Computational Modeling of Anisotropic Thermal Conductivity and Joule Heating on Printed Circuit Boards
A printed circuit board (PCB) consists of consecutive layers of dielectric material and current carrying traces and vias. Conducting system level simulations of PCB’s with detailed trace and via geometries is computationally very expensive. In the present study, the effects of the trace and via geometry in the physical model are taken into account by importing the corresponding ECAD data with which locally varying anisotrpoic thermal conductivity on the PCB is determined accordingly. Moreover, the effects of Joule heating in the current carrying traces are included by using a number of planar heat sources representing individual metal trace layers. The powermap on each of these layers is determined by solving the relevant electric field equations where the temperature dependency of the electrical field is also taken into account. The results are presented on a sample PCB and comparisons are made with the previous studies and conventional models. It is demonstrated that temperature values differ substantially depending on the method of Joule heating treatment used.