A Novel Model of the Aging Effect on the ON-State Resistance of SiC Power MOSFETs for High-Accuracy Package-Related Aging Evaluation

Package-related aging (PRA) defects can cause severe failures in SiC mosfet s, so an aging evaluation method is essential. on -state resistance ( R _ON ) is the most widely used aging indicator for SiC mosfet s. However, its performance is limited by the R _ON swing as aging levels develops. This phenomenon is contradictory to the conventional model of aging effect on R _ON . In this article, a novel aging effect model is proposed, where R _ON is divided into two components named R _AG and R _SW . R _AG is related to the PRA and R _SW is related to the chip-related aging (CRA). In this way, the swing phenomenon can be eliminated. A decoupling method based on the east square method is proposed to calculate R _AG , R _SW , and V _TH . This method can decouple the effect of PRA and CRA on R _ON . The proposed aging effect model and decoupling method are verified by experiments based on a thermal cycle accelerated aging test. Experimental results indicate that swing in R _SW is the root cause of the swing in R _ON . Finally, an online aging evaluation strategy is proposed. The accuracy of the PRA evaluation is improved by five times compared with conventional methods, and the CRA evaluation can be conducted simultaneously.