Numerical investigation on the temperature uniformity of micro-pin-fin heat sinks with variable density arrangement

Abstract

Temperature non-uniformity on chips has drawn the attention of researchers due to unwanted thermal stress development on chips resulting in a reduction in their life cycle and performance. In the present investigation, the heat transfer and flow characteristics of the coolant in the micro-pin-fin heat sink with variable density arrangement have been conducted numerically. The dimensions of the micro-pin-fin heat sink are 18.0 mm × 19.0 mm × 4.0 mm, and the height of the micro-pin-fin is 2 mm. Circular micro-pin-fin with diameters of 400, 500, and 600 μm, respectively have been considered. The power supply is 50 W with a heat source area of 10.0 mm × 10.0 mm. Water was the working fluid used while aluminum was used for the solid part of the heat sink. The operating pressure drop between the inlet and the outlet of the heat sink is fixed at 1500 Pa, 3000 Pa, and 5000 Pa. Ansys-Fluent was employed for the analysis. The results indicate that the temperature uniformity on the heat source for heat sink with variable density arrangement is better than that with staggered arrangement for about the same number of micro-pin-fins. The best effective thermal resistance is noted as 0.258 K/W among the heat sinks with all the configurations. In addition, the temperature difference per unit length on the heat source for heat sink with convergent arrangement at the pressure difference of 5000Pa and micro-pin-fin diameter of 600 μm was 1.34 K/mm, which is lower than the previously reported literature.