End-of-life investigation on the .XT interconnect technology

To meet the requirements of Infineon's 5th generation IGBT and diode, the .XT technology has been introduced [1,2]. It comprises a set of new packaging technologies - namely Cu wire bonding, diffusion soldering or silver sintering and soldering with strengthened Sn-based alloys. These technologies address all reliability relevant levels within the power module package in order to realize high lifetimes under thermo-mechanical stress. To explore the technology's full potential, active and passive thermal cycling test data were correlated with the responsible failure mechanisms. Thereby, a shift of the major damage location from the near-to-die interconnects towards the more distant interconnect layers (i.e., substrate and substrate solder joint) was observed. At the same time, by using .XT technologies it was possible to almost completely suppress bond wire lift-off and die attach degradation.