硅基微通道热沉制备与液冷散热性能研究

Fabrication of silicon-based microchannel heat sink and study on its heat transfer performance

为解决射频组件内热流密度350 W/cm^(2)的GaN功放芯片散热问题,设计并制备了一种分段式平直流道硅基微通道热沉。对热沉进行数值模拟,研究冷却液种类、流道槽宽和槽深对热沉散热性能和流动特性的影响,选择合适的冷却液,并对热沉进行流道尺寸优化。结果表明,65#防冻液最适合作为大功率射频组件散热的冷却液,流道槽宽同时影响热沉的散热能力和流阻,流道槽深只影响热沉的流阻,对热沉的散热能力几乎无影响。可通过优化流道槽宽调节散热能力,通过优化流道槽深调节流阻,实现热沉的解耦设计。优化后的热沉槽宽50μm、槽深500μm,满足射频组件内GaN功放芯片壳温<85℃,进出液口压差<100 kPa的使用要求。

To solve the heat dissipation problem of GaN chips with heat flux density 350 W/cm^(2) in RF components,a silicon-based microchannel heat sink with segmented straight channel was designed and fabricated.The flow and heat transfer characteristics of heat sinks with three types of coolants,different channel widths and depths were studied by numerical simulation.Suitable coolant was selected,and the channel size of the heat sink was optimized.The results show that 65#antifreeze is the most suitable coolant for cooling high-power RF components.The width of the channel affects both the heat transfer performance and flow resistance of the heat sink,while the depth of the channel only affects the flow resistance of the heat sink and has almost no effect on its heat transfer performance.The decoupling design of the heat sink can be achieved by optimizing the width of the channel to adjust the heat transfer performance,and by optimizing the depth of the channel to adjust the flow resistance.The optimized heat sink with channel width of 50μm and channel depth of 500μm can meet the heat dissipation needs of RF components,while the case temperature of chip is less than 85℃,and the pressure difference between inlet and outlet is less than 100 kPa.