Evaluation of commercially available SiC devices and packaging materials for operation up to 350°C

The characteristics of commercially available silicon carbide power devices and packaging technologies have been measured up to 350°C in order to obtain their reliability and suitability for use in a hybrid electric vehicle application. Electro-thermal simulations of representative power module packaging structures, using measured conduction losses, revealed the respective temperature profiles of the devices and packaging. By correlating lifetime data found from our passive thermal cycling of candidate packaging technologies, with the magnitude and number of thermal cycles extracted from simulated temperature profiles, the lifetime of high temperature power module packages has been predicted. It was found that the limiting factor for high temperature thermal cycled operation is the silicon nitride substrate material, followed closely by the pressure-less silver sinter die attach. In this case, no aluminum wirebond failures were observed.