Conduction and Convection Based Thermal Analysis of Printed Circuit Boards for Air-borne Applications

This paper presents a Finite Difference based method for thermal analyses of PCBs; and shows how this simplified technique can be used for detecting the problem areas and to provide the remedial measures for avoiding component overheating. The method is demonstrated using the example of an air-borne system with suspect thermal characteristics. The method provides for modeling the conductive and convective heat flow paths and calculates the component's steady-state, peak load operating temperatures, counting the effect of one on the other, in parallel. Results are compared for three different heat removal arrangements; i.e., pure conduction in vacuum, combined effect of conduction and convection, and finally after heat sink application. It was found that heat sinks could be very effective in reducing the component peak operating temperatures.