Application of CFD technology to electronic thermal management

Application of a computational fluid dynamics (CFD) tool to the thermal modeling of free convection cooled handheld/portable products and component level products is assessed. The results of two case studies are reviewed. The first case focuses on a sealed, system level enclosure typical of portable consumer products; while the second case looks at a component level analysis of a sealed multichip module (MCM) package possessing an internal cavity. Temperatures predicted by the simulations are compared to available experimental data as a means of assessing the software´s ability to adequately solve the coupled fluid dynamics/heat transfer problem. All simulation results were within 10% of experimental results for these two cases, indicating that the software is readily capable of providing good thermal performance predictions. For typical handheld portable products housed in a sealed case, the dominate mode of heat transfer from the components/circuit board to the outer case is via gaseous conduction. Convection typically fails to develop in such designs due to the dominance of viscous forces within the air confined between the circuit board and outer case