Fabrication of high surface to volume ratio structures and their integration in microheat exchangers for liquid cooling systems

• US 20080210405A1
• Filed: 01/06/2006
• Published: 09/04/2008
• Est. Priority Date: 11/01/2002
• Status: Active Grant

• Current Assignee: Vertiv Corporation (Vertiv Holdings Co.)
• Original Assignee: Cooligy Incorporated (Emerson Electric Company)
• Inventors: Munch, Mark, Zhou, Peng, McMaster, Mark, Datta, Madhav, Tsao, Paul, Brewer, Rick, Upadhaya, Girish
• Granted Patent: US 7,836,597 B2
• Time in Patent Office: Days
• US Class Current: 165/102
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take 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: F28F 13/185 Heat-exchange surfaces provided with microstructures or with porous coatings
• CPC Class Codes: F28F 2245/04 hydrophobic
• CPC Class Codes: F28F 3/12 Elements constructed in the shape of a hollow panel, e.g. with channels F28D1/02, F28D1/03 take precedence
• CPC Class Codes: H01L 21/4882 Assembly of heatsink parts
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• 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: Y10T 29/4935 Heat exchanger or boiler making
• CPC Class Codes: Y10T 29/49353 Heat pipe device making
• CPC Class Codes: Y10T 29/49366 Sheet joined to sheet
• CPC Class Codes: Y10T 29/49369 Utilizing bond inhibiting material

Abstract

An structure and method of manufacturing a microstructure for use in a heat exchanger is disclosed. The heat exchanger comprises a manifold layer and an microstructured region. The manifold layer comprises a structure to deliver fluid to the microstructured region. The microstructured region is formed from multiple windowed layers formed from heat conductive layers through which a plurality of microscaled apertures have been formed by a wet etching process. The plurality of windowed layers are then coupled together to form a composite microstructure.

Claims

1. A method of fabricating a heat exchanger comprising microstructures, the method comprising:

a. forming a plurality of microscaled apertures through a plurality of heat conductive layers using a material removal process to form a plurality of windowed layers; and

b. coupling the plurality of windowed layers together to form a composite microstructure.

2. The method of fabricating a heat exchanger of claim 1, wherein heat conductive layers comprise copper.

3. The method of fabricating a heat exchanger of claim 1, wherein the plurality of windowed layers are coupled together by brazing.

4. The method of fabricating a heat exchanger of claim 3, wherein the brazing is done with a brazing material comprising silver.

5. The method of fabricating a heat exchanger of claim 3, wherein one or more of the layers are plated with a brazing material prior to brazing.

6. The method of fabricating a heat exchanger of claim 1, further comprising a step of aligning apertures in each of the plurality of windowed layers before coupling the plurality of windowed layers together.

7. The method of fabricating a heat exchanger of claim 1, wherein the material removal process is an isotropic wet etching process.

8. The method of fabricating a heat exchanger of claim 7, wherein the isotropic wet etching process is selected from a group consisting of photo chemical machining, through mask chemical etching, through mask electrochemical etching, electroetching, and electrochemical micromachining.

9. The method of fabricating a heat exchanger of claim 1, wherein the composite microstructure comprises a micromesh.

10. The method of fabricating a heat exchanger of claim 1, wherein the step of forming microscaled apertures through each of the plurality of heat conductive layers using a material removal process comprises forming a first micropattern in a first side of each heat conductive layer and a second micropattern in a second side of each heat conductive layer.

11. The method of fabricating a heat exchanger of claim 10, wherein the first and second micropatterns are complementary to form continuous microchannels in the heat conductive layer.

12. The method of fabricating a heat exchanger of claim 10, wherein the first and second micropatterns are designed to form an overlapping micromesh structure in the heat conductive layer.

13. The method of fabricating a heat exchanger of claim 1, wherein the composite microstructure comprises a plurality of microchannels.

14. The method of fabricating a heat exchanger of claim 1, wherein the heat conductive layers have a thickness between about 50 and about 250 micrometers.

15. The method of fabricating a heat exchanger of claim 1, wherein the microscaled apertures formed in the heat conductive layers have dimensions between about 50 and about 300 micrometers.

16. A method of fabricating a micro-heat exchanger comprising a heat conductive high surface to volume ratio material (HSVRM) structure, the method comprising:

a. providing a lid structure made from a first material;

b. coupling a manifold structure with the lid structure, wherein the manifold structure is made from a second material and configured to distribute cooling fluid;

c. forming a plurality of microscaled apertures through a plurality of heat conductive layers comprised of a heat conductive material using a material removal process to form a plurality of windowed layers;

d. coupling the plurality of windowed layers together to form a composite HSVRM structure comprising the heat conductive material, wherein the HSVRM structure formed in each of the plurality of heat conductive layers are designed to form the composite HSVRM structure when the heat conductive layers are coupled together;

e. coupling the composite HSVRM structure with the manifold structure and the lid structure so that the manifold layer is configured to deliver fluid to the HSVRM structure; and

,

f. coupling a flat base structure comprising a third material with the composite HSVRM structure, the manifold structure, and the lid structure together to form micro-heat exchanger.

