Method and Apparatus for Cooling Electronics with a Coolant at a Subambient Pressure

• US 20070263356A1
• Filed: 05/02/2006
• Published: 11/15/2007
• Est. Priority Date: 05/02/2006
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Weber, Richard, Rummel, Kerrin, Wyatt, William
• Granted Patent: US 7,908,874 B2
• Time in Patent Office: Days
• US Class Current: 361/700
• CPC Class Codes: F25B 23/006 boiling cooling systems
• CPC Class Codes: F25B 43/00 Arrangements for separating or purifying gases or liquids in analysers or rectifiers F25B33/00; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat F25B40/00 takes precedence
• CPC Class Codes: F28D 15/0266 with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers F28D15/043 takes precedence
• CPC Class Codes: F28D 2021/0031 Radiators for recooling a coolant of cooling systems
• CPC Class Codes: F28F 23/00 Features relating to the use of intermediate heat-exchange materials, e.g. selection of compositions heat-transfer, heat-exchange or heat-storage materials C09K5/00
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01Q 1/02 Arrangements for de-icing; Arrangements for drying-out ; Arrangements for cooling; Arrangements for preventing corrosion

Abstract

According to one embodiment of the invention, a method is provided for cooling heat-generating structure disposed in an environment having an ambient pressure. The heat-generating structure includes electronics. The method includes providing a coolant, reducing a pressure of the coolant to a subambient pressure at which the coolant has a boiling temperature less than a temperature of the heat-generating structure, and bringing the heat-generating structure and the coolant at the subambient pressure into contact with one another, so that the coolant boils and vaporizes to thereby absorb heat from the heat-generating structure. In a more particular embodiment the coolant is either pure water or pure methanol with an electrical resistivity level of greater than one million Ohms-cm. Further, in another particular embodiment the method includes filtering the coolant to maintain its purity above a particular level.

Claims

1. A method for cooling heat-generating structure disposed in an environment having an ambient pressure, the heat-generating structure comprising electronics, the method comprising:

providing a coolant;

reducing a pressure of the coolant to a subambient pressure at which the pure water has a boiling temperature less than a temperature of the heat-generating structure; and

bringing the heat-generating structure and the coolant into contact with each other at a subambient pressure, so that the pure water boils and vaporizes to thereby absorb heat from the heat-generating structure.

2. The method of claim 1, wherein the coolant is pure water having an electrical resistivity greater than one million Ohms-cm.

3. The method of claim 1, wherein the coolant is methanol.

4. A method of claim 1, and further comprising filtering the coolant while at a subambient pressure to maintain a desired purity level.

5. The method of claim 1, further comprising circulating the coolant through a flow loop while maintaining the pressure of the pure water within a range having an upper bound less than the ambient pressure.

6. The method of claim 5, and further comprising configuring the loop to include a water purification system.

7. The method of claim 5, further comprising the configuring the loop to include a heat exchanger for removing heat from the pure water so as to condense the pure water to a liquid.

8. The method of claim 7, further comprising causing the heat exchanger to transfer heat from the coolant to a further medium having an ambient temperature that is less than the boiling temperature of the coolant at the subambient pressure.

9. The method of claim 5, further comprising configuring the loop to include a pump for circulating the pure water through the loop.

10. The method of claim 1, wherein bringing the heat-generating structure and the coolant into contact with each other comprises submerging the heat-generating structure into the coolant comprises submerging the heat-generating structure into a bath of the pure water while the pure water is flowing.

11. The method of claim 1, comprises flowing the coolant over the heat-generating structure.

12. The method of claim 11, wherein bringing the heat-generating structure and the coolant into contact with each other comprises submerging the heat-generating structure into the coolant comprises submerging the heat-generating structure into a bath of the pure water while the pure water is flowing.

13. The method of claim 11, wherein submerging the heat-generating structure into the coolant further comprises submerging the heat-generating structure into a bath of the pure water having an electrical resistivity greater than one million Ohms-cm.

14. The method of claim 1, and further comprising configuring the heat-generating structure to include a plurality of electronic modules and a porous mesh coupled to each electronic module.

