Keyboard switch assembly with printed circuit board

US4287394A · kind A · utility

Assignee

• Wilhelm Ruf KG · DE

Inventors

• Tibor Hargita · Munich, DE
• Ingo Berlitz · Putzbrunn, DE
• Herbert Hafner · Hohenkirchen, DE

Key dates

• Filing date: Jan 25, 1979
• Grant date: Sep 1, 1981
• Expiry date: Jan 25, 1999

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01H2231/032
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A circuit board and a method of making same having a plurality of conductor lines wherein at least one portion of at least one line is superimposed over a portion of at least one other line to define at least one intersection. A substrate is provided of insulating material and a first insulating coating is applied to at least one side of the substrate. A first set of conductive nonintersecting lines is applied to the varnished coating and a coating of insulating varnish is applied on and around the conductive lines only in the vicinity of the intersection. A second set of nonintersecting conductive lines define the intersection with the first set by being applied onto the substrate. The circuit board may be used in a multiple circuit keyboard switch assembly. A conventional type pushbutton bridging contact array selectively interconnects conductor lines at particular switch sites.