Embedded Two-Phase Cooling of High Flux Electronics Via Press-Fit and Bonded FEEDS Coolers

Abstract

The increasing heat densities in electronic components and focus on energy efficiency have motivated utilization of embedded two-phase cooling, which reduces system-level thermal resistance and pumping power. To achieve maximum benefit, high heat fluxes and vapor qualities should be achieved simultaneously. While many researchers have achieved heat fluxes in excess of 1 kW/cm2, vapor qualities are often below 10%, requiring a significantly large amount of energy spent on subcooling or pumping power, which minimizes the benefit of using two-phase thermal transport. In this work, we describe our recent work with cooling devices utilizing film evaporation with an enhanced fluid delivery system (FEEDS). The design, calibration, and experimental testing of a press-fit and bonded FEEDS test section are detailed here. Heat transfer and pressure drop performance was characterized and discussed. With the press-fit Si test chip, heat fluxes in excess of 1 kW/cm2 were obtained at vapor qualities approaching 45% and a coefficient of performance (COP) approaching 1400. With the bonded SiC test chip, heat fluxes in excess of 1 kW/cm2 were achieved at a vapor quality of 85% and heat densities approaching 490 W/cm3.

Membrane-Based Two Phase Heat Sinks for High Heat Flux Electronics and Lasers

“…Numerous strategies have been employed to enhance CHF in pool boiling as well as flow boiling, such as the use of biphilic and biconductive surfaces [15], [21], [22], functionalized surfaces [23], separated liquid-vapor pathways [26], [27], microchannel flow devices [28]- [37] with sintered surfaces and varying channel cross-sections, nanowires and nanostructures [38]- [41], addition of surfactants and nanoparticles [42]- [48], increasing surface roughness and wickability [16], [25], tuning surface wettability [20], and using microporous structures [49]- [52]. Recently, Rahman et al [16] demonstrated through biotemplating of microstructures that an increase in surface roughness and wickability facilitates liquid replenishment to the surface, enhancing CHF.…”

Air Cooling of Power Electronics Through Vertically Enhanced Manifold Microchannel Systems (VEMMS)

“…Thermal management of the switches has become a primary design goal in the packaging of power converters. Many aggressive cooling methods, such as jet cooling, spray cooling, and two-phase cooling, have been and are being developed which are capable of handling heat fluxes above 100 W/cm 2 , with some capable of dissipating near or above 1 kW/cm 2 [1][2][3][4][5]. However, such cooling methods usually involve additional complexity and lack sufficient understanding of the fundamental physics of liquid-vapor flow interaction, making accurate and reliable analysis and design optimization more difficult [6].…”

“…To improve performance over what has been reported in the literature, three major objectives are considered in this study: (1) reducing the number of layers and interfaces between the heat source and air; (2) improving the heat sink design to enable maximum heat transfer area while maintaining reasonable pressure drops; (3) creating a design with minimal footprint on board and reduced volume to enhance power density. Some of these targets, especially 2 and 3, are competing objectives.…”