Thermal Fatigue Life Evaluation of Aluminum Wire Bonds

For a reliability design, it is necessary to evaluate of the effects of thermal fatigue on Al wire bond's lifetime quantitatively due to the repetitive turning on and off a high current on a semiconductor power module. In this paper, we investigate the relationships among the thermal cycling temperature swing range DeltaT, the thermal cycling period, the maximum junction temperature T
_max
, and number of cycles to failure N/using a fast thermal cycling test method we developed. Furthermore, with the aim of predicting the power cycling lifetime, we examined whether the cumulative fatigue damage law can be applied to evaluation of wire bond lifetime