Overview

Custom electroformed mesh etching combines two complementary processes: nickel is first electrodeposited onto a photoresist-patterned mandrel to grow a fine-grained, low-stress foil, and photochemical etching then opens and refines the apertures to their final size. The resist pillars on the mandrel define where the holes will be, so the grown metal surrounds them; stripping the pillars leaves through-holes with near-vertical walls, and a light trim etch sets the final aperture, removes deposited nodules and cleans the hole wall. Materials are usually electroformed nickel 200, Ni-Fe Alloy 42, nickel-cobalt or copper, at 0.02–0.3 mm, with 0.025–0.10 mm most common for ultra-fine pitch.

For a buyer, custom electroformed mesh etching is chosen when the hole wall itself is the specification. A through-etched hole tapers as it deepens, but an electroformed wall stays above 85°, so the aperture is nearly the same at the top and bottom faces — critical for solder-paste release, light baffling and flow metering. Fine-grained deposits etch evenly and give low wall roughness, and a controlled trim etch pulls the diameter to ±0.005 mm without destroying that verticality. Because the wall is thick relative to the aperture, the mesh stays self-supporting at high open-area ratios where a punched screen would collapse.

Parameter Window

• Available Materials: electroformed nickel 200, Ni-Fe Alloy 42, nickel-cobalt, copper, with optional gold or platinum flash
• Material Thickness Range: 0.02–0.3 mm (0.025–0.10 mm typical for ultra-fine pitch)
• Tolerance: ±0.005 mm on aperture and pitch; ±0.01 mm on overall thickness
• Minimum Feature: 0.02 mm aperture at 0.03 mm pitch; sidewall angle > 85°; aspect ratio up to 5:1
• Surface Options: matte / bright as-deposited, passivated, blackened, gold flash, frame bonding, adhesive backing
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Mandrel Preparation — Polish and clean a stainless or titanium mandrel, then coat it with photoresist.
2. Pillar Pattern Exposure — Expose and develop an array of resist pillars; their positions become the holes.
3. Electroforming — Electrodeposit nickel or Alloy 42 around the pillars to target thickness under low stress.
4. Foil Release — Lift the grown foil off the mandrel and strip the pillars to reveal near-vertical through-holes.
5. Lamination & Trim Mask — Apply dry film and expose a trim pattern that sets final aperture and edge quality.
6. Precision Etching — Lightly etch to open apertures, blend the wall and remove nodules while limiting undercut.
7. Stripping & Stress Relief — Strip resist, neutralize and low-temperature anneal to stabilize the fine-grained deposit.
8. Wall Inspection — Measure sidewall angle, aperture and wall roughness by SEM or vision, then bond to frames if required.

Core Advantages

1. Near-vertical hole walls: Electroformed pillars leave walls at > 85°, so apertures stay the same size through the thickness.
2. Ultra-fine pitch: 0.02 mm holes on 0.03 mm pitch are achievable in thin nickel, beyond woven or punched mesh.
3. Smooth low-stress deposit: Fine-grained nickel etches evenly, giving low wall roughness with no burr or roll-over.
4. High aspect ratio: Thick walls relative to aperture keep a stiff, self-supporting screen at high open-area ratios.
5. Hybrid tuning: Electroforming sets the wall; a light etch trims aperture and cleans nodules without changing wall angle.
6. Flat and stable: Low internal stress and no mechanical forming keep the released foil flat and dimensionally stable.

Typical Applications

• Precision stencils: Solder paste and wafer bumping masks with vertical walls for clean paste release.
• Optical pinhole arrays: Calibrated micro-aperture arrays for imaging and sensor calibration.
• Fine filtration: High-open-area screens for fuel, ink and pharmaceutical microfiltration.
• EMI shielding windows: Ultra-fine conductive meshes that pass air while attenuating high frequencies.
• Encoder & code discs: Fine-pitch gratings where wall verticality defines signal fidelity.
• Instrument screens: Lightweight, traceable nickel meshes for sensors and flow conditioning.

Design Notes & Process Considerations

1. Wall angle target: State the minimum sidewall angle; electroformed walls stay near 85–90°, while etched-through walls taper.
2. Aperture versus thickness: Keep the aspect ratio (thickness : aperture) within about 5:1 or etchant exchange inside the hole suffers.
3. Etch allowance: Electroforming already defines the wall, so keep the trim etch light and specify maximum lateral removal.
4. Deposit stress: Request low-stress nickel or Alloy 42 and a stress-relief anneal, or the released foil will curl.
5. Open-area limit: At ultra-fine pitch, confirm the ligament can survive handling, bonding and cleaning.
6. Frame & handling: For custom electroformed mesh etching at thin gauges, specify a support frame early so the foil is never free-standing.