Thermomechatronics of power electronic packages

The coupled effects of mechanical stress and thermal performance on the electrical function of power electronics are combined within a new analytical framework designated thermomechatronics. The result is a new approach to analyzing the progressive performance degradation of the power electronics owing to the growth of thermomechanically induced fatigue cracks within the package bonds and interconnects. The present analysis focuses on relating the consequences of such cracks on the thermal resistance of the package, which governs the junction temperature of the electronics for fixed power dissipation. The rate of track growth during operation is then analyzed based on closed-form analytical solutions combined with physically based failure modes for the relevant materials. Finally, the manner in which the present results may be integrated with conventional circuit simulation tools is described.