In this article, we describe a new approach for the compact and energy-efficient cooling of converters where multiple miniaturized microfluidic cold plates are attached to transistors providing local heat extraction. The high pressure drop associated with microchannels was minimized by connecting these cold plates in parallel using a compact three-dimensional-printed flow distribution manifold. We present the modeling, design, fabrication, and experimental evaluation of this microfluidic cooling system and provide a design strategy for achieving energy-efficient cooling with minimized pumping power. An integrated cooling system is experimentally demonstrated on a 2.5-kW switched-capacitor dc–dc converter, cooling down 20 GaN transistors. A thermal resistance of 0.2 K/W was measured at a flow rate of 1.2 mL/s and a pressure drop of 20 mbar, enabling the cooling of a total of 300 W of losses in the converter using several milliwatt of pumping power, which can be realized with small micropumps. Experimental results show a tenfold increase in power density compared with the conventional cooling, potentially up to 30 kW/L. This proposed cooling approach offers a new way of coengineering the cooling and the electronics together to achieve more compact and efficient power converters.

中文翻译：

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用于高功率密度转换器的具有紧凑流量分配的多个功率器件的高效微通道冷却

在本文中，我们描述了一种用于转换器的紧凑和节能冷却的新方法，其中多个微型微流体冷板连接到提供局部热提取的晶体管。通过使用紧凑的 3 维印刷流量分配歧管并联连接这些冷板，可以最大限度地减少与微通道相关的高压降。我们介绍了这种微流体冷却系统的建模、设计、制造和实验评估，并提供了一种设计策略，以最小化泵送功率实现节能冷却。集成冷却系统在 2.5 kW 开关电容器 DC-DC 转换器上进行了实验演示，可冷却 20 个 GaN 晶体管。在 1.2 mL/s 的流速和 20 mbar 的压降下测得的热阻为 0.2 K/W，能够使用几毫瓦的泵浦功率冷却转换器中总共 300 W 的损耗，这可以通过小型微型泵来实现。实验结果表明，与传统冷却相比，功率密度提高了 10 倍，可能高达 30 kW/L。这种提出的冷却方法提供了一种将冷却和电子设备协同设计的新方法，以实现更紧凑和更高效的电源转换器。