Structures & Options
Structures for membrane switch we usually adopt:
There are other options for membrane switch, such as embedded LED, inserted EL back light layer, inserted ESD or EMI/RFI shielding layer and sealed structure (water proof function）:
Inserted Electroluminescent (EL) layer
Inserted between the graphic overlay and circuitry layer,
Can light when it is powered at dark night, so we can press the keys easily.
Can be powered by EL driver supplied by us.
Inserted shielding layer
Can be made of printed silver net or foil, carbonate net or aluminum foil.
Can avoid damage from ESD or EMI/RFI.
Has to be connected to the ground.
For membrane switch with Shielding layer, all silver lines on the circuitry layer have to be more than 3 mm away from the edge of the membrane switch, which is another measure to avoid ESD damage.
Sealed structure with water proof function
Applied in outdoor use or moist condition
an extra waterproof gasket can be placed around the circuit layer.
Width for the gasket should be more than 5 mm.
Water proof can reach IP 67.
If tail is toward membrane’s center and within membrane frame, no extra gasket is requested.