Evaluation of SiC MOSFET power modules under unclamped inductive switching test environment

Abstract

High power commercial SiC MOSFET modules have been evaluated under unclamped inductive switching (UIS) environment from the point of view of judging their failure ruggedness. The power modules with 1.7kV/300A and 1.2kV/180A rating were stressed with avalanche currents of their rated current value. One SiC MOSFET module sustained its avalanche current value when tested at rated forward current condition (i.e., 180A) while the other power module failed during avalanche test even before reaching to its nominal rating current value (i.e., 300A) at 25°C. It is further shown that avalanche current of SiC-MOSFET modules is approximately insensitive of temperature variation under UIS behavior. A maximum avalanche energy of 2.43 and 3.23J was extracted when tested at maximum avalanche current of 165 and 220A for 1.7kV/300A and 1.2kV/180A rated power modules, respectively. These numbers far exceed than that of equivalent Si based IGBTs.