Package for packing semiconductor devices and process for producing the same

摘要

In a package comprising a chip mounting base and a cap to be fitted on the base, the base comprises a metal substrate, an electrically insulating ceramic layer formed on the metal substrate, a patterned metal layer formed on the ceramic layer in a selected area thereof, a first mixed layer formed in an area near the interface between the metal substrate and the ceramic layer, and a second mixed layer formed in an area near the interface between the ceramic layer and the metal layer, and the cap comprises a metal substrate, an electrically insulating ceramic layer formed in at least the marginal portion of the side of the metal substrate which faces the base, and a mixed layer that is formed in an area near the interface between the metal substrate and the cermaic layer.