What’s Inside a Membrane Switch?

Posted by Casey Cephas | 3/23/20 7:15 AM

You can find them on TV remotes, treadmills, medical devices, and industrial equipment, just to name a few. But do you know how membrane switches work – or how they can benefit your product?

Let’s take a look inside a membrane switch to see how this thin, flexible application works and creates a dependable, user-friendly control panel.

Layers of a membrane switch.

A typical membrane switch is comprised of six integrated layers with additional components added for specific functionality.

  1. Faceplate – Typically screen-printed on durable material, the faceplate is the graphic layer with printed buttons, text, and branding. This part is also referred to as the graphic overlay or fascia.
  2. Selective adhesive – An adhesive sheet is customized to the shape of the overlay to prevent the button areas from sticking.
  3. Tactile layer – To produce a snap or click when a button is pressed, a round piece of plastic with pressure-sensitive adhesive on one side is placed inside the membrane switch. This tactile feel helps the operator know action has taken place.
  4. Spacer – Separating the top and bottom circuit layers, the spacer is typically formed from heat-stabilized polyester in between two layers of acrylic adhesives.
  5. Printed circuit – Using conductive silver inks, upper and lower circuits are printed on supporting dielectric substrates. The interconnection of electrical components (traces) is designed to produce a desired result.
  6. Mounting adhesive – A final adhesive sheet is placed on the back of the switch to aid in the assembly of the final device.

Advanced features and add-ons.

Depending on your application, membrane switches can be made with an array of optional components and features. Here are a few common add-ons.

  • Backer: Sometimes called a support layer, the backer is a rigid platform that is used for free-standing membrane switch assemblies.
  • Shielding: To prevent electromagnetic (EMI) or radio frequency interference, a layer of conductive material is added and grounded through a tail trace.
  • Protective coating – For applications used in harsh environments, durable coatings can be added to protect the faceplate from abrasion, sunlight, chemicals, moisture, or other factors.
  • Embossing – To improve the user experience and accuracy, keypads or buttons can be raised, also known as embossing.
  • Window – A selection of the faceplate is cut out and replaced with a layer of clear material to allow for the viewing of interior LCD displays or LED indicator lights.

High-quality membrane switches.

Membrane switches can be an effective, cost-efficient solution for a wide range of products and industries. While the finished product is relatively simple, it must be designed and made with expert knowledge and care. When you’re looking for a custom membrane switch that offers high-level functionality and durability, be sure to choose a manufacturing partner with the experience and capabilities in these applications.

Get started with membrane switches.

At Tapecon, we have over 100 years of experience helping customers solve their complex product challenges. Learn more about our membrane switches applications.

Topics: Interfaces, Printed Electronics, Membrane Switch

Written by Casey Cephas

Casey is the Marketing Coordinator at Tapecon Inc.

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