METHODS OF SEGMENTED THROUGH HOLE FORMATION USING DUAL DIAMETER THROUGH HOLE EDGE TRIMMING

摘要

Cost effective and efficient methods to maximize printed circuit board (PCB) utilization with minimized signal degradation are provided. The methods include electrically isolating a segmented via structure by controlling the formation of a conductive material within a plated via structure by utilizing different diameter drills within a via structure for trimming the conductive material at the via shoulder (i.e., the rim of a drilled two diameter hole boundary). The trimmed portion may be voided in the via structure for allowing electrically isolated plated through-hole (PTH) segments. One or more areas of trimmed rims within the via structure are used to form multiple stair like diameter holes to create one or more voids in the via structure. As a result, the formation of conductive material within the via structure may be limited to those areas necessary for the transmission of electrical signals.