A structure includes a substrate having a plurality of balls, a semiconductor chip, and an interposer electrically connecting the substrate and the semiconductor chip. The interposer includes a first side, a second side opposite the first side, at least one first exclusion zone extending through the interposer above each ball of the plurality of balls, at least one active through via extending from the first side of the interposer to the second side of the interposer, wherein the at least one active through via is formed outside the at least one first exclusion zone and wherein no active through vias are formed within the at least one first exclusion zone, and at least one dummy through via extending from the first side of the interposer to the second side of the interposer, wherein the at least one dummy through via is formed within the at least one first exclusion zone.