ABSTRACT In this study, permeability and capillary pressure of copper micropillar structures (height: 50 µm, diameter: 50 µm) in different arrangements (hexagonal, rectangular, and square) and different porosities (0.45/0.5, 0.6, 0.7, 0.8) are compared experimentally and numerically. The micropillar structures are fabricated on copper clad printed circuit board with electroplating, and the samples are coated with silica nanoparticles to enhance wettability. A forced liquid flow test is used to measure permeability of the samples, and capillary rate-of-rise measurement technique is used to determine the capillary pressure of the wicks. In the permeability model, the effect of meniscus curvature is considered, and the results are compared with other permeability models. Capillary pressure is predicted by using surface energy minimization tool, Surface Evolver. The test results show that the micropost array in rectangular arrangement have the highest permeability, and similar capillary pressure compared to other pillar arrangements with the same porosity, and thus show the highest capillary performance parameter. The effect of gravity on the sample characterization with capillary rate-of-rise test is also studied to investigate the feasibility of applying Washburn’s equation to test data.

中文翻译：

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不同排列的微柱阵列的毛细管性能

摘要 在本研究中，不同排列（六边形、矩形和正方形）和不同孔隙率（0.45/0.5、0.6、0.7、0.8）的铜微柱结构（高度：50 µm，直径：50 µm）的渗透率和毛细管压力分别为通过实验和数值进行比较。微柱结构通过电镀在镀铜印刷电路板上制造，样品涂有二氧化硅纳米颗粒以增强润湿性。使用强制液体流动测试来测量样品的渗透性，并且使用毛细管上升率测量技术来确定灯芯的毛细压力。在渗透率模型中，考虑了弯月面曲率的影响，并将结果与​​其他渗透率模型进行了比较。通过使用表面能最小化工具预测毛细管压力，表面进化器。测试结果表明，与具有相同孔隙率的其他柱排列相比，矩形排列的微柱阵列具有最高的渗透率和相似的毛细管压力，从而显示出最高的毛细管性能参数。还研究了重力对毛细管上升率测试样品表征的影响，以研究将沃什伯恩方程应用于测试数据的可行性。