Magnesium-based composite member, heat radiation member, and semiconductor device

1. A magnesium-based composite member provided with a through hole through which a fastening member for attachment is to be inserted, comprising:

a substrate provided with a substrate hole through which said fastening member is to be inserted and composed of a composite material of SiC and a matrix metal which is any of magnesium and a magnesium alloy; and

a receiving portion attached to said substrate and composed of a metal material different from said matrix metal,

said receiving portion being provided with a receiving portion hole through which said fastening member is to be inserted, and at least a part of an inner circumferential surface of said through hole being formed from an inner circumferential surface of said receiving portion hole, and

in said matrix metal, said SiC is present in a form of a porous body having open pores, the open pores of the porous body are filled with the matrix metal.

2. The magnesium-based composite member according to claim 1 , wherein

said composite material has a network portion for bonding SiC to one another,

said substrate hole is provided in a region where said composite material has said network portion, and

said receiving portion is arranged such that a head portion of said fastening member is in contact therewith.

3. The magnesium-based composite member according to claim 1 , wherein

said composite material contains said SiC by more than 70 volume %.

4. The magnesium-based composite member according to claim 1 , wherein

said receiving portion has a metal plate arranged such that a head portion of said fastening member is in contact therewith, and

in such a state that said head portion is in contact with said metal plate as said fastening member is fastened, said metal plate extends to project from a periphery of said head portion in a plan view.

5. The magnesium-based composite member according to claim 4 , further comprising a metal coating layer for covering at least one surface of said substrate, wherein

a periphery of said metal plate is joined to said metal coating layer, and

one surface of said metal plate is exposed at said metal coating layer.

6. The magnesium-based composite member according to claim 4 , further comprising a cylindrical portion covering at least a part of an inner circumferential surface of said substrate hole and composed of a metal material identical in type to said metal material.

7. The magnesium-based composite member according to claim 4 , wherein

said metal plate has an area at least 10 percent greater than an area of the head portion of said fastening member in the plan view.

8. The magnesium-based composite member according to claim 1 , having a coefficient of thermal expansion not lower than 4 ppm/K and not higher than 8 ppm/K and thermal conductivity not lower than 180 W/m·K.

9. A heat radiation member, formed from the magnesium-based composite member according to claim 1 .

10. A semiconductor device, comprising:

the heat radiation member according to claim 9 ; and

a semiconductor element mounted on said heat radiation member.

11. The magnesium-based composite member according to claim 1 ,

wherein in said matrix metal, said SiC is present in a form of being bonded by said network portion.

12. The magnesium-based composite member according to claim 11 , wherein

said substrate hole is provided in a region where said composite material has said network portion, and

said receiving portion is arranged such that a head portion of said fastening member is in contact therewith.