Methods and apparatus for improved electrical, mechanical and thermal performance of stacked IC packages are described. An IC package comprises a substrate, a first die, a second die, and an interposer with an opening in a first surface of the interposer configured to accommodate the first die. The first IC die is attached a first surface of the substrate. The interposer is mounted on the first surface of the substrate such that the first IC die is placed within the opening in the interposer. The second die is mounted on a second surface of the interposer. Wire bonds couple bond pads on the first surfaces of IC die are coupled to the first surface of the substrate. A mold compound encapsulates the first IC die, the second IC die, the interposer and the wire bonds.