新型径向平板热管传热性能的实验研究

Experimental Research on Heat Transfer Performance of Novel Radial Flat Heat Pipe

提出了一种能够代替金属基板,并能与大功率模块一体化设计的新型径向平板热管结构.相对于金属基板,该热管基板的优势在于利用两相沸腾换热对功率模块内的集中热源进行扩散,因此其热扩散能力大大高于以导热热扩散的金属基板,从而能够提高模块的功率密度.对径向平板热管进行了稳态和瞬态传热性能实验,并与铜基板的实验结果进行了对比.结果表明:与铜基板相比,径向平板热管具有更高的热扩散能力,可降低模块的结壳热阻;热管冷凝面具有良好的等温性,当芯片功率密度为176 W/cm2时,热管冷凝面的温差在3℃以内;热管模块启动过程中芯片达到相同温度需要的时间长,有利于克服功率“飙升”和提高功率器件抗热冲击的性能.

A novel radial flat heat pipe（RFHP） integrated with high power module instead of metal substrate was developed. Compared with metal substrate, the RFHP uses two-phase boiling heat transfer to diffuse heat in power module, and thus improve the thermal performance of the power module. The transient and steady heat transfer performance of the RFHP was experimentally measured and compared with that of copper substrate. Experiment result indicates that the RFHP has greater thermal diffusivity, and can reduce junction-to-case thermal resistance of the module. When power density is 176 W/cm^2, the temperature difference on the condensation section is within 3 ℃. The longer time period for the chip to reach the same temperature during RFHP module start-up can avoid power uprush and raise the ability of resisting thermal impact.