Overview

Precision terminal etching uses photochemical machining to cut terminal strips with fine contact fingers, slots and mounting holes out of thin conductive sheet. A photoresist is laminated, exposed with the terminal artwork and developed, then the unprotected metal is dissolved in a matched etchant to leave a flat, burr-free strip. Terminals are typically made from brass (C26000), copper or phosphor bronze (C5191), supplied between 0.1 mm and 0.8 mm thick. Because the profile is chemically removed rather than stamped, the fingers come out straight, sharp and free of the roll-over and burrs that degrade insertion force and contact quality.

For connectors, headers and screw-clamp assemblies, the terminal must slide into its mating contact with a controlled insertion force while keeping resistance low. Etching holds finger width and pitch to a tight tolerance, so every position in a strip behaves the same. The clean, stress-free edges resist fatigue and plate evenly, keeping contact resistance stable over repeated mating cycles. This is why precision terminal etching is specified for fine-pitch headers and terminal blocks where stamped parts cannot hold the same dimensional control.

Parameter Window

• Available Materials: brass C26000, pure copper C11000, phosphor bronze C5191
• Material Thickness Range: 0.1–0.8 mm
• Tolerance: ±0.02 mm on finger width, ±0.05 mm on pitch
• Minimum Feature: 0.1 mm finger width, 0.15 mm slot width
• Surface Options: gold plating, tin plating, nickel plating, selective plating
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Terminal Design — Convert the finger layout to vector artwork and check finger width, pitch and tip geometry against the mating contact.
2. Material Selection — Choose brass for economy and spring, copper for maximum conductivity, phosphor bronze for fatigue life.
3. Cleaning & Lamination — Degrease the sheet and laminate dry film with no bubbles so the fingers etch clean and straight.
4. UV Exposure — Expose the terminal artwork registered to the strip edge for accurate finger pitch.
5. Development — Wash out the unexposed resist to open the fingers and slots, then inspect for under-developed gaps.
6. Etching — Spray etch at controlled temperature; finger width is set by time, pressure and conveyor speed.
7. Stripping & Finishing — Remove resist, neutralize, then plate gold, tin or nickel on the contact area.
8. Inspection & Packaging — Verify finger width, pitch and flatness, then pack on trays to protect the fingers.

Core Advantages

1. Controlled insertion force: Finger width and pitch are held to microns, so insertion and withdrawal force repeat across the strip.
2. Low contact resistance: Clean, flat fingers plate evenly and make a stable, low-resistance connection.
3. Burr-free fingers: Chemical removal leaves no stamping roll-over, so fingers insert smoothly without shaving.
4. Fine pitch: Fingers down to 0.1 mm wide support high-density terminal and header designs.
5. No tooling cost: Each layout is a new film, keeping prototypes and short runs economical.
6. Batch consistency: Every finger on a strip etches at the same rate, so force and conductivity stay uniform.

Typical Applications

• Fine-pitch headers: Terminal strips for high-density board-to-board headers.
• Terminal blocks: Contact fingers for screw-clamp and spring-clamp connectors.
• Edge connectors: Gold-plated fingers for PCB edge-card interfaces.
• FPC terminals: Fine fingers for flexible printed circuit termination.
• Battery terminals: Conductive tabs and fingers for battery packs.
• Relay and switch terminals: Contact strips for relay and switch assemblies.

Design Notes & Process Considerations

1. Finger versus pitch: Keep finger width and slot clearance balanced so insertion force stays within spec.
2. Plating callout: Name the plating and thickness on the contact area to hold resistance stable over life.
3. Insertion cycles: Specify the required mating cycles so material and geometry are sized for it.
4. Spring temper: Choose spring temper for phosphor bronze or brass when the finger must hold clamping force.
5. Edge condition: Require burr-free edges, since edge burrs raise insertion force and shave plating.
6. Carrier design: Provide tab or carrier features so fingers stay straight through plating and assembly.