Research On Thermoelectric Cooling Technology For High Heat-Flux Electronic Devices

With the development of science and technology,electronic devices are changing towards the direction of high power and microminiaturization,resulting in high heat-flux when electronic devices work.In particular,when the dynamic power chip is operated under pulse power,it will produce extremely high heat-flux.Thus its temperature will rise sharply in a short time,and finally reach a peak temperature.The high temperature will seriously affect the efficiency and stability of the chip operation.The problem of thermal management of electronic devices is becoming more and more serious,and efficient thermal management technology is urgently needed to ensure the efficiency,reliability,safety and durability of electronic devices.Having the advantages of no refrigerant,no vibration,small volume,high reliability and high refrigeration density,and being able to provide accurate temperature control,the thin-film thermoelectric cooler(TEC)has an irreplaceable position in chip cooling.Firstly,a novel type of the thin-film TEC with a couple of thermoelements electrically connected in parallel and then electrically connected in series is proposed.The geometric model for the novel parallel thin-film TEC is set up.Under normal operating conditions(0 thermoelement breaks down)and accident conditions(2 or 4 thermoelements break down),the cooling performances(maximum cooling capacity,maximum cooling temperature difference,coefficient of performance)of the novel parallel thin-film TEC and the traditional series thin-film TEC is compared using finite element method to carry out the numerical simulations.The results show that the cooling performance of the novel parallel thin-film TEC is better than that of the traditional series t thin-film TEC under both normal operation conditions and accident conditions.In addition,when the number of broken thermoelements changes,the fluctuations of the cooling performance for the novel parallel thin-film TEC is less than that for the t traditional series thin-film TEC.It is proved that the novel parallel thin-film TEC has better cooling performance and operation reliability.This study provides theoretical guidance for the optimization of cooling performance of the thin-film TEC,and also provides a basis for the stability and reliability design of the thin-film TEC operation.This study provides theoretical guidance for the optimization of thermoelectric film refrigeration performance,and also provides a basis for the stability and reliability design of thermoelectric film operation.Then,according to the heat-dissipation demand of high heat-flux chip,transient cooling of the thin-film TEC is used to control the peak temperature of dynamic power chip based on the whole cooling system.The transient cooling performance of the thin-film TEC integrated on chip is studied by finite element numerical simulation.The results show that cooled by the transient cooling effect of the thin-film TEC,the peak temperature of dynamic power chip can decrease by 10.3℃.And the appropriate current pulse(0.8A),smaller chip heat-flux density,smaller thermoelement thickness,more thermoelement number and smaller thermal contact resistance are beneficial to reduce the peak temperature of the chip.The study of the influence of various factors on the performance of thin-film TEC provides a reference for the thermal design of modern high-power electronic devicesFinally,an experiment to control the peak temperature of dynamic power chip by thermoelectric module is built.The dynamic power chip is simulated by ceramic heating plate,and the effect of using the transient cooling to control the peak temperature is experimentally studied.By measuring the temperature of the ceramic heating plate,it is found that the peak temperature of the ceramic heating plate decreases by 7.67℃ at the voltage pulse of 10V,which verifies the feasibility of transient cooling effect to control the peak temperature of the chip.Besides,comparing the experimental data with the simulation results,the difference between the results is 3.9%,which is in good agreement.That proves the correctness of the numerical simulation in this paper.