CTE-MATCHED HEAT PIPE
Heat sinks having a mounting surface with a coefficient of thermal expansion matching that of silicon are disclosed. Heat pipes having layered composite or integral composite low coefficient of expansion heat sinks are disclosed that can be mounted directly to silicon semiconductor devices.
1 . A heat transfer device comprising:
an interior chamber defined at least in part by a layered-composite wall, the layered-composite wall including a first layer of material comprising a coefficient of thermal expansion that is substantially similar to the coefficient of thermal expansion of silicon, the first layer disposed between and directly engaging second layers of material comprising a coefficient of thermal expansion greater than the coefficient of thermal expansion of silicon, wherein the wall has a periphery that is out of plane with respect to a remainder of the wall.
2 . A heat transfer device according to claim 1 wherein the first layer comprises molybdenum and the second layers comprise oxygen-free electronic copper foil.
3 . A heat transfer device according to claim 1 wherein the first layer comprises a coefficient of thermal expansion of about 10 ppm/° C. or less.
4 . A heat transfer device according to claim 1 wherein the first layer is selected from the group consisting of aluminum nitride, molybdenum, and graphite.
5 . A heat transfer device according to claim 1 wherein the second layers are selected from the group consisting of copper, copper alloys, nickel, and nickel alloys.
6 . A heat transfer device according to claim 1 wherein the second layers are the same material.
7 . A heat transfer device according to claim 1 , wherein heat flows from a heat source through the layered-composite wall to the interior chamber.
8 . A heat transfer device according to claim 1 , wherein the wall is directly mounted to at least one silicon device.
9 . A heat pipe comprising:
a body defining an interior chamber, the interior chamber defined at least in part by a layered-composite wall, the layered-composite wall including a first layer of material comprising a coefficient of thermal expansion that is substantially similar to the coefficient of thermal expansion of silicon, the first layer disposed between and directly engaging second layers of material comprising a coefficient of thermal expansion greater than the coefficient of thermal expansion of silicon, wherein the wall has a periphery that is out of plane with respect to a remainder of the wall;
a wick disposed on portions of the body that define the interior chamber; and
a working fluid.
10 . A heat pipe according to claim 9 wherein the first layer comprises molybdenum and the second layers comprise oxygen-free electronic copper foil.
11 . A heat pipe according to claim 9 wherein the first layer comprises a coefficient of thermal expansion of about 10 ppm/° C. or less.
12 . A heat pipe according to claim 9 wherein the first layer is selected from the group consisting of aluminum nitride, molybdenum, and graphite.
13 . A heat pipe according to claim 9 wherein the second layers are selected from the group consisting of copper, copper alloys, nickel, and nickel alloys.
14 . A heat pipe according to claim 9 wherein the second layers are the same material.
15 . A heat pipe according to claim 9 , wherein the working fluid contacts one of the second layers of the layered-composite wall.
16 . A heat pipe according to claim 9 , wherein the layered-composite wall is coupled to a heat source and heat is transferred from the heat source through the layered-composite wall to the working fluid.
17 . A heat pipe according to claim 9 , wherein the wall is directly mounted to at least one silicon device.
18 . A heat pipe comprising:
a body defining an interior chamber, the interior chamber defined at least in part by a layered-composite wall of molybdenum disposed between layers of oxygen-free electronic copper foil, wherein the wall has a periphery that is out of plane with respect to a remainder of the wall;
a wick disposed on portions of the body that define the interior chamber; and
a working fluid.
19 . A heat pipe according to claim 18 , wherein the working fluid contacts one of the second layers of the layered-composite wall.
20 . A heat pipe according to claim 18 , wherein the layered-composite wall is coupled to a heat source and heat is transferred from the heat source through the layered-composite wall to the working fluid.