Thermal performance evaluation of various heat sinks for air cooling

Three different types of the heat sinks, including extrusion fin, plain fin, and cell fin are under considerations. The extruded heat sink is the most popular because it is inexpensive and easy to make. However, the fin of this type heat sink is relatively thick which results in small number of fins on the heat sink. In other words, the surface for the convective heat transfer is limited. A CFD analysis is performed to characterize the performance of the individual heat sinks. A copper heat sink is mounted to a component on the printed circuit board (PCB) which is cooled by the air with the velocities at 1.5, 2.5, 3.5, and 5.5 m/sec, respectively. In order to simulate the real board condition, the flow by-pass which is an important phenomenon to the performance of the heat sink is included in the analysis. The purpose of this study is to obtain the heat transfer coefficient as well as the thermal resistance of the individual heat sinks at various flow velocities. In addition, the effects of the flow by-pass on the heat sink performance will also be examined.