Edge connectors fail in the field more often from vague plating notes than from mysterious "weak gold." If your PCB plugs into a backplane, card slot, or test fixture repeatedly, the gold finger region is a wear surface first and a solderable pad second. Specifying it like an ordinary ENIG pad is a classic quoting trap.
Overseas buyers sourcing edge-connector boards from China need language that makes plating, bevel, and mask keep-outs bid-comparable. Without that language, two factories can both claim "gold fingers" and deliver very different insertion life.
What gold fingers are doing
Gold fingers are the plated contacts along a board edge that mate with a connector. They need stable contact resistance, corrosion resistance, and durability across the insertion cycles your product actually sees. Visual and mechanical acceptance typically rejects scratches and gouges in the contact area, discoloration or oxidation, plating peel, contamination, pits in critical zones, and exposed copper.
Those criteria only help if thickness, stack, and geometry are defined up front.
Hard gold versus finishing gold
Many board finishes use thin immersion gold over electroless nickel (ENIG) for solderability on SMT pads. Edge-wear fingers usually need electrolytic hard gold over nickel at a thickness chosen for insertion life, not for reflow wetting alone. Copying ENIG pad thickness onto fingers is how contact resistance drifts after a few hundred mating cycles.
Nickel underplate matters as a diffusion and wear foundation. Call out both gold and nickel targets, or at least the hard-gold thickness and nickel requirement your connector vendor expects. If selective plating is used, draw which regions are hard gold, which are ENIG or other finishes, and where plating bars are required for electrolytic processing.
Geometry and mask discipline
Beveling the leading edge helps the card enter the connector without scraping plating off the front of the fingers. Specify bevel angle and depth when the connector family needs it. Keep soldermask off wear surfaces; mask creep onto fingers is a workmanship defect that no amount of thicker gold will forgive.
Outline, scoring, and routing near fingers should leave the contact area flat and clean. Dents from poor depanelization become field failures that look like connector problems.
Applications and inspection expectations
Motherboards, graphics cards, industrial controllers, communication blades, and any product with frequent board insertion rely on finger quality. Define whether fingers are wear-critical (many mating cycles) or mainly for infrequent service access. That single note changes how aggressively thickness and inspection are applied.
Ask for inspection against IPC visual criteria you actually purchase, including magnified checks for copper exposure and surface damage in the contact zone. Peel or tape tests for adhesion belong in the quality agreement when reliability risk is high.
Making the RFQ buildable
A complete finger note set usually includes hard-gold thickness, nickel underplate, bevel callout, selective finish map, mask keep-outs, and any plating-bar or tab requirements. Pair those notes with the board outline so CAM can see mechanical and plating constraints together.
XFPCB manufactures gold fingers PCB constructions as part of a controlled PCB fabrication process. Send finger callouts in the same package as Gerbers and stackup notes so plating and outline DFM happen before panels are committed.