Stacked packages and microelectronic assemblies incorporating the same

A microelectronic assembly comprising:

• a plurality of units superposed on one another to form at least one stack having a vertical direction, each unit including one or more microelectronic devices, a main substrate and one or more interposers, each interposer overlies only a portion of the bottom surface of the main substrate each unit having a top surface and a bottom surface, top unit terminals exposed at the top surfaces of the main substrate and bottom unit terminals exposed at the bottom surfaces of the one or more interposers, the top and bottom unit terminals being provided at a set of ordered column positions,
• wherein each top unit terminal associated with the set of ordered column positions, except the top unit terminals at the highest ordered column position, is connected to a respective bottom unit terminal of the same unit at a next higher ordered column position,
• wherein each bottom unit terminal associated with the set of ordered column positions, except the bottom unit terminals of the lowest unit in the stack, is electrically connected to a respective top unit terminal of the next lower unit in the stack at the same column position, and
• wherein each top unit terminal at the highest ordered column position is connected to a respective bottom unit terminal of the same unit at the lowest ordered column position.