Fiberglass Reinforcement
Glass reinforcement fabric with a flat, uniform fiber structure provides a highly consistent dielectric barrier in thin multi-layer printed circuit boards. Utilizing 1067 spread glass reduces the size of resin-rich pockets between warp and weft fibers. This structural change prevents local variations in impedance across differential transmission lines.
Electrical Performance
Dielectric homogeneity represents the primary benefit of selecting this material over standard open-weave alternatives. In high-speed signal propagation, the non-uniform distribution of glass and resin creates a varying dielectric constant that skews signal arrival times. Spreading the glass filaments evenly ensures that both lines of a differential pair experience the same effective dielectric constant, preventing differential skew and signal degradation.
Laser drilling for microvias becomes more predictable when the density of the glass pattern is uniform. Standard glass fabrics with bundled yarns cause the drill to encounter sudden transitions between soft resin and hard glass, resulting in uneven via walls or incomplete ablation. The flattened structure of 1067 spread glass distributes the glass mass evenly, allowing the laser energy to ablate the material uniformly and produce clean microvia holes.
Fabrication Impact
Mechanically, the flatter profile improves the overall flatness of the cured dielectric layer. This dimensional stability reduces the risk of warpage during subsequent sequential lamination cycles. This uniform fabric style maintains a flat, planar surface.
