Overview

A battery contact is an electrical part first and a mechanical part second, and a battery contact etching service is judged on both. The contact carries current through a small cross-section, so its resistance budget is tight: bulk resistance from the metal, constriction resistance at the mating spot, and film resistance from whatever oxide or contamination sits on the surface. Etching contributes to the last two by leaving a flat, burr-free face and a clean, residue-free surface after stripping and rinsing, which is where stamped parts often need an extra tumbling step that then rounds the very face that must stay flat.

Contacts are usually made from nickel 200, nickel-plated steel, copper C1100 or beryllium copper, in strip from 0.05 mm to 0.4 mm. Etching forms the outline, the spring fingers, the locating windows and the solder or weld pad in one pass, with a rectangular cut section instead of the roll-over that shearing produces. Because there is no mechanical work, thin nickel strip keeps its temper uniform along the part, so contact force does not vary from one finger to the next.

Parameter Window

• Available Materials: nickel 200/N4, nickel-plated steel, copper C1100, beryllium copper, nickel silver
• Material Thickness Range: 0.05–0.4 mm
• Tolerance: ±0.05 mm on outline and pad position, burr-free edge, flatness 0.03 mm per 100 mm
• Minimum Feature: 0.10 mm slot and 0.12 mm window at 0.1 mm stock
• Surface Options: nickel plating, selective gold on contact pads, gold flash, passivation, ultrasonic degrease, reel taping
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Electrical and Mechanical Review — Check current path, finger length, contact force and pad area against strip thickness before fixing the layout.
2. Material Selection — Match nickel 200 for corrosion resistance, nickel-plated steel for cost, copper for conductivity, and confirm temper for spring fingers.
3. Cleaning and Lamination — Degrease and laminate both faces, since any inclusion becomes a pinhole that later traps etchant under the resist.
4. Exposure — Expose outline, fingers and pad windows in hard contact, registering the pattern so pad position stays within tolerance.
5. Development — Wash out the pattern and inspect fine slots between fingers before the strip enters the bath.
6. Etching — Control dwell so the cut section stays rectangular; over-etching thins the current path and raises resistance.
7. Stripping and Ultrasonic Cleaning — Remove resist, neutralize and ultrasonically clean; residual chemistry on a contact face shows up later as rising resistance.
8. Plating and Contact Test — Apply nickel or selective gold, passivate, then sample contact resistance, plating thickness and edge condition before taping.

Core Advantages

1. Burr-free edges: No sheared roll-over means no burr to pierce separator film or insulation paper, and no tumbling step that would round the contact face.
2. Rectangular cut section: The etched wall stays square through the thickness, so the current-carrying section matches the drawing and the resistance budget holds.
3. Flat pads for welding: Solder and weld pads arrive flat and clean, which keeps spot-weld nuggets consistent and avoids cold joints on nickel tabs.
4. Selective gold where it counts: Gold can be confined to the actual contact spot, cutting precious metal use while keeping low and stable contact resistance.
5. Uniform spring temper: Chemical cutting adds no work hardening, so every finger on a strip has the same stiffness and the same contact force.
6. Specification to shipment: As a battery contact etching service we can hold one resistance and cleanliness specification from sample to production, and test against it per lot.

Typical Applications

• Battery tabs and nickel strips: Connection tabs welded to cells, with etched locating notches and clean weld zones.
• Spring contacts: Finger and pogo-style contacts for battery holders, where finger length sets contact pressure.
• Coin cell contacts: Small radius contacts and retaining windows for button-cell compartments in wearables.
• Battery pack terminals: Terminal plates and inter-cell connectors with etched windows for screw or rivet fixing.
• Charging dock pins: Etched pin arrays and carrier strips for dock connectors before insert moulding.
• Fuse and protection links: Etched fuse elements and thermal links with a defined neck width for current limiting.

Design Notes & Process Considerations

1. Current path width: Size the neck at the required current density, and remember that etch tolerance is ±0.05 mm, so a 0.3 mm neck may arrive at 0.25 mm.
2. Contact force and finger length: Longer fingers give softer contact; state the target force and the deflection, because temper and thickness decide both.
3. Burr and separator clearance: Where a contact sits against separator film, call out burr-free edges explicitly and avoid sharp internal corners that concentrate stress.
4. Plating and oxide control: Nickel passivates slowly but still builds a resistive film; specify gold on the contact spot and a clean, oxide-free weld zone.
5. Pad geometry: Give pad size, position tolerance and whether the pad is flush or half-etched, since a recessed pad changes weld head access.
6. Cleanliness acceptance: Define residue limits and require ultrasonic cleaning after stripping; a battery contact etching service should report resistance on a sample basis, not just dimensions.