Power MOSFET screening to improve field-reliability of power supplies

The field-failures of a power converter depends on the reliability characteristics of circuit components, package and interconnect parasitics, thermal management and cooling, load characteristics, and the field operating environment, among other factors. In this paper, power supply field-reliability improvement by careful screening of power MOSFET's is reported. A new power MOSFET screening criteria is proposed that leads to dramatic improvement in the mean-time-between-failure (MTBF) of compact computer/telecom power supplies. Using the new screening criteria, nearly an order of magnitude improvement in power supply MTBF is demonstrated.