Membrane Switch Design & Manufacturing

Switch to Technomark for Reliable Performance

Backed by over two decades of engineering and manufacturing experience, Technomark continues to provide the most dependable membrane switches. Our engineering department will apply the best industry standards and practices to your individual needs. Then our ISO certified quality system will ensure precise, repeatable fabrication.

Look what a well-designed membrane switch can do:

  • Give your product an attractive face that portrays your corporate identity.
  • Group keys and displays into an intuitive, organized user interface.
  • Eliminate time-consuming wiring of discrete switches.
  • Seal openings around displays or touchscreens.
  • Create a smooth, easy to clean front panel.
  • View our capabilities brochure
  • And more. What are your objectives?
Digital full color printed graphic overlay for a membrane switch

Full color printed membrane switches

Two custom shape membrane switch designs

Custom shape membrane switch designs

Dome button switch components front and back sides shown

Dome button switch components

Soft touch elastomer membrane switch

Soft touch elastomer membrane switch

What is a Membrane Switch & How is it Constructed?

Illustration of a membrane switch construction

The easiest way to understand what a membrane switch is to reference an all-time favorite device-the microwave.  The membrane switch on the microwave is the buttons—the human interface layer—that communicates to the microwave that you’d like to reheat your food for one minute.

Membrane Switch Construction

A membrane switch consists of various layers laminated together. The layers of a basic membrane switch construction include a membrane overlay, spacer, printer circuit, rear adhesive, and tail filler. The membrane switches environment and requirements can vary the way the switches plug into its interface. For example, if shielding is necessary, a two-circuit membrane switch design would be a better construction choice. Replace the printed silver circuit with a copper and polyimide construction for more stringent environmental requirements. These construction designs are often called “Kapton” circuits. These circuits offer an advantage over current carrying capacity and better resistance to moisture. You can explore more construction possibilities by downloading our membrane switch design guide or contacting us for support.

Membrane Switch Options

You can rest assured that Technomark uses the highest standards in manufacturing, and that includes the use of the best materials. We will provide the Membrane Switch options you need for a successful manufactured project.

Contact us if you don’t see what you need. We like to apply our creativity and wide-range experience to new challenges.

Graphic Overlays

  • Hardcoated polyester or polycarbonate in gloss, matte, or textured finishes
  • Screen printed solid colors or digital CMYKW for lower cost and halftones. We can even print digital full-color​ logos over metallic backgrounds.
    Private label options. Vary the overlay graphics and logo while using a common underlying switch. Or we can add a pocket that lets you insert paper printed custom legends from the behind the overlay.
  • Screen printed selective texture. Leave windows gloss for clarity, create decorative effects, or use gloss to distinguish keys from surrounding texture.
  • Single level, two-level​, or tactile snap embossing. Add rim or “pillow” emboss to keys, emboss logos, or add braille dots or locator bumps to keys.
  • Anti Newton’s rings spacers. Transparent dots prevent rainbow effects in windows when they are in contact with transparent layers like touchscreens or ITO shields.
  • Deadfronts blend into backgrounds to keep icons concealed until they are lit.
  • Urethane coating can be applied over windows or other areas for a three dimensional effect.

Circuits

  • Screen printed polyester with integral ribbon tails is the most common and inexpensive construction. Keys can be arranged in matrix or common bus configurations.
  • Two-sided printed switches allow traces to run under domes and LEDs, connecting to the upper side via printed holes​ and permit higher density circuitry.
  • Etched copper/polyimide flex-circuits allow finer traces, such as 0.5 mm pitch tails, and solder mounting of components (instead of silver epoxy). They can be single or double-sided​ and typically have gold plated contacts.
  • Printed circuit boards (PCBs) accommodate connectors and other components on the rear side in addition to domes and LED’s on the front.

Components

  • Embedded phototransistors let you adapt backlighting levels to ambient light.
  • Other SMT components such as current limiting resistors, pullup resistors, and switching diodes are usually part of the interface electronics but can be integrated into the switch.

Connections

  • Crimped connectors on ribbon tails have 0.1” pitch receptacles to mate with standard pin headers. Technomark has in house tooling for FCI (Berg), TEC (AMP), Molex, Nicomatic, and Memcon connectors. Latches, polarity plugs, and detents are optional.
  • Exposed contacts mate with 1 mm pitch ZIF connectors on your PCB. 0.5 mm pitch is possible with etched flex-circuits.

