The reliability of Aluminium wire bonds in IGBTs is reported to be positively affected by a high temperature ultrasonic bonding or a post annealing treatment after wire bonding. This study focusses on the effect of the later and aims to explain the increase in lifetime recorded after power cycling tests on treated vs untreated modules. The reliability enhancement is linked to the microstructure modification of the Al wire/metallization interface as a result of the heat treatment. Using scanning and transmission electron microscopy, the microstructure evolution of heat-treated modules after power cycling is analyzed. The damage mechanisms of the heat treated, and non-treated Al top interconnects are compared. It is observed that the heat treatment improves the bonding interface thus slowing down the degradation of the wire bonds.

据报道，IGBT 中铝线键合的可靠性受到高温超声波键合或引线键合后的后退火处理的积极影响。本研究侧重于后者的影响，旨在解释经过处理与未处理模块的功率循环测试后记录的寿命增加。可靠性的提高与热处理导致的铝线/金属化界面的微观结构改变有关。使用扫描和透射电子显微镜，分析了功率循环后热处理模块的微观结构演变。比较了热处理和未经处理的铝顶部互连的损坏机制。观察到热处理改善了键合界面，从而减缓了引线键合的退化。