Transient 3D Heat Flow Analysis for High Power Insulated Gate Bipolar Transistors Using the Transmission Line Matrix

This paper presents a 3D transmission line matrix (TLM) implementation for the solution of transient heat flow in power devices. The miniaturization of electronic networks creates problems of heat dissipation. Good thermal management is therefore essential. Simulating power electronic systems presents peculiar challenges due to the need of detailed modeling of both circuitry and control algorithms. The Transmission Line Matrix method (TLM) is a powerful tool for analyzing thermal effect in electronic circuits and high power devices. In this paper, thermal analysis for a 1200 A, 3.3 kV IGBT (Insulated Gate Bipolar Transistor) module was investigated and analyzed using the Three-Dimensional Transmission Line Matrix (3D-TLM) method. The results show a three-dimensional visualization of self-heating phenomena in the device, including the effect of the use of Metal Matrix Composite (MMC) materials as a base plate over conventional materials for electronic packaging thermal control and the use of the ceramics as substrates. This paper reviews the present status of the use of various thermal heat spreaders such as AlSiC MMC, Cu-Mo and Graphite-Cu MMC and comparing those to copper based heat spreaders. Also covered is the use of AlN, Diamond and BeO as substrates and their effect in dissipating the heat flux in heat sources localized in IGBT module designs. The effects of the geometry of the module and specific material thicknesses are taken into account because they play an important role in dissipating the generated heat and outweigh the thermal properties of the module. The TLM method is found to be a versatile tool that is ideally suited to the modeling of many power electronic devices, and proved very useful in the study of transient thermal effects in a variety of device structures.