Chip stack cooling structure

An apparatus comprises a first die, a thermal cooler formed over at least a portion of the first die, a second die formed over at least a portion of the thermal cooler, and a plurality of through-silicon vias providing electrical connections between the first die and the second die. The thermal cooler comprises a plurality of fluid channels for fluid cooling of the first die and the second die, the plurality of fluid channels being formed horizontally through the thermal cooler. The plurality of through-silicon vias are formed vertically through the first die, the thermal cooler and the second die.