A Hybrid Micro/Nanostructured Wick for New Generation High Performance Heat Carriers/Spreaders

S. Tej, D. Horner, S. Moghaddam
University of Florida, US

Keywords: phase change heat transfer, wich structures, micro and nanofluidics, heat pipe

Summary:

The need for more functional devices/systems along with the electronics industry’s ability to fabricate increasingly dense integrated circuits have led to an ever-increasing generation of waste heat in CPUs, power electronics, and advanced radar systems. The efficacy of the thermal management systems now dictates the performance limit of these applications. Due to the low-cost and high reliability, hermetically sealed two-phase heat carriers/spreaders have become one of the most effective thermal management tools. However, the efforts to expand the use of this concept to many other applications have been hampered by the limitations of the existing wick structures. The wick capillary pressure and permeability determine the heat removal capability and the distance over which the heat can be pumped. Over the past 1-2 decades many efforts have been conducted to enhance these two properties. Recently proposed nanoscale wicks cause a significant fluid pressure drop that in turn results in a lower mass flow rate and corresponding heat removal leading to an even lower performance than the existing wick structures. In this presentation, we discuss results of an extensive analytical and experimental study on micro and nanoscale wicks as well as a new hybrid multi-scale wick with an order of magnitude higher performance than the existing wick structures.