This paper reports a heat sink that uses a composite phase change material (PCM) made from a copper foam infused with a Field's metal eutectic alloy that melts at 60°C to achieve both high cooling and the ability to buffer transient temperature spikes. We integrate this composite PCM heat sink with circuit board mounted gallium nitride (GaN) devices that dissipate heat flux as large as 50 W/cm². To design the PCM heat sink and understand its behavior, we developed a three-dimensional finite element method (FEM) simulation of the integrated assembly. We fabricated and characterized five composite PCM heat sink devices, where each device had a different PCM thermal buffer. The thermal buffers had varying Cu volume fraction and thickness. The PCM heat sinks were integrated with top-cooled or bottom-cooled GaN devices on printed circuit boards. Measurements of PCM heat sink performance showed that during phase change, the device junction temperature was reduced by 10-20°C compared to a solid Cu reference heat sink, depending on the device heating power which was as high as 6 W. The PCM heat sink cooling time was increased by up to 2X compared to a solid Cu heat sink of the same geometry. Finally, we developed and validated a reduced order resistance-capacitance (RC) circuit model that can guide the design of future PCM heat sinks. This work demonstrates the potential for PCM heat sinks to be integrated with high power GaN devices and shows methods for the design and modeling of PCM heat sinks.

本文报告了一种散热器，该散热器使用由泡沫铜制成的复合相变材料（PCM），并注入Field的金属低共熔合金，该合金在60°C的温度下熔化，以实现高冷却和缓冲瞬态温度峰值的能力。我们将此复合PCM散热器与安装在电路板上的氮化镓（GaN）器件集成在一起，该器件可散发高达50 W / cm ^2的热通量。为了设计PCM散热器并了解其性能，我们开发了集成组件的三维有限元方法（FEM）仿真。我们制造并表征了五个复合PCM散热器设备，其中每个设备具有不同的PCM热缓冲器。热缓冲剂具有变化的Cu体积分数和厚度。PCM散热器与印刷电路板上的顶部冷却或底部冷却的GaN器件集成在一起。PCM散热器性能的测量结果表明，在相变过程中，与固态Cu参考散热器相比，器件结温降低了10-20°C，具体取决于器件的加热功率高达6W。PCM热与相同几何形状的固态Cu散热器相比，散热器的冷却时间最多可增加2倍。最后，我们开发并验证了降阶电阻电容（RC）电路模型，该模型可以指导未来PCM散热器的设计。这项工作展示了PCM散热器与高功率GaN器件集成的潜力，并展示了PCM散热器的设计和建模方法。