Surface mount technology heat sinks for D/sup 2/PAK and D/sup 3/PAK power semiconductors

A new surface mount heat sink has been developed for the D/sup 2/PAK and D/sup 3/PAK components. Experimental and analytical studies have been carried out, characterizing the thermal performance of the components on a printed circuit card with and without the heat sink. The addition of a surface mount heat sink reduces the total thermal resistance of the components as much as a factor of two in forced convection applications, and approximately 20 to 30% in the case of natural convection. This highlights the importance of the thermal path through the card and the component itself. In situations where the conjugate effect of heat transfer is particularly strong as in the present case, the total thermal resistance is not a linear function of heat input as the ratio of heat partition into different paths depends on the amount of total heat dissipation. This non-linear behavior is observed in the measurements and analytical results. It was also revealed through comparisons between the measurements and computed results, that the heat dissipation through the insulating foam under the back surface of the card cannot be ignored.