Keyboard switch assembly with printed circuit board

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.