Influence of a floating plane on effective ground plane inductance in multilayer and coplanar packages

Abstract

The impact of a floating metal layer on the effective ground plane inductance has been investigated in both multilayer (ground planes) and coplanar (ground conductors) packages. For the multilayer case, both thick and thin film geometries were examined, and the results were compared to a thin film coplanar configuration. It was seen that the floating plane actually increases the ground plane inductance in the multilayer case and decreases the ground plane inductance in the lead frame case. Examining the current density in the floating and ground plane and the ground's partial self-inductance and ground-signal partial mutual inductance give a detailed explanation for this phenomenon.Index Terms-Coplanar transmission line, eddy currents, floating metal, package inductance, stripline transmission line.

Encoding-Based Minimization of Inductive Cross-Talk for Off-Chip Data Transmission

“…There has been much work into the reduction of parasitic inductance through package advancement [3,6,5]. Since the performance limitation is caused by the parasitic inductance in the level 1 and level 2 interconnects of the IC package, many packaging technologies have been developed.…”