A Quick PCB Thermal Calculation for Power Electronic Devices with Exposed Pad Packages

Abstract:
Thermal design of PCBs in electronic systems is critical to maintain device operating temperatures below specified limits. Although the predictions from full-field CFD simulations are accurate, the computational cost and model generation time could be fairly high. Thus, it is preferable to use a quick estimation tool to design a preliminary layout of PCBs with different heat-dissipating components. The present methodology does not rely on accurate CFD modeling. It can be extended to forced convection and other PCB constructions simply by adjusting the film coefficient values and knowledge of how the board going to be constructed (e.g. number and thickness of metal layers). A calculator using this methodology can be developed as a stand-alone or a web-based application, and would be valuable when initially laying out multiple components on PCB, prior to undertaking a computationally expensive detailed CFD simulation of the entire PCB with all components.