Power Device Burned Completely—And Now, How to Find the Root Cause?

If power modules suffer failures, frequently the destruction energy is so high that the component (and also neighbored circuitry) burns down completely. For failure analysis, just some pieces of carbonized leftovers and molten metal balls are available. Of course, no useful analysis on component level is possible in such cases. However, a combination of system-related failure anamnesis and dedicated measurements on new reference systems and surviving parts of the failed system, allows many useful conclusions towards the failure root cause. This paper highlights the most important approaches and questions to be evaluated in such cases.