Panel Assembly Options

  • Metal backers come in a variety of materials, finishes, and hardware options.
  • Touchscreens can be integrated into switches and overlays. At the simplest level, the overlay covers and seals the gap between the screen and enclosure. A full switch can add buttons around the edge for improved user experience.
  • Interface electronics. Technomark has provided custom electronics for functions from powering LEDs to converting key presses to HID-compliant​ USB keyboard output.

Switch Keys

  • Tactile metal snap domes, in sizes from 6 to 25 mm and forces from 200 to 700 g, give strong tactile feedback under all temperature conditions.
  • Embossed polyester tactile domes cost less for high volume parts with many keys. They can be formed in the overlay or hidden inside internal layers.
  • Non-tactile keys are the least expensive and longest lasting.
  • Capacitive touch sensors have no moving parts. They can be operated through durable, rigid front panels like acrylic or glass and adapt well to backlighting. Technomark’s ITO scribing capabilities open up new possibilities for transparent control panels.
  • Large area keys can be pressed at any point and can cover the entire switch surface if desired. Typical applications are allowing handheld devices to be triggered without looking at them, or hands-off switches that can be operated by a knee or foot.
  • Membrane Switch Wikipedia

Lighting Effects

  • Indicator LEDs in single, bicolor, or RGB versions are a common and inexpensive option.
  • Side fire LEDs work with light guide film to disperse light within a defined area. They can light individual keys, icons, or logos. You can even have a key or logo light different colors as signals to the user. The more LED’s the more brightness, making them suitable for low-level​ backlighting in dim conditions to a ​brightness that can stand out even in high-level​ indoor lighting.
  • Electroluminescent (EL) backlighting can be added as a single layer beneath keys to give a pure, uniform illumination. EL adapts easily to complex shapes and switches with many cutouts. They require an AC inverter for power, vs simple DC for LEDs.
  • Fiber optic layers can backlight switches using a single LED but have more constraints on size and geometry.
  • NVIS compatible EL backlights and indicator LEDs do not interfere with night vision systems.
  • Integration with your PCBA. If your design includes a PCB behind the switch, you can place the LEDs on it to shine through windows in the switch. This saves cost and allows larger lit areas. A new option is overlays with light guide film to mount directly to a PCB and receive its light from side fire LEDs on the circuit.

Shielding

  • Shields integrated into switches can intercept ESD to prevent damage to circuits, contain EMI/RFI within circuits, or keep EMI/RFI from other sources outside your circuit. Options include screen printed grids, solid foil, and transparent conductive ITO for window areas.

Environment

  • UV stable overlay materials and window clarifying overprints withstand continuous exposure to sunlight.
  • Perimeter seals, including VHB gaskets, meet IP65 standards.
  • High humidity requires special techniques to prevent silver migration and circuit degradation. Technomark has extensive experience with switches used in these conditions.

Agency Approvals

  • ISO 9001:2015 certified
  • ITAR registered
  • RoHS / REACH / Conflict Minerals
  • UL PDGQ2 approved labeling

Frequently Asked Questions

Which type of tactile feedback dome works best in a higher heat environment?

Stainless Steel domes will out perform a polyester tactile dome in this situation.

Can you surface mount LEDS on my Membrane Switch?

Yes. We do it all the time!

What are the quantities required for prototypes and production?

For prototyping we typically do 5 to 10 parts or a  lot-fixed number.

Production quantities vary from five to thousands. 

To make sure you receive the highest quality parts, we require that we receive final approval from you before production commences. Our Design Team has the ability to create your product from an idea, drawing, picture, and more.

Is tactile feel needed on any of the dome types?

We offer both metal domes, which can be either stainless steel or gold plated, and poly domes. Tactile feel is not required and open to customer preference.

What are the different types of termination you offer?

AMP, Berg, Nicomatic. Different centers and of course open contacts for ZIF application.

What are typical metal dome sizes?

8MM, 10MM, 12MM, 14MM, 20MM

What is the actuation force of domes?

Dome force ranges from 85 grams to 700 grams.

What is your lead time?

Because we manufacture custom products our “lead times” are dependent on volume and complexity of the project.  We make every effort to deliver your part the way you want it, when you want it.

How robust is an EL lamp over a stainless steel dome incorporated in a membrane switch?

We have tested our EL lamps up to 1,000,000 cycles without showing any degradation or failure.

Request a Quote Online

Our team can get you started on your next project.

The Technomark design and engineering  team will work with you to fully understanding your needs, from collaboration, design verification, sourcing the best materials, prototyping, and manufacturing to your exacting standards.

Before delivery, parts are visually inspected and electrically tested for functionality.

Technomark, Inc. 

11574 Encore Circle
Minnetonka, MN 55343

800.352.3493
952.912.1700

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