JP2012057252A - Aluminum-silicon carbide composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum-silicon carbide composite material suitable as a base-plate for a power module.SOLUTION: There is provided the plate-like aluminum-silicon carbide composite material which is obtained through steps of: filling mixed powder 4 of 20-40 vol.% of metal powder mainly composed of aluminum powder and 60-80 vol.% of ceramic powder containing 90 vol.% of the silicon carbide having an average particle diameter of 10-350 μm, into dies 1, 2, 3 for performing forming; heating the mixed powder 4 at a temperature from the temperature which is lower than the lowest fusing point in the metal powder by 100K to a temperature T(K) less than the lowest fusing point to form a compact containing the ceramic powder by (Vf) vol.% with the pressure (P) of ≥30 MPa; pressurizing and forming the compact for a time t(second) satisfying 92≤16.23+(-0.54)×Vf+5.60×ln(P)+0.10×T+ln(t) to form the shape of one main surface into a protruding shape; and densifying the compact to have ≥92% relative density, so that thermal expansion coefficient of 25-150°C and warping variation per 200 mm at heating and cooling processes can satisfy the prescribed values.

Description

The present invention relates to an aluminum-silicon carbide composite suitable as a base plate for a power module and a heat dissipation component using the same.

Today, as the integration and size of semiconductor elements increase, the amount of generated heat continues to increase, and the issue is how to efficiently dissipate heat. A copper or aluminum metal circuit is formed on the surface of a ceramic substrate such as an aluminum nitride substrate or a silicon nitride substrate having high insulation and high thermal conductivity, and a metal heat sink made of copper or aluminum is formed on the back surface. This circuit board is used as a power module circuit board.

A typical heat dissipation structure of a conventional circuit board is formed by soldering a base plate via a metal plate, for example, a copper plate, on the back surface (heat dissipation surface) of the circuit board, and copper is generally used as the base plate. there were. However, in this structure, when a thermal load is applied to the semiconductor device, a crack caused by a difference in thermal expansion coefficient between the base plate and the circuit board occurs in the solder layer, and as a result, heat radiation becomes insufficient and the semiconductor element is There was a problem of malfunction or damage.

Therefore, an aluminum-silicon carbide composite has been proposed as a base plate having a thermal expansion coefficient close to that of a circuit board. As a method for producing the aluminum-silicon carbide composite for the base plate, a molten forging method (Patent Document 1) in which a silicon carbide porous body is impregnated with a molten aluminum alloy (Patent Document 1), an aluminum alloy porous silicon body is made of aluminum alloy. A non-pressure impregnation method (Patent Document 2) in which molten metal permeates without pressure has been put into practical use. On the other hand, in terms of cost, a powder metallurgy method in which aluminum powder and silicon carbide powder are mixed and heat-molded is advantageous, and an aluminum-silicon carbide composite by the same production method is also being studied (Patent Document 3). 4). However, the aluminum-silicon carbide composite by the powder metallurgy method has a problem that the thermal conductivity and the like are lower than those of the melt forging method.

The base plate is often used by being joined to a heat radiating fin, and the shape and warpage of the joined part are also important characteristics. For example, when joining the base plate to the heat radiating fins, it is common to apply heat radiating grease with high thermal conductivity and screw it to the heat radiating fins or heat radiating unit using the holes provided in the peripheral edge of the base plate. If there are a lot of minute irregularities on the plate, a gap will be created between the base plate and the heat radiating fins, and even if high heat conductive heat radiating grease is applied, the heat transfer will be significantly reduced. As a result, the ceramic circuit board and base There existed a subject that the heat dissipation of the whole module comprised with a board, a radiation fin, etc. will fall remarkably.

Therefore, there is a method of warping by cutting the surface of the base plate by machining, but since the aluminum-silicon carbide composite is very hard, it requires a lot of grinding using a tool such as diamond, and the cost is high. There was a problem of becoming.

Japanese Patent No. 3468358 JP-T-5-507030. JP-A-9-157773 JP-A-10-335538 Patent 3792180

The present invention has been made in view of the above situation, and an object thereof is to provide an aluminum-silicon carbide composite suitable as a base plate for a power module.

As a result of intensive studies to achieve the above object, the present inventor has optimized the particle size and content of silicon carbide powder in the aluminum-silicon carbide composite, and the temperature in the temperature range below the melting point of aluminum, The present invention was completed by obtaining the knowledge that the thermal conductivity can be improved by optimizing the heat molding conditions of pressure and time. Furthermore, the knowledge that the formation of holes in the plate-like aluminum-silicon carbide composite, the warp shape, and the warp stability can be imparted by complexing easily processable materials and adjusting the mold shape during thermoforming. The present invention has been completed.

That is, the present invention relates to aluminum powder, aluminum alloy powder, or metal powder containing a mixed powder of metal other than aluminum and aluminum of 20 volume% to 40 volume%, and silicon carbide having an average particle diameter of 10 μm to 350 μm of 90 volume% or more. A ceramic powder containing 60 volume% to 80 volume% is pressure-molded at a temperature 100K lower than the lowest melting point of the metal powder to a temperature lower than the lowest melting point of the metal powder. The thermal expansion coefficient up to 150 ° C. satisfies the range of actual measurement / calculated value = 1.1 to 1.3, and the heat radiation surface after 30 times of heating and cooling treatment in the temperature range of −40 ° C. to 125 ° C. It is a plate-shaped aluminum-silicon carbide composite having a warp variation on the long axis of 50 μm or less per 200 mm.

In addition, the present invention provides a mixed powder containing 20 mass% to 40 mass% of magnesium containing 0.5 mass% to 5.0 mass% of magnesium by adding magnesium powder or aluminum and magnesium alloy powder to aluminum powder or aluminum alloy powder. A mixed powder of 60% by volume to 80% by volume of ceramic powder containing 90% by volume or more of silicon carbide having an average particle diameter of 10 μm to 350 μm at a temperature lower by 100K than the lowest melting point among metal powders to metal powder And the thermal expansion coefficient from 25 ° C. to 150 ° C. satisfies the range of actually measured value / calculated value = 1.1 to 1.3, and −40 Plate-like aluminum-silicon carbide composite in which the amount of warpage change on the major axis of the heat radiating surface after 30 heating / cooling treatments in the temperature range of 950 ° C. to 125 ° C. is 50 μm or less per 200 mm It is.

Furthermore, the present invention is a plate-like aluminum-silicon carbide composite having a plate thickness of 2 to 6 mm manufactured through the following steps.
(1) Ceramic powder containing 20% by volume to 40% by volume of metal powder containing aluminum powder, aluminum alloy powder or mixed powder of aluminum and other metals, and 90% by volume or more of silicon carbide having an average particle size of 10 μm to 350 μm Step (2) for producing mixed powder of 60% by volume to 80% by volume (2) Step for filling the mixed powder into a mold and press-molding with a surface pressure of 10 MPa or more to produce a molded body (3) Aluminum formed body Or heating to a temperature T (K) lower than the lowest melting point of the metal powder of an aluminum alloy or other metal to a temperature T (K) lower than the lowest melting point of the metal powder. (4) Heating to the temperature T (K) The molded body containing Vf (volume%) of the ceramic powder was subjected to a pressure P (MPa) of 30 MPa or more using a concave mold having a shape of 0 to 500 μm per 200 mm on one main surface, and 92 ≦ One main surface of the aluminum-silicon carbide composite material is pressure-formed at time t (seconds) satisfying 6.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t) Forming a convex shape of 0 to 500 μm per 200 mm and densifying the relative density to 92% or more (5) forming holes and tap holes or countersinks in the obtained aluminum-silicon carbide composite Process

The present invention is a plate-like aluminum-silicon carbide composite having a metal layer of 50 μm to 300 μm on the surface and having a plate thickness of 2 to 6 mm, which is produced through the following steps. A plate-like aluminum-silicon carbide composite having a metal layer of 50 μm to 300 μm on the surface and having a plate thickness of 2 to 6 mm, which is manufactured through the following steps.
(1) When the mixed powder described in the preceding paragraph (2) is filled in the mold, the mixed powder and the metal foil are applied at a surface pressure of 10 MPa or more so that a metal layer is formed on one side or both sides of the molded body. Step of producing a molded body having a metal layer of 50 μm to 300 μm on one side or both sides by pressure molding (2) The temperature of the molded body is 100 K lower than the lowest melting point of metal powder of aluminum, aluminum alloy or other metal to metal Step of heating to a temperature T (K) below the lowest melting point of the powder (3) A molded body containing ceramic powder Vf (volume%) heated to a temperature T (K) is 0 per 200 mm on one main surface. Using a concave mold having a shape of ˜500 μm, satisfying 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t) at a pressure P (MPa) of 30 MPa or more. Press molding at time t (seconds) (4) Step of forming a convex shape of 0 to 500 μm per 200 mm and densifying the main surface of the aluminum-silicon carbide composite to a relative density of 92% or more (4) The obtained aluminum-silicon carbide composite Forming holes and tap holes or countersinks in the body

In addition, the present invention is manufactured through the following steps, and has a metal layer of 50 μm to 300 μm on the surface, and the aluminum-silicon carbide having a thickness of 2 to 6 mm whose hole surface is covered with the metal layer Quality complex.
An aluminum-silicon carbide composite having a metal layer of 50 μm to 300 μm on the surface and having a hole surface covered with the metal layer, which is manufactured through the following steps.
(1) When filling the mixed powder described in the previous paragraph into a mold, the mixed powder and the metal foil are pressure-molded at a surface pressure of 10 MPa or more so that a metal layer is formed on one or both surfaces of the molded body. Step (2) for producing a molded body having a metal layer of 50 μm to 300 μm on one side or both sides A hole is formed in a molded body having a metal layer on the surface by molding after molding or after molding into the hole of the molded body Step of placing a metal material having a diameter of 90% or more of the diameter of the hole (3) The molded body is at a temperature 100K lower than the lowest melting point of the metal powder of aluminum or aluminum alloy or other metal to the most of the metal powder Step (4) Heating to temperature T (K) below the low melting point (4) Concave mold having a shape of 0 to 500 μm per 200 mm on one main surface of a molded body containing ceramic powder heated to temperature T (K) Pressure of 30 MPa or more using (MPa), and pressure-molded at a time t (second) satisfying 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t), and aluminum-carbonized The step of forming a convex shape of 0 to 500 μm per 200 mm in the shape of one main surface of the silicon composite, and densifying the relative density to 92% or more (5) Metal material of the obtained aluminum-silicon carbide composite Forming a hole, tap hole or countersink having a shape 0.3 to 0.95 times the diameter of the metal material in the part by machining

