Machines or workstations operating in low-light conditions (such as traffic or medical applications) require membrane switches for internal lighting.

What Is Backlighting in Membrane Switch?

Backlighting involves adding components to the membrane switch that can illuminate the front surface of the user interface. When activated, the light can be concentrated in a specific area, or concentrated in the entire display area when using the device.

Membrane switches do not require backlighting, but this feature does add many useful benefits to the final product, including:

Improving visibility for the user when the product is operated in a dark or dimly lit environment

Making inputs and keys easier to find and read

Drawing attention to a certain area, such as indicator lights on a control panel

Enhancing appearances with a modern feel

Making products more accessible for consumers with disabilities

Backlighting Options

There are 4 main methods for incorporating backlighting into a membrane switch – each with unique advantages and disadvantages.

LEDs:

LEDs are the most popular and economical method for keyboard backlighting. LEDs are most commonly used to backlight keys, icons and symbols. LEDs are also typically used as indicator lights. A combination of LEDs method can be designed to backlight the entire surface of a user interface.

Light Guide Film (LGF):

The light guide film is designed to evenly distribute the light of the top or side emitting LEDs to provide bright, uniform illumination. It also reduces the number of LEDs required, thus saving power consumption. The design and utilization of light guide film (LGF) technology has become one of the most common methods of interface backlight.

Electroluminescence (EL): 

Electroluminescent (EL) backlights have printing inks with luminescent phosphors. A thin layer of this ink is applied between the graphic overlay and the circuit. The EL is a good choice when you need uniform backlighting across the entire surface.

Fiber Optics: 

Last but not least, the light guide film (LGF) consists of a thin layer of special plastic, side-lit LED, usually placed between the pattern overlay and the circuit. This method provides brighter and more uniform backlight than LED alone.

Since membrane switches can be customized for your application, the possibilities are indeed limitless backlighting. For example, multiple backlighting methods can be integrated to create a truly unique and effective user interface. However, the addition of the backlight does increase the complexity of the membrane switch design, so it is important to have a manufacturing partner with experience in these compact components.

At JRPanel, we help design, test and produce high-quality membrane switches for a wide range of industries. With our material expertise and a range of printing and custom conversion capabilities, we can add a series of unique features, including (but not limited to) backlight technology.

Download Membrane Switch Design Guide here for your own products now!