Composite material
A composite material includes an SiC porous ceramic sintered body, which is formed by preliminarily sintering a porous body, having a coefficient of thermal expansion lower than the coefficient of thermal expansion of copper to construct a network therein. A copper alloy impregnating the porous ceramic sintered body includes copper and one or more additive elements which are prepared to impart a coefficient of thermal conductivity of 160 W/mK or higher to the composite material. The additive elements include up to 5% of at least one element selected from Be, Al, Si, Mg, Ti, Ni, Bi, Te, Zn, Pb, Sn, and mish metal, and also contain unavoidable impurities and gas components.
1. A composite material comprising:
a porous ceramic sintered body produced by preliminarily sintering a porous body having a coefficient of thermal expansion lower than the coefficient of thermal expansion of copper to construct a network therein, said porous ceramic sintered body comprising a compound selected from the group consisting of SiC, AlN, Si 3 N 4 , B 4 C, and BeO;
an oxide film formed on a surface of said porous ceramic sintered body having a thickness ranging from 0.01 μm to 10 μm; and
a copper alloy impregnated in said oxide film formed on said porous ceramic sintered body,
wherein said copper alloy comprises copper and one or more additive elements which are prepared to impart a coefficient of thermal conductivity of 160 W/mK or higher to said composite material.
2. A composite material according to claim 1 , wherein said copper and said additive elements are prepared to impart a coefficient of thermal conductivity of 180 W/mK or higher to said composite material.
3. A composite material according to claim 1 , wherein said additive elements comprise a material for increasing a solidification temperature range to 70° C. or higher and reducing a melting point when added to said copper.
4. A composite material according to claim 1 , wherein said copper alloy comprises at least one additive element selected from the group consisting of carbide generating elements, oxide generating elements, and surface-active elements for up to 5% of the copper alloy.
5. A composite material according to claim 1 , wherein said copper alloy comprises at least one additive element selected from the group consisting of Be, Al, Si, Mg, Ti, Ni, Bi, Te, Zn, Pb, Sn, and mish metal for up to 5% of the copper alloy.
6. A composite material according to claim 5 , wherein said copper alloy comprises Be and/or Te for 0.01% to 3.0% of the copper alloy.
7. A composite material according to claim 1 , wherein said composite material has an average coefficient of thermal expansion ranging from 4.0×10 −6 /° C. to 9.0×10 −6 /° C. at a temperature ranging from room temperature to 200° C.
8. A composite material according to claim 1 , wherein said porous ceramic sintered body comprises SiC, said SiC having a porosity ranging from 10 vol. % to 70 vol. %.