Overview

A high precision electroformed sieve is an ultra-fine micro-aperture screening foil built up by electrodeposition rather than woven from wire or punched from sheet. A polished conductive mandrel is coated with photoresist, imaged with the aperture pattern, and placed in a nickel plating bath; metal grows only on the exposed conductive areas, so when the grown foil is lifted off the mandrel it carries a dense array of straight-walled, burr-free holes whose diameter, pitch and web width are all defined by the same master artwork. Because the process is additive, apertures down to a few micrometres are practical, with almost no taper, no recast edge and no mechanical distortion — qualities that matter in particle-size analysis, standard test sieves, micro-filtration and precision powder classification.

For R&D and procurement teams, the high precision electroformed sieve answers a problem woven and punched screens cannot: wire cloth stacks tolerances on both wire diameter and opening, and punched thin stock tends to roll over and deform at small holes. In an electroformed part the aperture geometry is set once at the artwork stage and repeats from the first sample to the ten-thousandth foil, so calibration and grading stay consistent between lots. The same master can also carry graded apertures, shaped holes or an integral reinforcing rim in a single foil. Since the finished foil is thin — typically tens to a few hundred micrometres — it is normally bonded to a support ring or tension frame, and that mounting method should be settled at the design stage.

Parameter Window

• Available Materials: high-purity nickel, nickel-cobalt alloy, nickel-iron alloy, copper, with stainless-backed composite foils on request
• Material Thickness Range: 0.02–0.30 mm, with most micro-aperture sieves built at 0.03–0.10 mm
• Tolerance: aperture ±0.002 mm, pitch ±0.005 mm, cumulative position error ≤0.01 mm across the panel
• Minimum Feature: aperture down to 0.005 mm, minimum web 0.015 mm, near-vertical sidewalls
• Surface Options: matte, electropolished, gold or nickel anti-oxidation plating, hydrophobic/oleophobic coating, tensioned mounting rim
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Mandrel Preparation — Polish a stainless or titanium mandrel, degrease it and verify surface roughness so the grown foil releases cleanly.
2. Resist Coating — Apply a thick photoresist layer to the conductive face, sized to the target foil thickness, then bake to cure.
3. Pattern Exposure — Transfer the aperture array through high-resolution film or direct-write imaging, locking hole shape and pitch.
4. Development & Inspection — Wash away the selected resist areas to expose the conductive web zones, then check each panel for residue and defects.
5. Electroforming — Immerse the mandrel in a nickel electrolyte and grow metal layer by layer under controlled current density.
6. Thickness Control — Measure in-process and trim current so the foil stays uniform from edge to centre without thin spots.
7. Demolding & Stripping — Peel the formed foil from the mandrel, remove remaining resist, neutralize and rinse to a free-standing sieve.
8. Inspection & Packaging — Verify aperture, pitch and open area by vision measurement against the approved sample, then ship flat on lint-free liners.

Core Advantages

1. Micron-scale apertures: Additive growth holds openings around 5 µm, far below the practical floor of woven or punched screens.
2. Straight, burr-free holes: Near-vertical walls and clean edges give a tighter particle cut and more repeatable analysis results.
3. Excellent lot-to-lot repeatability: Aperture, pitch and web come from one master, so calibration hardly drifts between batches.
4. Shaped and graded patterns: Round, square, slot or graded apertures can share one foil without secondary assembly.
5. Thin and flat: Low-stress foils bond to support rings without curling, keeping the clamp seal reliable.
6. Cost-effective at low volume: A photomaster costs more than a punch tool up front, but revisions need only new artwork, which suits custom standard sieves.

Typical Applications

• Standard test sieves: Laboratory particle-size analysis and grading paired with a sieve shaker.
• Precision filtration: Final filtration of pharmaceutical, fine-chemical and electronic-grade liquids with low pressure drop.
• Inkjet and printing: Upstream nozzle filters and ink-path screens where uniform holes keep ejection even.
• Acoustic and dust protection: Micro-aperture membranes on microphones, earpieces and sensors that vent air but block particles.
• Fine powder classification: Particle sizing of battery materials and abrasives using graded-aperture foils.
• Optical and metrology: Aperture arrays used as diaphragms, masks or calibration targets requiring exact hole position.

Design Notes & Process Considerations

1. Aperture versus thickness: Keep the smallest hole at least one third of foil thickness; smaller openings tend to close or distort in thin stock.
2. Open area versus strength: Higher open area means better flow but a more fragile foil — state the target and allow a reinforcing rim or support ring.
3. Hole shape and layout: Specify round, square or hexagonal close packing; dense layouts raise open area but narrow the web, so check strength.
4. Mounting and tensioning: Thin foils need a defined support method, clamping force and sealing face to avoid tearing or wrinkling at assembly.
5. Coating allowance: Plated or repellent coatings add thickness, so call out plating thickness and confirm it will not shrink the aperture.
6. Complete drawing callouts: Give aperture, pitch, web, thickness, open area and tolerance together when ordering a high precision electroformed sieve, and include the master artwork and signed sample references with the order.