Integrated stacked microchannel heat exchanger and heat spreader

Integrated stacked microchannel heat exchanger and heat spreaders for cooling integrated circuit (IC) dies and packages and cooling systems employing the same are disclosed. In one embodiment, a stacked microchannel heat exchanger is operatively and thermally coupled to an IC die or package using an interstitial solder or a solderable material in combination with solder. In another embodiment, a stacked microchannel heat exchanger is operatively and thermally coupled to an IC die or package using an adhesive. In a further embodiment, a stacked microchannel heat exchanger is operatively coupled to an IC die or package by fasteners and is thermally coupled to the IC die or package using a thermal interface material. The integrated stacked microchannel heat exchanger and heat spreaders may be employed in a closed loop cooling system including a pump and a heat rejecter. The integrated stacked microchannel heat exchanger and heat spreaders are configured to support either a two-phase or a single-phase heat transfer process using a working fluid such as water.