Embedded die on interposer packages

A method of fabricating an assembly, the method comprising:

• providing an interposer having an uppermost surface above a bottommost surface, the bottommost surface of the interposer above and directly connected to circuitry, the circuitry comprising traces;
• connecting a first die above and directly to the circuitry, the first die laterally adjacent to the interposer, the first die having a top side and a bottom side, the top side opposite the bottom side, the first die having a first lateral sidewall and a second lateral sidewall, and the first die having an uppermost surface;
• forming a mold compound having a first portion and a second portion, the first portion laterally adjacent to the first and second lateral sidewalls of the die and in contact with the interposer, and the second portion beneath the bottom side of the die, wherein the first portion of the mold compound is continuous with the second portion of the mold compound, and wherein the mold compound has a bottommost surface at a same level as the bottommost surface of the interposer;
• and
• providing a package above the interposer and the first die;
• providing a second die intervening between the first die and the package;
• forming an underfill material between the package and the mold compound, the underfill material between the package and the interposer, and the underfill material in contact with the package;
• and
• providing an interposer via electrically coupling the package to the interposer.