Analysis and In-Situ Measurement of Thermal-Mechanical Strain in Active Silicon Power Semiconductors

Thermal-mechanical strain in silicon power devices is investigated using both finite element models and experimental techniques so that the reliability of power electronics modules can be improved by actively regulating strain to help guarantee predictable life while fully utilizing the capability of the device. Near-infrared photoelastic strain measurement and three- dimensional finite element modeling are applied to quantifying the critical strain magnitudes and locations during operation. Three-dimensional, transient, thermal-mechanical finite element models of IGBT devices are presented. Experimental results verifying the electrical-loss-driven thermal-mechanical strain in an electrically active discrete IGBT device are provided.