Packaging technology of power module for automotive applications

The number of in-vehicle power devices has been increasingly for motor controlling purposes. Power device packages should ideally be small and easy to mount. We have developed a small power module by assembling several power devices sealed with molding resin. Two new techniques were used to produce this module: one was the use of copper clips for high-current wiring, and the other was low-cost soldering using residue-free solder paste. This paper describes the features of the structure that uses copper clips, a soldering technique and process employing a newly developed soldering material, and the reliability of solder joints implemented with this material.