Substrate Thickness
Core materials in multi-layer board fabrication represent the base layers upon which circuit traces are etched and dielectric layers are stacked. Utilizing a sub-thirty micrometer core allows for the manufacture of extremely thin circuit boards, which are highly valued in mobile and wearable electronic devices. These thin cores are composed of resin-impregnated glass fabric or unreinforced polymer films that provide electrical isolation between adjacent signal layers.
Achieving this thin profile requires highly controlled chemical and mechanical processes to ensure thickness uniformity across the panel.
Build Process
Handling very thin cores during wet chemistry and etching processes requires specialized transport systems to prevent folding or tearing. The use of a sub-thirty micrometer core demands tensioned roll-to-roll processing or rigid carrier plates that support the thin substrate as it moves through chemical spray chambers.
Electrical Performance
High-speed digital circuits benefit from thin dielectric spacing because it increases the capacitive coupling between power and ground planes. This increased capacitance reduces power distribution network noise and stabilizes voltage levels during high-frequency switching events. The thin dielectric also reduces the trace width required to achieve a fifty-ohm characteristic impedance, allowing for higher wiring densities in high-density interconnect designs.
However, the reduced insulation distance increases the risk of dielectric breakdown if voltage surges occur.
