Fluid-containing cooling plate for an electronic component
View Patent ↗A fluid-containing cooling plate includes a bottom plate, a top plate, and metal wire or tubing formed into a circuit and sandwiched between the plates to form a chamber. The wire is plated or otherwise coated with a brazeable or solderable alloy which bonds it to the plates when the assembly is heated, thereby sealing the chamber. To make a two-phase cooling plate, slugs of plated metal are placed in the chamber and are bonded to the plates to provide support against collapse. The chamber is provided with a wicking structure, and is partially filled with an evaporable fluid via an inlet. A partial vacuum is then drawn, and the inlet is closed off. To make a single-phase cooling plate, wire partitions serving as baffles are provided in lieu of the slugs. These partitions can be arranged to provide a serpentine flow path between the inlet and an outlet, and are likewise plated with an alloy which melts to bond them to the plates.
1. A cooling assembly comprising:
a first metal plate having an internal surface and an opposed surface;
a second metal plate having an internal surface and an opposed surface, said internal surface of said second plate facing said internal surface of said first plate and being parallel to said internal surface of said first plate;
an elongate material consisting of one of a wire and a tube at least partially forming a circuit, said elongate material comprising a core plated with brazeable metal, said elongate material being sandwiched between and bonded to said internal surfaces by brazing to form a chamber;
an inlet for introducing a fluid into said; and
a wicking structure in contact with at least one of the internal surfaces for promoting evaporation of said fluid in said chamber.
2. A cooling assembly as in claim 1 wherein said elongate material has a round cross section.
3. A cooling assembly as in claim 2 wherein at least one of said plates has a trench formed in said internal surface, said trench having an arcuate profile which receives said elongate material.
4. A cooling assembly as in claim 1 wherein said core comprises a material which is more electrically or magnetically dissipative than the material of the plates, whereby said core can be heated by exposure to an oscillating electric field or an oscillating magnetic field.
5. A cooling assembly as in claim 4 wherein said metal core is an iron-based core coated with copper, whereby said brazeable metal may be melted by induction heating of said core.
6. A cooling assembly as in claim 1 wherein said inlet is formed by a tube which is received through one of said plates.
7. A cooling assembly as in claim 1 wherein the inlet is formed as a tube which is received through an interruption in the elongate material.
8. A cooling assembly as in claim 1 wherein said chamber contains a fluid which evaporates readily at operating temperatures of a component to be cooled by said assembly.
9. A cooling assembly as in claim 1 further comprising a wicking structure formed integrally with at least one of said internal surfaces.
10. A cooling assembly as in claim 1 further comprising a plurality of spacers sandwiched between and bonded to said internal surfaces in said chamber to prevent deformation of said plates under positive or negative pressure.
11. A cooling assembly as in claim 10 wherein the spacers are slugs of solid wire, said wire being coated with brazeable metal prior to cutting.
12. A cooling assembly as in claim 11 wherein the spacers are formed into a shape which prevents the spacers from rolling when the spacers are placed on a plate prior to bonding.
13. A cooling assembly as in claim 1 further comprising cooling fins fixed to one of said opposed surfaces.
14. A cooling assembly comprising:
a first metal plate having an internal surface and an opposed surface:
a second metal plate having an internal surface and an opposed surface, said internal surface of said second plate facing said internal surface of said first plate and being parallel to said internal surface of said first plate;
an elongate material consisting of one of a wire and a tube at least partially forming a circuit, said elongate material comprising a core plated with brazeable metal, said elongate material being sandwiched between and bonded to said internal surfaces by brazing to form a chamber; and
an inlet for introducing a fluid into said chamber; wherein said core is copper and said brazeable metal is silver.
15. The cooling assembly of claim 14 wherein said first and second plates are made of copper.
16. The cooling assembly of claim 14 wherein said elongate material is bonded to said plates at filleted joints formed by a silver alloy.
17. A cooling assembly comprising:
a first metal plate having an internal surface and an opposed surface;
a second metal plate having an internal surface and an opposed surface, said internal surface of said second plate facing said internal surface of said first plate and being parallel to said internal surface of said first plate;
an elongate material consisting of one of a wire and a tube at least partially forming a circuit, said elongate material being sandwiched between and bonded to said internal surfaces to form a chamber;
an inlet for introducing a fluid into said chamber; and
a plurality of spacers sandwiched between and bonded to said internal surfaces in said chamber to prevent deformation of said plates under positive or negative pressure;
wherein the spacers comprise slugs of solid wire, said wire being coated with brazeable metal prior to cutting.
18. A cooling assembly as in claim 17 wherein the spacers are formed into a shape which prevents the spacers from rolling when the spacers are placed on a plate prior to bonding.
19. A cooling assembly as in claim 17 wherein said elongate material has a round cross section.
20. A cooling assembly as in claim 19 wherein at least one of said plates has a trench formed in said internal surface, said trench having an arcuate profile which receives said elongate material.
21. A cooling assembly as in claim 17 wherein said core comprises a material which is more electrically or magnetically dissipative than the material of the plates, whereby said core can be heated by exposure to on oscillating electric field or an oscillating magnetic field.
22. A cooling assembly as in claim 17 wherein said inlet is formed by a tube which is received through one of said plates.
23. A cooling assembly as in claim 17 wherein the inlet is formed as a tube which is received through an interruption in the elongate material.