An interconnection element for conductive interconnection with another element having at least one of microelectronic devices or wiring thereon, comprising: a dielectric element having a major surface; a plated metal layer including a plurality of exposed metal posts projecting outwardly beyond the major surface of the dielectric element, at least some of the metal posts electrically insulated from each other by the dielectric element, the posts being defined by plating a metal onto exposed conductive co-planar surfaces of a conductive mandrel and conductive interior surfaces of openings in the conductive mandrel and subsequently removing the mandrel; and a plurality of terminals in conductive communication with the metal posts, the terminals being connected through the dielectric element to the metal posts, wherein the plated metal layer includes a first metal layer used to form a liner within the mandrel prior to removal of the mandrel, the first metal layer comprised of a metal which is not attacked by an etchant that attacks an underlying metal of the conductive mandrel, the liner having a surface defining an interior volume, a second metal layer overlying the first metal layer and at least partially occupying the interior volume, the metal liner being exposed upon removal of the mandrel and forming an outer layer of the posts; the first metal layer further including a plurality of metal wiring traces extending in at least one direction along the major surface of the dielectric element, at least some of the plurality of metal wiring traces extending between at least two of the plurality of exposed metal posts and conductively connecting the at least two conductive posts. a dielectric element having a major surface; a plated metal layer including a plurality of exposed metal posts projecting outwardly beyond the major surface of the dielectric element, at least some of the metal posts electrically insulated from each other by the dielectric element, the posts being defined by plating a metal onto exposed conductive co-planar surfaces of a conductive mandrel and conductive interior surfaces of openings in the conductive mandrel and subsequently removing the mandrel; and a plurality of terminals in conductive communication with the metal posts, the terminals being connected through the dielectric element to the metal posts, wherein the plated metal layer includes a first metal layer used to form a liner within the mandrel prior to removal of the mandrel, the first metal layer comprised of a metal which is not attacked by an etchant that attacks an underlying metal of the conductive mandrel, the liner having a surface defining an interior volume, a second metal layer overlying the first metal layer and at least partially occupying the interior volume, the metal liner being exposed upon removal of the mandrel and forming an outer layer of the posts; the first metal layer further including a plurality of metal wiring traces extending in at least one direction along the major surface of the dielectric element, at least some of the plurality of metal wiring traces extending between at least two of the plurality of exposed metal posts and conductively connecting the at least two conductive posts.