic particles with the ceramic fine powder, the ceramic fine powder can be used for molten metal mixed in molten aluminum or aluminum alloy and stirred. Further, the content of the ceramic fine powder can be further increased.
Further, in order to improve the wettability between the ceramic fine powder and aluminum or aluminum alloy, nickel plating may be applied to the ceramic particles.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 and 2, the composite material 1 of the first embodiment is composed of a main body portion 2 and a covering portion 2 </ b> A that covers the front and back surfaces of the main body portion 2 and is integrated with the main body portion 2. Yes.

  The main body 2 has a continuous phase formed by mixing aluminum or an aluminum alloy (hereinafter simply referred to as aluminum) 5 between the dispersed ceramic particles 4 without any gap. The thickness T of the composite material 1 is, for example, 3 mm. However, the thickness T is not limited to 3 mm, and may be 3 mm or more, or 3 mm or less.

  As the ceramic particles 4, particles such as SiC, A1N, BN, and carbon are used, and those having a relatively large particle size are used. As a relatively large particle size, for example, 0.15 mm (on a 100 mesh screen) or more is sufficient, but taking into consideration the thickness of the product, a particle size range of about 0.3 mm to 2.0 mm (48 to 9 mesh) Is preferred.

Here, when the particle size of the ceramic particles 4 is less than 0.15 mm, the gap between the ceramic particles 4 becomes too small, and the molten aluminum does not enter, resulting in poor impregnation. Further, when the ceramic particles 4 are used, the whole may have substantially the same particle size, but ceramic particles 4 having different particle sizes may be used in combination.
The particle size of the ceramic particles 4 refers to the size of the maximum circumscribed circle in the width direction and the thickness direction. Moreover, the ceramic particle body 4 may use not only a particle body but a fibrous thing together. Furthermore, carbon black, carbon balloon, etc. can be used as carbon.
In this embodiment, for example, SiC 4 having a particle size of 0.7 mm is used as the ceramic particles 4.

A suitable amount of SiC4 is 40 to 85% by volume. If it is less than 40% by volume, the thermal conductivity of the main body 2 in the composite material 1 will not be high, and if it exceeds 85% by volume, the strength of the main body 2 will be insufficient. On the other hand, the amount of aluminum is 15 to 60% by volume corresponding to the amount of SiC4.
As described above, since a relatively large amount of SiC4 having a relatively large particle size is contained in the main body 2, the thermal conductivity is set to 200 W / mK or more, and the linear expansion coefficient is set to about 9 to 12 × 10 ⁻⁶ . be able to.
Moreover, SiC4 is coated with ceramic fine powder in advance. The amount of the ceramic fine powder is preferably set to a ratio of, for example, 1: 0.2 to 0.4 with respect to SiC4.

The main body 2 described above can be manufactured by a manufacturing apparatus 10 as shown in FIG.
The manufacturing apparatus 10 includes a mold 20, a pouring unit 30, and a suction unit 40. The mold 20 includes a pair of plate-like bodies 21 and 22 and a pair of side plates (not shown) orthogonal to and coupled to the plate-like bodies 21 and 22, and the plate-like bodies 21 and 22 and the side plates. Thus, the cavity 20A is formed.
The pouring part 30 is formed with a runner 31 communicating with the upper end of the cavity 20A. The lower end of the cavity 20 </ b> A communicates with the vacuum box 41 that is sucked by the vacuum pump P.

In manufacturing the main body 2, first, SiC 4 coated with fine ceramic powder is filled in the cavity 20 </ b> A of the mold 20.
Next, while the inside of the cavity 20 </ b> A is sucked by the vacuum pump P, the molten aluminum 5 is introduced and filled from the runway 31 of the pouring part 30. The molten aluminum 5 is impregnated in the gap between the SiCs 4 in the cavity 20 </ b> A to form the main body 2.
A sheet-like receiving member (not shown) is provided between the lower part of the mold 20 and the suction part 40, for example. This receiving member does not allow the molten aluminum 5 to pass through, but has a number of extremely fine holes through which air can be sucked.

