EM-Electrothermal Analysis of Semiconductor Power Modules

We present in this paper an advanced electromagnetic (EM)-electrothermal analysis approach for the semiconductor power devices, with illustration on the insulated-gate bipolar transistor (IGBT) modules. This method distinguishes itself by dynamically integrating the EM domain into the circuit-type electrothermal coupling analysis, thus enabling the multi-dimensional simulation that spans in time from nanoseconds to seconds, and in space from chip level to system level. In particular, it contains a parametric-extracted electrothermal model of the IGBT chip and a comprehensive 0-D thermal network as well as an EM network extracted from the 3-D module packaging structure for each paralleling chip. The incorporation of the EM, as well as thermal networks representing the 3-D packaging structure, reveals essential information about the current imbalance, power dissipation imbalance, and thermal imbalance inside the IGBT module with paralleling chips, which have a strong influence on the module reliability. To demonstrate the application of this approach, an unfavorably designed 1700-V/450-A half-bridge IGBT power module is evaluated in the simulation circuit, with experimentally verified electrothermal IGBT chip model and thermal as well as EM networks. The results have shown that the EM-electrothermal analysis can successfully reveal the dynamic interaction among different physical domains and, thus, the current as well as temperature imbalance among the paralleling chips inside the power module. The predicted current imbalance also agrees with that from the experimental test.