Abstract: A semiconductor device includes a semiconductor substrate having electrodes brazed thereto. The electrode is made of a Cu-C composite material in which carbon fibers are embedded in copper matrix. The carbon fibers are so disposed as to be in a ring-like shape or a loop shape substantially in parallel with a surface of the semiconductor substrate onto which the electrode is brazed. The carbon fibers disposed in an outer peripheral portion have a higher longitudinal elastic modulus than that of the carbon fibers positioned at a central portion of the electrode. The electrode thus has a thermal expansion coefficient approximating to that of the semiconductor substrate. Content of copper can be increased at the central portion of the electrode for attaining a high thermal conductivity.

Abstract: A vacuum-type circuit breaker comprising an evacuated container, and a pair of contacts disposed in the container and adapted to be moved between an open position and a closed position to permit a circuit breaking arc to be generated across the contacts, the contacts being made of a copper alloy containing manganese. The vacuum-type circuit breaker provided with the contacts of the aforementioned type has a higher dielectric strength than conventional vacuum-type circuit breakers.

Abstract: Copper powder, carbon fibers arranged in random directions and a metal capable of reacting with carbon fibers are homogeneously mixed together, and the mixture is heated and molded under high pressure to form an integral composite. The so formed carbon fiber-copper matrix composite has no directional characteristic in mechanical properties, and the linear thermal expansion coefficient of the composite is low and the thermal stability of the composite is so high that when it is exposed to high temperature, no damage by thermal deformation is caused.