Simultaneous Imaging of Strain and Temperature using Single IR Camera

Abstract:
Thermal stress analysis is essential to ensure the reliability of power semiconductors. For this analysis, we propose a method to measure temperature and strain simultaneously. With a single infrared camera, we performed infrared thermography for temperature measurements and image correlations for strain measurements. Along with image processing, surface patterning using differences in emissivity was implemented for this technique. In a demonstration with an insulated-gate bipolar transistor chip, temperature and strain distributions were obtained both with fine spatial resolution. The strain distribution obtained by our setup showed good agreement with previous studies regarding delamination and crack propagation on power semiconductor chips. The system is applicable for thermal stress analysis of power devices, in particular, that are downsizing.