SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide a semiconductor device with improved heat transfer performance, without causing degradation in insulation. SOLUTION: An aluminum oxide layer 21 is formed on part of a cooler 13 by anode oxidation, and a polyimide layer 22 is formed thereon by electrodeposition coating, thereby integrating an insulation layer 20 that consists of the aluminum oxide layer 21 and the polyimide layer 22 with the cooler 13. A bus bar 12, having a semiconductor module 11 that contains a semiconductor element jointed, is mounted on the insulation layer 20. Since the cooler 13 and the insulation layer 20 are unified, there is no longer contact interfaces between the layer 20 and the cooler 13, thermal resistance on the interface is eliminated, and accordingly, heat transfer characteristics are improved by the corresponding amount. COPYRIGHT: (C)2007,JPO&INPIT