A liquid-cooled integrated circuit system comprising: two printed circuit assemblies (400A, 400B), each comprising: a system board, a plurality of printed circuit board sockets mounted in parallel on the system board, a plurality of liquid cooling pipes each mounted on the system board adjacent to and parallel to one of the printed circuit board sockets, a plurality of integrated circuit modules, each of the plurality of integrated circuit modules comprising a printed circuit board having a connector edge disposed in one of the printed circuit board sockets, and a plurality of heat spreaders, each thermally coupled with a corresponding one of the integrated circuit modules, wherein each of the plurality of heat spreaders comprises a pair of side plates (208 a, 208 b) located on opposite sides of a corresponding printed circuit board, and a top surface extending across an edge of the corresponding printed circuit board opposite the connector edge; wherein the printed circuit assemblies (400A, 400B) are configured to be arranged opposite one another such that the integrated circuit modules of the two printed circuit assemblies (400A, 400B) are interleaved with one another, and the top surfaces of the heat spreaders of each of the printed circuit assemblies (400A, 400B) are thermally coupled with the liquid cooling pipes of the other printed circuit assembly (400A, 400B). two printed circuit assemblies (400A, 400B), each comprising: a system board, a plurality of printed circuit board sockets mounted in parallel on the system board, a plurality of liquid cooling pipes each mounted on the system board adjacent to and parallel to one of the printed circuit board sockets, a plurality of integrated circuit modules, each of the plurality of integrated circuit modules comprising a printed circuit board having a connector edge disposed in one of the printed circuit board sockets, and a plurality of heat spreaders, each thermally coupled with a corresponding one of the integrated circuit modules, wherein each of the plurality of heat spreaders comprises a pair of side plates (208 a, 208 b) located on opposite sides of a corresponding printed circuit board, and a top surface extending across an edge of the corresponding printed circuit board opposite the connector edge; a system board, a plurality of printed circuit board sockets mounted in parallel on the system board, a plurality of liquid cooling pipes each mounted on the system board adjacent to and parallel to one of the printed circuit board sockets, a plurality of integrated circuit modules, each of the plurality of integrated circuit modules comprising a printed circuit board having a connector edge disposed in one of the printed circuit board sockets, and a plurality of heat spreaders, each thermally coupled with a corresponding one of the integrated circuit modules, wherein each of the plurality of heat spreaders comprises a pair of side plates (208 a, 208 b) located on opposite sides of a corresponding printed circuit board, and a top surface extending across an edge of the corresponding printed circuit board opposite the connector edge; wherein the printed circuit assemblies (400A, 400B) are configured to be arranged opposite one another such that the integrated circuit modules of the two printed circuit assemblies (400A, 400B) are interleaved with one another, and the top surfaces of the heat spreaders of each of the printed circuit assemblies (400A, 400B) are thermally coupled with the liquid cooling pipes of the other printed circuit assembly (400A, 400B).