  As described above, when the main body 2 formed of the mold 20 is taken out after cooling, the aluminum 5 and the SiC 4 appear on the front and back surfaces as described above, and due to the difference in contraction rate between the two 5 and 4. The front and back surfaces of the main body portion 2 have delicate irregularities as described above.

If the molten aluminum is solidified normally when the molten aluminum is solidified, the solidified shrinkage of the molten aluminum is large, so that a vacuum gap is formed at the interface between the SiC 4 and the aluminum 5. This vacuum gap significantly reduces the thermal conductivity. Therefore, this vacuum gap must be removed. The following methods are effective as methods for removing the vacuum gap.
A method in which the main body 2 is heated to a temperature at which the constituent aluminum 5 is in a semi-molten state, and pressure is applied to fill the vacuum gap with the aluminum 5.
A method of extruding the main body 2 at a temperature at which the constituent aluminum 5 is softened. In this method, the softened aluminum 5 fills the vacuum gap during the extrusion process.
A method of hot rolling the main body 2 at a temperature at which the constituent aluminum 5 is softened.
A method of hot forging the main body 2 at a temperature at which the constituent aluminum 5 is softened.
-While the molten aluminum 5 is being poured while the inside of the cavity 20A is sucked in vacuum, the molten aluminum is simultaneously pressurized.

  In any of the above methods, the particle size of SiC4 can be increased to 0.15 mm or more. Moreover, the content can also be 40 volume% or more. Further, nothing other than SiC4 and aluminum 5 may be used. Finally, it is possible to remove the void formed at the interface between SiC 4 and aluminum 5. As a result, it is possible to manufacture the composite material 1 having more excellent thermal conductivity.

As shown in FIG. 4, the covering portion 2 </ b> A is composed of an electroless nickel plating layer having a thickness dimension D applied to the front and back surfaces of the main body portion 2. The thickness D of the electroless nickel plating layer is, for example, 10 μm to 50 μm, and is a thickness that can fill the fine irregularities of the manufactured main body 2.
The electroless nickel plating layer is subjected to a predetermined pretreatment on the front and back surfaces of the main body 2 taken out from the mold 20, and then the main body 2 is accommodated in an electroless nickel plating apparatus (not shown). It is formed by plating. And the delicate unevenness | corrugation of the front and back of the main-body part 2 is filled with this electroless nickel plating layer, and it has become a highly accurate smooth surface. Therefore, depending on the type of the member to be attached, it can be used as it is without performing secondary surface processing.

An example of the usage state of the composite material 1 as described above is shown in FIG. 5 as a schematic diagram.
In this use example, the surface of the covering portion 2A is used in a state where the surface is subjected to electroless nickel plating, and secondary processing such as polishing is not performed. In addition, the surface of 2 A of coating | coated parts is a smooth surface to the extent which satisfy | fills the adhesiveness requested | required between to-be-attached members.

  As shown in FIG. 5, for example, a power semiconductor element 50 for MPU is fixed to an A1N chip 51, and the A1N chip 51 is fixed to a covering portion 2 </ b> A of the composite material 1. Therefore, the composite material 1, the A1N chip 51, and the conductor circuit wiring 53 are attached to each other with a high degree of adhesion. The power semiconductor element 50 is connected to a conductor circuit wiring 53 by a wire 52.

According to the present embodiment as described above, the following effects are obtained.
(1) The main body 2 of the composite 1 is composed of 40 to 85% by volume of SiC4 having a relatively large particle size and 15 to 60% by volume of aluminum 5, and the aluminum 5 forms a continuous phase in the gap between the SiC4, And since it is formed so that there may be no gap in the interface of SiC4 and aluminum 5, thermal conductivity can be made 200 W / mK or more. As a result, the composite material 1 with high thermal conductivity can be obtained, and can be used as an excellent heat dissipation substrate.

(2) Since the linear expansion coefficient of the composite material 1 can be suppressed to about 9 to 12 × 10 ⁻⁶ , the composite material 1 is difficult to expand. Therefore, when it is attached to a member to be attached such as a power transistor, it is possible to prevent peeling due to repeated use caused by a difference in expansion coefficient between them, and to extend the life of the composite material 1.