The present invention is an aluminum-silicon carbide composite having a plate thickness of 2 to 6 mm, which has a metal layer of 50 μm to 300 μm on the surface and has holes penetrating on the front and back, manufactured through the following steps. .
(1) A step of forming a hole in a molded body having a metal layer on the surface described in the previous paragraph by machining after molding or after molding. (2) The molded body is made of aluminum, an aluminum alloy or other metal powder. (3) A step of heating to a temperature T (K) lower than the lowest melting point among metal powders, and (3) a molded body containing Vf (volume%) ceramic powder heated to the temperature T (K) Is a pressure P (MPa) of 30 MPa or more using a concave shape having a shape of 0 to 500 μm per 200 mm on one main surface, and 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) +0 .10 × T + ln (t) is pressure molded at time t (seconds) to form a convex shape and a hole of 0 to 500 μm per 200 mm on one main surface of the aluminum-silicon carbide composite, Density 9 Step of densifying to 2% or more

The present invention is manufactured through the following steps, and has a metal layer on the surface, the surface of the tap hole or countersink hole is covered with the metal layer, and a plate thickness of 2 to 6 mm having holes penetrating the other front and back This is an aluminum-silicon carbide composite.
Aluminum-silicon carbide having a metal layer on the surface, the surface of the tap hole or countersink hole being covered with the metal layer, and having holes penetrating on the other front and back, characterized by being manufactured through the following steps Quality complex.
(1) Temperature T (K) of the molded body and the metal material described in the previous paragraph at a temperature 100K lower than the lowest melting point of aluminum or an aluminum alloy or other metal powder to a temperature below the lowest melting point of the metal powder. (2) Using a concave mold having a shape of 0 to 500 μm per 200 mm on one main surface, a compact P containing ceramic powder heated to a temperature T (K) at a pressure T (30 MPa or more) MPa), and pressure-molded at a time t (second) satisfying 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t), and aluminum-silicon carbide Forming a convex shape of 0 to 500 μm per 200 mm in the shape of one main surface of the carbon composite and densifying the relative density to 92% or more (3) on the metal portion of the obtained aluminum-silicon carbide composite Forming a tapped hole or countersink by machining, and further forming a hole penetrating the aluminum-silicon carbide composite in the front and back sides

The present invention is a metal foil to be composited with an aluminum-silicon carbide composite, and an aluminum-silicon carbide composite in which the metal material is aluminum or an aluminum alloy.

The present invention relates to a composite of aluminum and ceramic fibers of 0.01 to 0.2 mm using ceramic fibers having a Vf of 2% by volume to 10% by volume instead of the metal foil used for the aluminum-silicon carbide composite. Is an aluminum-silicon carbide composite formed on one or both surfaces of the aluminum-silicon carbide composite.

The present invention is an aluminum-silicon carbide composite composed of independent silicon carbide particles in which silicon carbide particles having an average particle diameter of 10 μm to 350 μm are obtained when the aluminum-silicon carbide composite is immersed in a NaOH solution. .

The present invention is an aluminum-silicon carbide composite in which the outer peripheral shape of an aluminum-silicon carbide composite is processed by water jet processing, laser processing, or grinding.

The present invention is 25 ° C. of thermal conductivity of 150W / (m · K) or more, 25 ° C. to 150 DEG ° C. thermal expansion coefficient of ^{5 × 10 -6 / K~12 × 10} -6 / K, 3 -point bending strength of It is an aluminum-silicon carbide composite having 100 MPa or more and a relative density of 92% or more.

In the present invention, in a state where a stress of 10 kPa or more is applied so as to bend to a constant curvature, it is subjected to creep deformation by heat treatment at a temperature of 400 to 550 ° C. for 30 seconds or more, and a convex warpage shape is formed on the heat radiation surface side. This is a method for producing an aluminum-silicon carbide composite to be applied.

The present invention is for a power module in which the surface of an aluminum-silicon carbide composite is plated, one main surface is soldered or brazed to a ceramic circuit board, and the other main surface is used as a heat dissipation surface. It is a base plate.

The aluminum-silicon carbide composite of the present invention has characteristics of low thermal expansion and high thermal conductivity. The present invention optimizes the particle size and content of silicon carbide powder in an aluminum-silicon carbide composite obtained by heat-molding metal powder such as aluminum powder and silicon carbide powder at a temperature lower than the melting point of the metal. As a base plate for power modules equipped with semiconductor devices that require high reliability, aluminum-carbonized steel with stable warping behavior due to heating and cooling treatment is remarkably improved. The silicon composite is supplied at low cost.

Explanatory drawing which shows the preparation methods of an aluminum-silicon carbide composite (Example 1, laminated state before compounding) Explanatory drawing which shows the structure of an aluminum silicon carbide composite (Example 1, sectional structure of an aluminum silicon carbide composite) Explanatory drawing which shows the structure of an aluminum-silicon carbide composite (Example 2, sectional structure of an aluminum-silicon carbide composite) Explanatory drawing which shows the preparation methods of an aluminum-silicon carbide composite (Example 3, lamination state before compounding) Explanatory drawing which shows the structure of an aluminum-silicon carbide composite (Example 3, sectional structure of an aluminum-silicon carbide composite) Explanatory drawing which shows the structure of an aluminum silicon carbide composite (Example 4, sectional structure of an aluminum silicon carbide composite)

The aluminum-silicon carbide composite of the present invention comprises a first component made of an aluminum alloy whose main component is aluminum and a second component whose main component is silicon carbide. In the composite body in which different kinds of materials are combined as in the present invention, heat can be exchanged with each other because the interfaces of the different kinds of materials are firmly connected. For this reason, when the adhesion at the interface is poor, the thermal conductivity of the composite is governed by the matrix material (in the present invention, an aluminum alloy), and how high the thermal conductivity of the reinforcing material (in the present invention, silicon carbide) itself is. Even so, the thermal conductivity characteristics of the entire composite are less than the matrix material. The basic idea of the present invention is how to firmly adhere the metal component and the reinforcing material in the composite, and as a technique, the pressure and time for pressure forming the metal component at a temperature below the melting point are optimized. By doing so, the interface between the two is strengthened by densification utilizing the creep deformation of aluminum, and the desired characteristics are achieved.

Particularly important characteristics of the aluminum-silicon carbide composite of the present invention are thermal conductivity and coefficient of thermal expansion. For this reason, as a reinforcing material to be used, it is necessary that the raw material itself has a high thermal conductivity and a low thermal expansion coefficient, and silicon carbide is preferable. Furthermore, the heat transfer mechanism differs between silicon carbide and aluminum. For this reason, the heat transfer loss at the interface between the two materials greatly affects the thermal conductivity of the composite, and reducing the area of this interface (using silicon carbide powder having a large particle diameter) results in a composite It is effective in improving the thermal conductivity of

As a reinforcing material used for the aluminum-silicon carbide based composite of the present invention, it is preferable to contain 60 to 80% by volume of ceramic powder containing 90% by volume or more of silicon carbide. If the silicon carbide content is less than 90% by volume, it becomes difficult to maintain the low thermal expansion property and high thermal conductivity of the aluminum-silicon carbide composite. The ceramic powder is at least one selected from silicon nitride, aluminum nitride, boron nitride, diamond, and graphite, and may be added to silicon carbide as required in terms of strength, heat conduction, workability, and the like.

The average particle diameter of the silicon carbide powder is preferably 10 to 350 μm. With respect to the particle size of the silicon carbide powder, the average particle diameter is 10 μm or more from the viewpoint of thermal conductivity and densification of the aluminum-silicon carbide composite. On the other hand, when the average particle diameter exceeds 350 μm, the surface roughness of the aluminum-silicon carbide composite decreases and the strength characteristics decrease, which is not preferable. If the content of the silicon carbide powder is less than 60% by volume, the thermal conductivity of the aluminum-silicon carbide composite is lowered, and the thermal expansion coefficient is increased, which is not preferable. On the other hand, if the content of the silicon carbide powder exceeds 80% by volume, the aluminum-silicon carbide composite is insufficiently densified, and the strength and thermal conductivity are undesirably lowered. In order to increase the content of silicon carbide powder and achieve densification, it is preferable to mix silicon carbide powders having different average particle sizes. In this case, the average particle diameter of the silicon carbide powder is calculated from the average particle diameter and content of each silicon carbide powder. For this reason, when carrying out particle size blending, a powder having an average particle size of less than 10 μm and / or more than 350 μm can also be used. Furthermore, using a silicon carbide powder close to a spherical shape is effective for increasing the content.

The metal powder used in the present invention is an aluminum powder, an aluminum alloy powder, or a mixed powder of metal other than aluminum and aluminum. The composition of the aluminum alloy and the mixed powder of metal other than aluminum and aluminum is preferably 77 to 100% by mass of aluminum, 0 to 20% by mass of silicon, and 0 to 3% by mass of magnesium. As this metal powder, (1) a mixed metal powder is used, (2) a mixed metal powder and an alloy powder are used (for example, an aluminum powder, a silicon powder and an aluminum-magnesium alloy powder are used), (3 ) It is possible to use an alloy powder containing a predetermined amount of the three components. When the silicon component exceeds 20% by mass, the thermal conductivity of the obtained alloy is lowered, and as a result, the obtained thermal conductivity is lowered, which is not preferable. On the other hand, when the silicon component exceeds 20% by mass, the thermal conductivity of the obtained alloy is lowered, and the thermal conductivity of the obtained aluminum-silicon carbide composite is lowered, which is not preferable. The magnesium component has an effect of improving the adhesion between the obtained alloy and silicon carbide, and if it exceeds 5% by mass, it becomes easy to produce aluminum carbide (Al ₄ C ₃ ) at the time of compounding, and the thermal conductivity and strength are increased. It is not preferable in terms of the aspect.

