Quasi-distributed Temperature Detection of Press Pack IGBT Power Module Using FBG Sensing

In-situ temperature near the chips in a multiple-chip power semiconductor module is important information for thermal design validation, condition monitoring and overheat protection. Due to the compact packaging structure and clamping force, online detection of the temperature is challenging for a press pack module. This study attempts to achieve measurement by integrating optical Fiber Bragg Grating (FBG) sensors into the device. Different integration schemes are examined using experiments and theoretical analysis to show the effects on the transient performance. It is shown that FBG sensors with plate housing can effectively indicate the transient temperature ripple in normal converter operation, owing to the fast dynamic response of a small size sensor. The package integration has only minimal effects on the original distributions of electrical, thermal and mechanical quantities within the power module.