An overview and comparison of various refrigeration methods for microelectronics cooling

Small-scale refrigerators, termed mesoscale refrigerators, are possible cooling solutions for high-power microelectronics. The performance of mesoscale refrigerators has not yet been experimentally demonstrated, although a recent theoretical model indicated that at temperatures near room temperature and above, a vapor compression refrigerator may compete successfully with a thermoelectric cooler having extremely high efficiency [1]. The present study proposes an overview and comparison between several alternative refrigeration methods used to actively cool the electronic components in a power microelectronics system. Three systems are evaluated, namely a miniaturized classical mechanical vapor compression system using an off-the-shelf compressor, a miniaturized system with ejector used for vapor compression, and finally a miniaturized refrigeration system with absorption, designed for similar cooling powers. The efficiency and COP of each system will be evaluated, together with associated reliability and cost related issues. The specifics of all proposed systems are based on the optimized performance of the miniaturized components of the various refrigeration systems, designed to fit the smaller scale power electronics populating a printed circuit board (PCB) in a high-power microelectronics system. For all designs, an array of micro-channels is used for vaporizer/condenser units. Several components of the refrigeration system are thermally evaluated for cooling powers ranging from 20- 100 W, with direct application to high power telecom units. Several advantages and/or disadvantages of these refrigeration-based cooling methods are highlighted. The study is concluded by identifying the pros and cons of implementing such systems to real-life microelectronics applications.