When a user manipulates a membrane switch, ESD(electrostatic discharge) could happen and the voltage can reach up to 15KV, which is potentially harming the circuits and embedded components in membrane switch. To protect the membrane switch from being damaged by EDS, ElecFlex provides the following 2 solutions.
1. Screenprint a grid on an additional layer by using silver or conductive ink.
This layer has to be grounded and will be placed between the circuit layer and the graphic overlay. When ESD happens, the discharge will follow to the earth ground through this grounded grid layer. And the circuits and components will be protected.
2. Add an additional grounded conductive foil under the graphic overlay, typically Aluminum foil. In this way, the circuit will be protected with the discharge reaching earth ground via this Aluminum foil.