Experimental Investigation Of Novel Thermoelectric Liquid Cooling Technique

More and more dense of semiconductor circuits and miniature of micro electronicdevice result in higher heat load and heat flux on the chips. The excessive case temperaturehas huge influence on the chips’ stability and reliability. In order to maintain the chips at acertain temperature range and run normally, more efficient cooling techniques are requiredurgently, especially the over-clock of the chips needs sub-ambient cooling supporting.In this paper, a novel thermoelectric liquid cooling technique was proposed to meetthe cooling of microelectronic chips. And then, a novel liquid thermoelectric coolingdevice combined with thermoelectric cooling and traditional liquid cooling was developedand assembled for sub-ambient temperature cooling and heat dissipation in over-clockingor super calculating. A model of thermoelectric cooling for central processing unit (CPU)heat dissipation was established based on the mechanism of thermoelectric cooling andcooling characteristics of electronic chips. Subsequently, calculate and analyze the casetemperature、cooling capacity、coefficient of performance (COP)、operating current andthermal resistance of heat sink using this model, so as to guide the experiment latter. Afterthat, the experimental platform was set up including the heat source heating system、windspeed control system、temperature acquisition system and electric power supply system.Finally, the experimental study was carried out on thermal resistance、maximum heatcapacity、 cooling capacity、 cooling effect and efficiency of the novel liquidthermoelectric cooling device by setting the calorific value of virtual heat source、flowrate of fans and operating condition of thermoelectric cooler.Results demonstrated that there was an optimal working voltage of TEC to make thewhole radiator get the lowest thermal resistance and highest cooling capacity. Sodetermining the best working voltage was the most significant. With the heat flux of heatsource at28.5W·cm2and cooling air flow rate of5and9m·s1, the optimum operatingvoltage of TEC was28and32V respectively. In addition, TEC was conducive to heat dissipation especially in high ambient temperature (35℃). TEC also refrigerated andresponded rapidly after powered on, so microchips could run safely under overclocking.With the heat flux of heat source at28.5W·cm2and cooling air flow rate of5m·s1, thecase temperature of the heat source was reduced by3℃in merely10s and the maxtemperature drop5.4℃appeared after30s. What’s more, TEC realized sub-ambienttemperature cooling. The maximum heat dissipating capacity was7W·cm2when casetemperature was the same as ambient temperature，operating voltage of TEC was48V andthe cooling air flow rate was3~5m·s1.The experiment also indicated, the liquid cooling system was beneficial to COP ofTEC. The maximum COP and heat flux were3.5and15.7W·cm2respectively at the casetemperature was10℃higher than ambient temperature, operating voltage of TEC4~48Vand the cooling air flow rate of3~5m·s1. Besides, the maximum heat dissipating capacitywas45.2W·cm2and the lowest total thermal resistance was0.107℃·W1at casetemperature of65℃and cooling air flow rate of3~9m·s1. The more effect liquidthermoelectric cooling technology is able to satisfy the demand of microelectronics chipcooling.