The content of these metal powders is 20 to 40% by volume with respect to the obtained aluminum-silicon carbide composite. Here, the content (volume%) of the metal powder defines the content (volume%) with the average density of the metal powder being 2.7 g / cm ³ . If it is less than 20% by volume, the amount of metal powder at the time of hot press molding is insufficient, and densification of the aluminum-silicon carbide composite is insufficient. On the other hand, if it exceeds 40% by volume, a dense aluminum-silicon carbide based composite can be obtained, but this is not preferable because the thermal expansion coefficient of the aluminum-silicon carbide based composite becomes too large. Regarding the particle size of these metal powders, an average particle size of about 10 to 100 μm is suitable. If the average particle size is less than 10 μm, the densification is inhibited by oxidation of the metal particle surface, which is not preferable. On the other hand, when the average particle diameter exceeds 100 μm, it is difficult to make the metal particles more dense due to creep deformation, which is not preferable.

The mixing method of the raw material powder of the present invention is not particularly limited as long as the individual raw materials are uniformly mixed. Ball mill mixing, mixing with a mixer, and the like are possible. Regarding the mixing time, a time that does not allow oxidation and pulverization of the raw material powder is preferable, and depending on the mixing method and the filling amount, it is generally about 15 minutes to 5 hours. If the mixing time is short, insufficient densification of the aluminum-silicon carbide composite or non-uniformity of the composite structure may occur. On the other hand, if the mixing time is too long, the raw material powder is pulverized by oxidation and pulverization, and as a result, the thermal conductivity of the aluminum-silicon carbide composite may be lowered. Moreover, if it can be removed at the heating stage at the time of hot press molding, a shape-retaining binder or the like can be used as necessary.

The mold used in the hot press molding of the present invention is suitably made of an iron material such as cast iron or stainless steel from the viewpoint of strength, and although expensive, ceramics such as silicon nitride can also be used. Furthermore, a graphite mold can also be used. The mold is used by applying a release agent on the surface from the surface of the mold release property with the composite obtained by hot press molding. As the mold release agent, a mold release agent such as graphite, alumina, boron nitride or the like is suitable. In addition, by forming a thin film such as alumina on the mold and then applying a release agent, it is possible to obtain excellent mold release properties and extend the life of the mold. In addition, a release plate such as a graphite sheet can be used between the mold and the product as necessary.

In the present invention, a mixed powder of metal powder and silicon carbide powder is filled in a mold, and heat-molded at a temperature not higher than the melting point of the metal powder, thereby densifying plate-like aluminum-silicon carbide having a thickness of 2 to 6 mm. It is a quality complex. In this case, the plate thickness of the obtained plate-like aluminum-silicon carbide composite is adjusted by the amount of mixed powder filled in the mold. When the plate thickness is less than 2 mm, when used as a base plate for a power module, heat transfer in the surface direction is insufficient, and the heat dissipation characteristics of the entire power module are deteriorated. On the other hand, if the plate thickness exceeds 6 mm, the thermal resistance of the base plate itself increases due to the increase in the plate thickness, and as a result, the temperature of the semiconductor element increases excessively, which is not preferable. A more preferable plate thickness of the plate-like aluminum-silicon carbide composite is 3 to 5 mm.

In the present invention, the mixed powder is filled in a mold and pressure-molded to produce a molded body. The molding pressure of pressure molding is 10 MPa or more. If the pressure at the time of pressure molding is less than 10 MPa, the densification is insufficient, so that it becomes difficult to handle the molded body, and it is not preferable because it tends to be chipped. Further, the upper limit of the press pressure is not limited in terms of characteristics, but 300 MPa or less is appropriate from the strength of the mold and the strength of the apparatus.

In the present invention, the molded body is filled in a mold subjected to a release treatment, and heated to a temperature T (K) lower than the lowest melting point among metal powders to be used. The heating temperature is preferably in the range of a temperature that is 100K lower than the lowest melting point of the metal powder to be used and less than the lowest melting point of the metal powder. When the temperature is lower than 100 K lower than the melting point, the metal powder is not easily deformed, and the aluminum-silicon carbide composite is insufficiently densified, which is not preferable. On the other hand, when the heating temperature exceeds the melting point, aluminum leaks during molding, and characteristic variations such as thermal conductivity and strength tend to occur, which is not preferable.

In the present invention, pressure, temperature, time, and ceramic filling amount are main conditions that affect the relationship between the thermoforming conditions and the density of the aluminum-silicon carbide composite. Logarithm of molding pressure (ln (P)) and density are proportional, molding temperature (T) and density are proportional, logarithm of molding time (ln (t)) and density are proportional, and ceramic filling amount The density decreases as Vf increases.

In the present invention, a multiple regression analysis of these relational expressions is performed, and it is derived that a dense body having a relative density of ≧ 92% can be obtained by satisfying the following expression. A molded body containing Vf (volume%) of ceramic powder heated to a temperature T (K) at a pressure P (MPa) of 30 MPa or more and a relational expression 92 ≦ 12.23 + (− 0.54) × Vf + 5.60 × ln ( P) Press molding at time t (seconds) so as to satisfy + 0.10 × T + ln (t).

The aluminum-silicon carbide composite is pressure-molded at a temperature below the melting point and then cooled to room temperature. For the purpose of removing the strain at the time of compounding, annealing treatment of the aluminum-silicon carbide composite may be performed.

The annealing treatment performed for the purpose of removing strain at the time of compounding is preferably performed at a temperature of 400 ° C. to 550 ° C. for 10 minutes or more. If the annealing temperature is less than 400 ° C., the distortion inside the composite may not be sufficiently released, and the shape may change due to heat treatment after machining. On the other hand, when the annealing temperature exceeds 550 ° C., the aluminum alloy in the composite may be melted. When the annealing time is less than 10 minutes, even if the annealing temperature is 400 ° C. to 550 ° C., the distortion inside the composite is not sufficiently released, and the shape may be changed by the heat treatment after machining.

When the surface of one side or both sides of the aluminum-silicon carbide based composite is covered with a metal layer mainly composed of aluminum, it is suitable for plating the aluminum-silicon carbide based composite.

As the material of the metal layer on the surface, aluminum or aluminum alloy that is easily in close contact with the aluminum-silicon carbide composite is preferable, and pressure molding is performed at a temperature lower than the melting point of the aluminum or aluminum alloy by 100K to a temperature lower than the melting point. Thus, the composite can be formed on the surface of the aluminum-silicon carbide composite.

The thickness of the metal layer formed on one or both surfaces of the aluminum-silicon carbide composite is preferably 50 to 300 μm. If the thickness of the metal layer is 50 μm or more, the plating property can be ensured. On the other hand, if the thickness of the metal layer exceeds 300 μm, the thermal expansion coefficient of the aluminum-silicon carbide composite increases, which is not preferable.

Furthermore, this surface layer is formed on a single-sided or double-sided ceramic fiber having a thickness of 0.1 to 1.0 mm and a Vf (ceramics content) of 2 to 10% by volume on a mold that has been subjected to a mold release process during lamination. It can be prepared by placing, filling a mixed powder of metal powder and silicon carbide powder, and press-molding at a temperature below the lowest melting point of the metal powder. In the aluminum-silicon carbide composite obtained by the above production method, a surface layer made of an aluminum-ceramic fiber composite having a thickness of 0.01 to 0.2 mm is formed on both main surfaces.

In the aluminum-ceramic fiber composite layer, the content other than the aluminum alloy is preferably less than 30% by volume because of the plating property. For this reason, as ceramic fiber arrange | positioned in a metal mold | die, thickness is 0.1-1.0 mm and Vf shall be 2-10 volume%. When the thickness of the ceramic fiber exceeds 1.0 mm, a sufficiently densified aluminum-ceramic fiber composite layer cannot be obtained by hot press molding, which is not preferable. The lower limit of the thickness of the ceramic fiber is not limited by characteristics, but is preferably 0.1 mm or more from the viewpoint of handling properties. Moreover, when Vf of ceramic fiber exceeds 20 volume%, content other than the aluminum alloy of the aluminum-ceramic fiber composite layer obtained exceeds 30 volume%, and plating property falls and it is not preferable. The lower limit of Vf is not limited by characteristics, but is preferably 3% by volume or more from the viewpoint of handling properties. Although it does not specifically limit as a ceramic fiber, Ceramic fibers, such as an alumina fiber, a silica fiber, and a mullite fiber, can use preferably from a heat resistant surface.

In the present invention, a convex warp of 0 to 500 μm per 200 mm is formed on one main surface by hot press molding using a mold having a concave warp of 0 to 500 μm per 200 mm during hot press molding. Can be granted. In this case, by machining the die surface into a concave shape with a warp amount of 0 to 500 μm, the obtained plate-like aluminum-silicon carbide composite can obtain an ideal spherical heat dissipation surface. Therefore, good heat dissipation characteristics can be obtained. When the plate-like aluminum-silicon carbide composite of the present invention is used as a base plate for a power module, if the amount of warpage is less than 0 μm per 200 mm in length, the base plate and the radiating fin are not assembled in the subsequent module assembly process. Even if high thermal conductivity heat dissipation grease is applied, the heat transfer performance is significantly reduced, resulting in a significant decrease in the heat dissipation performance of the module composed of ceramic circuit board, base plate, heat dissipation fins, etc. May end up. On the other hand, if the amount of warpage exceeds 500 μm, a crack may occur in the base plate or the ceramic circuit board at the time of screwing at the time of joining to the heat radiating fin, which is not preferable.

