Dynamic Reverse Bias Test: Electro-Thermal Characterization of SiC MOSFETs

Beyond the traditional static biased tests, novel dynamic electric assessments are being developed for wide band-gap devices and package solutions, to assess their reliability behaviour in the automotive environment. In the dynamic reverse bias (DRB) test, the power devices are dynamically stressed with very high slew rates of drain-source voltage for one thousand hours. The test evaluates the reliability at applicative-like conditions in terms of switching frequency and bus voltage. This paper presents a DRB test characterization: more in details, all the most relevant electrical and thermal aspects are both characterized. Hence, the voltage waveforms are assessed to ensure the compliance with guideline and the alignment with the application. Main test parameters, such as frequency, temperature and voltage, are correlated by dedicated analysis. Moreover, power losses due to device’s capacitances are calculated by a straightforward approach. A thermal experimental method is developed to perform a benchmark.