Measurement and Correlation-Based Methodology for Estimating Worst-Case Skew Due to Glass Weave Effect


Skew is unintentionally introduced within a differential pair, through misalignment of conductors and glass fiber bundles in Printed Circuit Board (PCB) dielectric layers. Manufacturers do not control interposition of specific glass bundles to supplied board design (artwork). Therefore, an unknown and random factor is added to each produced PCB. Current paper describes a method that utilizes a set of measurements and numerical models to estimate worst-case skew for the aforementioned effect. First, test vehicles are built, and then cross-sections are analyzed with Scanning Electron Microscope (SEM) for precise measurements. Numerical models are constructed to correlate with real DUT; after correlation is achieved, relative location of conductors to glass bundles is swept to obtain best and worst case skew.

Meeting Name

2017 IEEE International Symposium on Electromagnetic Compatibility, Signal and Power Integrity, EMC+SIPI2017 (2017: Aug. 7-11, Washington, DC)


Electrical and Computer Engineering

Keywords and Phrases

Automobile manufacture; Design for testability; Electromagnetic compatibility; Glass; Numerical methods; Numerical models; Scanning electron microscopy; Weaving; Dielectric layer; Differential pairs; Glass fiber bundles; High-speed digital signals; Precise measurements; Printed circuit boards (PCB); Relative location; Skew; Printed circuit boards; Glass weave; High-speed digital signal; PCB dielectric; Worst-case estimation

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


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© 2017 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Aug 2017