Further, as a method of forming the warp of the plate-like aluminum-silicon carbide composite of the present invention, the plate-like aluminum-silicon carbide composite is 10 kPa or more so as to bend into a curvature that results in a warp of 100 to 1000 μm per 200 mm. In a state where the stress is applied, the film is subjected to creep deformation by heat treatment at a temperature of 400 to 550 ° C. for 30 seconds or more to give a convex warp of 50 to 500 μm per 200 mm. When the stress applied during the heat treatment is less than 10 kPa, the amount of bending is insufficient, and the desired amount of warpage cannot be obtained. Further, even if the processing temperature is less than 400 ° C. or the processing temperature is 400 to 550 ° C., if the processing time is less than 30 seconds, sufficient creep deformation cannot be caused, and the desired amount of warpage cannot be obtained. When the treatment temperature exceeds 550 ° C., problems such as a decrease in density due to the movement of the metal component in the composite occur, which is not preferable.

When the plate-like aluminum-silicon carbide composite having a convex warp on one main surface is heated and cooled, the amount of change in warpage per 200 mm in length is preferably 100 μm or less, more preferably 50 μm or less. It is. If the amount of change in warpage is greater than 100 μm, the warp of the base plate of the power module may be greatly deformed, resulting in insufficient heat dissipation from the power module to the heat sink.

The heating and cooling treatment is not particularly limited as long as the object is maintained at a predetermined temperature. For example, after the plate-like aluminum-silicon carbide composite is held in a temperature atmosphere of −40 ° C. for 30 minutes. , Maintained in a temperature atmosphere of 125 ° C. for 30 minutes, and can be made one cycle.

Since the aluminum-silicon carbide composite of the present invention is compounded by densification by creep deformation of a metal mainly composed of aluminum, it is compared with a complex of molten aluminum and ceramics such as a molten metal forging method or die casting method. In addition, since the residual stress in the composite is small, the amount of change in warpage during the heating and cooling treatment of the base plate is small.

Next, the example of the processing method of the aluminum-silicon carbide composite of this invention is demonstrated. Since the aluminum-silicon carbide composite is a very hard and difficult-to-process material, the aluminum-silicon carbide composite can be directly drilled. However, an easily processable metal material, preferably aluminum or aluminum, is used in the drilled portion. By compounding the alloy, holes, countersinks, and tap holes can be easily formed. In addition, only a portion requiring a complicated processing shape such as a countersink or a tap hole portion can be made into an easily processable material, and the through hole can be processed into an aluminum-silicon carbide composite.

As the easily processable material, a workable material such as graphite or boron nitride can be selected in addition to the metal aluminum or aluminum alloy.

When aluminum or an aluminum alloy is compounded in the hole processed portion, it is preferable to perform the hole processing 0.3 to 0.95 times the diameter of the aluminum or aluminum alloy portion. When the hole diameter is larger than 0.95 times, the tool for metal processing hits the aluminum-silicon carbide composite part, and the life is reduced. If the hole diameter is smaller than 0.3 times, the interface may crack due to the difference in thermal expansion coefficient between the aluminum-silicon carbide composite and the aluminum or aluminum alloy portion.

The aluminum-silicon carbide composite is a very hard and difficult-to-work material, but the outer peripheral portion can be processed by a water jet processing machine. As a result, the obtained aluminum-silicon carbide composite has a structure in which the aluminum-silicon carbide composite is exposed at the outer periphery. Here, the said hole part should just be provided so that an up-and-down surface may be penetrated so that it can be screwed to another heat radiating component.

The aluminum-silicon carbide based composite of the present invention can be processed on the outer peripheral portion even by using laser processing. The obtained aluminum-silicon carbide composite has a structure in which the aluminum-silicon carbide composite is exposed on the outer periphery. Although the aluminum-silicon carbide composite of the present invention can be processed using a normal diamond tool or the like, it is a very hard and difficult-to-process material, so from the viewpoint of tool durability and processing cost. Processing by a water jet processing machine or laser processing is preferable. Furthermore, the main surface of the aluminum-silicon carbide based composite of the present invention can be polished or ground as necessary.

When the aluminum-silicon carbide composite of the present invention is used as a base plate for a power module, particularly important characteristics are thermal conductivity and thermal expansion coefficient. For this reason, as the reinforcing material to be used, silicon carbide having a high thermal conductivity and a low thermal expansion coefficient is selected. Further, since the heat transfer mechanism is different between silicon carbide and aluminum, at the interface between the two materials. In order to suppress heat transfer loss, the area of this interface is reduced (use of silicon carbide powder having a large particle diameter) and the mixing ratio is optimized, thereby improving the thermal conductivity and reducing the thermal expansion coefficient. I have control. In the present invention, the metal powder to be used is heat-molded at a temperature lower than the lowest melting point so that the interface between the aluminum deformed by creep deformation and the silicon carbide powder as the reinforcing material is adhered, and the aluminum-silicon carbide It controls the porosity of the composite and improves the heat conduction characteristics.

The thermal conductivity in the plate thickness direction at a temperature of 25 ° C. of the aluminum-silicon carbide composite of the present invention is 150 W / mK or more. A thermal conductivity of less than 150 W / mK is not preferable because sufficient heat dissipation characteristics cannot be obtained when used as a heat dissipation component such as a base plate for a power module. The upper limit of the thermal conductivity is not limited in terms of characteristics, but is 300 W / mK or less due to the characteristics of silicon carbide itself.

In the present invention, since the aluminum-silicon carbide composite is produced by hot press molding, the resulting aluminum-silicon carbide composite inevitably has anisotropy in characteristics due to the orientation of the raw material powder. . In the composite of the present invention, due to the orientation of silicon carbide having a high thermal conductivity, the thermal conductivity in the main surface direction is larger than the thermal conductivity in the plate thickness direction, and the thermal conductivity in the plate thickness direction is higher than that in the main surface direction. It is preferable that it is 80% or more of the rate.

The thermal expansion coefficient of the aluminum-silicon carbide composite of the present invention at a temperature of 25 ° C. to 150 ° C. is 5 × 10 ^{−6 to} 12 × 10 ⁻⁶ / K. When used as a heat radiating component such as a base plate for a power module, matching of the thermal expansion coefficient with the ceramic circuit board to be joined is very important. If the thermal expansion coefficient is less than 5 × 10 ^{−6 /} K or more than 12 × 10 ⁻⁶ / K, the thermal load during the operation of the semiconductor element causes destruction of the bonding layer (solder layer, etc.) and ceramics, resulting in heat dissipation characteristics. May decrease, which is not preferable.

The coefficient of thermal expansion of the aluminum-silicon carbide composite of the present invention at a temperature of 25 ° C. to 150 ° C. is calculated based on the assumption that the interface between aluminum and silicon carbide is completely adhered to the actual value. It is preferable that the ratio of actually measured values reflecting the complete adhesion state satisfy the range of actually measured values / calculated values = 1.1 to 1.3. When the actual measurement value / calculated value is less than 1.1, the residual stress in the aluminum-silicon carbide composite is likely to remain large because the adhesion at the interface between aluminum and silicon carbide is too good, and the warp change during heating and cooling treatment The amount may be large. If the measured value / calculated value is greater than 1.3, the adhesion between the aluminum and silicon carbide interface is poor and densification is insufficient, resulting in a decrease in properties such as relative density, thermal conductivity, and strength. This is not preferable.

The calculation method of the calculated value of the thermal expansion coefficient was calculated using the following Turner formula, which is a theoretical formula of the thermal expansion coefficient of the particle-dispersed composite material.

αc: Thermal expansion coefficient of composite, αp: Thermal expansion coefficient of particles, αm: Thermal expansion coefficient of matrix Vp: Volume ratio of particles, Vm: Volume ratio of matrix Kp: Volumetric modulus of particles, Km: Volume of matrix Elastic modulus

The porosity of the aluminum-silicon carbide composite of the present invention is less than 8% by volume. When the porosity exceeds 8% by volume, characteristics such as thermal conductivity are deteriorated, and when used as a heat dissipation part such as a base plate for a power module, the corrosion resistance of the module itself due to the permeation of moisture from the usage environment, etc. Problems occur and are not preferred.

The three-point bending strength of the aluminum-silicon carbide composite of the present invention is preferably 100 MPa or more. When the aluminum-silicon carbide composite is used as a heat radiating part such as a base plate for a power module, if the three-point bending strength is less than 100 MPa, cracks due to screwing, or chipping due to vibration during use, etc. There is a problem and is not preferable. There is no restriction on the upper limit of the three-point bending strength, but in order to extremely improve the three-point bending strength, it is necessary to increase the amount of silicon carbide added and to pulverize. As a result, the resulting aluminum -The thermal conductivity of the silicon carbide composite decreases.

When the aluminum-silicon carbide composite according to the present invention is used as a base plate for a power module, it is generally used after processing a mounting hole or the like and then joining to a ceramic circuit board by soldering. For this reason, it is necessary to apply Ni plating to the surface of the aluminum-silicon carbide composite. The plating method is not particularly limited, and any of electroless plating and electroplating may be used. The thickness of the Ni plating is preferably 1 to 20 μm. If the plating thickness is less than 1 μm, plating pinholes are partially generated, solder voids (voids) are generated during soldering, and the heat dissipation characteristics from the circuit board may be deteriorated. On the other hand, when the thickness of the Ni plating exceeds 20 μm, plating peeling may occur due to a difference in thermal expansion between the Ni plating film and the surface aluminum alloy. The purity of the Ni plating film is not particularly limited as long as it does not hinder solder wettability, and may contain phosphorus, boron, or the like. Furthermore, it is also possible to apply gold plating to the Ni plating surface.

The joining of the aluminum-silicon carbide composite and the ceramic circuit board according to the present invention can be brazed via an active metal brazing material. The active metal brazing material may be a paste, but an alloy foil is preferred for handling. In this case, the active metal brazing material preferably has a lower melting point than the alloy as the metal component of the aluminum-silicon carbide composite. For example, Cu 1-6 mass% Al—Cu alloy foil, 2018 alloy foil containing 4 mass% Cu and 0.5 mass% Mg, 2017 alloy foil containing 0.5 mass% Mn, and JIS alloy 2001, Alloy foils such as 2003, 2005, 2007, 2011, 2014, 2024, 2025, 2030, 2034, 2036, 2048, 2090, 2117, 2124, 2218, 2224, 2324, 7050, and 7075 can be used. Further, it is possible to use a material containing up to 5% by mass of a third component such as Mg, Zn, In, Mn, Cr, Ti, Bi and the like.

