03. Electronics Packaging and Thermal Management

This study investigates the effects of fin cuts on the heat sink in natural convection using experimental and numerical simulation methods. With the fixed values of heat sink envelop volume of 10mm x 10mm x 2mm, heat dissipation of 10 W, ambient temperature of 30°C, and radiation emissivity of 0.8 for the extruded aluminum with anodize treatment, fins having 0 to 3 cross cuts of 8 different cut widths were numerically simulated. Twenty-five sets of heat sinks are compared to explore the difference between the designs of the fin profiles for horizontal heat sinks. Numerical analysis and experimental results show that the bottom center temperature of the heat sink with fin-cuts yields up to 5°C less than the heat sink without fin-cut. The effects of heat transfer area, the ratio of fin cut width to heat sink length on the thermal resistance of the heat sinks are discussed. The heat sink with three cuts of 12 mm cut-width yielded a lower thermal resistance of 2.74 K/W, as compared with 3.3 K/W of the heat sink without fin-cut. Although cutting fins results in surface area reduction, the natural convection is enhanced by the fin cuts.