(3) Since the surface of the main body 2 is formed with subtle irregularities due to the difference in shrinkage between SiC4 and aluminum 5, the electroless nickel plating process can be performed even if the object is SiC4. The above unevenness can be eliminated. Since the surface of the electroless nickel plating layer is a high-precision smooth surface, grinding or polishing can be omitted in order to attach the composite material 1 to a member to be attached such as a power transistor. This can save you time and effort.

(4) Since the covering portion 2A of the main body portion 2 is formed of an electroless nickel plating layer, and the surface thereof is a high-precision smooth surface having irregularities of about 10 to 20 μm, for example, the thermal conductivity is 200 W. / MK or higher composite material 1 is connected to a mounted member such as a power transistor, various semiconductor device components, a glass substrate for a liquid crystal panel, a heat equalizing plate for plasma television manufacture, etc., while maintaining high precision adhesion. Can be made. Accordingly, rapid heat dissipation is possible, so that the function as a heat dissipation substrate can be sufficiently achieved.

(5) Since SiC 4 is pre-coated with ceramic fine powder, aluminum 5 is filled in the gaps between the SiC 4 grains, and when shrinking, the ceramic fine powder clinging to SiC 4 is shrunk when aluminum 5 shrinks. Since the action of pulling the aluminum 5 occurs, the shrinkage of the aluminum 5 can be suppressed even slightly. As a result, voids generated at the interface between the SiC4 grains and the aluminum 5 can be reduced, and the composite material 1 having higher performance thermal conductivity can be obtained.

(6) Since the thermal conductivity of the composite material 1 is 200 W / mK or higher and has a high thermal conductivity, the composite material 1 is used as a product that requires high thermal conductivity, for example, a heat source of a projector. It can be used as a heat dissipation measure for certain lamps, for panel heaters, for heating surfaces of far-infrared heaters, for ironing surfaces, such as frying pans, rice cooker pots, cooking pots, etc. It can also be used, and can be used in various fields.

Next, a second embodiment of the present invention will be described based on FIG.
In this embodiment and the following embodiments, the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

The composite material 1 </ b> A according to the second embodiment includes the main body 2 and a covering portion 2 </ b> B that covers the front and back surfaces of the main body 2 and is integrated with the main body 2.
The covering portion 2B has a two-layer structure, the first layer on the main body portion 2 side is formed by the covering portion 2A, and the electroplating layer 2C formed by electroplating the surface of the covering portion 2A is the second layer. It has become. The electroplating layer 2C is formed by subjecting the main body 2 to electroless nickel plating, and then accommodates it in a plating bath for electroplating (not shown).

According to the second embodiment as described above, the following effects can be obtained in addition to substantially the same effects as the above (1) to (6).
(7) Even if the ceramic 4 is exposed on the surface of the main body 2 due to the difference in shrinkage between the ceramic 4 and the aluminum 5, unevenness on the surface of the main body can be eliminated by the electroless nickel plating process. In addition, since the electroplating which is less expensive than the electroless nickel plating is applied to the surface of the electroless nickel plating, the overall cost can be reduced.

Next, a third embodiment of the present invention will be described with reference to FIGS.
The composite material 1 </ b> B of the third embodiment includes a main body portion 3 and a covering portion 3 </ b> A that covers one surface of the main body portion 3 and is integrated with the main body portion 3.

The main body 3 has substantially the same configuration as the main body 2, but is different from the first and second embodiments in that the covering portion 3 </ b> A is manufactured at the same time as the main body 3.
As shown in FIG. 8, the covering portion 3 </ b> A protrudes outward from one surface of the main body portion 3, and is a vertical direction that is a direction orthogonal to the paper surface of FIG. Are formed by a plurality of continuous protrusions 300.
The protrusion 300 is formed of a molten aluminum in a longitudinal groove 22A formed in one plate-like body 22 among a pair of plate-like bodies 21 and 22 constituting a cavity 20A of the mold 20 and a pair of side plates (not shown). Formed by inflow and filling.

