Correlating Glass Bundle Pitch Variation with High Frequency Phase Skew
Matching glass bundle pitch to trace geometry and using spread glass weaves eliminates local permittivity variations, bounding differential phase skew within tolerance.
1067 Weave Style
Physical Specification
Lightweight glass fabric specifications define the structural base for thin dielectric layers in multilayer printed circuit boards. The 1067 weave style is a standard designation for a fabric weighing roughly 30 grams per square meter, often selected for builds requiring a balance between thickness and mechanical strength. This glass cloth provides the necessary reinforcement to prevent substrate fracturing during the drilling of small vias.
Dielectric Consistency
Resin distribution depends on the physical gaps between the yarns of the reinforcement material. In the 1067 weave style, these gaps are relatively large compared to spread-glass varieties, which sometimes leads to localized variations in the dielectric constant. Variations in the material properties cause signal timing issues at very high frequencies.
Lamination Interaction
Lamination interaction must account for the specific absorption characteristics of the glass fabric to ensure complete wet-out of the fibers. Vacuum-assisted pressing forces the liquid resin into the spaces of the 1067 weave style to eliminate air pockets that might otherwise cause delamination under thermal stress. Successful integration of this fabric requires precise control over temperature and pressure cycles during the initial bonding phase to maintain a consistent finished thickness.
Practitioners measure the resulting thickness with micrometer gauges or cross-sectional microscopy to verify compliance with the design stackup.