Membrane switches, also known as membrane panels or keypads, are lightweight, all-in-one printed electrical circuits engineered to sustain millions of actuations. Membrane switches are constructed with layers of thin, flexible, and conductive materials rather than bulky, rigid materials, making them an optimal choice in most cases.
All membrane switches have at least five layers.
The graphic overlay, a membrane switch's top layer and point of human-machine interface, is typically made of polyester or polycarbonate. In addition to indicating user functions, overlay graphics can provide branding, asset management, compliance, and safety information. Membrane switch overlays are easily customizable.
A retainer layer is used to secure the placement of metal domes in tactile switches.
A spacer layer allows for the switch's open position, so that a break in conductivity can occur.
A circuit layer facilitates the flow of electricity. Its conductivity can result from the use of conductive inks or from conductive copper traces that appear when a flexible film substrate is etched away.
Metal- or poly-dome and dome spacer layers are added to tactile switches, and a non-conductive shielding layer can be added whenever a higher level of insulation or resistance is needed.
Shielding, often constructed with solid aluminum foil or by printing with carbon or silver ink, is used to eliminate electrostatic discharge, electromagnetic interference, or radio frequency interference.
Silicone rubber keypads or keyboards can be added to the overlays of membrane switches, touchscreens and other user-interface products. Because silicone rubber is moldable and can be compressed, it offers a comfortable, durable, tactile experience. Silicone rubber keypads are also waterproof and dust proof, and they can be designed with laser-etched graphics, high-gloss finishes, and other aesthetic features.
Backlighting options, such as LED, fiber optics, light guide film,, and electro-luminescense, can be added to membrane switches to provide a better user-experience.combines the best features of an electro-mechanical and a flat panel into a single, thin, and robust keypad that can reliably function in extremely harsh environments.
Client Applications
An industrial supply company needed a keypad designed to improve warehouse security. After consulting with Cubbison Company's engineers and walking through two prototype iterations, the client settled on a multi-color, polyester keypad that would respond well to touch, yet withstand high temperatures and environmental contaminants.
Printed circuit layers use conductive inks, typically silver or copper, to facilitate the flow of electricity. Ink takes little to no space, so a printed membrane switch remains flexible and compact. Because substrates and inks have varied levels of conductivity and resistance, they are an important part of membrane switch design.
The Cubbison Company offers two types of customizable flexible circuits: silver-flex and copper-flex.
Silver-flex circuits use silver inks as the circuit element, with the ink printed on flexible polyester layers. They are often ideal because they are:
Copper-flex circuits use a very thin layer of copper affixed to a flexible film substrate that, when etched away, exposes copper conductive traces. This structure accommodates complex and dense circuit patterns that are suitable for environments with excessive vibration or extreme temperature swings, including aerospace, medical, energy, and military applications.
Copper-flex circuits:
are easily customized as single- or double-sided, tactile or non-tactile, and with or without backlighting, shielding, and other options
Duraswitch® technology helps create a thin and robust keypad that can reliably function in extremely harsh environments. Duraswitch utilizes two unique technologies, PushGate® and thiNcoder®, which increase longevity by eliminating the scraping, flexing, and grinding common to traditional membrane switches.
Watch this brief video for an introduction to our membrane switch expertise.
The Cubbison Company has created a 4-step design guide to help you maximize the quality, reliability, and efficiency of your membrane switch.
Download the free Membrane Switch Design Guide. From there, you can request a quote or contact our design engineers to discuss you project in more detail: salesengineer@cubbison.com or call (800) 733-4133.