Long term Reliability Testing of HV-IGBT modules in worst case traction operation

High reliability level is required for IGBT modules used in power converter s in railway traction application which however are subject to high stress because of the typical cycling operation which causes thermomechanical fati gue. The paper reports about Ansaldo Trasporti activity in IGBT's reliabili ty testing. Facility simulating worst case traction operation is described and the result after operation is presented: due to such stressing action, a solder delamination at the baseplate seems to be the first failure mechan ism to be excited. (C) 1999 Elsevier Science Ltd. All rights reserved.