Heat exchange enhancement

• US 20070230185A1
• Filed: 03/31/2006
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Abandoned Application

• Current Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Original Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Inventors: Shuy, Geoffrey
• Application Number:
  US11/396,388
• Publication Number:
  US 20070230185A1
• Time in Patent Office: Days
• US Class Current: 362/294
• CPC Class Codes: B60Q 1/20 Fog lights
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 45/48 with means for conducting heat from the inside to the outside of the lighting devices, e.g. with fins on the outer surface of the lighting device
• CPC Class Codes: F21V 29/51 using condensation or evaporation of a fluid, e.g. heat pipes
• CPC Class Codes: F21V 29/71 using a combination of separate elements interconnected by heat-conducting means, e.g. with heat pipes or thermally conductive bars between separate heat-sink elements
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F28D 15/0233 the conduits having a particular shape, e.g. non-circular cross-section, annular F28D15/0241, F28D15/0266 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 21/04 of ceramic; of concrete; of natural stone
• CPC Class Codes: H01L 23/3731 Ceramic materials or glass H01L23/3732, H01L23/3733, H01L23/3735, H01L23/3737, H01L23/3738 take precedence
• CPC Class Codes: H01L 23/3735 Laminates or multilayers, e.g. direct bond copper ceramic substrates
• 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: H05K 7/20427 having radiation enhancing surface treatment, e.g. black coating
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A heat exchange device that includes a structural section and a thin layer of material attached to a surface of the structural section. The thin layer of material has a thickness less than 100 microns. The combination of the structural section and the thin layer of material has a higher thermal transfer coefficient than the structural section alone, the thermal transfer coefficient representing an ability to exchange thermal energy with an ambient gas.

Claims

1. An apparatus comprising:

a heat exchange device comprising

a structural section; and

a thin layer of material attached to at least a portion of a surface of the structural section, the thin layer of material having a thickness less than 100 microns;

wherein the combination of the structural section and the thin layer of material has a higher thermal transfer coefficient than the structural section alone, the thermal transfer coefficient representing an ability to exchange thermal energy with an ambient gas.

2. The apparatus of claim 1 wherein the structural section comprises a metal substrate.

3. The apparatus of claim 2 wherein the metal substrate comprises at least one of aluminum, beryllium, lithium, magnesium, titanium, zinc, and zirconium.

4. The apparatus of claim 2 wherein the metal substrate comprises an alloy of at least two of aluminum, beryllium, lithium, magnesium, titanium, zinc, and zirconium.

5. The apparatus of claim 1 wherein the structural section comprises a ceramic substrate.

6. The apparatus of claim 5 wherein the ceramic substrate comprises at least one of aluminum oxide, aluminum nitride, titanium oxide, titanium nitride, zirconium oxide, and zirconium nitride.

7. The apparatus of claim 1 wherein the thin layer comprises a first sub-layer and a second sub-layer, the first sub-layer being substantially impermeable to air molecules, the second sub-layer being at least partially permeable to air molecules.

8. The apparatus of claim 1 wherein the thin layer comprises a ceramic material.

9. The apparatus of claim 8 wherein the ceramic material comprises at least one of aluminum oxide, aluminum nitride, aluminum carbide, beryllium oxide, beryllium nitride, beryllium carbide, lithium oxide, lithium nitride, lithium carbide, magnesium oxide, magnesium nitride, magnesium carbide, silicon carbide, silicon oxide, silicon nitride, titanium carbide, titanium oxide, titanium nitride, zinc carbide, zinc oxide, zinc nitride, zirconium carbide, zirconium nitride, and zirconium oxide.

10. The apparatus of claim 8 wherein the ceramic material comprises a combination of at least two of aluminum oxide, aluminum nitride, aluminum carbide, beryllium oxide, beryllium nitride, beryllium carbide, carbon, lithium oxide, lithium nitride, lithium carbide, magnesium oxide, magnesium nitride, magnesium carbide, silicon carbide, silicon oxide, silicon nitride, titanium carbide, titanium oxide, titanium nitride, zinc carbide, zinc oxide, zinc nitride, zirconium carbide, zirconium nitride, and zirconium oxide.

11. The apparatus of claim 1 wherein the combination of the structural section and the thin layer of material has a lower minimum surface potential than the structural section alone.

12. The apparatus of claim 1 wherein the combination of the structural section and the thin layer of material has a surface that can trap more gas molecules per unit area than a surface of the structural section alone when the gas molecules has an average temperature below a threshold value.

13. The apparatus of claim 1 wherein the structural section has a first solid-gas heat exchange coefficient cl, and the combination of the structural section and the thin layer of material has a second solid-gas heat exchange coefficient c2, and |c1-c2|/c1 is greater than 30%.

14. The apparatus of claim 1 wherein the combination of the structural section and the thin layer of material is constructed and designed to dissipate heat to the ambient gas at a rate that is faster than the structural section alone without the thin layer by more than 30%.

15. The apparatus of claim 1 wherein the thin layer comprises a material having a thermal conductivity that is less than that of the structural section.

16. An apparatus comprising:

a heat exchange device comprising;

a structural section; and

a thin layer of ceramic material attached to at least a portion of a surface of the structural section, the thin layer of ceramic material having a thickness less than 100 microns, at least some of the thin layer of material being at least partially permeable to air molecules.

17. The apparatus of claim 16 wherein the thin layer comprises a first sub-layer and a second sub-layer, the first sub-layer comprising a solid layer that is substantially impermeable to air molecules, the second sub-layer having a porous structure that is at least partially permeable to air molecules.

