| Semiconductor lasers are widely used in industrial processing, laser medical treatment, laser communications, information display, aviation aerospace and other fields owing to their high conversion efficiency, long life, small size, light weight, high reliability, directly modulated and easily integrated with other semiconductor devices, etc., If the heat dissipation caused by high-power laser light output in module is not eliminated promptly, it would result in temperature rises lead to increasing the threshold current, reducing the efficiency and drifting the wavelength which affects the beam quality of laser. Temperature controlling is an important area in researching direction of high-power semiconductor lasers, At present, microchannel heat sink as the main cooling mode have become a key factor to support high-performance during semiconductor lasers working.Based on the theory of computational fluid dynamics(CFD), in this paper, basic control equations of experiment parameters were established, and defined as discrete equations by finite volume method. Then the physical and mathematical model data of microchannel heat sink were loaded into the FLUENT software with boundary conditions and initial parameters, which used the Realizable k-? turbulent flow model. Finally the numerical calculation of microchannel heat sink with post-processing was accomplished.The thermal performance of microchannel heat sink are mainly affected by structure factors like: import and export width, channel width and spacing, channel ridge height and length. The flow distribution of channel, 4 single factors include microchannel width, spacing, channel length and wall roughness influencing on the chip surface temperature rise and pressure drop as the thermal performance are researched by numerical simulation analysis methods under the conditions of the determine width of inlet and outlet and the microchannel height. The improved scheme that optimizing the microchannel structure of inflow layer is proposed to achieve water flow homogenization in backwater hole. The results showed that the surface temperature decreases with the microchannel spacing, width and channel length decreasing but the trend is slowing, the pressure drop decreases with channel width and distance increasing and decreases with channel length increasing. Within a certain range, the temperature decreases with wall roughness increasing, while the pressure drop along increases. Within specific appearance dimensions, the optimal channel structure size parameters were obtained by numerical simulation analysis; It is theoretically verified that the surface quality of SLM forming parts can enhance the feasibility of thermal performance in heat sink, Thermal resistance of heat sink with optimal structure was 0.34 K / W and pressure drop was 0.9bar.The factors that manufacturing process parameters influence on the density and surface roughness of heat sink; forming quality of pure nickel tiny structures and heat sink placed way and support adding methods during forming process are approached in study of SLM manufacturing nickel microchannel heat sink using EOS M270. Best quality molding process parameters, molding the size range and support adding method are obtained. Based on all those achievements, the microchannel heat sink through numerical optimization has been manufactured.The microchannel heat sink of which surface was treated was welded with a laser bar output power of 80 W and had tests of laser power and spectral parameters. Under the conditions of the flow rate which was 0.3L/min, the chip surface temperature is 18℃.It is calculated that this microchannel heat sink thermal resistance is 0.39K/W and pressure drop is 1.4bar, which meet chip cooling requirements. Experiment results showed a very good agreement with the simulation trend. |
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