Patent ID: 8736066

Claim:
A microelectronic assembly, comprising: a first element consisting essentially of at least one of semiconductor or inorganic dielectric material; a microelectronic element attached to the first element such that a surface of the first element faces a major surface of the microelectronic element, the microelectronic element having a plurality of conductive pads exposed at the major surface, the microelectronic element having active semiconductor devices therein; a first opening extending from an exposed surface of the first element towards the surface thereof which faces the microelectronic element, and a second opening extending from the first opening to a first one of the conductive pads, wherein where the first and second openings meet, interior surfaces of the first and second openings extend at different angles relative to the major surface of the microelectronic element; and a conductive element extending within the first and second openings and contacting the at least one conductive pad, the conductive element having at least one of cylindrical or frusto-conical shape, a first portion of the conductive element tapers uniformly from a first width adjacent the exposed surface of the first element to a second width at a first location within the second opening, and a second portion of the conductive element tapers uniformly from a third width adjacent the rear surface of the microelectronic element to a fourth width at the first location.