  As shown in FIG. 9, the longitudinal groove 22 </ b> A is continuously formed in the longitudinal direction (vertical direction in the embodiment) in which the molten aluminum flows on the entire surface on one side of the one plate-like body 22. As shown in FIG. 8, the longitudinal groove 22A has a triangular cross section with a root width dimension W of, for example, 0.5 mm, an angle α as a draft angle of, for example, about 60 °, and a depth D of, for example, 0.5 mm. It is formed in the space. Therefore, SiC 4 having a particle size of 0.7 mm can hardly enter the vertical groove 22A.

Adjacent vertical grooves 22A are continuous with each other in the width direction, and the vertical grooves 22A have a sawtooth shape when viewed from a direction perpendicular to the vertical grooves 22A.
Note that the longitudinal groove 22A is not only formed vertically, but may be formed along a slight inclination of, for example, an inclination angle of about 5 degrees. Alternatively, for example, a groove meandering in an S shape may be used. In short, any groove that allows the molten aluminum 5 to flow smoothly can be used.

  The dimensions of the width W, the angle α, and the depth D of the vertical groove 22A are not limited to the above-mentioned dimension of 0.5 mm. For example, the width W may be 0.5 mm or less, or may be 0.5 mm or more. However, if the width W is made too small, the molten aluminum 5 becomes difficult to flow, so it is preferable to suppress it to about 0.3 mm, for example. Moreover, since SiC4 will penetrate | invade easily if it enlarges too much, it is more preferable to suppress to about 0.6 mm.

The above composite material 1B can be manufactured with the manufacturing apparatus 10 shown in FIG. 3 mentioned above.
That is, one plate-like body 22 constituting the mold 20 of the manufacturing apparatus 10 can be manufactured by the same procedure as described above by forming the longitudinal groove 22A. The plate-like body 22 of the mold 20 is arranged so that the longitudinal groove 22A faces the cavity 20A.

  After the composite material 1B is manufactured, it is necessary to perform planar processing in order to obtain a smooth surface of the covering portion 3A including the protruding portion 300. In this case, for example, a hot press can be used. As the procedure, first, the main body 3 is placed on a predetermined mounting table (not shown), a hot press is brought into contact with the upper end of the protruding portion 300, and then a large number of heat is applied while gradually applying heat by the hot press. The tip of the protruding portion 300 is pressed. Thereby, the protrusion part 300 is crushed and a smooth surface is formed.

Alternatively, the covering portion 3 </ b> A made up of a large number of protruding portions 300 may be ground or polished with a tool to obtain a smooth surface with high accuracy.
Further, the surface processing of the covering portion 3A is not limited to the above-described hot pressing, grinding, and polishing processing, and may be performed by rolling, for example. That is, after the composite material 1B is taken out from the mold 20, the composite material 1B is annealed at a predetermined temperature, for example, 200 ° C. to 300 ° C., so that it can be easily rolled, and the protruding portion is passed between the rolling rolls. 300, that is, the covering portion 3A may be rolled to obtain a highly accurate smooth surface. In this case, if the rolling is performed by a dimension between the apex and valley of the projecting portion 300 having a triangular cross section, for example, half the dimension of 0.5 mm, that is, 0.25 mm, the apex and valley are filled with each other. Accordingly, a smooth finished surface can be easily obtained. Accordingly, a rolled 0.25 mm covering portion 3A is formed on the surface of the composite material 1B.

According to the third embodiment as described above, the following effects can be obtained in addition to substantially the same effects as the above (1), (2), (5), and (6).
(8) Since the root width dimension W of the multiple vertical grooves 22A formed in one plate-like body 22 is 0.5 mm, SiC 4 having a particle size of 0.7 mm vigorously moves in the cavity 20A. When falling well and continuously, they hardly enter the longitudinal grooves 22A. As a result, when the surface of the composite material 1 is planarized, the protruding portion 300 made of aluminum filled in the longitudinal groove 22A may be processed, so that a highly accurate smooth surface can be easily obtained. it can.

(9) The multiple protrusions 300 constituting the covering portion 3A can be formed by flowing molten aluminum 5 into the multiple vertical grooves 22A formed in the cavity 20A of the mold 20, and the vertical grooves 22A Since it is formed in the vertical direction in the same direction as the inflow direction of the molten metal of aluminum 5, the molten metal of aluminum 5 flows smoothly. Therefore, even if the width dimension W of the protrusion 300 is small, the protrusion 300 can be easily formed.

