Gradient-based End-of-life Criterion of Power Semiconductor Modules

This paper proposes a gradient-based End-of-Life (EOL) criterion with the application example in power semicon-ductor modules. The widely used criterion to determine the EOL of IGBTs in power cycling test is certain percentage of increase of the on-state voltage. Nevertheless, it suffers from significant inconsistency among testing samples in the EOL-based cycle-to-failure with respect to its actual cycle-to-failure considering the thermal limit, that is, the cycle-to-failure margin. The proposed EOL criterion is based on the evolution of the change rate of the on-state voltage, which shows much more consistent cycle-to-failure margins. Experimental case studies demonstrate the application of the proposed EOL criterion and its advantages.