Application of the hierarchical Schur algorithm to the boundary element method for 3D capacitance extraction shifts the speed bottleneck from inversion of the influence matrix to its calculation. We show how the numerical integration required for the latter can be accelerated by an order of magnitude with the aid of a multipole expansion in Cartesian formulation. The scheme differs essentially from that of the FASTCAP extractor.
U. Geigenmüller, N. P. van der Meijs