(10) Planar processing of the multiple protrusions 300 constituting the covering portion 3A is performed by using a hot press, grinding or polishing with a tool, or annealing aluminum by heating the protrusions 300 at a predetermined temperature. Processing can be performed, and the protruding portion 300 can be rolled to obtain a highly accurate finished surface. As a result, since the selection of surface processing is expanded, surface processing according to equipment can be performed.

Next, a fourth embodiment of the present invention will be described based on FIGS.
As shown in FIG. 10, the composite material 1 </ b> C of the fourth embodiment includes a main body portion 7 and a shielding member embedded at a position entering the inside by a dimension L from one surface in the thickness direction of the main body portion 7. 6, and a covering portion 7 </ b> A is formed between the shielding member 6 and the one side surface.

As shown in FIGS. 11 and 12, the shielding member 6 includes a wire mesh 61 and a support member 62 that supports the wire mesh 61.
The wire net 61 is formed by weaving a wire member 61A. As the thickness of the copper wire of the wire member 61A, a wire diameter of, for example, 0.5 mm is used, and the mesh thereof is, for example, 0.4 mm. The communication hole 61D is configured by the 0.4 mm mesh.
Further, since the communication hole 61D is 0.4 mm, as shown in FIG. 12, SiC 4 having a particle size of, for example, 0.7 mm cannot pass through the communication hole 61D, and a part of the tip 4A of the SiC 4 is partially removed. It is stuck.

  The support member 62 is formed of, for example, a copper plate having a thickness of 0.5 mm, and includes a frame body 62A, a vertical beam 62B, and a horizontal beam 62C. For example, six large openings 62D are formed. The width dimensions of the frame body 62A, the vertical beam 62B, and the horizontal beam 62C are, for example, 0.5 mm.

  When the shielding member 6 is attached to the cavity 200 </ b> A of the mold 200, the distance between the one side surface of the cavity 200 </ b> A and the metal mesh 61 is the dimension L. Further, if plane processing is performed at a position inside the dimension L1 from the one side surface of the cavity 200A, processing can be performed without touching the SiC 4, and a high-precision smooth surface 7B can be formed as indicated by the finish symbol. Can be obtained.

Even though the wire mesh 61 is embedded in the covering portion 7A, the wire mesh 61 and the support member 62 are made of copper, and the thermal conductivity of copper is 0.938 cal / cm · / sec / ° C. In contrast, the thermal conductivity of aluminum 5 is 0.534 cal / cm · / sec / ° C., and copper has a much higher thermal conductivity than aluminum 5. Therefore, even if the metal mesh 61 and the support member 62 are embedded in the covering portion 4A, the high thermal conductivity of the composite material 1C is not hindered at all.
In addition, the melting point of copper is 1083 degrees, whereas the melting point of aluminum 5 is 660 degrees, and copper is much higher than aluminum 5, so that the preheating mold cavity 200A has aluminum 5 Even if the molten metal is injected, the metal mesh 61 and the support member 62 do not sag.

According to the fourth embodiment as described above, the following effects can be obtained in addition to substantially the same effects as the above (1), (2), (5), and (6).
(11) A wire mesh 61 embedded inside the cavity 20A from the one side surface by a predetermined dimension L has a communication hole 61D, and the diameter of the communication hole 61D is smaller than the grain size of SiC4 used. Therefore, aluminum 5 is filled in covering portion 7A between wire mesh 61 and one side surface of main body portion 7, but SiC4 does not enter. Therefore, when the composite material 1C is used, the aluminum 5 constituting the covering portion 7A and a part of the support member 62 may be planarized, so that the machining is easy and the highly accurate smooth surface 7B can be formed in a short time. Can be obtained.

(12) Since the wire mesh 61 is formed by weaving the copper wire member 61, it can be easily manufactured, and when the wire member 61 is weaved, the size of the mesh, that is, the communication hole 61D is arbitrarily changed. Therefore, it is possible to flexibly cope with SiC 4 having different particle sizes.

