基于热阻拓扑关系的高频电源金氧半场效晶体管的散热设计及仿真

Thermal Design and Simulation of MOSFET in High-Frequency Power Supply Based on Thermal Resistance Network

研究了高频电源中金氧半场效晶体管(MOSFET)的散热设计问题,分析了MOSFET的热性能参数,建立了单个和耦合器件散热的热阻拓扑模型,推导出各接触面的温度公式,由此得到工程中选取散热器的切实依据,并用于实际高频电源中耦合MOSFET的散热处理.同时,采用计算流体动力学分析软件ICEPAK对所选散热器按工况进行仿真验证.结果表明,该热阻拓扑模型可满足工程设计的要求.

This paper described the thermal design of metal-oxide-semiconductor field-effect transistor （MOSFET） which is typically applied in high-frequency power supply. After introducing the thermal parameters of MOSFET, the thermal risistance networks for single and couple pieces were established respectively, and further temperature formulations at each interface were deduced. Based on the above work, a suitable heat sink was figured out to solve the thermal problem in a high-frequence power supply which contains four MOSFETs compactively fix in a PCB. Finally, the performance of heat sink was verified with the help of computational fluid dynamics（CFD）software ICEPAK, and the thermal risistance networks are proved to be practical in engineering application