METHODS OF FORMING SEGMENTED VIAS FOR PRINTED CIRCUIT BOARDS

Novel methods for forming a printed circuit board (PCB) having one or more segmented vias are provided, including improved methods of removing the catalyst after the plating process when forming a segmented via in the PCB. After the electroless plating, excess catalyst on the surface of the plating resist is removed using a catalyst remover, such as an acidic solution that includes at least nitrite or nitrite ion and halogen ion, or the catalyst remover may be an etchant for plating resist, such as alkaline permanganate compound solution or plasma gas comprising at least one of oxygen, nitrogen, argon and tetrafluoromethane, or a mixture of at least two of these gasses. After removal of the excess catalyst, electrolytic plating is then applied to the through holes and the outer layer circuit or signal traces are formed. That is, the etching of paths on the conductive foils/layers of the core structure.