(13) Since the shielding member 6 is configured by attaching the wire mesh 61 to the support member 62, the wire mesh 61 does not wave or partially dent. In addition, since the melting point of copper is much higher than the melting point of the aluminum 5, even if the molten aluminum 5 is poured into the preheated mold cavity 200A, the metal net 61 and the support member 62 will not fall. Therefore, the shielding member 6 can be mounted stably.

Next, a fifth embodiment of the present invention will be described based on FIG.
In each of the above embodiments, the manufacturing apparatus 10 is used to manufacture the main body 2, the main body 3, and the main body 7. However, in the fifth embodiment, the composite material 1D is manufactured by the die casting machine 300. is there.

As shown in FIG. 13, a movable mold 321 and a fixed mold 322 are attached to a movable mold 310 and a fixed mold 311 of a die casting machine 300, respectively, and these molds 321 and 322 are divided surfaces (parting). Lines; P · L) are in contact with each other and are firmly clamped.
Nests 323 and 324 are fitted into the movable mold 321 and the fixed mold 322, respectively, and a cavity 321 </ b> A is formed on the contact surface of these inserts 323 and 324. The main body 2 is supported and attached to the cavity 321A by a support tool (not shown).
The thickness of the cavity 321A is, for example, 0.5 mm thicker than the thickness of the main body 2, and aluminum is injected into the gap of 0.5mm to form the covering 2G. It has come to be.

  A movable bush 331 and a fixed bush 332 are mounted inside each of the movable mold 321 and the fixed mold 322, and a runner 330 is formed by these. The runner 330 and the cavity 321 </ b> A are connected by a gate 340. A hot water reservoir 343 connected to the cavity 321A via a hot water outlet 341 is formed on the outer periphery of the cavity 321A and on the opposite side of the bushes 331 and 332. A degassing portion 344 is continuously formed in the hot water pool 343 so that air in the cavity 321A is released to the atmosphere at the time of injection.

  The molten metal of aluminum supplied from a hot water supply port (not shown) and injected by the sleeve flows into the runner 330, and the molten metal is filled into a gap between the cavity 321A and the main body 2 from the molten metal port 340, and the covering portion 2G. Is formed. A part of the molten metal is filled in the hot water pool 343 via the hot water outlet 341.

According to the fifth embodiment as described above, the following effects can be obtained in addition to substantially the same effects as the above (1), (2), (6), and (7).
(14) Since the production cycle of the composite material 1D is possible in a short time and can be mass-produced, it is possible to easily cope with a large amount of demand.

(15) After the main body 2 manufactured by the mold 20 is mounted on the movable mold 321 of the die casting machine 300 and the cavity 321A of the fixed mold 322, a molten aluminum is formed in the gap between the cavity 321A and the main body 2. Since the covering portion 2G is formed by filling, the covering portion 2G is formed only of aluminum. As a result, the covering portion 2G can be easily formed and can be easily processed, so that a highly accurate smooth surface can be easily formed.

The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the first embodiment, the cover part 2A is formed by performing electroless nickel plating on the front and back surfaces of the main body part 2 manufactured by the mold 20, but the present invention is not limited to this. The coating portion 3A formed by the multiple protrusions 300 of the third embodiment may be subjected to an electroless nickel plating process to form a smooth surface.

  In the fifth embodiment, the body 2 formed by the mold 20 is mounted in the cavity 321A of the die casting machine 300, and the aluminum 5 is injected to form the covering 2G. Not exclusively. For example, the die 20 in which the vertical groove 22A of the third embodiment is formed is used for the die casting machine, and a molten metal in which SiC4 and aluminum 5 are mixed at a predetermined ratio is injected into the cavity of the die to form a composite. A material may be formed.

  Further, in the fifth embodiment, after the molded body portion 2 is mounted in the mold cavity 321A, the molten aluminum is injected, but this is not limitative. For example, instead of the main body 2 formed by the mold 20 according to the first embodiment, a preform used in a high pressure casting method as described in, for example, Japanese Patent Application Laid-Open No. 11-170027 is used. May be. This preform is formed of ceramic particles or fibers such as silicon carbide. After the preform is mounted in the cavity 20A, a molten aluminum is injected into the cavity 20A to impregnate the preform with aluminum. You may form a coating | coated part simultaneously with forming a main-body part.

