中文摘要：

相比于单层热沉，双层热沉显著改善芯片温度均匀性。本文建立了双层热沉的三维流固耦合模型，采用参数递进优化法，对硅基水冷双层热沉的几何结构（流道数Ⅳ、下层流道高度Hc1、上层流道高度Hc2和肋条宽度Wr）及上下两层通道的流速比t进行了优化研究。结果表明，在泵功0．2W和热流密度100W·cm^-2时，最佳的双层热沉结构和通道流速比分别为：Nopt=70，Hc1，opt=200μm，Hc2，opt=650μm，Wr1opt=71．48μm和topt=1．85，相比于同样操作条件和几何参数的单层热沉，热阻降低了11．3％，热沉的最大温差从单层热沉的4．6K降低到0．5K，显著改善了热沉的温度均匀性。

英文摘要：

As compared with single-layer microchannel heat sink （SL-MCHS）, double-layer mi- crochannel heat sink （DL-MCHS） can significantly improve the temperature uniformity of electric elements. This work uses a three-dimensional solid-fluid conjugate model incorporated with a pro- gressive optimization procedure to optimize the cooling performance of a water-cooled, silicon-based DL-MCHS. Four geometric parameters （channel number N, bottom channel height H~I, upper channel height He2, and vertical rib width Wr） and coolant velocity ratio of upper channel to bottom channel, t, are selected as optimized variables. The results show that at a fixed pumping power of 0.05 W and a heat fluxes qw=100 W.cm-2, the optimal geometric structure and coolant velocity ratio for the DL-MCHS are Nopt=70, Hcl,opt=200 ~tm, Hc2,opt：650 btm, Wr,opt=71.48 μm, and topt=1.85. The thermal resistance of the optimal DL-MCHS is reduced by 11.3% compared to the SL-MCHS, and the maximum temperature difference is reduced to 0.5 K, which is far less than 4.2 K of the SL-MCHS.