Reliable IGBTs for hybrid/electrical vehicles (H)EV

In recent years, the automotive industry has brought stringent reliability constraints on power electronic systems with focus on cost-effective solutions. The high voltage and high current required in hybrid electric vehicles (HEVs) and electric vehicles (EVs) present technical challenges for power conversion beyond those normally associated with vehicle electrical and electronic systems. An increasing demand for fuel and energy efficiency warrants light weight and small volume power control unit (PCU) in (H)EV applications. Insulated Gate Bipolar Transistor (IGBT) is the power device of choice for the power control unit (PCU) which typically consists of one to two inverters plus a boost converter. The inverters require relatively low switching frequency (up to 20 kHz) and high current while the boost converter warrants high switching frequency up to 170 kHz and relatively low current. Cost reduction in the IGBT modules is the key factor to make (H)EV cars affordable. IGBTs are of paramount importance for the reliability of (H)EV power train due to their high internal electric fields and subject to large junction temperature swings during normal operation. In this tutorial, we review the design, fabrication, and package of reliable IGBTs for automotive industry and discuss the strategies to further improve its reliability.