Research On Microchannel Cooling System Based On Piezoelectric Drive

With the advancement of Micro-Electro-Mechanical System processing technology,the package size of micro-electronic devices is rapidly reduced?and the heat flux density is rapidly increasing,which affects the stability and life of the device.Therefore,the thermal design of micro-electronic devices has received extensive attention.Due to its small size,high heat exchange efficiency per unit area and strong controllability,the microchannel cooling system has become the focus of research on heat dissipation of microelectronic devices.As a major component of the microchannel cooling system,micro-pumps and microchannel heat sinks are key points to improve system thermal performance.Therefore,the structural design and improvement of the micro-pump,the structural design and optimization of the microchannel heat sink are of great significance for improving the heat dissipation performance of the microchannel heat dissipation system.The main structure has been redesigned on the basis of the classic piezoelectric drive pump.The model design of the lever and bridge external displacement amplifying mechanism was carried out respectively,and a hydraulic external amplifying mechanism was constructed.The dynamic analysis and numerical modeling of the three external amplification mechanisms are carried out,and the correctness of the model is verified by the finite element method.Among them,the hydraulic micro-displacement amplifying mechanism has the best performance,the magnification is 50.6,the frequency is 6.94kHz,and the structure volurne is only 240.211mm3.A dis-type shut-off valve was designed as a valve for the piezoelectric drive pump,and its dynamic and wet modal analysis was performed to determine its vibration performance.The vibration amplitude of the disc-type stop valve of the piezoelectric drive pump was 0.048mm.The output flow rate of the piezoelectrically driven pump was finally obtained to be 62.79 ml/min.In order to further improve the heat dissipation performance of the microchannel heat dissipation system,theoretical,simulation and experimental analysis are carried out on the structural optimization and sectional shape optimization of the rectangular microchannel heat sink.According to the effective set algorithm,the multi-objectives of the microchannel radiator are optimized,and a double normal distribution coupling model is established.The optimal microchannel is a 26-hole rectangular microchannel with a thermal resistance of 0.2574K/W and a required pump power of 3.243×10-5W.Based on the optimal rectangular microchannel heat sink,the cross-section simulation is optimized.The simulation results show that the performance of the new cross-section microchannel heat sink is 6.49%higher than that of the optimal rectangular heat sink.The microchannel heat dissipation system performance experimental platform was built.The experimental results of thermal resistance of rectangular microchannel have an error of 7.45%from theoretical analysis,and the experimental and theoretical errors of required pump power are 2.32%.The heat dissipation performance of the new cross-section microchannel heat sink is 11.2%higher than that of the rectangular microchannel heat sink.