Abstract: As the integration of electronic chips becomes higher and higher, the corresponding thermal management problems become more and more serious, and the effective design of heat sinks has become a good solution. The variable density topology optimization method is used to optimize the design of the forced air-cooled heat sink, and a pseudo three-dimensional optimization model consisting of a thermally conductive base layer and a heat flow design layer is established; more practical convection boundaries are considered, and the RAMP method to interpolate the thermal conductivity and convection heat transfer coefficient is used. Taking the minimization of pressure drop as the optimization goal, and taking the minimum value of air absorption heat Q as 2 W as the thermal constraint, the optimization results under three sets of base temperature T_b (314 K, 330 K, 350 K) are analyzed. Finally, the numerical simulation of the tensile three-dimensional heat sink is used to verify the physical validity of the pseudo three-dimensional optimization model. The results show that during the process of increasing the base temperature T_b, and the smoothness of the fins is improved but the surface area is shrinking, accounting for 18%, 16% and 14% of the design area; the objective function φ gradually decreases, respectively 0.073, 0.036, 0.025; the maximum velocity in the design area gradually decreases, but the velocity and temperature distribution are more uniform. The velocity and temperature changes along the Z axis in the 3D heat sink simulation results are very small, thus verifying the physical validity of the pseudo 3D optimization model.

Key words: topology optimization, interpolation model, base temperature, pseudo three-dimensional optimization model