High-frequency characteristics analysis and optimization of coaxial-like TGVs

The Coaxial-Like through-glass vias (TGVs) are frequently used vertical interconnect transmission structures in radio frequency (RF) three-dimensional(3D) integrated circuits (ICs). This paper addresses the TGV’s structure in high-density 3D packaging by proposing a multi-parameter co-optimization methodology that integrates electromagnetic modeling, response surface methodology (RSM), and genetic algorithm (GA), significantly enhancing its high-frequency transmission performance. Innovatively, a 3D full-wave electromagnetic simulation model of the coaxial-like TGV is established to systematically analyze the influence of via pitch p, via radius r, and number of ground vias n on the insertion loss S21. An analytical model for RLGC parasitic parameters based on electromagnetic theory is derived. A second-order response surface model correlating S21 with key structural parameters is constructed via Box-Behnken experimental design, and globally optimized using a genetic algorithm, resulting in an optimized parameter set (p = 82.05 μm, r = 10.44 μm, n = 10) for S21 at 100 GHz. Simulation results verify that the optimized S21 improves by 0.0052 dB compared to the baseline model, with a relative enhancement of 21.94%. This study not only provides a theoretical foundation and optimization framework for high-performance TGV design, but also offers an effective solution for low-loss interconnects in 3D integrated RF devices.