18. The apparatus of claim 17 wherein the first sub-layer has a thickness less than 10 microns.

19. The apparatus of claim 17 wherein the second sub-layer has a thickness less than 25 microns.

20. The apparatus of claim 17 wherein the second sub-layer comprises spikes at its surface.

21. The apparatus of claim 20 wherein the spikes have heights less than 250 nanometers and diameters less than 1 micron.

22. An apparatus comprising:

a heat exchange device comprising;

a structural section to define a structure of the heat exchange device; and

a thin layer of ceramic material attached to at least a portion of a surface of the structural section, the thin layer of ceramic material having a thickness less than 100 microns, the thin layer of material comprising spikes each having a diameter less than 1 micron at mid-height.

23. An apparatus comprising:

a composite substrate comprising;

a substrate; and

a thin layer of material attached to a surface of the substrate, the thin layer of material having a thickness less than 100 microns;

wherein the composite substrate has a minimum surface potential that is lower than the minimum surface potential of the substrate alone without the thin layer.

24. An apparatus comprising:

an electronic device; and

a heat exchange structure on which the electronic device is attached, the heat exchange structure comprising

a structural section to define a structure of the heat exchange structure, and

a thin layer of material coupled to at least a portion of a surface of the structural section, the thin layer of material having a thickness less than 100 microns;

wherein the combination of the structural section and the thin layer of material has a higher thermal transfer coefficient than the structural section alone, the thermal transfer coefficient representing an ability to exchange thermal energy with an ambient gas.

25. The apparatus of claim 24 wherein the electronic device comprises a light emitting diode.

26. The apparatus of claim 24 wherein the electronic component is directly attached to the thin layer of material.

27. An MR-16 lamp comprising:

a heat exchange device comprising;

a structural section; and

a thin layer of ceramic material attached to a surface of the structural section, the thin layer of ceramic material having a thickness less than 100 microns; and

light emitting diodes mounted on the heat exchange device and configured to dissipate heat through the heat exchange device.

28. The MR-16 lamp of claim 27 wherein the thin layer of ceramic material comprising spikes each having a diameter less than 1 micron at mid-height.

29. The MR-16 lamp of claim 27 wherein the thin layer of ceramic material comprises a first sub-layer and a second sub-layer, the first sub-layer being substantially impermeable to air molecules, the second sub-layer being at least partially permeable to air molecules.

30. A wall wash lamp comprising:

a heat exchange device comprising;

a structural section; and

a thin layer of ceramic material attached to a surface of the structural section, the thin layer of ceramic material having a thickness less than 100 microns; and

light emitting diodes mounted on the heat exchange device and configured to dissipate heat through the heat exchange device.

31. The wall wash lamp of claim 30 wherein the thin layer of ceramic material comprising spikes each having a diameter less than 1 micron at mid-height.

32. The wall wash lamp of claim 30 wherein the thin layer of ceramic material comprises a first sub-layer and a second sub-layer, the first sub-layer being substantially impermeable to air molecules, the second sub-layer being at least partially permeable to air molecules.

33. The wall wash lamp of claim 30, further comprising a control circuit for controlling an overall color emitted by the light emitting diodes.

34. A vehicle lamp comprising:

a heat exchange device comprising;

a structural section; and

a thin layer of ceramic material attached to a surface of the structural section, the thin layer of ceramic material having a thickness less than 100 microns;

light emitting diodes mounted on the heat exchange device and configured to dissipate heat through the heat exchange device; and

an enclosure to enclose the light emitting diodes in a water-tight compartment.

35. The vehicle lamp of claim 34 wherein the thin layer of ceramic material comprising spikes each having a diameter less than 1 micron at mid-height.

36. The vehicle lamp of claim 34 wherein the thin layer of ceramic material comprises a first sub-layer and a second sub-layer, the first sub-layer being substantially impermeable to air molecules, the second sub-layer being at least partially permeable to air molecules.

37. The vehicle lamp of claim 34, further comprising a lens to focus light from the light emitting diodes.

38. A method comprising:

exchanging thermal energy between a structural portion of a heat dissipation device and a thin layer of material attached to a least a portion of a surface of the structural portion, the structural portion defining a structure of the heat dissipation device,

the thin layer of material having a thickness less than 100 microns and comprising a first sub-layer and a second sub-layer, the first sub-layer comprising a solid layer that is substantially impermeable to air molecules, the second sub-layer having a porous structure that is at least partially permeable to air molecules; and

exchanging thermal energy between the thin layer of material and air molecules.

39. A method comprising:

forming a thin layer of material on a substrate, wherein the thin layer of material has a thickness less than 100 microns, and the combination of the thin layer and the substrate can exchange thermal energy with an ambient gas faster than the substrate without the thin layer.

40. The method of claim 39 wherein forming the thin layer of material on the substrate comprises forming a first sub-layer and a second sub-layer, the first sub-layer being impermeable to the ambient gas, the second sub-layer being at least partially permeable to the ambient gas.

41. The method of claim 39 wherein forming the thin layer of material comprises forming spikes having heights less than 250 nanometers and diameters less than 1 micron on the surface of the thin layer.

42. The method of claim 39 wherein forming the thin layer of material on the substrate comprises a plating process.

43. The method of claim 39 wherein the plating process comprises using an electrolyte comprising at least one of aluminum oxide, aluminum nitride, aluminum carbide, beryllium oxide, beryllium nitride, beryllium carbide, boron oxide, carbon, lithium oxide, lithium nitride, lithium carbide, magnesium oxide, magnesium nitride, magnesium carbide, silicon carbide, silicon oxide, silicon nitride, titanium carbide, titanium oxide, titanium nitride, zinc carbide, zinc oxide, zinc nitride, zirconium carbide, zirconium nitride, and zirconium oxide.

44. A method comprising:

forming a thin layer of ceramic material on a substrate, the thin layer of ceramic material having a thickness less than 100 microns, the thin layer of ceramic material comprising spikes each having a diameter less than 1 micron at mid-height.