Dynamic Study Of Thermoelectric On The Cooling Of Hot Spot Of Chip

The dissipation problem of hot spot with high heat flux density has become a bottleneck that restricting the development of the chip industry.The micro thermoelectric cooler is particularly suitable for the heat dissipation requirements of hot spots due to its large cold flow density,small size,accurate temperature control,easy packaging and integration.However,the current researches on the heat dissipation of hot spot with micro thermoelectric cooler mainly focus on the steady-state heat load conditions,which does not meet the requirements of engineering application.Therefore,this paper studies the dynamic characteristics of the micro thermoelectric cooler on hot spot cooling,discusses the working conditions of the four heat dissipation structures,and analyzes the influences.In this paper,the heat dissipation characteristics of the hot spot and the substrate are analyzed according to the heat transfer model of the hot spot.The multi-physics coupling model of the micro thermoelectric cooler on hot spot cooling is established.Under dynamic heat load(including standby heat load,high frequency heat load and low frequency heat load),four heat dissipation structures are designed for hot spot:traditional heat dissipation structure,micro thermoelectric heat dissipation structure,mini contact heat dissipation structure,the combination structure of micro thermoelectric cooler and mini contact.The heat dissipation abilities of these four heat dissipation structures are analyzed.The effects of current,heat load,heat transfer coefficient and mini contact structure on heat dissipation are further studied,and the applicable working conditions of four heat dissipation structures are also discussed.The results show that the application of micro thermoelectric cooler and mini contact can effectively reduce the hot spot temperature under high frequency heat load,but the temperature drop effect under standby heat load and low frequency heat load is not obvious.The heat dissipation enhancement of the mini contact is determined by its material,and is less affected by the mini contact structure.Further researches found that the conventional heat dissipation structure is suitable for chip hot spots with a dynamic heat flux density below 270 W/cm~2.The combination structure of micro thermoelectric and mini contact is suitable for the hot spot with dynamic heat flux density between 270 W/cm~2～720 W/cm~2.The mini contact structure is suitable for hot spots with dynamic heat flux density above720 W/cm~2.For multi-hotspot chip,the use of a coordinated heat dissipation scheme can effectively reduce the chip temperature and improve the uniformity of chip temperature.In addition,the heat dissipation effect of the micro thermoelectric cooler is greatly affected by the current.As the current increases,the hot spot temperature first decreases and then increases,and the substrate temperature continues to rise.This research exhibits important reference value for the application,optimization and design of micro thermoelectric cooler in hot spot cooling.