15. The method of claim 14, wherein each electronic module is electrically connected to at least one other of the plurality of electronic modules.

16. The method of claim 1, and further comprising configuring the heat-generating structure to include:

a frame having a plurality of frame voids;

a plurality of modules each disposed in respective ones of the frame voids, each module comprising an array of circuit substrates separated by void regions through which coolant may flow, each circuit substrate comprising;

a substrate; and

at least one electrical circuit disposed on the substrate.

17. The method of claim 16, wherein configuring the heat-generating structure further includes providing a plurality of pin fins extending from the substrate.

18. An apparatus for cooling a heat-generating structure disposed in an environment having an ambient pressure, the apparatus comprising:

a coolant;

a pressure reduction system operable to reduce a pressure of the coolant to a subambient pressure at which the coolant has a boiling temperature less than a temperature of the heat-generating structure; and

a submerged assembly operable to submerge the heat-generating structure in the coolant such that heat from the heat-generating structure causes the coolant to boil and vaporize, so that the coolant absorbs heat from the heat-generating structure as the coolant changes state.

19. The apparatus of claim 18, wherein the coolant is selected from the group consisting of pure water and pure methanol having an electrical resistivity greater than one million Ohms-cm.

20. The apparatus of claim 18, wherein the cooling system further includes a purification system operable to maintain the purity of the coolant at a level so the coolant has an electrical resistivity greater than one million Ohms-cm.

21. The apparatus of claim 18, and further comprising a water purification system for purifying the coolant.

22. The apparatus of claim 18, further comprising a heat exchanger for removing heat from the coolant so as to condense the coolant to a liquid.

23. The apparatus of claim 21, and further comprising a pump for circulating the coolant.

24. The apparatus of claim 18, and further comprising the heat-generating structure, the heat-generating structure comprising a plurality of electronic modules and a porous mesh coupled to each electronic module.

25. The apparatus of claim 24, wherein each electronic module is electrically connected to at least one other of the plurality of electronic modules.

26. The apparatus of claim 18, wherein the heat-generating structure comprises:

a frame having a plurality of frame voids;

a plurality of modules each disposed in respective ones of the frame voids, each module comprising an array of circuit substrates separated by void regions through which coolant may flow, each circuit substrate comprising;

a substrate; and

at least one electrical circuit disposed on the substrate.

27. The apparatus of claim 26, and further comprising a plurality of pin fins extending from each substrate.

33. The apparatus of claim 24, and further comprising:

a coolant;

a pressure reduction system operable to reduce a pressure of the coolant to a pressure at which the coolant has a boiling temperature less than a temperature of the heat-generating structure; and

a submerged assembly in which the porous mesh and the plurality of electronic modules connected to the mesh are submerged within the coolant.

28. An apparatus comprising:

a porous mesh; and

a plurality of electronic modules connected to the porous mesh.

29. The apparatus of claim 28, and further comprising at least one interconnect electronically coupling one of the plurality of electronic modules to at least one other of the plurality of electronic modules.

30. The apparatus of claim 29, wherein at least one of the electronic modules comprises a plurality of thermally conductive bumps electrically connected to the at least one interconnect.

31. The apparatus of claim 28, and further comprising pure water having an electrical resistivity greater than one million Ohms-cm, the porous mesh and the plurality of electronic modules submerged in the pure water.

32. The apparatus of claim 31, wherein the pure water comprises pure water flowing relative to the porous mesh and the plurality of porous modules.

34. An apparatus comprising:

a frame having a plurality of frame voids;

a plurality of modules each disposed in respective ones of the frame voids, each module comprising an array of circuit substrates separated by void regions through which coolant may flow, each circuit substrate comprising;

a substrate; and

at least one electrical circuit disposed on the substrate.

35. The apparatus of claim 34, and further comprising pure water, the frame and plurality of modules submerged within the pure water.

36. The apparatus of claim 34, and further comprising methanol, the frame and plurality of modules submerged within the methanol.

37. The apparatus of claim 34, and further comprising a coolant, the frame and plurality of modules submerged within the coolant.

38. The apparatus of claim 37, wherein the coolant is at a pressure less than 14.7 psia.