  In the third embodiment, the covering portion 3A is formed of aluminum filled in a large number of longitudinal grooves 22A. In the second embodiment, the covering portion 2B is an electroless nickel plating layer subjected to electroless nickel plating. However, the present invention is not limited to this. After forming the main body 2, for example, electroless nickel plating may be applied between the adjacent protrusions 300, or the main body 2 may be coated with aluminum, nickel, or the like by vacuum deposition. It may be formed.

  Next, examples of the present invention will be described.

In order to manufacture the main body 2 of the composite material 1, SiC particles having a particle size of 0.35 to 0.85 mm (a particle size of 42 to 20 mesh) are placed in a mold having a cavity having a thickness of 3 mm and a cavity volume of 58. % Amount was filled, and at the same time, the inside of the cavity was sucked into vacuum by a vacuum pump from the lower end of the mold. While continuing the suction, a molten metal of casting aluminum AC3A at 690 ° C. to 700 ° C. was injected from the upper part of the mold, and the gap between the SiC particles was impregnated with the 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 for 3 minutes.
As a result, the mold was cooled to such an extent that aluminum did not flow. Therefore, the mold was opened, the main body 2 was taken out, and was completely solidified at room temperature.
In addition, in this Example, it manufactured in order to verify high thermal conductivity.

About this main-body part, the thermal conductivity measurement by an electron microscope observation and the laser flash method was performed. As a result, as shown in FIG. 14, it was found that voids 6 exist at the interface between SiC 4 and aluminum 5. On the other hand, the thermal conductivity was 138 W / mK. The following treatment was performed in order to eliminate the voids 8 at the interface between the SiC particles and the aluminum 5 and further improve the thermal conductivity.
(A) The aluminum AC3A was processed at a temperature of 450 ° C., 500 ° C., and 550 ° C. at which the aluminum AC3A is in a semi-molten state or a softened state, respectively, with a pressure of 2 ton / cm 2 for 5 minutes. As a result, as shown in FIG. 15, it can be seen that the gaps at the interface between the SiC particles and aluminum are almost eliminated. 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 a very high thermal conductivity was obtained.
(B) After heating to 450 ° C. in a furnace, it was taken out from the furnace and rolled to 1.3 mm at a rolling rate of 10%. In this case, the voids at the interface between the SiC particles and the aluminum were almost eliminated. The thermal conductivity was also 205 W / mK, and a high value was also obtained in this case.
(C) The plate-shaped molded body, that is, the main body 2 was subjected to a forging process at a forging temperature of 460 ° C. As a result, there were almost no voids at the interface between the SiC particles and the aluminum. The thermal conductivity was 240 W / mK, and good results were obtained in this case as well.

  In order to manufacture the main body 2, a mold having a cylindrical cavity having a diameter of 100 mm is filled with SiC particles having a particle size of 0.7 to 7 mm (24 to 10 mesh) in an amount of 52% of the cavity volume. At the same time, the inside of the cavity was sucked into vacuum by a vacuum pump from the lower end of the mold. While continuing the suction, a molten aluminum at 690 ° C. to 700 ° C. of casting aluminum AC3A was poured from the upper part of the mold, and the molten aluminum was impregnated into the gaps of the SiC particles. Up to this point, the temperature of the mold was 550 ° C., and then the mold temperature was set to 530 ° C. for solidification for 3 minutes. As a result, the mold was cooled to such an extent that aluminum did not flow. Therefore, the mold was opened and the cylindrical main body was taken out and completely solidified at room temperature.

  The cylindrical main 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-like main body was evaluated in the same manner as in Example 1, almost no voids were observed at the interface between the SiC particles and aluminum. Further, the thermal conductivity was a very high value of 265 W / mK.

Next, a comparative example for each of the embodiments will be described.
As in each example, a mold having a cavity with a thickness of 3 mm was filled with SiC particles having a particle size of 0.35 to 0.85 mm in an amount of 58% of the cavity volume. However, vacuum is not sucked from the bottom of the mold, and a molten aluminum of 690 ° C. to 700 ° C. of casting aluminum AC3A is injected from the upper part of the mold to try to impregnate the molten aluminum in the gaps of the SiC particles. did. After cooling and solidification, the mold was opened and aluminum was not sufficiently impregnated.

