Membrane switches have generally four types of structures.

1. LED embedded membrane switch

The circuit structure of the LED circuit is relatively simple, but the LED window must be embossed. If the LED is not embossed, the membrane panel will burst open and the LED will be easily damaged. The 0603 has small LED height dimensions and small circuit pads.Soldering is more difficult. The height of the 0806 LED is usually 0.8mm, the pad is larger, and the soldering is relatively easy; the height of the 1206 LED is large, the pad is larger, and the soldering is easier. Membrane switches with LEDs are usually designed with an electrostatic shielding layer on the panel, which can better protect the function of the membrane circuit from being affected.

2. Waterproof membrane switch

There are two types of waterproof structure membrane switches. The waterproof structure is generally designed as an embedded structure. One structure is to divide the same material into two parts to make a finished product, and the circuit part is embedded in the waterproof frame of the panel to form a product. This structure is more commonly used, and each layer of adhesive must use waterproof adhesive; another structure is to use the same material as the thickness of the upper and lower circuits and the isolation layer, and use the panel to make the outer frame structure of the membrane keypads, and the circuit part is embedded panel among them. Choose 3M9495LE or 3M4920 model for waterproof adhesive.

3. Backlight membrane switch

The light-guiding structure refers to embedding a light-guiding sheet in a traditional membrane switch, and using side-light LEDs to illuminate the keys. Membrane switches can be used at night and in places with insufficient light, which is more ornamental. When making the light guide membrane keyboard, pay attention to the design of the membrane panel and the side of the membrane switch without light leakage. All adhesives must be black. The black adhesive can effectively shield the strong light of the LED. After adding the light guide sheet, the tactile sense of the keys will be weakened. Add spacers on the back of the key position on the panel to make the tactile sense stronger.

4. Half-fold membrane switch

The half-fold structure membrane switch can also be considered when the number of keys is particularly large and the overall product size is small, and there is no space for making circuit lines. It is designed as an upper and lower circuit structure. This structure pays special attention to the folding process under heating. There is an effect on where the circuit bends over time.

Each type membrane switch structure has its own characteristics. When designing, select the most suitable structure according to customer requirements to produce high-quality products.

More information visit:www.jcftechnology.com