Overview

An electroformed mesh etching process combines two precision steps: nickel is first grown on a patterned mandrel to form a thin, low-stress foil, then photochemical etching opens, trims or thins that foil to its final aperture geometry. Electroforming delivers gauges from 0.02 to 0.20 mm with excellent thickness uniformity, and etching adds the fine apertures, sharp edges and border features that are hard to grow directly. The critical point is the handoff: the nickel must be stress-relieved and clean enough for resist to adhere, and the etchant must be compatible with a pure, fine-grained deposit. Managed together, the two steps yield a flat mesh with holes down to 0.03 mm.

Sequence decides yield here. Some programs image and etch the apertures directly on the electroformed foil; others etch a sacrificial carrier, electroform onto it, then strip and finish. In both cases the resist must bond to a low-stress nickel surface, so a light micro-etch and a controlled drying step precede lamination. Ferric chloride or a dedicated nickel etchant is held at fixed Baume and temperature to avoid undercutting a 0.02 mm web. A well-documented electroformed mesh etching process also records bath stress, deposit thickness and frame tension, because a mesh that curls on release will not register in the final assembly.

Parameter Window

• Available Materials: electroformed nickel, low-stress nickel, nickel-iron alloy, nickel-copper laminate on request
• Material Thickness Range: 0.02–0.20 mm deposit, trimmed by etching to final gauge
• Tolerance: ±0.005 mm on deposit thickness, ±0.01 mm on aperture, position ±0.015 mm over 200 mm
• Minimum Feature: 0.03 mm aperture, 0.03 mm web at 0.02 mm foil
• Surface Options: bare, passivated, gold flash, framed at 30–40 N/cm, bonded to a support ring
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Mandrel Preparation — Clean and passivate the cathode mandrel, then image the pattern that defines the initial deposit or apertures.
2. Nickel Electroforming — Grow nickel at controlled current density and bath chemistry to a target thickness, logging internal stress throughout.
3. Release & Stress Relief — Peel the foil from the mandrel, then anneal lightly to relax deposit stress before any imaging step.
4. Surface Activation — Apply a mild micro-etch and dry the low-stress nickel so dry film resist wets and adheres uniformly.
5. Lamination & Exposure — Laminate resist on both faces and expose registered artwork that defines apertures, trim lines and the solid border.
6. Controlled Etching — Spray nickel-compatible chemistry at fixed Baume and temperature to open holes without undercutting thin webs.
7. Stripping & Framing — Strip resist, rinse, then tension-bond the mesh to a frame at 30–40 N/cm while the border still carries it.
8. Inspection & Traceability — Verify aperture size, deposit thickness, flatness and tension, then file the bath and stress records with the lot.

Core Advantages

1. Thin uniform gauges: Electroforming gives 0.02 mm foil with thickness uniformity that rolling cannot match at that gauge.
2. Sharp etched apertures: Chemical opening adds clean, burr-free holes and trim edges to a deposit that is already stress-free.
3. Fine webs: Compatible etchant and low spray pressure hold 0.03 mm webs without undercut or lifting.
4. Two-step flexibility: Apertures, half-etch steps and borders can be assigned to either the mandrel or the etch step, whichever is cheaper.
5. Documented stress: Bath stress and deposit thickness are logged per lot, so curl and registration are predictable, not discovered late.
6. Repeatable handoff: A controlled electroformed mesh etching process keeps resist adhesion and etch rate stable from lot to lot.

Typical Applications

• Precision sieve meshes: Ultra-fine nickel screens for particle classification and reference standards.
• Encoder and optical grids: Fine aperture arrays for optical encoders and light-shaping masks.
• EMI and shielding foils: Thin perforated nickel shields for high-frequency board-level protection.
• Fuel-cell gas diffusion layers: Micro-apertured nickel supports with a framed border for stack assembly.
• Aerosol and ink screens: Fine hole arrays for nebuliser and printhead dosing components.
• Micro-stencil masters: Thin nickel foils used as durable masters for repeated printing or deposition.

Design Notes & Process Considerations

1. Assign features by step: Decide which apertures are grown on the mandrel and which are etched, since each move shifts cost and tolerance.
2. Deposit stress: Specify maximum internal stress and a stress-relief step, or the foil will curl the moment it leaves the cathode.
3. Resist adhesion: Require a light activation before lamination; low-stress nickel is smooth and resist will lift without it.
4. Etchant compatibility: Choose chemistry matched to fine-grained nickel, and state the etch factor so thin webs are not undercut.
5. Border and carrier: Keep a solid rim through release and stripping, then frame at the stated tension before removing it.
6. Thickness after etch: Give final gauge, not deposit gauge, because etching thins the foil and changes the aperture wall ratio.