Refrigeration device and a method for producing the same

• US 7,044,212 B1
• Filed: 08/25/2000
• Issued: 05/16/2006
• Est. Priority Date: 08/25/2000
• Status: Expired due to Fees

• Current Assignee: N F T Nanofiltertechnik GmbH
• Original Assignee: Net Nanofiltertechnik GmbH
• Inventors: Hofmann, Wilfried
• Primary Examiner(s): Walberg, Teresa J.
• Application Number:
  US10/362,865
• Time in Patent Office: 2,090 Days
• Field of Search: 165/185, 165/80.3, 165/80.2
• US Class Current: 165/185
• CPC Class Codes: F28D 2021/0078 in the form of cooling walls
• CPC Class Codes: F28F 13/00 Arrangements for modifying heat-transfer, e.g. increasing, decreasing F28F1/00 - F28F11/00 take precedence
• CPC Class Codes: F28F 13/18 by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
• CPC Class Codes: F28F 13/185 Heat-exchange surfaces provided with microstructures or with porous coatings
• CPC Class Codes: H01L 23/3677 Wire-like or pin-like cooling fins or heat sinks
• 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

Abstract

The cooling device, particularly for electronic components, such as microprocessors, consists of a substrate (1), which features a heat-inlet surface that is in thermal contact with an object (6) to be cooled and a heat-dissipation surface. The heat-dissipation surface has a defined structure, preferably in the form of continuous channels (2), and has a significantly larger surface area than the heat-inlet surface. At least the heat-inlet surface, but preferably also all or significant portions of the heat-dissipation surface are provided with a thin coating (3) made of heat-conductive material. Another improvement is obtained because the surface features a coating made of fine particles (21), e.g., made of metal or metal oxide, which further increases the surface area.

Claims

1. A substrate of a cooling device comprising

a heat-inlet surface that can be brought into thermal contact with an object to be cooled, wherein the heat-inlet surface includes grooves, and

a heat-dissipation surface significantly larger than the heat-inlet surface due to channels formed in the substrate, the channels being fluidly connected to the grooves of the heat-inlet surface.

2. A substrate according to claim 1 wherein the ratio of heat-dissipation surface to heat-inlet surface is greater than 10.

3. A substrate according to claim 1 wherein the ratio of the heat-dissipation surface to the heat-inlet surface is approximately 400 to 700 or greater.

4. A substrate according to claim 1 wherein the channels extend through the substrate and are essentially perpendicular to the heat-inlet surface.

5. A substrate according to claim 4 wherein the inner walls of the channels are provided with a coating made of heat-conductive material.

6. A substrate according to claim 4 wherein the channels have square, rectangular, or circular cross sections.

7. A substrate according to claim 1 wherein at least the heat-inlet surface is provided with a coating made of heat-conductive material.

8. A substrate according to claim 1 wherein the surface of the substrate opposite the heat-inlet surface is provided with a coating made of a heat-conductive material.

9. A substrate according to claim 8 further comprising a first substrate and a second substrate, wherein the second substrate is in heat-conducting contact with the first substrate, wherein there are grooves in the second substrate and the coating made of heat-conductive material is deposited on the second substrate.

10. A substrate according to claim 9, wherein the second substrate is thinner than the first substrate.

11. A substrate according to claim 1 wherein the grooves are parallel to each other and parallel to the heat-inlet surface.

12. A substrate according to claim 4 wherein the channels have cross sections that change in the longitudinal direction of the channels (direction of flow).

13. A substrate according to claim 1 wherein the heat-dissipation surface is further increased by roughening.

14. A substrate according to claim 13 wherein the roughening is generated by deposited particles.

15. A substrate according to claim 14 wherein the particles are heat conductive.

16. A substrate according to claim 15 wherein the particles are metal or metal-oxide particles.

17. A substrate according to claim 14 wherein the diameter of the particles is on the order of magnitude of micrometers or nanometers.

18. A substrate according to claim 13 wherein the particles are deposited directly on the substrate.

19. A substrate according to claim 13 wherein the particles are deposited on a heat-conductive coating deposited on the substrate defining the heat-inlet surface.

20. A substrate according claim 13 wherein the substrate has a trapezoidal cross section, wherein inclined side walls are also coated with the particles.

21. A substrate according to claim 13 characterized in that the roughening of the heat-dissipation surface is performed by a deposited, sponge-like, porous layer.

22. A process of making a substrate of a cooling device comprising:

forming a plurality of channels in the substrate to at least in part define a heat-dissipation surface, and

depositing a heat conductive layer on a surface of the substrate, the heat conductive layer having a plurality of grooves in fluid connection with the channels of the substrate and defining a heat-inlet surface that can be brought into thermal contact with an object to be cooled.

23. Process according to claim 22 wherein the channels are formed by etching.

24. Process according to claim 23 wherein the channels are etched by anisotropic etching and have a diameter or cross section that changes over their longitudinal direction.

25. Process according to claim 22 wherein the channels are formed at least in part by a stamping process.

26. Process according to claim 22 wherein the channels are formed by a process using lithography and electroforming.

27. Process according to claim 22, wherein the heat-conductive layer is applied by vapor deposition.

28. Process according to claim 22, wherein the heat-conductive layer consists of silver, copper, aluminum, or materials with at least approximately the same good thermal conductivity (λ

).

29. Process according to claim 22, wherein the heat-conductive layer is thinner than the substrate.

30. Process according to claim 29 wherein the heat-conductive layer has a thickness of ca. 10μ

.