Self-Driven Electronic Cooling Based on Thermosyphon Effect of Room Temperature Liquid Metal

Thermal management has been a critical issue for the safe running of an electronic device. Driving liquid metal with low melting point to extract heat from the thermal source is highly efficient because of its superior thermophysical properties over conventional coolant such as water or the like. In this paper, utilizing thermosyphon effect to drive room temperature liquid metal for electronic cooling was proposed for the first time with its technical feasibility demonstrated. This may lead to a self supported cooling which just utilizes the waste heat produced by the hot chip to drive the flow of liquid metal. And the device thus fabricated will be the one without any external pump and moving elements inside. A series of conceptual experiments under different operational conditions were performed to evaluate the cooling performance of the new method. Meanwhile, the results were also compared with that of water cooling by ways of thermal infrared graph and temperatures acquired by thermocouples. According to the measurements, it was found that the cooling performance of liquid metal was much stronger than that of water, and this will become even better with the increase of heat load, and height difference between the cooler and heater. A theoretical thermal resistance model was established and convective heat transfer coefficient was calculated to interpret the phenomenon with uncertainty analyzed. With further improvement of the present system and liquid metal coolant, this method is expected to be flexibly useful for heat dissipation of light-emitting diode (LED) street lamp, desk computer and radio remote unit (RRU), where confined space, efficient cooling, low energy consumption, dust-proof and water-proof are critically requested.