Overview

A tactile dome array is a set of metal snap domes arranged on a carrier film or frame so that each dome sits over a contact pad on a PCB, closes the circuit when pressed and springs back on release. Photochemical etching is used to half-etch ultra-thin stainless steel into spherical dimples, registration holes and a surrounding carrier web in one flat sheet, while precision electroforming deposits nickel onto a mandrel to grow thin-walled domes with very consistent spring force. Both routes are chemical or electrochemical rather than die-cut, so the part leaves the line burr-free and stress-free, with snap ratio and travel set by the artwork and formed geometry.

Typical material is spring-temper 301/304 stainless steel, beryllium copper or electroformed nickel between 0.03 mm and 0.15 mm, with dome diameters from 3 mm to 12 mm and actuation force from about 100 gf to 500 gf. Because the array is imaged rather than punched, dome pitch, orientation and carrier outline follow the customer key layout exactly. As a dome switch array factory we support custom layouts, rapid prototype arrays for feel and force validation, and volume supply on reels or sheets for automated placement, with force–displacement and lifecycle data supplied for each lot.

Parameter Window

• Available Materials: spring-temper 301/304 stainless steel, beryllium copper, electroformed nickel, nickel-iron alloy
• Material Thickness Range: 0.03–0.15 mm (electroformed nickel down to 0.02 mm)
• Tolerance: ±0.01 mm on dimple depth, ±0.02 mm on array position
• Minimum Feature: 0.08 mm half-etch step, 0.15 mm registration hole
• Surface Options: Ni/Au plating, passivation, anti-oxidation treatment, release liner or adhesive lamination
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Artwork & DFM Review — Convert the key layout into vector artwork and check dimple depth, registration holes and carrier border against 0.03–0.15 mm stock.
2. Material Selection — Choose 301/304 spring temper or beryllium copper to match the target force and confirm strip flatness before lamination.
3. Cleaning & Lamination — Degrease the strip and laminate dry-film photoresist on both faces under controlled heat and pressure.
4. UV Exposure — Expose the dimple and hole array through high-resolution film registered to the strip datum for panel-level accuracy.
5. Development — Wash out unexposed resist to open the half-etch regions, then inspect the shallowest dimples for residue.
6. Controlled Etching — Spray etchant matched to the alloy, holding ±0.01 mm on depth through time, temperature and conveyor speed.
7. Stripping & Finishing — Remove resist, neutralize, then plate Ni/Au, apply anti-oxidation and laminate a release liner or adhesive.
8. Inspection & Packaging — Sample force–displacement curves, travel and array position against the approved first article, then reel or sheet-pack.

Core Advantages

1. Burr-free contact faces: Chemical forming leaves no sheared edge, so domes do not scratch pads or pierce the release liner during placement.
2. Uniform feel: Dimple depth and array position come from one film, so force is consistent across the panel with no hard or soft keys.
3. No hard tooling: A new layout or force target is a new film or etch time, keeping prototype and small-batch programs economical.
4. Stable spring life: Stress-free domes resist force decay over high-cycle pressing and do not take a permanent set.
5. Placement ready: Carrier web, registration holes and outline are formed together, so the whole array aligns in one automated step.
6. Documented performance: Reels, sheets and framed sets run on one line with force and lifecycle data issued per lot — what a dome switch array factory is expected to deliver.

Typical Applications

• Remote controls: Tactile arrays for appliance and set-top-box remotes with uniform force and crisp feedback.
• Industrial keypads: Metal dome arrays for control panels and sealed keyboards that resist oil and contamination.
• Medical instrument panels: Key arrays for monitoring and diagnostic devices that are flat, cleanable and repeatable.
• Automotive consoles: Dome arrays for centre-stack and steering-wheel keys that withstand temperature and humidity swings.
• Handheld terminals: Thin arrays for scanners and radios where space is tight and placement must be fast.
• Membrane switches: A dome layer bonded to the circuit layer, aligned as one sheet without per-dome registration.

Design Notes & Process Considerations

1. Depth versus thickness: Calculate dimple depth together with stock thickness; too deep a half-etch weakens the root and the dome collapses after a few cycles.
2. Array datum: Give pitch from pad centres and call out orientation and registration-hole tolerance, not just dome diameter, to avoid placement drift.
3. Carrier border: Leave an unetched solid rim for handling and specify corner radii so the web does not tear or lift during reeling.
4. Force specification: State actuation force, travel and return ratio plus the test plunger diameter, otherwise force data cannot be compared.
5. Plating effect: Name the coating and thickness, since Ni/Au plating changes stiffness and shifts the force target.
6. Panelization: Group several layouts on one sheet with shared registration marks to cut handling cost on repeat dome switch array factory orders.