The surge capability of high voltage rectifiers

The failure mode under forward surge current conditions is investigated from theoretical and experimental viewpoints. The hypothesis that current filamentation occurs when the intrinsic carrier concentration becomes comparable to the injected concentration is confirmed by experimental measurements on rectifiers. The device junction temperature is deduced from separate measurements of the forward voltage drop, under pulsed conditions, as a function of case temperature and current. The measured time-dependence of junction temperature is in good agreement with the predictions of a simple one-dimensional heat flow model.