Composite member

Abstract

A composite member suitable for a heat radiation member of a semiconductor element and a method of manufacturing the same are provided. This composite member is a composite of magnesium or a magnesium alloy and SiC, and it has porosity lower than 3%. This composite member can be manufactured by forming an oxide film on a surface of raw material SiC, arranging coated SiC having the oxide film formed in a cast, and infiltrating this coated SiC aggregate with a molten metal (magnesium or the magnesium alloy). The porosity of the composite member can be lowered by improving wettability between SiC and the molten metal by forming the oxide film. According to this manufacturing method, a composite member having excellent thermal characteristics such as a coefficient of thermal expansion not lower than 4 ppm/K and not higher than 10 ppm/K and thermal conductivity not lower than 180 W/m·K can be manufactured.

1 . A composite member made of a composite of magnesium or a magnesium alloy and SiC, characterized in that
 said composite member has porosity lower than 3%,   said SiC is present in a form dispersed in said magnesium or said magnesium alloy, and   said composite member contains 50 volume % or more and 86.3 volume % or less of said SiC.   
     
     
         2 . The composite member according to  claim 1 , characterized in that
 said composite member has thermal conductivity not lower than 180 W/m·K.   
     
     
         3 . The composite member according to  claim 1 , characterized in that
 said composite member has a coefficient of thermal expansion not lower than 4 ppm/K and not higher than 10 ppm/K.   
     
     
         4 . A composite member, characterized by comprising:
 a substrate composed of a composite material made of a composite of magnesium or a magnesium alloy and SiC and containing 50 volume % or more SiC; and   a metal coating layer covering at least one surface of said substrate.   
     
     
         5 . The composite member according to  claim 4 , characterized in that
 a metal component of said composite material and a metal forming said metal coating layer have a continuous texture.   
     
     
         6 . The composite member according to  claim 4 , characterized in that
 a metal component of said composite material and a metal forming said metal coating layer are different in composition.