A heatsink assembly 10 comprises a heat conductive base 12 having a surface 14. The assembly further comprises at least a first heat conductive plate 16 and a second heat conductive plate 18. A first heat conductive spacer 20 is sandwiched between the surface and the first plate. The first spacer holds the first plate parallel to and in spaced relationship relative to the surface, to define a first passage 22 for a cooling fluid medium between the surface and the first plate. A second heat conductive spacer 24 is sandwiched between the first plate and the second plate. The second spacer holds the second plate parallel to and in spaced relationship relative to the first plate, to define a second passage 26 for the cooling medium. A link 28 connects the first plate, the second plate, the first spacer and the second spacer in heat exchanging relationship to the base.