Membrane switch technology has come a long way in the last 20 years. Membrane switches were first introduced for use in microwave ovens as an easy to clean alternative to bulky mechanical switch assemblies. These early examples of membrane switch technology were of questionable quality and were not the proven robust technology of membrane switches manufactured today. Today's membrane switch technology offers a vast array of alternatives and features to enhance the device it is incorporated with.

Graphic Overlays- The graphic overlay is the top layer of membrane switch technology and the one that most impresses your customer. Graphic overlays are printed in one of two manners. Traditional screen printing is used when volumes are quite high and the high cost of set-ups can be amortized over a number of parts. Each color requires a new screen and new set-up. For example, an 8 color job would require 8 screens and 8 set-ups on the screen printing press. Some membrane switch manufacturers are now digitally printing graphic overlays. This new technology incorporates 4-color process laying all colors down at once. The graphic designs are unlimited with this technology as anything that can be created by computer graphic programs can be printed on this equipment The advantage of digital printing is the potential to print many different unique designs without the high set-up costs of screen printing. The disadvantage of digital printing is that it may not be able to exactly match all spot or Pantone colors.

Polycarbonate was the early choice for membrane switch overlay materials. Polycarbonate's ease of printing and ease of die-cutting made it an attractive substrate for graphic overlays. However, polycarbonate did have a weakness when it was embossed. It would sometimes begin to exhibit cracking at just 25,000 actuations. Polyester was then introduced as a more durable alternative to polycarbonate. Life cycle tests show polyester keypads can be actuated over 1,000,000 times before showing any kind of wear.

Tactile Membrane Switches – Customers often prefer some type of feedback when pressing a key. Domes can be assembled as part of membrane switch technology to provide tactile feedback. The two types of domes used in a membrane switch are polyester and stainless steel. Most customers prefer stainless steel domes for their feel and lower overall cost.

Backlighting – There are three types of backlighting used in membrane switch technology. LED's or light emitting diodes are the most popular when selectively backlighting text and graphics. LED's are typically the lowest cost backlighting alternative. Electroluminescence (EL) uses a printable ink with embedded light-emitting phosphors to illuminate the membrane keypad. The Timex Indigo watch is a popular application where EL is used as a backlighting medium. Fiber optic is used to create a thin flexible lighting layer that goes between the overlay and domed switches.

Touch Screens – Originally designed for industrial applications, touch screens are being used everywhere you look. We provide both digital and analog resistive touch screens depending on your application. Touch screens are a great example of the innovation brought about by membrane switch technology.