Forced Convective Heat Transfer from LSI Packages in an Air-Cooled Wiring card Array

Abstract
The resistance to heat flow from finned LSI packages to the cooling air flow has been studied by combining the physical models with the results of heat transfer experiments, flow visualization experiments, and pressure drop measurements. Although crude assumptions are employed in analytical modeling, the proposed method of prediction of heat transfer and pressure drop has proved useful to cooling system designers. A notable finding is the advantage obtained by placing the packages in a staggered arrangement on the card. This reduces the local air temperature rise by as much as 70% over the conventional in-line arrangement, where the fan power is given as a constraint.