Infrared image correlation for thermal stress analysis of power devices

摘要

Thermal stress analysis is indispensable to improve the reliability of power devices. We propose a technique to observe a temperature distribution and a thermal strain simultaneously for thermal stress analysis of power devices. A temperature distribution is measured by an infrared (IR) camera and a thermal strain is measured by a digital image correlation (DIC) with IR images under a power cycling test. To apply DIC to IR images, we propose techniques to make a random pattern on the surface which can be recognized by IR camera even if a surface temperature is changed. This technique realises an observation with completely same field of view even in a localized area on power devices. This method provides an experimental means to verify simulation results of thermal stress analysis.