Experiments on a novel vapor chamber

A novel vapor chamber is proposed and tested in this study. Multi-layer copper mesh is sintered to the inner surface of the bottom plate as the evaporator wick. Parallel channels, with inter-channel openings, are made on the inner surface of the top plate. The peaks of the channel walls directly contact with the wick so that the channels function as vapor path, condenser and structural supporters simultaneously. The corrugated channel walls provide not only an enlarged condensation area, but also a shortcut for a portion of the liquid condensed on the channel surface to be directly absorbed back to the wick. The rest of the condensed water will be driven by the vapor flow along the channel to both ends and enter the wick. These liquid flow paths yield smaller flow resistance, instead of passing through a long distance in porous wick as in the conventional design. The anti-dry-out capability leads to larger maximum heat dissipating capacity. More important, the simple structure can lead to easy manufacturing and low cost. The test module includes a copper plate-fin heat sink in combination with a top fan. With temperatures are measured at various locations on the heat sink base and the heater surface, the thermal resistances of the vapor chamber are determined against heat loads. With a 2 cm times 2 cm heating area, the vapor chamber resistance decreases from 0.08 to 0.03 when the heat load increasing from 80 W to 460 W, without reaching dry-out limit.