Separation of Bond-Wire and Solder Layer Failure Modes in IGBT Power Modules

Thermal stress of the power semiconductor is one of the most important indicators for the reliability assessment of power electronics based power systems. The mapping of the IGBT junction temperature is usually required to analyze the thermal stress and loss dissipation. However, it is difficult to identify inherent mechanisms of the bond-wire and solder layer failure modes in IGBT power modules. In order to solve the problem, a novel method is proposed to separate the root causes of the bond-wire lift-off and solder layer fatigue by measuring the on-state voltage drop through a sinusoidal loading current based on an H-bridge circuit. By comparing on-state voltage drop at the intersection current and the peak current of converter, experimental results are presented in order to verify the effectiveness and feasibility of the proposed method.