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The components are tiny compared to mechanical counterparts

making membrane switches extremely portable and easy to incorporate into product designs, even if available touchpad space is limited. Dome Retainer / Upper Circuit Layer – This is one of two potential membrane layers with conductive and dielectric circuitry printed onto it. Tactile switches will typically use a dome retainer in place of this layer.

Membrane keypad construction will typically be either “single layer” or “double layer” construction., depending on the features required. For single layer keypads, one liên hệ layer is usually printed on the reverse side of the graphic overlay panel. For double layer construction, the top circuit is printed on a separate layer. Permark’s technical and sales staff can advise on solutions to suit your specific design. This type of membrane switch uses silver paste as the upper circuit layer of the switch.

Unfortunately, many HMIs are currently built using single-sided membrane switches, which introduce unnecessary risk into your device design. Graphic Overlay– Graphic overlays are typically constructed of polyester, the material of choice due to its superior chemical resistance and flex life compared to polycarbonate. CSI can either digitally print, screen-print, or employ a combination of both methods to insure you get the right colors, textures, and finishes your Silver Flex membrane switch design requires.

membrane switch

Integral single point LED’s can be mounted onto the bottom layer lower circuit. Termination can then be provided from the same connector tail as the switches, if the graphic layer is embossed to accommodate the LED’s. The graphic does not need to be embossed if the LED termination is provided on a separate tail. There are three standard methods for back lighting membrane switches. Pressure-sensitive adhesives are thin layers of tape that adhere domes to the circuit. Adhesives can help protect the switch from debris, provide a moisture barrier, or other environmental factors.

(It is regularly applied to products such as mobile phones and automobile dashboards.) However, this lighting option is not good for long term use. Once EL layers reach their half-life , their brightness begins to fade rapidly. LEDs produce bright spots and are best used as indication lights rather than as panel backlighting. Surface-mount LEDs can be attached to the circuit layer or placed on a separate LED layer. In addition to mounting LEDs to function as indicators, specialty lighting like Light Guide Film can be used to backlight graphics evenly. The core of a membrane switch’s functionality lies in the meeting of electrical contacts on different layers of the switch.