Accelerated Degradation Modeling of Power MOSFET Under Multiple Stresses

Power MOSFET is one of the most critical components in power electronic converters. However, it often performs a lower reliability index under multiple stresses. Conventional single-stress accelerated degradation test (ADT) and corresponding statistical inference are unable to evaluate its reliability accurately. In this article, a new accelerated degradation model is designed by combining multi-stress accelerated model and the generalized Wiener process model. This comprehensive model not only establishes the relationship between drift coefficient and multiple stresses but also take the nonlinearity and uncertainties existing in degradation process into consideration. Subsequently, an ADT with temperature, electrical and vibration stresses for power MOSFET is carried out to obtain the degradation data under different stress levels, which is employed for unknown parameter estimation. Comparative analysis demonstrates that the proposed model can provide a more accurate and reasonable reliability assessment result.