Innovative Methodology for Predictive Reliability of Intelligent Power Devices Using Extreme Electro-thermal Fatigue

In this paper, an innovative methodology for predictive reliability of intelligent power devices used in automotive applications is considered. Reliability management is done at all levels of the technological process. This method is based on the failure analysis along with electro-thermo- mechanical modeling and on extreme fatigue testing. A new power MOS device has been electrically fatigued in order to evaluate its failure modes. Using a thermally regulated test bench, electrical pulses were applied to the device until failure. This failure is associated to several structural changes that have been investigated through acoustic and electron microscopy. Delamination was observed preferentially at the solder between the copper heat sink and the die.