The embodiments herein relate to an apparatus and medium for selective partitioning of a via in a printed circuit board as to produce an electrically isolating portion between two electrically conducting portions in said via. The apparatus and medium implement a step of prior to drilling the hole for the via, laminating plating resist layers to the printed circuit board at a distance from each other corresponding to a desired length of the electrically isolated portion of the via. After drilling, copper is added to selected portions of the interior of the via in two different processing steps followed by a step of removing undesired copper as to produce the electrically isolating portion.