Cooling performance of heat sinks with corrugated-fins

Heat sinks with corrugated fins have been developed for effective cooling of large-scale integrated circuit (LSI) packages. These heat sinks are so light that they are suitable for cooling small and light LSI packages with low/high heat generation, e.g. quad flat package (QFP), ball grid array (BGA) package, chip scale package (CSP), etc., which are contributing to the downsizing of electronic equipment. In this study, the cooling performance of the heat sinks in forced air convection was experimentally investigated from a practical use point of view. When the cross-section areas both of a heat sink and a test section were the same, the effect of geometrical dimensions of the heat sinks on heat transfer and pressure loss characteristics were predictable within ±15% accuracy. When the cross-sectional area of the test section duct was more than approximately twice the size of a heat sink, the average heat transfer coefficient, which is useful information for design of heat sinks in practical use, could be predicted within ±20% accuracy. On the other hand, the effect of the ratio of heat source area to base plate area on cooling performance became stronger as heat transfer from the heat sink improved. When the air flow direction varied, thermal resistances obtained in the range under 45° of flowing angles showed little difference