Overview

Etched EMI mesh is a conductive metal grid produced by photochemical machining, where the open cells and the thin conductive webs between them are both defined by a resist pattern and dissolved out of solid sheet. The result is a flat, one-piece grid that blocks or attenuates electromagnetic fields by presenting a continuous conductive path across its surface. Because the grid is etched rather than woven, the joints are solid metal rather than crossed wires, so conductivity is uniform and there is no contact resistance at the intersections.

What matters for shielding is conductivity and cell density: the mesh aperture must be small relative to the wavelength being blocked, and the web must stay conductive and unbroken. Etched EMI mesh is made in stainless steel, copper or nickel from 0.03 mm to 0.3 mm thick, with cell sizes and web widths scaled to the target frequency band. It is used for ventilation apertures in shielded enclosures, display windows, optical filters, gasket backing and antenna screens, where air and light must pass but interference must not.

Parameter Window

• Available Materials: stainless steel 304/316L, copper C1100, nickel, optional Monel
• Material Thickness Range: 0.03–0.3 mm
• Tolerance: aperture size ±0.02 mm, pitch ±0.05 mm across the panel
• Minimum Feature: aperture and web down to 0.05 mm
• Surface Options: as-etched, electropolished, passivated, tin or nickel plated
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Shielding Requirement Review — Convert the frequency band into an aperture size and open-area target for the required attenuation.
2. Pattern Design — Lay out the grid with cell size, web width and orientation, adding border lands for mounting.
3. Material Selection — Choose stainless for durability, copper for conductivity, or nickel for corrosion resistance.
4. Cleaning & Lamination — Degrease the sheet and laminate dry film resist on both sides for double-side etching.
5. Double-Side Exposure — Expose the grid with front-to-back registration so webs etch straight and uniform.
6. Etching — Etch with matched chemistry, controlling time and temperature to reach aperture size with limited undercut.
7. Stripping & Finishing — Strip resist, neutralize, then electropolish or plate to stabilize conductivity and finish.
8. Inspection & Packaging — Measure aperture, pitch and web width optically, check conductivity, then pack flat.

Core Advantages

1. Uniform conductivity: Solid-metal joints avoid the contact resistance of woven mesh, so shielding is even across the panel.
2. Controlled cell density: Aperture size and web width are set by artwork, matched to the frequency being shielded.
3. Flat and stable: An etched grid is rigid and flat, unlike woven mesh that can shift or fray at cut edges.
4. Burr-free cells: Double-side etching leaves clean edges that need no deburring and will not snag.
5. No tooling: Any grid pattern is a new film, so prototype shields and design changes cost nothing to re-tool.
6. Alloy flexibility: Stainless, copper and nickel run on one line for matched electrical and corrosion requirements.

Typical Applications

• Enclosure ventilation apertures: EMI shielding over air vents while maintaining airflow.
• Display windows: Transparent-area shielding grids for screens and indicators.
• Optical filters: Fine grids that pass light while attenuating interference.
• Gasket backing: Rigid conductive backing for EMI gaskets and seals.
• Antenna screens: Grounding and shielding grids for RF assemblies.
• Waveguide covers: Perforated covers that shield while allowing controlled transmission.

Design Notes & Process Considerations

1. Aperture versus frequency: Size the cell well below the wavelength of the highest frequency to block, or attenuation drops sharply.
2. Web width and open area: Balance web width against open area; wider webs add conductivity but reduce airflow and light.
3. Material conductivity: Choose copper for maximum attenuation, stainless where strength and corrosion matter more.
4. Edge treatment: Specify a solid border land for mounting and grounding continuity around the perimeter.
5. Plating: Call out tin or nickel plating to protect against oxidation that raises contact resistance over time.
6. Flatness: For large panels, state flatness so the mesh seats evenly against the enclosure and ground plane.