Membrane Keyboards are realized on the flexible circuit boards on the basis of polyester film by thickness of 0.125-0.150 mm. Conductors on the flexible bottom layer are formed by two main methods.
- Screen printing of conducting inks with graphite, nickel or silver fillers or with their combinations in the capacity of the conducting material. Circuit resistance up to 300 ohm.
- Conductors etching of the circuit board on the lamination to the polyester or polyamide film to copper foil with the following local galvanic nickel plating of the contact areas at the places of membranes’ installation. Tactile effect on the membrane keyboards is reached at the expense of frontal plate’s film forming or at the expense of the cast-in switching metallic membranes installation.