Patent ID: 7294928

Claim:
A semi-finished circuit board assembly comprising: (a) a circuit board having a top surface and contact pads exposed at said top surface; (b) a bottom unit including at least one bottom unit chip, said bottom unit having mounting connections facing downwardly toward said circuit board and top connections facing upwardly away from said circuit board, at least some of said mounting connections being aligned with at least some of said contact pads, at least some of said top connections being unoccupied and available to receive one or more additional microelectronic elements, at least some of the unoccupied top connections of said bottom unit overlying at least one said bottom unit chip, wherein said bottom unit includes a substrate incorporating a dielectric element having an upper surface facing upwardly away from said circuit board and a lower surface facing downwardly toward said circuit board, a plurality of mounting pads exposed at the lower surface of said dielectric element and a plurality of top connection pads exposed at the top surface, said at least one bottom unit chip being mounted beneath said lower surface, said mounting connections including said mounting pads, said top connections including said top connection pads.