membrane switch

Membrane switch Backlight and Application

Vmanx membrane switch usually has 4 layers or more. The top layer of the membrane switch is a graphical interface for the user to interact with the machine. Another key layer is printed circuits. It is a flexible circuit made of copper and polyimide materials. These layers are often assembled using pressure sensitive adhesives, although inexpensive designs can be combined by other mechanical means such as a keyboard enclosure. The contact between the two traces can be achieved by printed shorting pads or by metal domes standing on the legs.

Backlighting

There are three standard methods for back lighting membrane switches.

The first option is using Light Emitting Diodes (LEDs) to back light. However, LEDs create bright spots and are not suitable for overall back lighting of a panel, but rather as indicator lights. LEDs can either be surface mounted to the circuit layer or be placed on a separate LED layer.

A second option is optical fiber. In a typical design, two or more layers of woven fiber-optic cloth are used to form a rectangular light-emitting area. The fibers coming off one end are then bundled into a circular ferrule and coupled to one or more LED light sources. Remote light sources offer 10,000 to 100,000 hours of life. Optical fibers are not affected by extremes in humidity (0% to 100%) or temperature (-40 to + 85 deg C).

The third standard option is to use electroluminescent (EL) lamps. They are lower priced compared to fiber optics and offer additional design flexibility. The color of light emitted from an EL lamp can vary depending on the phosphors that are used. Some common colors are blue/green and yellow/green, white, blue and orange. EL lamps have a half-life of approximately 3000–8000 hours depending upon the quality of the phosphor. Once they reach their half-life, the brightness starts to fade rapidly. EL lamps are thus not a good choice if the lamp is on for an extended period of time. Fading or flashing could double the life of the lamp.

Applications

Classic applications for membrane switches include microwave oven panels, air conditioning control panels, and TV remote controls. The tactile feedback of the keys can be provided by embossing the top PET layer or embedding a metal dome, a polyester dome, or forming a graphic layer.

The advantages of membrane switches contain ease of cleaning, strong sealing capabilities, and small form factor. Membrane switches can be used with other control systems such as touch screens, keyboards, and lighting. They can also be as complex as membrane keypads and switch panels in cell phones and computers.

Depending on the industry and application, membrane switches are also known as membrane keypads and membrane keypads.

For more information about the membrane switch, please visit Vmanx’s official website to view: https://vmanx.com/