Research On The Flowpath Optimization Of Microchannel Heat Sinks And Heat Transfer Performance

Rapid developments in high density and power chips have led to the micro-electronics components with a serious heating problem. It will affect the performance and reliability of chips, causes internal structure destroys, device deformation and function failure et al. Under for this situation, thermal design has become a key link to micro-electronic device structure design. Hence, to take away heat through surface cooling of microchannel heat sink design is emphasized in this field, the characteristic of small size, low-cost and high cooling efficiency cannot only meet heat dissipation requirements, but also ensure the operation reliability. In this paper, the structure parameters of rectangular microchannel heat sink and its optimization are studied as well as the flow and heat transfer performance that we optimized earlier. The specific works are as following:(1) The influence of single factor of microchannel heat sink on the structure parameters is studied, the primary and secondary order of the influenced factors on the surface junction temperature of heat sink is obtained: number of microchannel ? height of fin? width of fin ? height of microchannel ? width of microchannel; based on the single factor influence, discrete optimization results are obtained by using the method of orthogonal experiment: a=1mm, b=0.5mm, c=0.8mm, N=21, t=0.5mm.(2) According to the single microchannel structure and mathematical model, taking the thermal resistance and pressure drop as objective functions, a nonlinear,multi-objective and multi-constrained optimization model is proposed for the microchannel heat sink based on the thermal resistance network model, obtains the appropriate results when the weighting coefficient ω1 between 0.2 and 0.4, the corresponding optimization for structure size are N=25~32, b=0.62~0.85 mm,c=0.22 mm, a=1.3mm, t=0.2mm; from the material cost point, taking the thermal resistance and weight as objective functions, obtains the appropriate results when the weighting coefficient ω1 between 0.4 and 0.6, the corresponding optimization for structure size are N=20~29, b=1.12~0.75 mm, c=0.2mm, a=1.3mm, t=0.2mm, which provides an optimal material cost options.(3) Based on the comparison between before and after optimized results, the numerical methods used to study the heat transfer characteristics, flow andcomprehensive performance of microchannel, obtains whether the temperature distribution of high and low, or gradient uniformity, or flow stability, or unit thermal resistance and the pump power required, the optimized model is better than the before one; we study for different environments the impacts of various heat flux and inlet temperature on fluid flow and heat transfer; using JF Factor as Performance Evalution Critera(PEC), empirical formula for calculating the average Nusselt Number was fitted according to the numerical simulation results of microchannel.(4) We construct the experimental test platform, process three kinds of microchannel model and carry out experimental measurement. Combined with the experimental data, we obtain the optimized model is better than the before one. The optimized results can better control the heat source temperature distribution.