| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat sink of copper or copper alloy on which a semiconductor substrate is mounted by solder jointing, capable of stably preventing formation of voids, caused by Cu diffusion when Pb-free solder is used and defective solder wettability, for proper bonding characteristics to a power module case. SOLUTION: In a semiconductor substrate 7 is mounted by solder jointing 2 on a heat sink 1 of copper or copper alloy, Ni plating is applied on a surface, on which the semiconductor substrate is mounted (substrate-mounting surface) and on the surface (rear surface) on the opposite side of it. The fluctuation width in the Ni plating thickness at five points, including the proximity of an end surface and a central part of plate surface, is 2.0μm or smaller, on the substrate mounting surface and the rear surface, as well. Those, especially having an end face on which no Ni plating is applied, become appropriate objects. COPYRIGHT: (C)2008,JPO&INPIT |
