Claims
- 1. A circuit board comprising a substrate of insulating material; an insulating varnish coating applied to at least one side of the substrate; a first set of nonintersecting conductive lines on each varnish coating; a coating of insulating varnish on and around the conductive lines only in the vicinity of desired intersections; a second set of nonintersecting conductive lines which have at least one portion of at least one line thereof superimposed over a portion of at least one other line of the first set of lines and separated therefrom by the insulating varnish coating; a plurality of groups of electrically conducting switch contact pads, wherein each switch contact pad is associated with a particular conductor line; a plurality of actuatable pushbuttons each cooperating electrically with one of the switch contact pads on the circuit board to electrically connect same; and a coating of conductive varnish over the exposed portions of the first and second sets of conductive lines.
- 2. A circuit board according to claim 1 furthur comprising a coating of conductive varnish over the exposed portions of the first and second sets of conductive lines.
- 3. The circuit board according to claim 1 wherein the conductive strips are hermetically encapsulated by the first mentioned insulating varnish coating and the conductive varnish coating.
- 4. The circuit board according to claim 1 wherein the conductive lines comprise one of a strip of conductive varnish or a metallic strip with a coating of conductive varnish thereover.
- 5. A circuit board according to claim 1 wherein the pushbuttons comprise an elastic mat disposed upon the circuit board and including integral pushbutton shaped elements and electrically conducting contacts disposed inside the pushbutton elements and in alignment above one group of switch contact pads, wherein each contact is moveable towards its corresponding group of switch contact pads on the circuit board to electrically connect same.
- 6. The circuit board according to claim 1 wherein the switch contact pads comprise one of a printed metal base portion covered by a conducting varnish or a base of conductive varnish.
- 7. The circuit board according to claim 1, wherein the conductive strips are hermetically encapsulated by the first mentioned insulating varnish coating and the conductive varnish coating.
- 8. The circuit board according to claim 1, wherein the conductive lines comprise one of a strip of conductive varnish or a metallic strip with a coating of conductive varnish thereover.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7624175 |
Jul 1976 |
DEX |
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RELATED APPLICATIONS
This application is a continuation in part of U.S. applicant Ser. No. 802,104, filed May 31, 1977, now abandoned.
US Referenced Citations (9)
Non-Patent Literature Citations (1)
Entry |
Webster's New World Dictionary of the American Language, College Edition, World Publishing Co., 1968, pp. 615 and 1612. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
802104 |
May 1977 |
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