Overview

Precision mesh etching is defined by numbers, not by the fact that holes exist. Aperture diameter, pitch, wall angle and open area all carry tolerances, and those tolerances decide whether the mesh filters to the intended cut point, passes the intended flow, or blocks a nozzle. Photochemical machining meets that requirement because the hole is formed by chemistry acting through a mask: there is no punch, no drill and no wire, so nothing pushes the material sideways and nothing leaves a burr on the exit face.

The controlling variables are the thickness-to-aperture ratio and the registration between the two faces. A 0.08 mm aperture in 0.05 mm foil etches cleanly from both sides; the same aperture in 0.2 mm stock tapers visibly and loses open area. Holding ±0.01 mm on aperture therefore starts with choosing foil thin enough for the pattern, then controlling resist thickness, exposure dose and dwell time with equal discipline.

Parameter Window

• Available Materials: 304/316L stainless steel, nickel 200, copper C110, aluminum 5052
• Material Thickness Range: 0.02–0.30 mm
• Tolerance: aperture ±0.01 mm; pitch ±0.01 mm; total wall taper ≤0.02 mm
• Minimum Feature: 0.03 mm aperture at 0.02 mm foil; 0.05 mm at 0.05 mm foil
• Surface Options: passivation, electropolish, nickel plating, black oxide, flatten and deburr
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Capability Review — Compare aperture, pitch and stock thickness against the etchable ratio, and state the achievable tolerance before the drawing is frozen.
2. Foil Verification — Measure thickness at several points across the sheet; a 4% gauge variation moves aperture and open area by a comparable amount.
3. Lamination — Apply dry film on both faces under controlled heat and pressure, with an inspection step for bubbles that would become blocked holes.
4. High-Resolution Exposure — Expose through fine-grain film in hard contact, registering front and back to the same targets so the two etch fronts meet in the middle.
5. Development — Wash out resist and confirm aperture openings under a microscope; under-developed holes etch undersize and cannot be corrected later.
6. Two-Sided Etching — Etch both faces simultaneously with matched spray pressure, so the wall profile is symmetrical and the taper is split between the two sides.
7. Stripping and Flattening — Remove resist, neutralize, then flatten or electropolish where the sheet must sit flat in a housing or against a seal.
8. Metrology and Release — Measure aperture, pitch, open area and taper on a vision system, run a flow check on a sample, and release with the data attached.

Core Advantages

1. Aperture tolerance of ±0.01 mm: Holes are defined by the film and held by dwell time, so a 0.10 mm nominal aperture stays inside a band that a drilled or woven mesh cannot match.
2. Symmetrical walls: Etching from both faces splits the taper, giving a wall close to vertical and an effective open area that matches the drawing rather than the entry side only.
3. No blocked or bridged holes: There is no punch to smear metal and no wire to leave a burr, so fine pitch arrays stay open across the full panel.
4. Open area held batch to batch: Because aperture and pitch are both controlled, the calculated open area stays within a few percent, which keeps pressure drop predictable.
5. Any hole shape from the same process: Round, square, hexagonal, slot and tapered holes are all artwork, so a filter design can change hole form without changing suppliers.
6. Inspection data, not just parts: Aperture, pitch, taper and flow results ship with the lot, so incoming inspection can sample against numbers instead of re-qualifying the part.

Typical Applications

• Fine filtration: Absolute-rated screens with 0.05 mm apertures for fuel, hydraulic fluid and process water.
• Inkjet and nozzle filters: Fine mesh upstream of print heads, where a single blocked hole ruins a nozzle plate.
• Medical filtration: 316L mesh for blood and reagent filters, requiring clean edges and proven aperture control.
• Acoustic mesh: Fine aperture grilles where open area sets both sound transmission and dust ingress.
• Sensor protection: Dust and moisture barriers in front of pressure ports, with open area matched to response time.
• Electrolyser and fuel cell screens: Nickel and stainless mesh that must pass gas or liquid at a defined pressure drop.

Design Notes & Process Considerations

1. Choose foil before chasing tolerance: Aperture tolerance of ±0.01 mm is routine at 0.05 mm stock and difficult at 0.2 mm; thin material is the first lever, not tighter process control.
2. Specify the measurement side: Aperture measured on the entry face reads larger than on the exit face when there is taper; name the face and the method in the drawing.
3. Give open area as a range: Aperture and pitch both carry tolerance, so open area should be a band, not a single value, or every lot will need a deviation.
4. Watch the ligament width: The metal between holes must stay above roughly half the foil thickness, otherwise the mesh distorts or tears during handling.
5. Say how flow will be checked: Airflow or water flow at a reference pressure is a better functional acceptance test than geometry alone, and it catches partial blockages.
6. Plan the frame and handling: Precision mesh etching parts should carry a solid border for clamping and transport, so the fine field is never touched before assembly.