PHASE TRANSITION COOLING IN LED LIGHTING DEVICES

• US 20140151721A1
• Filed: 03/14/2013
• Published: 06/05/2014
• Est. Priority Date: 11/30/2012
• Status: Abandoned Application

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Orsley, Timothy James, Trutna, William Richard
• Application Number:
  US13/828,190
• Publication Number:
  US 20140151721A1
• Time in Patent Office: Days
• US Class Current: 257/88
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/648 the elements comprising fluids, e.g. heat-pipes

Abstract

A lighting device is provided comprising a chip-on-board (COB) light emitting diode (LED) light source, a phase transfer fluid disposed in a hermetically sealed phase transfer fluid chamber, a phase transfer fluid wicking structure, a distributed color conversion medium, and a glass containment plate. The color conversion medium is distributed in two dimensions over an emission field of the lighting device within the glass containment plate. The COB LED light source comprises a thermal heat sink framework and at least one LED and defines the hermetically sealed phase transfer fluid chamber in which the phase transfer fluid is disposed. The glass containment plate is positioned over the hermetically sealed phase transfer fluid chamber and contains the distributed color conversion medium. The phase transfer fluid wicking structure is transparent to at least a portion of the operating wavelength bandwidth of the LED and is configured within the hermetically sealed phase transfer fluid chamber to encourage transport of phase transfer fluid, permit vaporization of transported phase transfer fluid, and receive condensed phase transfer fluid vapor.

Claims

1. A lighting device comprising a chip-on-board (COB) light emitting diode (LED) light source, a phase transfer fluid disposed in a hermetically sealed phase transfer fluid chamber, a phase transfer fluid wicking structure, a distributed color conversion medium, and a glass containment plate, wherein:

the color conversion medium is distributed in two dimensions over an emission field of the lighting device within the glass containment plate.

the COB LED light source comprises a thermal heat sink framework and at least one LED and defines the hermetically sealed phase transfer fluid chamber in which the phase transfer fluid is disposed;

the glass containment plate is positioned over the hermetically sealed phase transfer fluid chamber, contains the distributed color conversion medium, and defines high operating temperature regions T_H of the lighting device;

the thermal heat sink framework of the light source defines low operating temperature regions T_C of the lighting device; and

the phase transfer fluid wicking structure is transparent to at least a portion of the operating wavelength bandwidth of the LED and is configured within the hermetically sealed phase transfer fluid chamber to

(i) encourage the transport of phase transfer fluid along a fluid transport path extending from low operating temperature regions T_C of the lighting device to high operating temperature regions T_H of the lighting device within the fluid chamber,

(ii) permit vaporization of the transported phase transfer fluid in the high operating temperature regions T_H of the lighting device, and

(iii) receive condensed phase transfer fluid vapor in the low operating temperature regions T_C of the lighting device for return transport to the high operating temperature regions T_H of the lighting device via the phase transfer fluid wicking structure.

2. The lighting device as claimed in claim 1 wherein the phase transfer fluid wicking structure encourages the transport of phase transfer fluid through capillary action.

3. The lighting device as claimed in claim 1 wherein the phase transfer fluid wicking structure comprises a wicking media disposed on an interior surface of the hermetically sealed phase transfer fluid chamber.

4. The lighting device as claimed in claim 1 wherein the phase transfer fluid wicking structure comprises glass frit disposed on an interior surface of the hermetically sealed phase transfer fluid chamber.

5. The lighting device as claimed in claim 1 wherein the phase transfer fluid wicking structure comprises fluid transfer grooves, a glass mesh, a glass fiber network, or other topographical formations in an interior surface of the hermetically sealed phase transfer fluid chamber.

6. The lighting device as claimed in claim 1 wherein the fluid wicking structure extends from a chip-on-board portion of the thermal heat sink framework to portions of the hermetically sealed phase transfer fluid chamber in closest thermal communication with the distributed color conversion medium.

7. The lighting device as claimed in claim 1 wherein the fluid wicking structure extends from the low operating temperature regions T_C of the lighting device to the high operating temperature regions T_H of the lighting device.

8. The lighting device as claimed in claim 7 wherein the fluid transport path of the wicking structure extends along an indirect route from the low operating temperature regions T_C of the lighting device to the high operating temperature regions T_H of the lighting device.

9. The lighting device as claimed in claim 8 wherein the indirect route is configured such that a significant portion of the fluid transport path of the wicking structure lies outside of a vapor transport path defined between the high operating temperature regions T_H of the lighting device and the low operating temperature regions T_C of the lighting device.

10. The lighting device as claimed in claim 1 wherein:

the glass containment plate comprises a glass matrix; and

the distributed color conversion medium comprises a phosphor distributed in the glass matrix.

11. The lighting device as claimed in claim 1 wherein:

the glass containment plate comprises a glass frame; and

the distributed color conversion medium comprises a quantum dot structure contained within an interior volume of the glass frame.

12. The lighting device as claimed in claim 1 wherein:

the glass containment plate comprises a glass matrix;

the distributed color conversion medium comprises a phosphor distributed in the glass matrix;

the lighting device further comprises a quantum dot plate disposed over the glass containment plate to define a supplemental emission field of the lighting device; and

the emission field defined by the distributed phosphor color conversion medium is spatially congruent with, but spectrally distinct from, the supplemental emission field defined by the quantum dot plate.

13. The lighting device as claimed in claim 12 wherein:

the quantum dot plate that is disposed over the glass containment plate comprises a quantum dot structure and opposing glass panels that are sealed at complementary edges to define an interior volume; and

the quantum dot structure is contained within the interior volume of the quantum dot plate.

14. The lighting device as claimed in claim 12 wherein an emission spectrum of the emission field defined by the quantum dot plate adds optical warmth to an emission spectrum of the emission field defined by the distributed phosphor color conversion medium.

15. The lighting device as claimed in claim 1 wherein:

the COB LED light source comprises an LED array; and

the light source encapsulant is distributed over the LED array.

16. A lighting device comprising a chip-on-board (COB) light emitting diode (LED) light source, a phase transfer fluid disposed in a hermetically sealed phase transfer fluid chamber, a phase transfer fluid wicking structure, a distributed color conversion medium, and a glass containment plate, wherein:

the color conversion medium is distributed in two dimensions over an emission field of the lighting device within the glass containment plate.

the COB LED light source comprises a thermal heat sink framework and at least one LED and defines the hermetically sealed phase transfer fluid chamber in which the phase transfer fluid is disposed;

the glass containment plate is positioned over the hermetically sealed phase transfer fluid chamber and contains the distributed color conversion medium; and

the phase transfer fluid wicking structure is transparent to at least a portion of the operating wavelength bandwidth of the LED and is configured within the hermetically sealed phase transfer fluid chamber to encourage transport of phase transfer fluid, permit vaporization of transported phase transfer fluid, and receive condensed phase transfer fluid vapor.