Compact electrothermal models for unbalanced parallel conducting Si-IGBTs

For high current applications, silicon IGBTs are normally connected in parallel to deliver the required current ratings. The devices are normally designed to have identical electrothermal parameters for equal current and power sharing. However, over the mission profile of the device, non-uniform degradation of the electro-thermal properties like solder delamination or gate contact resistance as well as unequal heat extraction from the heat sink, can cause the parallel connected IGBTs to have different electrothermal properties. In this paper, a compact and accurate electro-thermal model for parallel connected IGBTs has been developed and validated by experimental measurements.