Thermal Impedance Matrix Characterization of IGBT Modules with Different Configurations

The trend for increasing power density could lead to more significant thermal interactions among chips within a power module, rendering that thermal coupling cannot be neglected. To analyze this phenomenon, the thermal impedance matrix is frequently utilized. Within the current research, Temperature-Sensitive-Electrical-Parameter (TSEP) based thermal impedance characterization emerges as a non-invasive and commonly accepted method. However, the existing study, provides the measurement circuits for self-thermal impedance, leaving a gap for assessing mutual thermal impedance. To address this issue, this paper thoroughly investigates plausible measurement circuits, thereby identifying potential challenges in thermal transient measurement (i.e., thermal calibration and cooling curve measurement). Furthermore, these analyses are performed in three highly representative configurations of IGBT modules. Additionally, all tests in this study utilize a well-established platform, enhancing the direct potential applicability of the results to practical scenarios.