某功放模块散热冷板设计与仿真分析

Design and Simulation Analysis of Cooling Plate for a Power Amplifier Module

针对某型设备功率放大模块高功耗散热需求,尤其是其中发热量较大的GaN芯片散热需求,设计一款散热冷板。其中单个功放模块热量1080 W,冷板散热量2160 W,根据设备的散热需求进行理论计算,确定液冷板需求的流量。然后结合热仿真软件FloEFD对冷板进行结构设计及整体方案的优化设计,通过优化冷板流道、去掉原有功放模块外壳,内部器件直接贴装在散热冷板表面,减小垂向热传导距离、减少转接面层数增强冷板散热能力。优化前后热仿真对比,功放芯片节温从280℃降到190℃,优化效果明显,满足GaN芯片节温小于225℃使用需求。在试验验证中,安捷伦数据采集仪测试结果显示放大模块壳体温度与热仿真数据接近,红外热成像仪测试结果显示功放芯片满功率运行时节温约201℃,验证数据说明热仿真结果与实际数据接近,冷板设计满足功放器件的热设计需求。

Aiming at the high-power heat dissipation demand of the power amplifier module of a certain type of equipment,especially the heat dissipation demand of GaN chip with large heating capacity,a heat dissipation cold plate was designed,in which the heat of a single power amplifier module was 1080 W,and the heat dissipation capacity of the cold plate was 2160 W.According to the heat dissipation demand of the equipment,the theoretical calculation was carried out to determine the flow required by the liquid cooling plate.Then combined with the thermal simulation software FloEFD,the structural design and overall scheme optimization design of the cold plate were carried out.By optimizing the cold plate channel,removing the original power amplifier module shell,and the internal devices were directly mounted on the surface of the cooling cold plate,the vertical one-dimensional heat conduction distance was reduced,the number of heat conduction interfaces was reduced,and the heat dissipation capacity of the cold plate was enhanced.The thermal simulation comparison before and after optimization showed that the power amplifier chip's temperature saving was reduced from 280℃to 190℃,which met the needs of GaN chip's temperature saving less than 225℃.In the test verification,the test result of Agilent data acquisition instrument showed that the shell temperature of the amplification module was close to the thermal simulation data.The test result of infrared thermal imager shows that the temperature of the power amplifier chip was about 201℃when it was running at full power.The verification data shows that the thermal simulation result is close to the actual data,and the cold plate design meets the thermal design requirements of the power amplifier device.