[Example 1]
Silicon carbide powder A (manufactured by Taiyo Random Corporation / average particle size: 120 μm, density: 3.2 g / cm ³ ): 141.4 (32.5% by volume) g, silicon carbide powder B (manufactured by Taiyo Random Corporation / Average particle size: 10 μm, density: 2.2 g / cm ³ ): 141.4 g (32.5% by volume), aluminum powder (Alcoa Corp./average particle size: 25 μm): 128.0 g in a ball mill for 1 hour After mixing, 402.7 g of the mixed powder was weighed. Next, a cast iron mold 1 (outer dimension: 250 × 200 × 50 mm, inner dimension: 190 × 140 × 50 mm) and mold 2 (lower part: 250 × 200 × 20 mm, upper part: 189.9 shown in FIG. × 139.9 × 10 mm, warp of 200 μm per 200 mm) after applying graphite and boron nitride as a release agent, and then laminating and placing pure aluminum foil (100 μm) on the surfaces of the molds 2 and 3, A molded body of the mixed powder and aluminum foil was produced. Similarly, a mold 3 (189.9 × 139.9 × 60 mm) coated with a release agent was laminated, and preformed with a hydraulic press at a surface pressure of 50 MPa.

Next, this laminate was heated in an electric furnace to a temperature of 600 ° C. in an air atmosphere and held for 15 minutes, so that the temperature of the laminate was 600 ° C. The heated laminate was heat-molded with a hydraulic press at a surface pressure of 100 MPa for 3 minutes through a heat insulating material having a thickness of 5 mm, and then the pressure was released to cool to room temperature. Next, the mold 2 is removed, the mold 3 is pushed in with a hydraulic press, the molded body is taken out, and then the graphite sheet arranged for mold release is peeled off, and a 190 × 140 × 5 mmt aluminum-silicon carbide composite Got the body.

The obtained aluminum-silicon carbide composite uses a garnet having a particle size of 100 μm as abrasive grains under the conditions of a pressure of 250 MPa and a processing speed of 50 mm / min by a water jet processing machine (Abrasive Jet Cutter NC manufactured by Sugino Machine). Then, the outer peripheral portion was processed into a shape of 187 mm × 137 mm × 5 mm.

Next, this aluminum-silicon carbide composite was subjected to Φ7 drilling at 8 edges and Φ8.6 countersink at 4 edges using a diamond tool at a machining center.

Result of measuring the shape of the heat radiating surface of the obtained aluminum-silicon carbide composite with a contact-type two-dimensional contour measuring machine (manufactured by Tokyo Seimitsu Co., Ltd .; contour record 1600D-22) and measuring the amount of warpage per 200 mm. 200 μm.

The aluminum-silicon carbide composite is held in an air bath atmosphere at −40 ° C. and 125 ° C. for 30 minutes, respectively, and the shape of the heat radiating surface after 30 heating / cooling treatments is performed. It was 190 micrometers as a result of measuring with Tokyo Seimitsu company; Contour record 1600D-22) and measuring the amount of curvature per 200 mm.

Next, after blasting with alumina abrasive grains under conditions of a pressure of 0.3 MPa and a conveyance speed of 1.0 m / min to clean, electroless Ni—P and Ni—B plating are performed, and the composite surface is 8 μm thick. A plating layer (Ni—P: 6 μm + Ni—B: 2 μm) was formed. The obtained plated product was good with no pinholes confirmed with the naked eye.

From the aluminum-silicon carbide composite obtained by thermoforming, a specimen for thermal conductivity measurement in the plate thickness direction (diameter 11 mm, thickness 3 mm) and a specimen for thermal expansion coefficient measurement (3 × 3 × 10 mm) are obtained by grinding. ) And. Using each test piece, the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was measured with a thermal dilatometer (manufactured by Seiko Denshi Kogyo; TMA300), and the thermal conductivity at 25 ° C. was measured with a laser flash method (manufactured by Rigaku Corporation); LF / TCM-8510B). As a result, the thermal conductivity in the plate thickness direction at a temperature of 25 ° C. was 160 W / mK, and the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was 9.9 × 10 ⁻⁶ / K (actual value / calculation). Value = 1.3).

A three-point bending strength measurement specimen (3 × 4 × 40 mm) was prepared from the aluminum-silicon carbide composite by grinding, and the three-point bending strength was measured with a bending strength tester. . Furthermore, the density of the aluminum-silicon carbide composite was measured by the Archimedes method, and the porosity was calculated. As a result, the porosity was 4.0% by volume. When a compact containing 65% by volume of ceramic powder heated to a temperature of 873K is heat molded at 100 MPa for 180 seconds, the following formula {16.23 + (− 0.54) × Vf + 5.60 × ln (P) +0.10 The value of × T + ln (t)} was 99.

[Example 2]
Silicon carbide powder A (manufactured by Taiyo Random Co./average particle size: 120 μm, density: 3.2 g / cm ³ ): 141.4 g (32.5% by volume), silicon carbide powder B (manufactured by Taiyo Random Co., Ltd./average Particle size: 10 μm, density: 2.2 g / cm ³ ): 141.4 g (32.5% by volume), aluminum powder (Alcoa / average particle size: 25 μm): 126.3 g, magnesium powder (average particle size) : 50 μm): 1.3 g was mixed with a ball mill for 1 hour, and 402.2 g of the mixed powder was weighed. Next, in the same manner as in Example 1 except that a 50 μm aluminum foil was used, a molded body of mixed powder and aluminum foil was prepared by 50 MPa pre-molding, and φ8 A through hole having a diameter of 10.2 mm was formed in the molded body at 2 mm and at four edges. A pure aluminum material having a diameter of Φ8.0 mm and a diameter of Φ9.0 mm was placed in the through hole, and was laminated on the mold 1, the mold 2, and the mold 3 to produce a laminate.

  Next, this laminate is subjected to thermoforming in the same manner as in Example 1 to form an aluminum-carbonized carbon having a metal layer of 50 μm on the surface of 190 × 140 × 5 mmt and pure aluminum materials of Φ8 and Φ10. A silicon composite was obtained.

The obtained aluminum-silicon carbide composite was processed into a shape of 187 mm × 137 mm × 5 mm by grinding the outer peripheral portion.

Next, a pure aluminum portion of this aluminum-silicon carbide composite is machined with a metal processing tool using a tool for metal processing at a hole portion of Φ7 at a peripheral edge portion of 8 and a countersunk hole of Φ8.6 at a peripheral edge portion of four locations. Processed.

Result of measuring the shape of the heat radiating surface of the obtained aluminum-silicon carbide composite with a contact-type two-dimensional contour measuring machine (manufactured by Tokyo Seimitsu Co., Ltd .; contour record 1600D-22) and measuring the amount of warpage per 200 mm. 190 μm.

The aluminum-silicon carbide composite is held in an air bath atmosphere at −40 ° C. and 125 ° C. for 30 minutes, respectively, and the shape of the heat radiating surface after 30 heating / cooling treatments is performed. It was 194 micrometers as a result of measuring with Tokyo Seimitsu company; Contour record 1600D-22) and measuring the amount of curvature per 200 mm.

Next, after blasting with alumina abrasive grains under conditions of a pressure of 0.3 MPa and a conveyance speed of 1.0 m / min to clean, electroless Ni—P and Ni—B plating are performed, and the composite surface is 8 μm thick. A plating layer (Ni—P: 6 μm + Ni—B: 2 μm) was formed. The obtained plated product was good with no pinholes confirmed with the naked eye.

From the aluminum-silicon carbide composite obtained by hot press molding, a specimen for measuring thermal conductivity in the plate thickness direction (diameter 11 mm, thickness 3 mm) and a specimen for measuring thermal expansion coefficient (3 × 3 ×) by grinding. 10 mm) and. Using each test piece, the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was measured with a thermal dilatometer (manufactured by Seiko Denshi Kogyo; TMA300), and the thermal conductivity at 25 ° C. was measured with a laser flash method (manufactured by Rigaku Corporation); LF / TCM-8510B). As a result, the thermal conductivity in the plate thickness direction at a temperature of 25 ° C. was 175 W / mK, and the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was 9.8 × 10 ⁻⁶ / K (actual value / calculation). Value = 1.3).

A three-point bending strength measurement specimen (3 × 4 × 40 mm) was prepared from the aluminum-silicon carbide composite by grinding, and the three-point bending strength was measured with a bending strength tester. As a result, it was 210 MPa. . Furthermore, as a result of measuring the density of the aluminum-silicon carbide composite by the Archimedes method and calculating the porosity, the porosity was 3.0% by volume.

[Example 3]
Silicon carbide powder A (manufactured by Taiyo Random Co./average particle size: 120 μm, density: 3.2 g / cm ³ ): 141.4 g (32.5% by volume), silicon carbide powder B (manufactured by Taiyo Random Co., Ltd./average Particle size: 10 μm, density: 2.2 g / cm ³ ): 141.4 g (32.5% by volume), aluminum powder (Alcoa / average particle size: 25 μm): 125.0 g, aluminum-magnesium alloy powder ( Al: Mg = 50: 50, average particle size: 40 μm): 2.6 g was mixed with a ball mill for 1 hour, and 402.2 g of the mixed powder was weighed. Next, a molded product having through holes Φ7.0 mm at eight edge peripheral portions by pre-molding at 10 MPa in the same manner as in Example 1 except that a 200 μm aluminum foil was used and the mold of FIG. 4 was used. Was made. A laminate was prepared by laminating the mold 1, the mold 2 and the mold 3.

  Next, this laminate was heat-molded in the same manner as in Example 1 to form a metal layer of 200 μm pure aluminum on the surface of 190 × 140 × 5 mmt, and through holes Φ7.0 mm at eight edge portions. The obtained aluminum-silicon carbide composite was obtained.

Using the obtained aluminum-silicon carbide composite with a water jet processing machine (Abrasive Jet Cutter NC manufactured by Sugino Machine) under the conditions of a pressure of 250 MPa and a processing speed of 50 mm / min, a garnet having a particle size of 100 μm is used as abrasive grains. Then, the outer peripheral portion was processed into a shape of 187 mm × 137 mm × 5 mm.

