Patent ID: 7392836
Filing Date: 2008-07-01
Classification: F28D,F28F,H01L

Abstract:
1. A discrete flat-plate heat spreader for a heat generating device, comprising: an enclosed metal chamber, the chamber having a bottom, an exterior surface of the bottom being adapted to be disposed in contact with said heat generating device; a two-phase vaporizable coolant recycled in said chamber to remove heat from said heat generating device; a flow pathway comprising an upper section and a lower section, said upper section being in contact with an inner top surface of said chamber for vapor condensation and heat dissipation, said upper section having a set of continuous grooves configured to each be a vapor passage, the grooves being made of a non-porous metal, and configured to be in contact with said lower section, said grooves having side walls and edges configured to conduct condensed liquid coolant along a longitudinal direction of said grooves under capillary action toward said lower section, said lower section functioning as part of a recycling passage for the condensed coolant; and a wick in said lower section, said wick being disposed in heat exchange contact with an inner surface of the chamber bottom, a portion of said wick functioning as an evaporator and another portion of said wick functioning as a liquid passage to draw condensed coolant from said upper section via said grooves by capillary attraction force, said coolant collected within said evaporator waiting to be vaporized by the heat from said heat generating device disposed against the exterior surface of the chamber bottom; and a plurality of cut-out openings in the side walls of said grooves, said side walls being partially cut to define said cut-out openings without disrupting the continuity of said grooves in the longitudinal direction thereof, said cut-out openings being located at least over said wick and covering at least the area adapted to be in contact with said heat generating device to facilitate coolant vapor diffusing into said grooves to be condensed therein on said groove walls and in groove corners, and thereafter be induced to flow along said groove corners by the capillary action therein.