A microelectronic unit, comprising: a carrier structure having a front surface, a rear surface remote from the front surface, and a recess having an opening at the front surface and an inner surface located below the front surface of the carrier structure, the carrier structure including at least one of semiconductor material or glass; a microelectronic element having a bottom surface adjacent the inner surface, a top surface remote from the bottom surface, and a plurality of contacts at the top surface; terminals electrically connected with the contacts of the microelectronic element, the terminals being electrically insulated from the carrier structure; and a dielectric region contacting at least the top surface of the microelectronic element, the dielectric region having a planar surface located coplanar with or above the front surface of the carrier structure, wherein the terminals are exposed at the surface of the dielectric region for interconnection with an external element, wherein the dielectric region extends between sidewalls of the recess and the microelectronic element, the microelectronic unit further comprising a plurality of conductive vias, each conductive via extending from a first end at a major surface of the dielectric region through the carrier structure to a second opposed end at the rear surface of the carrier structure, wherein each conductive via comprises a portion passing through the dielectric region between the microelectronic element and one of the sidewalls of the recess, and characterised in that a first width of the conductive via at the first end is less than a second width of the conductive via at the opposite second end. a carrier structure having a front surface, a rear surface remote from the front surface, and a recess having an opening at the front surface and an inner surface located below the front surface of the carrier structure, the carrier structure including at least one of semiconductor material or glass; a microelectronic element having a bottom surface adjacent the inner surface, a top surface remote from the bottom surface, and a plurality of contacts at the top surface; terminals electrically connected with the contacts of the microelectronic element, the terminals being electrically insulated from the carrier structure; and a dielectric region contacting at least the top surface of the microelectronic element, the dielectric region having a planar surface located coplanar with or above the front surface of the carrier structure, wherein the terminals are exposed at the surface of the dielectric region for interconnection with an external element, wherein the dielectric region extends between sidewalls of the recess and the microelectronic element, the microelectronic unit further comprising a plurality of conductive vias, each conductive via extending from a first end at a major surface of the dielectric region through the carrier structure to a second opposed end at the rear surface of the carrier structure, wherein each conductive via comprises a portion passing through the dielectric region between the microelectronic element and one of the sidewalls of the recess, and characterised in that a first width of the conductive via at the first end is less than a second width of the conductive via at the opposite second end.