17. The method of fabricating a micro-heat exchanger of claim 16, wherein the heat conductive material is copper.

18. The method of fabricating a micro-heat exchanger of claim 16, wherein the lid structure, the manifold structure, the plurality of windowed layers, and the flat base structure are all coupled together by brazing.

19. The method of fabricating a micro-heat exchanger of claim 18, wherein the brazing is done with a brazing material comprising silver.

20. The method of fabricating a micro-heat exchanger of claim 16, further comprising a step of aligning apertures in each of the plurality windowed layers before coupling the plurality of windowed layers together.

21. The method of fabricating a micro-heat exchanger of claim 16, wherein the microscaled apertures are formed within the heat conductive layers by an isotropic wet etching process.

22. The method of fabricating a micro-heat exchanger of claim 21, wherein the material removal process is selected from a group consisting of photo chemical machining, through mask chemical etching, through mask electrochemical etching, electroetching, and electrochemical micromachining.

23. The method of fabricating a micro-heat exchanger of claim 16, wherein the composite HSVRM structure comprises a micromesh.

24. The method of fabricating a micro-heat exchanger of claim 23, wherein forming the microscaled apertures through each of the plurality of heat conductive layers by a material removal process comprises forming a first micropattern in a first side of the each heat conductive layer and a second micropattern in a second side of each heat conductive layer.

25. The method of fabricating a heat exchanger of claim 24, wherein the first and second micropatterns are complementary to form continuous microchannels in the heat conductive layer.

26. The method of fabricating a heat exchanger of claim 24, wherein the first and second micropatterns are designed to form an overlapping micromesh structure in the heat conductive layer.

27. The method of fabricating a micro-heat exchanger of claim 16, wherein the composite HSVRM structure comprises a plurality of microchannels.

28. The method of fabricating a micro-heat exchanger of claim 16, further comprising fine finishing of the flat base structure.

29. The method of fabricating a micro-heat exchanger of claim 16, further comprising forming a plurality of fluid ports in the lid structure.

30. The method of fabricating a micro-heat exchanger of claim 16, wherein the number and thickness of the plurality of heat conductive layers that compose the composite HSVRM structure are chosen to optimize pressure drop and thermal resistance characteristics of the micro-heat exchanger.

31. The method of fabricating a heat exchanger of claim 16, wherein the heat conductive layers have a thickness between about 50 and about 250 micrometers.

32. The method of fabricating a heat exchanger of claim 16, wherein the microscaled apertures formed in the heat conductive layers have dimensions between about 50 and about 300 micrometers.

33. A microstructured heat exchanger comprising a plurality of heat conductive layers, each having a plurality of elongated microscaled apertures formed by material removal therefrom, wherein the plurality of elongated microscaled apertures are aligned and the plurality of heat conductive layers are coupled together to form a HSVRM structure, wherein each elongated aperture in a first heat conductive layer is in communication with more than three elongated apertures of at least one adjacent heat conductive layer.

34. The microstructured heat exchanger of claim 33, wherein the heat conductive layers comprise copper.

35. The microstructured heat exchanger of claim 33, wherein the windowed layers are coupled together by brazing.

36. The microstructured heat exchanger of claim 33, wherein the material removal is isotropic.

37. The microstructured heat exchanger of claim 33, wherein the number and thickness of the plurality of heat conductive layers are chosen to optimize pressure drop and thermal resistance characteristics of the microstructured heat exchanger.

38. A microstructured heat exchanger comprising a plurality of heat conductive layers, each having a plurality of elongated microscaled apertures formed by material removal therefrom, wherein the plurality of elongated microscaled apertures are aligned and the plurality of heat conductive layers are coupled together to form a HSVRM structure wherein each elongated aperture in a first heat conductive layer is in communication with only one elongated aperture of any adjacent heat conductive layer.

39. The microstructured heat exchanger of claim 38, wherein the plurality of elongated microscaled apertures are the same in each of the plurality of heat conductive layers.

40. The microstructured heat exchanger of claim 38, wherein the material removal is isotropic.

41. The microstructured heat exchanger of claim 38, wherein the windowed layers are coupled together by brazing.

42. The microstructured heat exchanger of claim 38, wherein the number and thickness of the plurality of heat conductive layers are chosen to optimize pressure drop and thermal resistance characteristics of the microstructured heat exchanger.

43. A method of fabricating a heat exchanger comprising microstructures, comprising:

a. forming a plurality of windowed layers using a material deposition process, the windowed layers comprising a heat conductive material and including a plurality of microscaled apertures; and

b. coupling the plurality of windowed layers together to form a composite microstructure.