Overview

A custom brass EMI mesh is a perforated shielding component that blocks electromagnetic interference while still letting air or light pass through an enclosure. Photochemical machining opens dense arrays of apertures in thin brass foil, giving a flat, burr-free screen with a tightly controlled open area and continuous conductive paths between the holes. Brass C26000 and C26800 offer good conductivity, solderability and formability, and are typically supplied from 0.05 mm to 0.40 mm with aperture tolerance of ±0.02 mm.

Engineers choose a custom brass EMI mesh when a vent, window or display must meet shielding requirements without a solid plate. The etched pattern keeps the web continuous, so attenuation stays predictable across the panel, while the apertures are small relative to the wavelengths being blocked. Because each layout is a phototool rather than a die, a custom brass EMI mesh is economical for both prototypes and volume runs, and the hole pattern can be tuned to balance airflow against shielding effectiveness.

Parameter Window

• Available Materials: brass C26000/C26800, phosphor bronze, copper, nickel silver
• Material Thickness Range: 0.05–0.40 mm (common 0.10, 0.15, 0.20, 0.30 mm)
• Tolerance: ±0.02 mm on aperture, ±0.03 mm on profile, ±10% on open-area ratio
• Minimum Feature: 0.20 mm aperture, 0.15 mm web, 0.35 mm pitch
• Surface Options: degreased, passivated, Ni/Sn/Au plating, tinned, framed or adhesive-backed
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Artwork Review — Confirm aperture size, pitch, open-area ratio and the attenuation target against the enclosure drawing.
2. Material Selection — Choose brass temper and thickness by shielding need, and check the coil for flatness.
3. Cleaning & Lamination — Degrease and laminate dry film on both faces with resist thickness matched to the aperture.
4. UV Exposure — Expose both faces through registered film so the web stays continuous across the panel.
5. Development — Wash out unexposed resist and verify that all apertures open cleanly without residue.
6. Etching — Spray-etch with brass-matched chemistry, controlling time and speed for straight conductive webs.
7. Stripping & Finishing — Strip resist, neutralize, then passivate or plate Ni/Sn/Au for solderability and corrosion resistance.
8. Inspection & Packaging — Measure aperture and open area, check web continuity and flatness, then pack with a report.

Core Advantages

1. Shielding with airflow: Dense etched apertures block interference while leaving a controlled open area for ventilation.
2. Continuous conductive web: The metal between holes is one piece, so attenuation is uniform and predictable.
3. Burr-free flat screen: Chemical removal leaves no rolled edges, so the mesh bonds evenly to a bezel or gasket.
4. Tunable open area: Aperture size and pitch can be balanced against airflow and shielding without changing tooling.
5. Easy to join: Brass takes tin, nickel or gold plating, so the screen solders or bonds into an assembly reliably.
6. Tool-free revisions: A custom brass EMI mesh is re-patterned from a film, so new vent layouts avoid die charges.

Typical Applications

• Enclosure vents: Perforated panels that cool electronics while keeping emissions inside the housing.
• Display and window shields: Fine meshes laminated over screens that preserve visibility and add attenuation.
• RF windows: Aperture arrays in waveguide or antenna covers that pass a defined band and damp others.
• EMI gasket cores: Etched brass carriers that add shielding to a conductive elastomer gasket.
• Faraday screens: Grounded mesh layers in instruments that isolate a sensitive stage from stray fields.
• Shielded ventilation grilles: Decorative yet functional grilles for test equipment and communication racks.

Design Notes & Process Considerations

1. Aperture versus wavelength: Keep the largest aperture well below the wavelength to be attenuated, and state the target band.
2. Web and open area: Specify minimum web (typically 0.15 mm) and open-area ratio, since they set both strength and attenuation.
3. Plating and solderability: Name the plating and thickness if the mesh will be soldered or bonded into a frame.
4. Flatness and bonding: Call out flatness per 100 mm so the screen seats evenly against a gasket without gaps.
5. Grounding path: Show how the mesh contacts the chassis, because a floating screen loses much of its shielding value.
6. Inspection criteria: Agree aperture, open area and sampling plan; documenting these on the drawing cuts review cycles.