Thermal stress related packaging failure in power IGBT modules

Thermomechanical stress behavior and its influence on the reliability of large area die bonding of 400 A/1200 V IGBT modules were studied in this paper. The forming and growing process of voids and cracks in the solder layers of fine-prepared IGBT cross sectional samples was quasi-dynamically observed during thermal cycling test. In consideration of the thermal mismatch in IGBT packaging, thermal stress behavior in an IGBT sandwich structure versus temperature changes, was numerically simulated and supported by the experimental results.