Impact of test stress (Tcmin) on intermittent operating life

Intermittent operating life is one of the most important reliability items in the application of power semiconductor devices. The intermittent operating lifetime is affected by several factors, such as the variables temperature swing ΔT, Tmin, power-on-time (ton), chip thickness, bonding technology, diameter (D) of bonding wire, current per wire bond (I) and package type. In this paper, we report on the effect of Tcmin on the intermittent operating life test. The test results under these two different start conditions are analyzed and discussed. Failure analysis is also used, to understand the failure mechanisms induced by intermittent operating life tests. The results show, when fixing other test conditions, the higher Tcmin is, the shorter the intermittent operating lifetime is. And the power-off-time can be shorten by rising Tcmin, but the power-on-time is not influenced.