Numerical investigation of glass-weave effects on high-speed interconnects in printed circuit board

Numerical method is used to investigate the glass weave effects on via coupling and trace transmission properties. Studies indicate that a simple two-dimensional periodic structure is accurate enough for via coupling simulations while more complicated three-dimensional glass-weave structures have to be used for studies of trace transmission properties. Analytical formulas are provided to estimate the first resonant frequency of the glass weaves. The impact of trace-glass-weave orientations on resonances of traces has been investigated for both single-ended and differential striplines. It has been demonstrated that statistical Gaussian distribution of pitch sizes due to fabrication tolerance and the dielectric losses can reduce the glass-weave effects. The studies here are useful for better understanding of the high-frequency signal integrity performance of printed circuit boards.