液冷功放模块的优化设计及试验验证

Optimization Design and Experimental Verification of Liquid Cooling Power Amplifier Module

随着功率放大芯片的热流密度越来越高,局部高温已成为设备性能下降甚至失效的主要原因。针对某机载平台中高热耗的功放模块,文中首先对设备的液冷散热进行了理论计算,确定了液冷所需的流量。然后结合仿真计算对功放模块的结构进行了优化设计,通过增加局部底板厚度来提高热扩散能力。结合试验测试,对模块的热安装方式进行了优化设计,选取导热硅脂作为模块与冷板的界面材料。在高温验证试验中,优化后模块的芯片壳温降低了13.7℃,低于最高允许壳温,满足设备的热设计要求。

As the heat flux density of power amplifier chips is getting higher and higher, local high temperature has become the main reason for equipment performance degradation or even failure. Aiming at the power amplifier module with high heat consumption in an airborne platform, this paper firstly calculates the liquid cooling heat dissipation of the equipment and determines the flow rate required for liquid cooling. Then combined with the simulation calculation, the structure of the power amplifier module is optimized. By increasing the thickness of the local bottom plate, the thermal diffusion ability is improved. Combined with experimental tests, the thermal installation method of the module is optimized and thermal grease is selected as the interface material between the module and the cold plate. In the high temperature experiment, the chip case temperature of the optimized module is reduced by 13.7℃, which is lower than the maximum allowable case temperature and meets the thermal design requirements of the equipment.