Aging precursors and degradation effects of SiC-MOSFET modules under highly accelerated power cycling conditions

A highly accelerated power cycling test platform using current source converter for SiC-MOSFET power modules is proposed. The control principles of delta and average junction temperatures are introduced. By using isolated thermal fibers, the junction temperature (Tj) variations can be monitored during the test process without removal of silicone gel. The power module is tested in the conditions of ΔTj=60 °C, mean temperature Tjm=145 °C and the maximum Tj=175 °C. By means of device analyzer, the degraded conditions of electrical parameters after power cycling test are fully investigated and compared. As a result, the effects of degradation on the static and dynamic characteristics during conventional operation are discussed. Finally, the research results can help examine the failure precursors and then estimate the remaining useful lifetime of SiC MOSFET modules.