Electro-thermal simulation of bond wires in power modules for realistic mission profiles

For the successful electrification of global transportation, the reliability of power electronic modules is of major importance. Today, one of the main reasons for module failure is the thermo-mechanically induced fatigue of bond wires as a result of strong load variations. A multitude of studies have been conducted to analyze the operational stress of bond wires based on thermal simulations using simple repetitive load patterns. This paper proposes a compact electro-thermal model for detailed time-efficient simulations of the thermal stress within bond wires. It incorporates the impact of parasitic electromagnetic coupling effects for an accurate loss determination over a wide frequency range. Finally, the bond wire model is embedded into a system simulation of the drive train of an electric vehicle. This allows to determine the realistic temperature distribution along the bond wires over time for specific mission profiles.