US Patent 7609520 Heat spreader with vapor chamber defined therein

A heat spreader includes a bottom wall (12) and a cover (14) hermetically connected to the bottom wall. Cooperatively the bottom wall and the cover define a space (11) therebetween for receiving a working fluid therein. A wick structure (15) is received in the space and thermally interconnects the bottom wall and the cover. The wick structure includes at least a carbon nanotube array, which can conduct heat from the bottom wall to the cover and draw condensed liquid of the working fluid from the cover toward the bottom wall.