Improved physical model in layered media for via structures

Abstract

In this paper, the physical model is extended for vias embedded in layered media between two parallel-plate pairs. The effect of this inhomogeneity on signal integrity analysis is crucial, but is rarely studied especially by using the equivalent circuit model. The model presented in this paper is constituted by upper and lower via-to-plane capacitances which are different from each other due to the inhomogeneous dielectrics and equivalent impedance matrix of the parallel-plate cavity with equivalent wave number. The via-to-plate capacitance with layered media is calculated by using cascaded Green’s function with image theory and integral equation method based on partial capacitance, which is the main contribution in this paper. The parallel-plate impedance is calculated by using the cavity resonator method. Transverse resonance method as well as an equivalent approximation method is used for wave number evaluation. For the first time, the circuit model presented in this paper is used for the issue of layered media, which is much simpler with sufficient accuracy up to 20 GHz when compared with analytical method. The model is validated with full-wave simulations.

Keywords:

• Partial capacitance
• integral equation method
• via-to-plane capacitance
• layered media

Notes

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 61201006] and China Postdoctoral Science Foundation [Project No.2014M562295].