Counter-flow expanding channels for enhanced two-phase heat removal

A structure for cooling a chip comprising:

• a single heat transfer structure thermally coupled to the chip, wherein the single heat transfer structure comprises expanding coolant channels, wherein each expanding coolant channel has a flow direction from a channel inlet to a channel outlet, wherein the flow direction of one of the expanding coolant channels is in a different direction than another one of the expanding coolant channels, wherein a width of each channel inlet is less than a width of each channel outlet such that a width of each expanding coolant channel increases across its entire length, and wherein at least one sidewall of each channel is curved;
• and
• a manifold providing an inlet pathway to the channel inlets of the expanding coolant channels and an outlet pathway from the channel outlets of the expanding coolant channels.

A chip cooling structure comprising:

• an interposer cold plate thermally coupled to a bottom of a chip stack comprising fluid channels, each fluid channel extending from an inlet on one side of the interposer cold plate to an outlet on an opposite side of the interposer cold plate, wherein the inlet of each fluid channel is smaller than the outlet of each fluid channel such that a width of each fluid channel increases along its entire length, and wherein at least one sidewall of each channel is curved;
• and
• wherein all fluid channels are asymmetrical about a centerline extending from inlet to outlet, the fluid channels located along opposite sides of the interposer cold plate structure are asymmetrical such that their width increases only in one direction.