Selecting Dielectric Substrates for High Speed Multilayer Stackup Design
Selecting dielectric substrates requires balancing dissipation factor, glass weave uniformity, foil roughness, and panel yields to meet high-speed impedance targets.
Style 1035 Glass
Lightweight Fabric
Fine fiberglass threads woven into a tight pattern provide a very thin reinforcement layer for advanced circuit boards. The style 1035 glass is a specific weave used when the design needs to minimize the thickness of the dielectric between copper layers. This fabric is much thinner than the common 1080 or 7628 styles and is often found in mobile phones and wearable devices.
Laser Compatibility
Thin fabrics with high resin content are easier to drill using laser systems because there is less glass for the beam to penetrate. A style 1035 glass layer allows for the creation of smaller microvias with cleaner edges, which improves the reliability of the plating. The weave is tight enough to provide dimensional stability but light enough to keep the overall stackup height very low.
Using this fabric also helps to achieve a more uniform surface for fine-line etching on the outer layers.
Vertical Minimization
Hardware designs select this glass style when every micron of thickness matters for the final product assembly. The style 1035 glass provides a consistent base for the resin, ensuring that the dielectric constant remains stable across the entire board. It is typically more expensive than thicker fabrics but is necessary for achieving the high density routing required by modern chips.
This material represents the limit of what can be achieved with traditional woven reinforcement in ultra-thin electronics.