Communication Products Rectangulaire Metal Dome

When a keypad lives on a factory floor, a construction site or a patrol officer belt clip, the button underneath it has to survive conditions that consumer-electronics domes were never designed for. The rectangular metal dome we build for outdoor communication products is not a re-sized version of a consumer dome. It is a purpose-built snap dome with four extended legs, a wider crown, and SUS304 stainless steel chosen specifically for its corrosion resistance and low-temperature performance.

For more than two decades, Shanyo has supplied rectangular domes to keypad manufacturers building two-way radio housings, outdoor GPS devices, marine control panels and industrial HMI keypads. The notes below explain how these domes are specified, why the rectangular shape matters, and what to ask your dome supplier before approving a sample.

Why a Rectangular Dome Instead of Round?

Round domes are the default for most consumer keypads. But when the plunger on a membrane keypad or silicone button is rectangular instead of circular, a round dome leaves dead space and uneven leg contact. A four-leg rectangular dome matches the plunger footprint, distributes the snap force evenly across four contact points, and prevents the dome from rotating out of alignment during high-vibration operation.

For outdoor communication devices specifically, the rectangular shape also gives designers more layout flexibility in dense keypads with closely spaced buttons. The legs can be trimmed or extended to fit around SMD components on the FPC or PET circuit without sacrificing the tactile click.

Material and Plating for Outdoor Environments

We stamp these domes from SUS304 stainless steel rather than the SUS301 used for most consumer domes. SUS304 has higher chromium and nickel content, which improves resistance to salt spray, humidity and automotive under-hood chemicals. The trade-off is a slightly lower spring rate, which we compensate for with a thicker blank (typically 0.10-0.13mm vs 0.08-0.10mm for SUS301 consumer domes).

On the contact side, standard plating is nickel for general outdoor use. For coastal or washdown environments, we recommend gold-plated contacts, which maintain contact resistance under 10 ohms even after 100,000 actuations in salt-spray testing. If your keypad is sealed against moisture, the dome itself sees little corrosion, but the contact plating still matters for long-term signal integrity.

Typical Specifications

Common Applications

Our rectangular domes ship into several outdoor product categories:

• Two-way radios and walkie-talkies: PTT buttons and channel selectors where gloved operation requires 300gf or higher force.
• Outdoor GPS and marine electronics: Navigation keypads exposed to salt spray and direct sunlight.
• Industrial control panels: Factory HMI stations, conveyor controllers and machine-mounted keypads.
• EV charge ports and automotive exterior buttons: Door handles, trunk release and charge-port controls that see wide temperature swings.

For automotive-grade requirements, we also supply automotive snap domes tested to IATF 16949 standards. If your device uses an integrated dome sheet rather than loose domes, see our dome sheet arrays page for die-cut arrays on PET with adhesive backing.

Design Tips for Rectangular Dome Keypads

From our application engineering team, three points come up on nearly every outdoor keypad project:

1. Size the plunger to the dome, not the other way around. The silicone or rubber plunger should contact the crown at 60-70% of the dome width. A plunger that touches the legs changes the snap force unpredictably. A plunger too small will slide off-center.

2. Account for cold-temperature force shift. SUS304 becomes stiffer below -20C. A dome rated at 300gf at room temperature can measure 330-340gf at -40C. If your spec is tight, ask for a low-temperature force curve in the sample report.

3. Specify leg coplanarity. On outdoor keypads with adhesive-backed PET circuits, leg warpage of more than 0.05mm causes rocking and inconsistent contact. We hold coplanarity to 0.03mm on rectangular domes as standard.

How to Order Samples

Send us your keypad drawing or a description of the plunger size, target actuation force and environment. Our engineering team will recommend a standard rectangular dome size from stock within one business day and ship samples in 48 hours. For custom sizes, tooling lead time is typically 7-10 days. Every shipment includes a force-curve chart and a salt-spray or life-cycle report for the production lot.

Request samples through the contact page or email our sales team directly. We welcome both prototype runs and production programs of 50,000 pieces and up.

About Shanyo: Qingdao Shanyuan Precision Electronic Technology Co., Ltd. manufactures metal domes, dome arrays, silicone keypads, FPC circuits and stamped components for automotive, medical and outdoor communication OEMs. Visit www.yo-shan.com.