Lifetime Prediction of an IGBT Power Electronics Module under Cyclic Temperature Loading Conditions

The lifetime of an IGBT power electronics module under cyclic temperature loading conditions has been analyzed using Finite Element Analysis method. The failure mechanisms that have been taken into account are the fatigue of the chip-mount-down solder joint, the substrate attach solder joint, the busbar solder joint and the Aluminum wirebond. The results show that the lifetime of the module is about 1000 cycles under the -40 to 125C cyclic temperature loading condition. The critical failure location has been found to be the busbar solder joint and the lack of compliance of the busbar design is the cause of the problem. The objective of this paper is to demonstrate the methodology of using physics of failure approach for the reliability analysis of power electronics modules and highlights the important design parameters that affect the thermal-mechanical fatigue failures of these components.