Result of measuring the shape of the heat radiating surface of the obtained aluminum-silicon carbide composite with a contact-type two-dimensional contour measuring machine (manufactured by Tokyo Seimitsu Co., Ltd .; contour record 1600D-22) and measuring the amount of warpage per 200 mm. 220 μm.

The aluminum-silicon carbide composite is held in an air bath atmosphere at −40 ° C. and 125 ° C. for 30 minutes, respectively, and the shape of the heat radiating surface after 30 heating / cooling treatments is performed. It was 185 micrometers as a result of measuring with Tokyo Seimitsu company; Contour record 1600D-22) and measuring the amount of curvature per 200 mm.

Next, after blasting with alumina abrasive grains under conditions of a pressure of 0.3 MPa and a conveyance speed of 1.0 m / min to clean, electroless Ni—P and Ni—B plating are performed, and the composite surface is 8 μm thick. A plating layer (Ni—P: 6 μm + Ni—B: 2 μm) was formed. The obtained plated product was good with no pinholes confirmed with the naked eye.

From the aluminum-silicon carbide composite obtained by hot press molding, a specimen for measuring thermal conductivity in the plate thickness direction (diameter 11 mm, thickness 3 mm) and a specimen for measuring thermal expansion coefficient (3 × 3 ×) by grinding. 10 mm) and. Using each test piece, the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was measured with a thermal dilatometer (manufactured by Seiko Denshi Kogyo; TMA300), and the thermal conductivity at 25 ° C. was measured with a laser flash method (manufactured by Rigaku Corporation); LF / TCM-8510B). As a result, the thermal conductivity in the plate thickness direction at a temperature of 25 ° C. was 185 W / mK, and the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was 9.7 × 10 ⁻⁶ / K (actual value / calculation). Value = 1.3).

A three-point bending strength measurement specimen (3 × 4 × 40 mm) was produced from the aluminum-silicon carbide composite by grinding, and the three-point bending strength was measured with a bending strength tester. As a result, it was 230 MPa. . Furthermore, as a result of measuring the density of the aluminum-silicon carbide composite by Archimedes method and calculating the porosity, the porosity was 2.5% by volume.

[Example 4]
Silicon carbide powder A (manufactured by Taiyo Random Co./average particle size: 120 μm, density: 3.2 g / cm ³ ): 141.4 g (32.5% by volume), silicon carbide powder B (manufactured by Taiyo Random Co., Ltd./average Particle size: 10 μm, density: 2.2 g / cm ³ ): 141.4 g (32.5% by volume), aluminum powder (Alcoa / average particle size: 25 μm): 117.8 g, silicon powder (manufactured by Elchem) / Average particle size: 10 μm) 6.3 g, Magnesium powder (average particle size: 50 μm): 1.3 g were mixed in a ball mill for 1 hour, and 401.4 g of the mixed powder was weighed. Next, in the same manner as in Example 1 except that 300 μm aluminum foil (A3003 material) was used, a molded body of the mixed powder and the aluminum foil was produced by 50 MPa pre-molding, and the peripheral portion 4 was machined. A through hole having a diameter of 10.2 mm was formed in the molded body at the place. A Φ10.0 mm aluminum material (A5052 material) was placed in the through hole, and was laminated on the mold 1, the mold 2 and the mold 3 to produce a laminate.

Next, this laminate is subjected to thermoforming in the same manner as in Example 1 to form an aluminum-silicon carbide composite having a 300 μm aluminum metal layer and a Φ10 mm aluminum material on a 190 × 140 × 5 mmt surface. Got.

Using the obtained aluminum-silicon carbide composite with a water jet processing machine (Abrasive Jet Cutter NC manufactured by Sugino Machine) under the conditions of a pressure of 250 MPa and a processing speed of 50 mm / min, a garnet having a particle size of 100 μm is used as abrasive grains. Then, the outer peripheral portion was processed into a shape of 187 mm × 137 mm × 5 mm.

Next, a pure aluminum portion of the aluminum-silicon carbide based composite is formed at a machining center by using a metal processing tool to form M4 tapped holes in the aluminum material portions at four peripheral portions, and using a diamond tool. Then, through-holes Φ7 mm were processed at eight places on the peripheral edge.

Result of measuring the shape of the heat radiating surface of the obtained aluminum-silicon carbide composite with a contact-type two-dimensional contour measuring machine (manufactured by Tokyo Seimitsu Co., Ltd .; contour record 1600D-22) and measuring the amount of warpage per 200 mm. 170 μm.

The aluminum-silicon carbide composite is held in an air bath atmosphere at −40 ° C. and 125 ° C. for 30 minutes, respectively, and the shape of the heat radiating surface after 30 heating / cooling treatments is performed. It was 215 micrometers as a result of measuring with Tokyo Seimitsu company; Contour record 1600D-22), and measuring the amount of curvature per 200 mm.

Next, after blasting with alumina abrasive grains under conditions of a pressure of 0.3 MPa and a conveyance speed of 1.0 m / min to clean, electroless Ni—P and Ni—B plating are performed, and the composite surface is 8 μm thick. A plating layer (Ni—P: 6 μm + Ni—B: 2 μm) was formed. The obtained plated product was good with no pinholes confirmed with the naked eye.

From the aluminum-silicon carbide composite obtained by hot press molding, a specimen for measuring thermal conductivity in the plate thickness direction (diameter 11 mm, thickness 3 mm) and a specimen for measuring thermal expansion coefficient (3 × 3 ×) by grinding. 10 mm) and. Using each test piece, the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was measured with a thermal dilatometer (manufactured by Seiko Denshi Kogyo; TMA300), and the thermal conductivity at 25 ° C. was measured with a laser flash method (manufactured by Rigaku Corporation); LF / TCM-8510B). As a result, the thermal conductivity in the plate thickness direction at a temperature of 25 ° C. was 160 W / mK, and the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was 9.1 × 10 ⁻⁶ / K (actual value / calculation). Value = 1.2).

A three-point bending strength measurement specimen (3 × 4 × 40 mm) was produced from the aluminum-silicon carbide composite by grinding, and the three-point bending strength was measured with a bending strength tester. . Further, the density of the aluminum-silicon carbide composite was measured by the Archimedes method, and the porosity was calculated. As a result, the porosity was 6.5% by volume.

[Example 5]
Silicon carbide powder A (manufactured by Taiyo Random Co./average particle size: 120 μm, density: 3.2 g / cm ³ ): 141.4 g (32.5% by volume), silicon carbide powder B (manufactured by Taiyo Random Co., Ltd./average Particle size: 10 μm, density: 2.2 g / cm ³ ): 141.4 g (32.5% by volume), aluminum-silicon alloy powder containing 5% by weight of silicon (average particle size: 30 μm): 125.5 g, Magnesium powder (average particle size: 50 μm): 1.3 g was mixed with a ball mill for 1 hour, and 402.7 g of the mixed powder was weighed. Next, in the same manner as in Example 1 except that an alumina fiber sheet having a Vf of 10% by volume and a thickness of 0.2 mmt was used, a molded body of mixed powder and aluminum foil was prepared by 50 MPa preforming, A laminate was produced.

Next, except that the preheating was performed at a temperature of 550 ° C., the laminate was heat-molded by the same method as in Example 1 to form 0.02 mm of aluminum and ceramic fibers on a 190 × 140 × 5 mmt surface. An aluminum-silicon carbide composite having a composite layer was obtained.

The obtained aluminum-silicon carbide composite was processed into a shape of 187 mm × 137 mm × 5 mm using a laser processing machine (STX-MK3 manufactured by Mazak) at a processing speed of 250 mm / min.

Next, this aluminum-silicon carbide based composite was machined at a machining center using a diamond tool to process through holes Φ7 mm at eight edge portions.

Result of measuring the shape of the heat radiating surface of the obtained aluminum-silicon carbide composite with a contact-type two-dimensional contour measuring machine (manufactured by Tokyo Seimitsu Co., Ltd .; contour record 1600D-22) and measuring the amount of warpage per 200 mm. The amount of warpage per 200 mm was 200 μm.

The aluminum-silicon carbide composite is held in an air bath atmosphere at −40 ° C. and 125 ° C. for 30 minutes, respectively, and the shape of the heat radiating surface after 30 heating / cooling treatments is performed. It was 230 micrometers as a result of measuring with Tokyo Seimitsu company; Contour record 1600D-22) and measuring the amount of curvature per 200 mm.

Next, after blasting with alumina abrasive grains under conditions of a pressure of 0.3 MPa and a conveyance speed of 1.0 m / min to clean, electroless Ni—P and Ni—B plating are performed, and the composite surface is 8 μm thick. A plating layer (Ni—P: 6 μm + Ni—B: 2 μm) was formed. The obtained plated product was good with no pinholes confirmed with the naked eye.

From the aluminum-silicon carbide composite obtained by hot press molding, a specimen for measuring thermal conductivity in the plate thickness direction (diameter 11 mm, thickness 3 mm) and a specimen for measuring thermal expansion coefficient (3 × 3 ×) by grinding. 10 mm) and. Using each test piece, the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was measured with a thermal dilatometer (manufactured by Seiko Denshi Kogyo; TMA300), and the thermal conductivity at 25 ° C. was measured with a laser flash method (manufactured by Rigaku Corporation); LF / TCM-8510B). As a result, the thermal conductivity in the plate thickness direction at a temperature of 25 ° C. was 170 W / mK, and the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was 8.6 × 10 ⁻⁶ / K (actual value / calculation). Value = 1.1).

A three-point bending strength measurement specimen (3 × 4 × 40 mm) was prepared from the aluminum-silicon carbide composite by grinding, and the three-point bending strength was measured with a bending strength tester. . Furthermore, as a result of measuring the density of the aluminum-silicon carbide composite by Archimedes method and calculating the porosity, the porosity was 4% by volume. When a compact containing 65% by volume of ceramic powder heated to a temperature of 823 K is heat molded at 100 MPa for 180 seconds, the following formula {16.23 + (− 0.54) × Vf + 5.60 × ln (P) +0.10 The value of × T + ln (t)} was 94.

