Electrical design of a low cost and high performance plastic ball grid array package-NuBGA

Abstract

This paper presents a new class of low cost, electrically and thermally optimized ball grid array packages, called NuBGA (new and useful ball grid array). The package is suitable for both low and high pin count applications. NuBGA is a cavity down package with a metal heatspreader covering the entire back surface of the package. Heat spreader is laminated with a single core double sided organic substrate. Optimized electrical performance is achieved using the design concepts of Split-Wrap-Around (SWA) and Split-Via-Connections (SVC). All traces on the core substrate can be designed into /spl mu/-stripline and co-planar stripline structures. Further enhanced thermal and electrical performance NuBGA can be achieved by applying an additional metal stiffener and thinner core substrate. In this paper, the presentation is focus on (1) the unique design concept, (2) the electrical analysis, (3) the electrical measurement, and (4) the performance comparison with standard packages.