US Patent 7935895 Structuring and circuitizing printed circuit board through-holes

Methods and apparatus for creating independent circuit connections within a through-hole of a substrate are described. According to one aspect of the present invention, a method includes defining a through-hole in a substrate, applying a conductive plating to a holewall of the through-hole, and selectively removing at least a first area of the plating. The through-hole has a height relative to a first axis, and the perimeter of the through-hole at each point along the first axis is approximately the same. Selectively removing the first area of the plating includes defining second areas of the plating. At least one of the plurality of second areas does not span a height of the hole.