Research on the influence of vias on signal transmission in multi-layer PCB

Vias are widely used in printed circuit board (PCB) nowadays especially in multi-layer PCB design for connecting signals from different layers and ground planes. Although vias make interconnection easy, they also give rise to discontinuity problem. As frequency increases, via can cause reflection that seriously affects system performance and the integrity of signal. In this paper, we use the full wave simulation software HFSS to model and simulate a multi-layer PCB via. The impact on signal integrity of the size of via (via radius, pad radius and anti-pad radius) is analyzed. Then an optimization method is proposed. The simulation results can be practical guidance for multi-layer PCB design.