Influence of repetitive short circuit events on the power cycling capability of IGBTs in a molded package

The influence of short circuit events on the power cycling lifetime was investigated. The transfer-molded IGBTs were grouped and then exposed to different number of short circuits, with different energy levels and different initial temperature conditions. After the short circuit treatment, a power cycling test was performed. The lifetime prediction showed no difference of virgin devices compared to devices which were exposed to a low number of short circuits in the range allowed in the datasheet. For devices exposed to higher energy and higher number of short circuits, a decreasing power cycling capability was observed. A supporting thermal simulation was carried out to provide a temperature estimation during the short circuit event.