Thermal evaluation of a cost-effective plastic ball grid array package-NuBGA

NuBGA is a low cost, single core, two-metal layer, cavity down plastic ball grid array package. With special design concepts, NuBGA provides electrical and thermal enhancements for electronic packaging applications. In this paper, the concepts of these innovative designs are briefly described. Thermal resistance of junction to air is investigated first by finite element simulations, and the results are then compared to experimental measurements. Thermal measurements are carried out for both with and without heat sink attachment. Geometric dependence of thermal resistance on structural parameters such as thickness of the copper heat spreader and organic substrate, power and ground planes in print circuit board, and the size of PCB are also discussed.