Mechanical simulation and modeling for reliability of 6-in-1 power module

Abstract

numerical modeling and simulation of temperature cycling test (TCT) and power cycling test (PCT) are applied to the design reliability analysis for a proposed 6-in-1 power module (PM) package. The fatigue life for both 95Sn5Sb solder interconnect and sintered Ag die attach (DA) joints under TCT and PCT conditions are calculated and compared with a reference power module package which has already passed the reliability test. The Coffin-mansion life model ductility factor is calculated from the test data for the reference power module and applied to the analysis of the fatigue life for the PM. The reliability of solder interconnect is in the same level as the reference module which passed the 1000 cycles of TCT and 50000 cycles of PCT. Sintered Ag DA joint has a very high reliability life. The structural reliability of interconnect for the proposed PM could be further enhanced by using sintered Ag as both DA and interconnect materials. Effect of package parameters such as DA and copper clip thickness are also investigated in this study. The results provided important guidelines for the PM package design.