In this paper, threats and opportunities in testing of megawatt power
electronic modules under short circuit are presented and discussed, together
with the introduction of some basic principles of non-destructive testing, a
key technique to allow post-failure analysis. The non-destructive testing
equipment at CORPE, center of reliable power electronics, Aalborg
University, Denmark, is presented and its features are discussed in detail,
together with some relevant results. Limitations of experimental analysis
have also been addressed, together with the introduction of a mixed
thermal-electrical simulation tool originally developed to study abnormal
conditions and helping to predict very fast and dangerous thermal transient
especially in case of worn out devices. The paper is concluded with an
overview on present challenges in next-generation semiconductors for such
high power ranges - basically silicon carbide - and new concepts for
nondestructive testing of ultrafast power modules adopting such a
technology.
Basic Principles of Ultrasonic Time Reversal Processing in Non-Destructive Testing