Tactile Membrane Switch with LED
The tactile membrane switch with LED has:
A. A graphic overlay, normally polyester, (Typical Thickness: 0.2mm).
C. The spacer, to allow selective making of the circuit, (Typical Thickness:
D. The lower circuit, with metal domes inserted, (Typical Thickness: 0.2mm).
Spacer #2, to separate the second circuit layer, and protect the LED which is mounted onto the second circuit, (Typical Thickness: 0.3mm).
Second circuit layer, with LED's mounted.Alternatively we can emboss the graphic overlay, to give the LED clearance, and mount the LED's on the first circuit layer, thus obviating the need for this layer, & spacer #2 and the associated costs.
(Typical Thickness: 0.2mm).
E. Adhesive layer to fix the label onto the product, (Typical Thickness: 0.1mm).
This then gives a typical thickness of between 0.8 and 1.3mm for a fully finished keypad with LED.
The dome flexes and gives when pressed, both making the circuit, and also giving the tactile effect.
(We can also produce tactile switches with LED'swith a mylar dome, which incorporates the layer structure
featured in the non tactile membrane switch, and an embossed dome for the touch feedback and of course the LED's).