Table 1 shows the surface of Examples 1 to 5 and the structure of the hole.

[Examples 6 to 9, Comparative Examples 1 to 5]
Aluminum powder (manufactured by Alcoa / average particle size: 25 μm), silicon carbide powder A (manufactured by Taiyo Random / average particle size: 120 μm), silicon carbide powder B (manufactured by Yakushima Electric Works / average particle size: 10 μm), Silicon carbide powder C (manufactured by Taiyo Random Corporation / average particle size: 180 μm), silicon carbide powder D (manufactured by Taiyo Random Company / average particle size: 250 μm), silicon carbide powder E (manufactured by Taiyo Random Company / average particle size) : 350 μm), silicon carbide powder F (manufactured by Taiyo Random Company / average particle size: 500 μm), silicon carbide powder G (manufactured by Taiyo Random Company / average particle size: 50 μm), silicon carbide powder H (manufactured by Taiyo Random Company) / Average particle size: 25 μm), silicon carbide powder I (manufactured by Taiyo Random Corporation / average particle size: 7 μm), silicon carbide powder J (manufactured by Taiyo Random Company / average particle size: 3 μm) are shown in Table 2. The mixture was mixed with a ball mill for 1 hour. Here, the density of the metal powder was calculated as 2.7 g / cm ³ . Next, a cast iron mold 1 (outer dimensions: 250 × 200 ×× 50 mm, inner diameter dimensions: 190 × 140 × 50 mm) and a mold 2 (lower part: 250 × 200 × 20 mm, upper part: 189. (9 × 139.9 × 10 mm, warp of 200 μm per 200 mm) was coated with graphite and boron nitride as a release agent, then laminated and placed on the upper surface of the mold 2 to fill the mixed powder. . Further, a graphite sheet is arranged on the upper part of the mixed powder, and a mold 3 (139.9 × 129.9 × 60 mm) coated with a release agent is laminated in the same manner, and preformed at a surface pressure of 10 MPa with a hydraulic press. Carried out.

Next, a 190 × 140 × 5 mmt aluminum-silicon carbide based composite was obtained in the same manner as in Example 1 except that the thermoforming conditions were 610 ° C. and 100 MPa for 10 minutes. The obtained aluminum-silicon carbide composite was prepared by grinding to produce a specimen for measuring thermal conductivity in the plate thickness direction (diameter 11 mm, thickness 3 mm) and thermal expansion coefficient measuring specimen (3 × 3 × 10 mm). did. Using each test piece, the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was measured with a thermal dilatometer (manufactured by Seiko Denshi Kogyo; TMA300), and the thermal conductivity at 25 ° C. was measured with a laser flash method (manufactured by Rigaku Corporation); LF / TCM-8510B). Further, a three-point bending strength measurement specimen (3 × 4 × 40 mm) was prepared from the aluminum-silicon carbide composite by grinding, and the three-point bending strength was measured with a bending strength tester. Furthermore, the density of the aluminum-silicon carbide composite was measured by the Archimedes method, and the porosity was calculated. Substituting the temperature, pressure, time, and Vf, which are thermoforming conditions, into the following formula {16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t)} Calculated.
The results are shown in Table 3.

The obtained aluminum-silicon carbide composite uses a garnet having a particle size of 100 μm as abrasive grains under the conditions of a pressure of 250 MPa and a processing speed of 50 mm / min by a water jet processing machine (Abrasive Jet Cutter NC manufactured by Sugino Machine). Then, the outer peripheral portion was processed into a shape of 187 mm × 137 mm × 5 mm.

Next, this aluminum-silicon carbide composite was subjected to Φ7 drilling at 8 edges and Φ8.6 countersink at 4 edges using a diamond tool at a machining center.

Next, after blasting with alumina abrasive grains under conditions of a pressure of 0.4 MPa and a conveying speed of 1.0 m / min to clean, electroless Ni—P and Ni—B plating are performed, and the composite surface is 8 μm thick. A plating layer (Ni—P: 6 μm + Ni—B: 2 μm) was formed.
The plating pits of the aluminum-silicon carbide composites of Examples 6 to 9 and Comparative Examples 1 to 5 were not observed, and it was confirmed that the chemical solution was good without bleeding.

[Examples 10 to 14]
Silicon carbide powder A (manufactured by Taiyo Random Company / average particle size: 120 μm, density: 3.2 g / cm ³ ): 152.2 g (35% by volume), silicon carbide powder B (manufactured by Taiyo Random Company / average particle size) : 50 μm, density: 2.2 g / cm ³ ): 152.2 g (35% by volume), aluminum powder (manufactured by Alcoa / average particle size: 25 μm): 109.8 g are mixed in a ball mill for 1 hour and mixed. 406.1 g of the powder was weighed. Next, a molded body having a pure aluminum metal layer on its surface was produced in the same manner as in Example 1.

[Comparative Examples 6-7]
Silicon carbide powder A (manufactured by Taiyo Random Co./average particle size: 120 μm, density: 3.2 g / cm ³ ): 163.1 g (37.5% by volume), silicon carbide powder B (manufactured by Taiyo Random Co., Ltd./average Particle size: 50 μm, density: 2.2 g / cm ³ ): 163.1 g (37.5% by volume), aluminum powder (Alcoa / average particle size: 25 μm): 91.5 g in a ball mill for 1 hour After mixing, 409.5 g of the mixed powder was weighed. Next, a molded body having a pure aluminum metal layer on its surface was produced in the same manner as in Example 1.

Next, the laminated body obtained by laminating the molded bodies of Examples 10 to 14 and Comparative Examples 6 to 7 was heated to the temperature shown in Table 4 in an air atmosphere and held for 15 minutes in an electric furnace. The temperature was set as shown in Table 4. The heated laminate was subjected to hot press molding at a surface pressure shown in Table 4 with a hydraulic press through a heat insulating material having a thickness of 5 mm, and then the pressure was released to cool to room temperature. Next, the mold 2 is removed, the mold 3 is pushed in with a hydraulic press, the molded body is taken out, and then the graphite sheet arranged for mold release is peeled off, and a 190 × 140 × 5 mmt aluminum-silicon carbide composite Got.

The obtained aluminum-silicon carbide composite was processed into a shape of 187 mm × 137 mm × 5 mm by grinding the outer peripheral portion.

Next, this aluminum-silicon carbide composite was subjected to Φ7 drilling at 8 edges and Φ8.6 countersink at 4 edges using a diamond tool at a machining center.

From the obtained aluminum-silicon carbide composite, a specimen for thermal conductivity measurement in the plate thickness direction (diameter 11 mm, thickness 3 mm) and a specimen for thermal expansion coefficient measurement (3 × 3 × 10 mm) are produced by grinding. did. Using each test piece, the thermal expansion coefficient at a temperature of 25 ° C. to 150 ° C. was measured with a thermal dilatometer (manufactured by Seiko Denshi Kogyo; TMA300), and the thermal conductivity at 25 ° C. was measured with a laser flash method (manufactured by Rigaku Corporation); LF / TCM-8510B). Further, a three-point bending strength measurement specimen (3 × 4 × 40 mm) was prepared from the aluminum-silicon carbide composite by grinding, and the three-point bending strength was measured with a bending strength tester. Furthermore, the density of the aluminum-silicon carbide composite was measured by the Archimedes method, and the porosity was calculated. The results are shown in Table 5.

[Comparative Example 8]
Except that a pure aluminum foil having a thickness of 20 μm (Comparative Example 8) was used as the pure aluminum foil for forming the surface metal layer, the produced mixed powder was molded in the same manner as in Example 1 and applied to the surface. Molded bodies having metal layers of pure aluminum having different thicknesses were produced.

  Next, this laminate was subjected to hot press molding in the same manner as in Example 1 to obtain a 190 × 140 × 5 mmt aluminum-silicon carbide composite.

The aluminum-silicon carbide composite obtained by hot press molding was subjected to a pressure of 250 MPa and a processing speed of 50 mm / min by a water jet processing machine (Abrasive Jet Cutter NC manufactured by Sugino Machine), with a particle size of 100 μm as abrasive grains. No. garnet was used to process the outer peripheral portion into a shape of 187 mm × 137 mm × 5 mm.

Next, this aluminum-silicon carbide composite was subjected to Φ7 drilling at 8 edges and Φ8.6 countersink at 4 edges using a diamond tool at a machining center.

Next, after blasting with alumina abrasive grains under conditions of a pressure of 0.4 MPa and a conveying speed of 1.0 m / min to clean, electroless Ni—P and Ni—B plating are performed, and the composite surface is 8 μm thick. A plating layer (Ni—P: 6 μm + Ni—B: 2 μm) was formed. In the plated product of Comparative Example 8, pinholes were observed with the naked eye and many stains due to the chemicals were observed.

[Example 15]
In order to give a warp to the aluminum-silicon carbide composite obtained in Example 1 after drilling and countersinking, a concave and convex mold made of carbon and provided with a warp of 240 μm per 200 mm was prepared. This concavo-convex mold was mounted on a hot press and heated to set the mold surface temperature at 510 ° C. The composite was placed between the concave and convex molds and pressed at 40 kPa. At this time, a thermocouple was brought into contact with the side surface of the composite to measure temperature. After maintaining the temperature of the composite at 500 ° C. for 3 minutes, the pressure was released and the product was naturally cooled to 50 ° C. Next, the obtained composite was annealed in an electric furnace at a temperature of 350 ° C. for 30 minutes in order to remove residual strain at the time of warping.

Result of measuring the shape of the heat radiating surface of the obtained aluminum-silicon carbide composite with a contact-type two-dimensional contour measuring machine (manufactured by Tokyo Seimitsu Co., Ltd .; contour record 1600D-22) and measuring the amount of warpage per 200 mm. 220 μm.

The aluminum-silicon carbide composite is held in an air bath atmosphere at −40 ° C. and 125 ° C. for 30 minutes, respectively, and the shape of the heat radiating surface after 30 heating / cooling treatments is performed. It was 200 micrometers as a result of measuring with Tokyo Seimitsu company; Contour record 1600D-22) and measuring the amount of curvature per 200 mm.

