Assessing solder interconnect reliability of control boards in power electronic systems using Physics-of-Failure models

The demand for power electronic systems to operate in harsh environmental conditions has increased over the past 20 years. These environments include those relating to deep oil-well drilling, automotive and aerospace applications. The miniaturization of the power module along with higher power densities have created elevated stress levels on ancillary subsystems, specifically the control circuitry. This study develops first-order methods and models to assess the solder interconnect reliability of critical components on the control circuitry in power electronic systems. Thermal and reliability simulations based upon Physics-of-Failure modeling techniques were conducted on a 2.2 kW variable-frequency drive to evaluate the susceptibility of component level failure mechanisms. CalcePWA, an interconnect reliability modeling software tool, was used as the primary vehicle to conduct these simulation models. A power cycling apparatus was constructed in order to calibrate the reliability models through accelerated testing of the drive.