Study On The Key Technology Of Embedded Microfluidic Heat Dissipation For Multi-chip Electronic Systems

With the continuous improvement of electronic system integration and the pursuit of high computing performance,the operating frequency of the chip and the heat dissipation power have increased simultaneously,and the heat flux density has exceeded 1000 W/cm~2.The heat dissipation of electronic chips has become one of the bottlenecks restricting its performance output.Recently,with the wide application of multi-chip component electronic systems with excellent system performance,the heat dissipation difficulty of the electronic system is further exacerbated.For example,AMD’s server chip AMD EPYC 7002 uses 64 cores and 128 threads,the maximum operating frequency is 3.4 GHz,and the thermal power consumption reaches 280 W.Tesla’s AI chip Dojo consists of 25 chips,and the thermal power consumption has reached 10 k W.The heat dissipation of the traditional multi-chip module system is based on an indirect thermal management technology,such as air cooling and indirect liquid cooling,and its heat dissipation capacity is limited to about 100 W/cm~2.These methods all have the following problems:(1)The electronic chip is bonded to an external heat sink through a thermal interface material to form an integrated module,which severely limits the heat transfer capability between the heat sink and the heat source.(2)Customize the heat dissipation system design according to the heat dissipation requirements of different electronic systems,so that a general heat dissipation scheme cannot be used to achieve thermal management,and the practical application efficiency is low.(3)In the entire liquid cooling circulation system,if a certain flow channel in the integrated module is blocked or damaged,it will cause irreversible damage to the entire electronic system.Therefore,it is urgent to develop a heat dissipation solution with efficient heat exchange capability,replaceability,and configurability for multi-chip component systems.Embedded cooling is a very attractive heat dissipation method for high heat flux chips.Compared with traditional indirect heat dissipation technology,it breaks through the thermal resistance limit of the thermal interface material layer between the heat sink and the electronic chip,and it has the advantages of integration,miniaturization,and high-efficiency heat dissipation.This paper analyzes the heat dissipation requirements of electronic systems with multiple high-power chips,and conducts related heat dissipation research for this requirement,and innovatively proposes a single chip embedded manifold micro-channel heat dissipation method and puzzle assembly.The concepts combine to realize an embedded cooling approach that is configurable and replaceable for multi-chip component systems.First of all,this thesis studies the heat dissipation of the embedded manifold micro-channel for the independent high heat flux density chip.The thermal-hydraulic performance of the heat exchange structure was experimentally evaluated using a liquid cooling cycle test platform.The results show that under the conditions of device heat flux density and working fluid flow rate of 1200 W/cm~2 and 400 m L/min,respectively,the surface temperature uniformity(array temperature standard deviation)and the maximum temperature of 8×50(number of manifold distribution channels:8;embedded microchannel width:50μm)cooling structure can be controlled within1.88°C and 69°C,which verifies that the embedded manifold micro-channel heat dissipation method can achieve effective thermal management of high heat flux chips.Aiming at the research on the heat dissipation characteristics of the multi-chip module system,an embedded cooling module with a size of 70 mm×88 mm×9 mm is used to dissipate heat for a 3×3 chip array to verify the feasibility of the multi-chip embedded cooling method.The experimental results show that each chip in the 3×3chip array is cooled independently,and there is no thermal coupling interference between each other.The temperature uniformity is 2.59℃at 400 W/cm~2 and 500m L/min,and the highest temperature of the chip array is less than 58.3℃.Under the same conditions,the effects of three different configurations of chip arrays on the heat dissipation characteristics of the cooling module were studied.The results show that the maximum pressure drop difference of the cooling system and the maximum temperature difference of the chip array are less than 1.6 k Pa and 5.58℃,respectively,which proves that the cooling module can meet the heat dissipation requirements of chip arrays with different configurations.In addition,the heat dissipation performance of a single chip in the cooling module remains unchanged after repeated assembly and disassembly,proving the replaceability of this cooling method.Therefore,the cooling method for multi-chip component systems proposed in this paper has the prospect of being applied to high-performance processors,AI computing components,and DC/DC power converters in the future.