THE FLOATING POTENTIAL APPROACH TO THE CHARACTERIZATION OF CAPACITIVEEFFECTS IN HIGH-SPEED INTERCONNECTS

Capacitive coupling between high speed interconnects may cause signal degradation in high density integrated circuits (ICs) and printed circ uit boards (PCBs). The usual approach to the electrical characterizati on of interconnects is to obtain the capacitance matrix by computing c harge densities from an integral equation. The latter yields dense, no n-symmetric matrices and is inadequate for complex geometries and mate rials. Finite element methods (FEMs) yield symmetric sparse matrices b ut differentiation of the solution is undesirable and the more accurat e energy-based calculation of capacitances is a lengthy process. A nov el approach to capacitance matrix computation based on the concept of floating potentials (FPs) is introduced. This approach obviates the ne ed to differentiate the solution and is more economical than the energ y approach.