Semiconductor device and method of making semiconductor device

Abstract

Inexpensive production is achieved while avoiding the degradation of electrical performance caused by the lowering of heat dissipation. The base plateused here has a linear expansion coefficient of 2 to 10 ppm/K, which differs from the linear expansion coefficient of the semiconductor chipby an absolute value of 7 ppm/K or smaller. The bonding layeris formed such that the thickness b thereof is 50 micrometers or smaller, which is thinner than the thickness c of the semiconductor chip. Since the thickness b of the bonding layeris thinner than the thickness c of the semiconductor chip, the bonding layerupon the heating of the semiconductor chipexhibits thermal expansion that is of relatively small significance, and thus follows the expansion and contraction of the base plate. Since the linear expansion coefficient of the base plateis set close to that of the semiconductor chip, a displacement occurring between the base plateand the semiconductor chipin response to a temperature change is relatively small.