New solderless structure power module for high reliability

Abstract:
We designed a power module with a power cycling lifetime that is more than 20 times longer than our current structure. The deterioration of wire, die-attach, or baseplate solder junctions is a major factor in the failure to reach the power cycling lifetime. Based on our experimental and analysis results, we designed a solderless structure as one possibility for achieving a high-reliability power module. This solderless structure uses an integrated substrate achieved by directly bonding the baseplate and insulated substrate without using solder. In addition to achieving high reliability due to the absence of locations susceptible to deterioration, it was found from analysis that this new structure has the effect of decreasing Tjmax and DeltaTj because of low heat resistance. Analysis showed that a 3.3-kV LV100 package with these technologies and Cu wire achieved a power cycling lifetime that is 56 times longer than the current structure.