Membrane switchcores with key cell contact elements connected together for continuous path testing

Claim 2

In a membrane switchcore comprising a flexible plastic film substrate, a conductive first circuit including a plurality of conductive first traces and a plurality of conductive first contact elements connected to each first trace, and a conductive second circuit including a plurality of conductive second traces and a plurality of conductive second contact elements connected to each second trace, wherein a first contact element and a second contact element are at each key cell of the matrix and adapted to be bridged by a movable contact for actuation of a key cell, the improvement wherein: each first contact element consists of an integral section of its respective first trace; each second contact element consists of an integral section of its respective second trace; and each first trace and its respective first contact elements define a continuous conductive path, and each second trace and its respective second contact elements define a continuous conductive path.

Claim 3

A membrane switchcore according to claim 1 further characterized in that: there are a plurality of first contact elements at each key cell of the matrix, and all first contact elements at a key cell consist of an integral nonbranched section of a first trace.

Claim 4

A membrane switchcore according to claim 1 further characterized in that: there are a plurality of second contact elements at each key cell of the matrix, and all second contact elements at a key cell consist of an integral nonbranched section of a second trace.

Claim 5

A membrane switchcore according to claim 1 further characterized in that: each first trace includes an integral nonbranched section defining one first contact element at a key cell of the matrix; each second trace includes two integral nonbranched sections defining two spaced second contact elements in a continuous conductive path through a key cell of the matrix; and the first contact element extends between the two second contact elements at a key cell of the matrix.

Claim 6

A membrane switchcore according to any one of claims 1-4 further characterized in that: the flexible plastic film substrate includes a surface forming a first surface of the switchcore; an insulating layer extends over said first surface and defines a second surface of the switchcore spaced from the first surface, the insulating layer including first openings surrounding the contact elements at each key cell of the matrix; the first traces including the first contact elements thereof are along the first surface of the switchcore; the second traces are along the second surface of the switchcore and the second contact elements thereof are along the first surface of the switchcore; and wherein a portion of a first trace crossing a portion of another trace is along the second surface of the switchcore to prevent shorting therebetween, and a portion of a second trace crossing a portion of another trace is along the first surface of the switchcore to prevent shorting therebetween.