Sintered Al-SiC is a heatspreader which can be processed in relatively complex shape such as “lid shape”. The specific gravity is 1/3 of Copper (Cu). By adjusting the composite ratio of Aluminum (Al) and Silicon Carbide (SiC), it is possible to customize the thermal expansion to required specification. With its young's modulus as small as 1/2 of iron, it can also be used as stress relaxation material. And, the surface has excellent adhesion of adhesive bonds.