Heat-conductive composite material.

摘要

A heat-conductive composite material comprises a three-layered core (14), which is composed of a copper sheet (11) of a high thermal expansion sandwiched between two metal sheets (12) of low thermal expansion each said two metal sheets (12) of low thermal expansion having a number of through-holes (13) in the direction of the thickness, the three sheets being laminated and integrated so that opposing surfaces of the core (14) are substantially flat and formed with the respective metal sheets (12) of low thermal expansion having a part of the copper sheet (11) filling and being exposed out of the metal surfaces of the sheets (12) of low thermal expansion through the through-holes (13). A copper foil layer (16) of high thermal expansion is welded to each of the outer surfaces of the core (14) to form a five layered composite material. The thickness (t1) of the copper sheet (11), the thickness (t2) of the metal sheets (12) and the thickness (t3) of the metal foil layers (16) are such as to satisfy the relations: -(a) t1 = 1t2 to 3t2 and -(b) t3