Sub-Optimum Design of a Forced Air Cooled Heat Sink for Simple Manufacturing

In order to maximize the power density of a converter, a systematic procedure for optimizing the cooling system is necessary. Solving the equations of the optimization procedure described in this paper can be performed numerically without much effort, but manufacturing the resulting optimum heat sink is often extremely difficult and expensive, and therefore impractical. Based on the optimization theory, the sensitivity of the thermal resistance of the heat sink to changes in the geometric design parameters is discussed. Diagrams show the expected increase in thermal resistance if the manufacturing process constrains the fin thickness to certain values. Based on this, one can design a sub-optimum heat sink that gives the minimum thermal resistance for a certain manufacturing procedure. Furthermore, it is shown how much additional manufacturing effort would be necessary to further improve the performance of the heat sink. The proposed procedure is verified experimentally.