POWER MODULE SUBSTRATE, POWER MODULE, AND METHOD FOR MANUFACTURING POWER MODULE SUBSTRATE

摘要

A power module substrate 10 or the like including an insulating substrate 1 with an upper surface and a lower surface, a metal plate 2 with an upper surface and a lower surface, the lower surface facing and being bonded to the upper surface of the insulating substrate 1, and a first electroplating layer 3 that partly covers the central portion of the upper surface of the metal plate 2. The first electroplating layer 3 includes at least a silver layer, and the grain size of silver in the silver layer is more than or equal to the grain size of a metal in an upper surface portion of the metal plate 2.