TSV modeling considering signal integrity issues

Since a TSV has a metal-insulator-semiconductor structure, it supports three fundamental modes namely, skineffect, slow-wave and dielectric quasi-TEM mode. In this contribution, we predict the frequency range of these modes, considering TSVs for interposer applications as an example. Furthermore, the impact of Si-resistivity on signal integrity is quantified and coaxial TSV configurations are proposed to minimize this impact

On the optimization of the return current paths of signal vias in high-speed interposers and PCBs using the M3-approach

In this paper, the return-current paths of signal vias transiting multilayered stack-ups are optimized using the M3-approach (methodologies, models, measures). A methodology for suppressing the excitation of parallel-plate modes in these stack-ups is first proposed. The result of this methodology is a stack-up with well-defined paths for the returning conduction currents. Secondly, a model of the stack-up is developed and experimentally verified using measurement results. The model is then applied to study the impact of the impedance of the return-current paths on the effectiveness of the proposed stack-up in suppressing the excitation of cavity resonance modes. Based on the results of this study, appropriate designs measures for optimizing the return-current paths of the signal vias are derived. To demonstrate the advantages of these measures, they are applied to fabricate a new test board with the proposed stack-up. The measurement results show excellent signal transmission and no dips in the insertion loss of the signal via for frequencies up to 20 GHz