New Method for Mitigating Weave-induced Differential Skew in PWBs

摘要

Weave induced skew in printed wiring boards (PWB) in high-performance computers has become a significant problem as data rates have increased. We present a new method to reduce weave induced skew. Using three-dimensional electromagnetic simulation, we have discovered that skew can be reduced by adjusting the line width to a specific value, and that the specific values are approximately the same for both stripline and microstripline. We have ascertained the effect in actual PWB manufacturing and measurement. As a result, we have verified by measurement that skew can be reduced to less than one-third. Investigation of a wider range of line width/weave pitches by simulation suggests that skew can be reduced to less than one-tenth of a usual structure.