冷却电子芯片的平板热管散热器传热性能研究

Experiments Investigation on Thermal Conductivity of Flat Heat Pipes Used to Cool Electric Die

通过采用均匀与非均匀热量分布的两种热源对平板热管散热器在冷却电子芯片中的传热性能进行了实验研究,了解其在不同热源加热条件下的传热特性。对比均匀加热条件的铜柱而言,硅质芯片作为热源可以更切实际地模拟计算机微处理器的热源边界条件。非均匀热量分布的芯片内部设置了3个受热区,其中热点的最大热流密度为690W/cm2。实验表明平板热管散热器工作过程中蒸发段的热传导和汽液两相之间的相变换热起重要作用。研究结果说明蒸发热阻在不均匀的加热条件下与均匀加热条件相比变化不明显,但与热源芯片的传热量成反比。

Experiments on heat transfer performance of flat heat pipes during cooling electric die were conducted with two different sets of test heaters （copper post heater and silicon die heater） to investigate the effects of non-uniform heating conditions on the thermal performance of vapor chambers. Compared with the copper post heater which provides ideal heating condition, the silicon chip package can replicate more realistic heat source boundary conditions of microprocessors. The chip contains three metallic heaters in order to simulate the hot spots on actual microprocessors. In the experiment, the highest heat flux from the hotspot heater was approximately 690 W/cm^2. The test results show that both conduction heat transfer and phase-change phenomena played key roles in the evaporator. In addition, the evaporating thermal resistance was almost insensitive to non-uniform heating conditions but was inversely proportional to the amount of power applied over the die area.