Full-Wave Analysis for Ground Via Placement with Layered Media Integral Equations

As signaling rates exceed 40 Gbps, detailed electromagnetic analysis of the Ground Return Vias (GRVs) becomes essential. Incorrect GRV placement, whether too far apart or poorly arranged in a ball-grid array, can cause a signal via's insertion loss (IL) to increase substantially. Historically, signal integrity (SI) engineers have placed GRVs near signal layer transitions following conventional practices, often without a precise understanding of the optimal quantity and spacing required. This paper proposes accurate full-wave electromagnetic analysis framework for via placement optimization. The method solves the layered medium Mixed Potential Integral Equation (MPIE) coupled with the Surface-Volume-Surface Electric Field Integral Equation (SVS-EFIE), making it suitable for analyzing composite 3D metal/dielectric structures within layered substrates encountered in GRV placement problems.