A cooling structure for large electronic boards with closely-spaced heterogeneous die and packages is disclosed. The assembly includes a frame having a plurality of openings. The assembly further includes a cold plate mounted to the frame. The cold plate includes at least one inlet and at least one outlet and fluid channels in communication with the at least one inlet and the at least one outlet. The assembly further includes a heat sink mounted within each of the plurality of openings which in combination with sidewalls of the openings of the frame and the cold plate form individual compartments each of which are in fluid communication with the fluid channels.