Membrane switch having crossing circuit conductors

Claim 1

A membrane switch assembly of the type comprising a substrate having first and second switch electrodes thereon which are adjacent to, and electrically isolated from, each other at a switch site, a membrane which is parallel to and adjacent to, the substrate, the membrane having a commoning conductor thereon at said switch site which is opposed to the first and second switch electrodes, separator means between the membrane and the substrate serving to maintain the membrane in spaced relationship to the substrate, the separator means being discontinuous at the switch side so that the membrane can be flexed towards said substrate with resulting contact of both the first and second switch electrodes by the commoning conductor thereby electrically to common the first and second switch electrodes, the membrane switch assembly being characterized in that: the substrate has a circuit conductor thereon which extends between the first and second switch electrodes, the commoning conductor comprises first and second commoning pads which are opposed to the first and second switch electrodes respectively, and which are separated from each other by a commoning conductor passageway which is opposed to the circuit conductor, the first and second commoning pads are electrically connected to each other by a bridging conductor on the membrane, the bridging conductor having first and second ends which are connected to the first and second commoning pads and having an intermediate portion which is located beyond the switch site and which extends over a portion of the membrane which is maintained in spaced relationship to the substrate by the separator means whereby upon flexure of the membrane in the vicinity of the switch site towards the substrate, the first and second commoning pads will contact the first and second switch electrodes thereby closing switch at the switch site, and the circuit conductor will not be contacted by the first and second commoning pads.