US Patent 9418924 Stacked die integrated circuit

An apparatus relates generally to an integrated circuit package. In such an apparatus, a package substrate has a first plurality of via structures extending from a lower surface of the package substrate to an upper surface of the package substrate. An die has a second plurality of via structures extending to a lower surface of the die. The lower surface of the die faces the upper surface of the package substrate in the integrated circuit package. The package substrate does not include a redistribution layer. The die and the package substrate are coupled to one another.