1 Mold 1
2 Mold 2
3 Mold 3
4 Mixed powder of metal powder and silicon carbide powder 4 'Metal-silicon carbide composite
5 Graphite sheet 6 Mold 4
7 Surface metal layer 8 Through hole (aluminum-silicon carbide composite part)
9 Countersink (aluminum-silicon carbide composite part)
10 Metal materials

Claims (14)

Ceramic powder containing aluminum powder, aluminum alloy powder, or metal powder containing 20% by volume to 40% by volume of mixed powder of aluminum and metal other than aluminum, and 90% by volume or more of silicon carbide having an average particle size of 10 μm to 350 μm 60% by volume to 80% by volume of mixed powder is pressure-molded at a temperature 100K lower than the lowest melting point of the metal powder to a temperature lower than the lowest melting point of the metal powder, from 25 ° C to 150 ° C. The thermal expansion coefficient of the measured value / calculated value satisfies the range of 1.1 to 1.3, and is on the long axis of the heat dissipation surface after 30 heating / cooling treatments in the temperature range of −40 ° C. to 125 ° C. A plate-like aluminum-silicon carbide composite having a warpage variation of 50 μm or less per 200 mm. By adding magnesium powder or aluminum and magnesium alloy powder to aluminum powder or aluminum alloy powder, mixed powder containing 20% by mass to 40% by volume of magnesium containing 0.5% by mass to 5.0% by mass and an average particle A mixed powder of ceramic powder 60 volume% to 80 volume% containing silicon carbide having a diameter of 10 μm to 350 μm in an amount of 90% by volume or more is 100K lower than the lowest melting point of the metal powder to the lowest melting point of the metal powder. The pressure expansion molding is performed at a temperature lower than 25 ° C., the thermal expansion coefficient from 25 ° C. to 150 ° C. satisfies the range of actual measurement / calculated value = 1.1 to 1.3, and the temperature is −40 ° C. to 125 ° C. Plate-like aluminum-silicon carbide, characterized in that the amount of warpage change on the major axis of the heat dissipation surface after 30 heating / cooling treatments in the range is 50 μm or less per 200 mm Coalescence. The aluminum-silicon carbide composite according to claim 1, wherein the aluminum-silicon carbide composite is passed through the following steps.
(1) The process of producing the mixed powder of Claim 1 or Claim 2.
(2) A step of filling the mixed powder in a mold and press-molding it with a surface pressure of 10 MPa or more to produce a molded body.
(3) A step of heating the molded body to a temperature T (K) that is 100K lower than the lowest melting point in the metal powder of aluminum, aluminum alloy, or other metal to less than the lowest melting point in the metal powder.
(4) A molded body containing Vf (volume%) of ceramic powder heated to a temperature T (K) is used with a concave P having a shape of 0 to 500 μm per 200 mm on one main surface at a pressure P (MPa) of 30 MPa or more. , 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t), and press-molded for a time t (seconds) satisfying the condition of aluminum-silicon carbide composite The step of forming the shape of one main surface into a convex shape of 0 to 500 μm per 200 mm and densifying to a relative density of 92% or more.
(5) A step of forming holes and tap holes or countersinks in the obtained aluminum-silicon carbide composite having a thickness of 2 to 6 mm. 3. The aluminum-silicon carbide composite according to claim 1, wherein a metal layer of 50 μm to 300 μm is formed on the surface through the following steps.
(1) When the mixed powder according to claim 1 or 2 is filled in a mold, the mixed powder and the metal foil are provided at a surface of 10 MPa or more so that a metal layer is formed on one side or both sides of the molded body. The process of producing the molded object which press-molds with a pressure and has a metal layer of 50 micrometers-300 micrometers on one or both surfaces.
(2) A step of heating the molded body to a temperature T (K) that is 100K lower than the lowest melting point in the metal powder of aluminum, aluminum alloy, or other metal to less than the lowest melting point in the metal powder.
(3) A molded body containing Vf (volume%) of ceramic powder heated to a temperature T (K) is used with a concave P having a shape of 0 to 500 μm per 200 mm on one main surface, and a pressure P (MPa) of 30 MPa or more. , 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t), and press-molded for a time t (seconds) satisfying the condition of aluminum-silicon carbide composite The step of forming the shape of one main surface into a convex shape of 0 to 500 μm per 200 mm and densifying to a relative density of 92% or more.
(4) A step of forming holes and tapped holes or countersinks in the obtained aluminum-silicon carbide composite having a thickness of 2 to 6 mm. 3. The aluminum-silicon carbide composite according to claim 1, wherein a metal layer of 50 μm to 300 μm is formed on the surface and a metal layer is formed on the surface of the hole through the following steps.
(1) When the mixed powder according to claim 1 or claim 2 is filled in a mold, the mixed powder and the metal foil are provided at a surface of 10 MPa or more so that a metal layer is formed on one side or both sides of the molded body. The process of producing the molded object which press-molds with a pressure and has a metal layer of 50 micrometers-300 micrometers on one or both surfaces.
(2) A step of forming a hole in a molded body having a metal layer on the surface by machining after molding or after molding, and placing a metal material having a diameter of 90% or more of the hole diameter in the hole of the molded body.
(3) A step of heating the molded body to a temperature T (K) that is 100K lower than the lowest melting point in the metal powder of aluminum, aluminum alloy, or other metal to less than the lowest melting point in the metal powder.
(4) A molded body containing Vf (volume%) of ceramic powder heated to a temperature T (K) is used with a concave P having a shape of 0 to 500 μm per 200 mm on one main surface at a pressure P (MPa) of 30 MPa or more. , 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t), and press-molded for a time t (seconds) satisfying the condition of aluminum-silicon carbide composite The step of forming the shape of one main surface into a convex shape of 0 to 500 μm per 200 mm and densifying to a relative density of 92% or more.
(5) A hole, a tap hole or a countersink having a shape 0.3 to 0.95 times the diameter of the metal material is machined in the metal material portion of the obtained aluminum-silicon carbide composite having a thickness of 2 to 6 mm. The process of forming by processing. 5. The aluminum-silicon carbide composite according to claim 4, wherein a metal layer having a thickness of 50 μm to 300 μm and a hole penetrating the front and back are formed on the surface through the following steps.
(1) A step of forming a hole in a molded body having a metal layer on the surface according to claim 4 by machining at the time of molding or after molding.
(2) A step of heating the molded body to a temperature T (K) that is 100K lower than the lowest melting point in the metal powder of aluminum, aluminum alloy, or other metal to less than the lowest melting point in the metal powder.
(3) A molded body containing Vf (volume%) of ceramic powder heated to a temperature T (K) is used with a concave P having a shape of 0 to 500 μm per 200 mm on one main surface, and a pressure P (MPa) of 30 MPa or more. , 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t), and press-molded for a time t (seconds) satisfying the condition of aluminum-silicon carbide composite A step of forming a convex shape of 0 to 500 μm per 200 mm, a thickness of 2 to 6 mm, and a hole on one main surface, and densifying to a relative density of 92% or more. 6. The aluminum-silicon carbide based composite according to claim 5, wherein a metal layer and a tapped hole or countersink surface are formed in the metal layer portion through the following steps and have holes penetrating the front and back.
(1) The molded body and the metal material according to claim 5 are heated to a temperature T (K which is 100K lower than the lowest melting point of aluminum, aluminum alloy or other metal powders to less than the lowest melting point of metal powders. The process of heating to.
(2) A molded body containing Vf (volume%) of ceramic powder heated to a temperature T (K) is pressure P (MPa) of 30 MPa or more using a concave mold having a shape of 0 to 500 μm per 200 mm on one main surface. , 92 ≦ 16.23 + (− 0.54) × Vf + 5.60 × ln (P) + 0.10 × T + ln (t), and press-molded for a time t (seconds) satisfying the condition of aluminum-silicon carbide composite The step of forming the shape of one main surface into a convex shape of 0 to 500 μm per 200 mm and densifying to a relative density of 92% or more.
(3) A tapped hole or countersink is formed in a metal portion of the obtained aluminum-silicon carbide composite having a thickness of 2 to 6 mm by machining, and further, a hole penetrating the aluminum-silicon carbide composite through the front and back sides Forming. 7. The aluminum-silicon carbide based composite according to claim 4, wherein the metal foil is aluminum or an aluminum alloy. The aluminum-silicon carbide based composite according to claim 5 or 7, wherein the metal foil and the metal material are aluminum or an aluminum alloy. Instead of the metal foil used for the aluminum-silicon carbide composite, ceramic fibers with Vf of 2 to 10% by volume are used, and a composite of aluminum and ceramic fibers of 0.01 to 0.2 mm is aluminum-carbonized. The aluminum-silicon carbide composite according to any one of claims 6 to 9, wherein the aluminum-silicon carbide composite is formed on one side or both sides of the silicon composite. The aluminum-silicon carbide composite according to any one of claims 1 to 10, wherein the outer peripheral shape of the aluminum-silicon carbide composite is processed by water jet processing, laser processing, or grinding. . In a state where stress of 10 kPa or more is applied so as to bend to a curvature of 100 to 1000 μm per 200 mm, it is subjected to creep deformation by heat treatment at a temperature of 400 to 550 ° C. for 30 seconds or more, and is convex on the heat radiation surface side The method for producing an aluminum-silicon carbide composite according to any one of claims 1 to 12, wherein a warped shape is imparted. 25 ° C. of thermal conductivity of 150W / (m · K) or more, 25 ° C. to 150 DEG thermal expansion coefficient ° C. is ^{5 × 10 -6 / K~12 × 10} -6 / K, 3 -point bending strength not less than 100 MPa, The aluminum-silicon carbide composite according to any one of claims 1 to 12, wherein a relative density is 92% or more. A power module wherein the surface of the aluminum-silicon carbide composite according to claim 13 is plated, one main surface is soldered or brazed to a ceramic circuit board, and the other main surface is used as a heat dissipation surface. Base plate.