  The present invention relates to a substrate for heat dissipation that absorbs and dissipates heat generated from a semiconductor such as an MPU or a power module, and a vacuum deposition apparatus, sputtering apparatus, CVD (chemical) as a film forming apparatus that forms a thin film on the surface of the substrate. Heat-emission substrate or carrier substrate used in vapor phase growth) equipment, heat equalizing plate for plasma TV production, housing used in electronic devices such as small personal computers and measuring devices, heat sink material, and vehicle control unit It is possible to absorb and dissipate the heat generated by the etc., or use it for the brake part or the like.

The longitudinal cross-sectional view which shows 1st Embodiment of the composite material which concerns on this invention. The cross-sectional view which shows the composite material of the said 1st Embodiment. The longitudinal cross-sectional view which shows the manufacturing apparatus which manufactures the composite material of the said 1st Embodiment. The longitudinal cross-sectional view which shows the detail of the composite material of the said 1st Embodiment. The longitudinal cross-sectional view which shows the use condition of the composite material of the said 1st Embodiment. The longitudinal cross-sectional view which shows 2nd Embodiment of the composite material which concerns on this invention. The longitudinal cross-sectional view which shows 3rd Embodiment of the composite material which concerns on this invention. The elements on larger scale which show the relationship between the metal mold | die of the said 3rd Embodiment, and a composite material. The whole perspective view which shows the vertical groove formed in one plate-shaped body of the said 3rd Embodiment. The longitudinal cross-sectional view which shows 4th Embodiment of the composite material which concerns on this invention. The perspective view which shows the relationship between the metal-mesh and support member of the said 4th Embodiment. The longitudinal cross-sectional view which shows the state which mounted | wore the cavity with the metal-mesh and support member of the said 4th Embodiment. The longitudinal cross-sectional view which shows 5th Embodiment of the composite material which concerns on this invention. FIG. 3 is a schematic cross-sectional view showing a state in which there is a gap in the composite material manufactured in Example 1. FIG. 3 is a schematic cross-sectional view showing a state in which voids of the composite material manufactured according to Example 1 have disappeared. Sectional drawing which shows the relationship between the ceramic of general composite material, and aluminum.

Explanation of symbols

1, 1A-1D ... Composite material
2, 3, 7 ... Main body
2A, 2B ... covering part
2C ... electroplating layer
3A, 3G ... covering part
4 ... SiC which is ceramic particles
5 ... Aluminum
7A ... covering part
10 ... Manufacturing equipment
20 ... Mold
20A ... cavity
22A ... Vertical groove
P ... Vacuum pump

Claims (4)

The ceramic particles having a relatively large particle size are 40 to 85% by volume, the aluminum or aluminum alloy is 15 to 60% by volume, and the aluminum or aluminum alloy forms a continuous phase in the gap between the ceramic particles, and In the composite material in which there is no gap at the interface between the ceramic particles and aluminum or aluminum alloy,
It is formed of a plate-shaped main body portion made of the ceramic particles and aluminum or an aluminum alloy, and a covering portion that covers at least one surface in the thickness direction of the main body portion and has excellent workability. Characteristic composite material. The composite material according to claim 1,
The composite material, wherein the covering portion is formed of an electroless nickel plating layer made of electroless nickel plating applied to a surface of the main body portion. The composite material according to claim 2,
An electroplated layer formed by electroplating is formed on the surface of the electroless nickel plated layer. A method for producing the composite material according to claim 2,
When the ceramic particles are combined with aluminum or an aluminum alloy using a mold, after the ceramic particles are accommodated in the cavity of the mold, the cavity of the mold is suctioned in vacuum The main body is formed by impregnating the gap between the ceramic particles with a molten aluminum or aluminum alloy, and after the main body is cooled in the mold, it is taken out of the mold, and then the main body A covering material is formed by an electroless nickel plating layer formed by performing electroless nickel plating on the front and back surfaces of the composite material.

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