Overview

Micro hole etching is a photochemical machining process that opens thousands of small holes in a thin metal foil at once, rather than drilling or punching them one at a time. A photoresist mask is exposed with the full hole pattern — diameter, pitch and layout — developed, and the exposed spots are dissolved by an etchant sprayed from both sides of the sheet. Because every hole in the pattern etches at the same rate, a foil can carry tens of thousands of identical apertures with diameters down to 0.05 mm and a pitch as fine as 0.15 mm. Typical foils are stainless steel 304/316L, nickel, titanium and copper, between 0.02 mm and 0.3 mm thick.

The value of micro hole etching is in what drilling and punching cannot do: it leaves no burr, no recast and no rolled edge around each hole, and it never tears the thin web between tightly spaced apertures. Because holes are dissolved rather than pushed through, the land between adjacent holes stays flat and intact, which is exactly what a filter, screen, aperture plate or fuel nozzle demands. The same phototool also reproduces the pattern identically across a batch, so flow and filtration characteristics repeat part after part.

Parameter Window

• Available Materials: stainless steel 304/316L, nickel, titanium, copper foils
• Material Thickness Range: 0.02–0.3 mm
• Tolerance: ±0.02 mm on hole diameter, ±0.03 mm on pitch
• Minimum Feature: 0.05 mm hole diameter at 0.05 mm stock, 0.15 mm pitch
• Surface Options: as-etched, passivated, gold-plated, annealed for flatness
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Pattern Design — Convert the hole layout to vector, set diameter, pitch and open-area ratio, and apply the etch compensation for undercut.
2. Foil Selection — Match alloy and gauge to the aperture; thinner foil for finer holes, work-hardened stock where flatness must survive handling.
3. Cleaning & Lamination — Degrease the foil and laminate dry film resist on both faces so each hole etches symmetrically from front and back.
4. Double-Sided Exposure — Expose the pattern in register on both sides so holes meet cleanly in the middle of the foil without a lip.
5. Development — Wash out the exposed resist dots to open every aperture, then inspect for under-developed or clogged holes.
6. Etching — Spray etchant from both sides at controlled temperature and speed; hole diameter and wall profile follow the resist geometry.
7. Stripping & Finishing — Remove resist, neutralize, then passivate, plate or anneal; annealing restores flatness to fine perforated foil.
8. Inspection & Packaging — Verify hole diameter, pitch and open area under optical measurement, then pack flat on liners or in rolls.

Core Advantages

1. Thousands of holes at once: A full perforated pattern etches in one pass, so a panel with tens of thousands of apertures costs no more than a single part.
2. Burr-free apertures: Dissolution leaves no burr or recast, so each hole is clean and round with no downstream deburring step.
3. Fine pitch without tearing: The land between holes stays flat and intact at pitches as tight as 0.15 mm, which punching would distort.
4. Uniform flow characteristics: Every hole in the pattern etches at the same rate, so flow rate and filtration repeat part to part.
5. No tooling, no wear: A design change is a new phototool, and there is no drill bit or punch to dull, so hole size never drifts.
6. Material flexibility: Stainless, nickel, titanium and copper run on the same line. Micro hole etching is therefore the reliable way to produce precision apertures in volume.

Typical Applications

• Filtration screens: Stainless foils with fine hole arrays for liquid and gas filters where open area must stay constant.
• Aperture plates: Precision apertures in nickel or titanium for optical and beam-limiting applications.
• Fuel and air nozzles: Small hole patterns in stainless for atomizer and burner nozzles that need uniform spray.
• MEMS and sensor meshes: Micro-perforated foils used as sensing windows and protective screens in sensors.
• Speaker grilles: Dense micro holes in stainless for acoustically transparent covers on earbuds and mics.
• Battery vent plates: Perforated nickel foils that vent gas while protecting cells in battery packs.

Design Notes & Process Considerations

1. Diameter versus thickness: Keep the minimum hole diameter at or above the foil thickness — 0.05 mm is realistic at 0.05 mm stock.
2. Pitch and open area: State the hole pitch and target open-area ratio; a finer pitch increases flow but weakens the land between holes.
3. Undercut compensation: Etching cuts sideways as it cuts down, so add an undercut allowance of about half the foil thickness to the artwork.
4. Land width rule: Keep the land between holes at least 1.0 × foil thickness so the web stays strong and does not tear.
5. Flatness and annealing: For large perforated panels, specify flatness per 100 mm and allow annealing after etching.
6. Edge definition: Confirm whether a straight or slightly tapered hole wall is acceptable. Micro hole etching keeps the wall profile consistent because chemistry, not tool wear, defines it.