Three-dimensional thermal modeling based on the two-port network theory for hybrid or monolithic integrated power circuits

This paper recalls how the two-port network theory can be extended to three-dimensional (3-D) conductive heat transfer in multilayered plane structures. Then it is shown how to build efficient computation tools by implementing this theory with help of fast Fourier transform (FFT) algorithms. These tools are particularly well-suited for the rapid thermal analysis of power components or hybrid and integrated power circuits. An illustration is given concerning thermal analysis of an insulated gate bipolar power transistor (IGBT) power module and computed results are compared with experiment.