Numerical Analysis of Novel Micro Pin Fin Heat Sink With Variable Fin Density

Numerical analyses to characterize and design micro pin fin heat sinks for cooling the 2016s IC chip heat generation are carried out in this paper. A novel design with variable fin density is proposed to generate a more uniform temperature of the IC chip junctions. The variable-density feature allows the gradual increase of the heat transfer area as coolant passes through the system. Single-phase water in the laminar regime is employed. Four different fin shapes (circle, square, elliptical, and flat with two redounded sides) are analyzed. The junction temperature and pressure drop variations in the heat sink generated by these shapes are presented. The effects of varying the fin length and height are also studied. The best heat sink configuration has a thermal resistance ranging from 0.14 to 0.25 K/W with a pressure drop lower than 90 kPa and a junction temperature similar to 314 K under the conditions studied. The temperature gradient at the bottom wall of the heat sink is considered as a parameter for comparing various heat sink designs. The novel cooling device has an overall temperature gradient lower than 2 degrees C/mm, which is significantly lower than the temperature gradients in other schemes reported in literature.