High efficiency LEDS and LED lamps

• US 8,338,849 B2
• Filed: 06/14/2012
• Issued: 12/25/2012
• Est. Priority Date: 06/27/2009
• Status: Active Grant

• Current Assignee: Cooledge Lighting Inc.
• Original Assignee: Cooledge Lighting Inc.
• Inventors: Tischler, Michael Albert, Odnoblyudov, Vladimir, Keogh, David
• Primary Examiner(s): Lee, Calvin
• Application Number:
  US13/523,576
• Publication Number:
  US 20120248477A1
• Time in Patent Office: 194 Days
• Field of Search: 257/13, 257/37, 257 83- 98, 257E51001-E51052, 438 22- 31
• US Class Current: 257/98
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: F21K 9/235 Details of bases or caps, i.e. the parts that connect the light source to a fitting; Arrangement of components within bases or caps F21K9/238 takes precedence
• CPC Class Codes: F21K 9/237 Details of housings or cases, i.e. the parts between the light-generating element and the bases; Arrangement of components within housings or cases F21K9/238 takes precedence
• CPC Class Codes: F21K 9/238 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 15/01 Housings, e.g. material or assembling of housing parts F21V15/02 takes precedence housings forming signs or letters G09F13/04
• CPC Class Codes: F21V 23/008 the casing being outside the housing of the lighting device
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 7/0066 specially adapted to cooperate with point like light sources; specially adapted to cooperate with light sources the shape of which is unspecified F21V7/16 - F21V7/30 take precedence
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 25/0753 : the devices being arranged next to each other
• CPC Class Codes: H01L 27/156 : two-dimensional arrays
• 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 2924/00014 : 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 2924/13033 : TRIAC - Triode for Alternating Current - A bidirectional switching device containing two thyristor structures with common gate contact
• CPC Class Codes: H01L 33/0093 : Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/28 : containing only elements of Group II and Group VI of the Periodic Table
• CPC Class Codes: H01L 33/30 : containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: H01L 33/34 : containing only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements
• CPC Class Codes: H01L 33/60 : Reflective elements
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H04N 1/02865 : using an array of light sources or a combination of such arrays, e.g. an LED bar
• CPC Class Codes: H05B 33/12 : Light sources with substantially two-dimensional radiating surfaces
• CPC Class Codes: H05B 45/10 : Controlling the intensity of the light
• CPC Class Codes: H05B 45/12 : using optical feedback
• CPC Class Codes: H05B 45/30 : Driver circuits
• CPC Class Codes: H05B 45/37 : Converter circuits
• CPC Class Codes: H05B 45/3725 : Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/40 : Details of LED load circuits
• CPC Class Codes: H05B 45/42 : Antiparallel configurations
• CPC Class Codes: H05B 45/44 : with an active control inside an LED matrix
• CPC Class Codes: H05B 45/60 : Circuit arrangements for operating LEDs comprising organic material, e.g. for operating organic light-emitting diodes [OLED] or polymer light-emitting diodes [PLED]
• CPC Class Codes: H05B 47/11 : by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H10K 50/00 : Organic light-emitting devices integrated devices or assemblies of multiple devices H10K59/00, H10K65/00; organic semiconductor lasers H01S5/36
• CPC Class Codes: H10K 59/00 : Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/876 : comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: Y02B 20/40 : Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

In various embodiments, lighting systems include an electrically insulating carrier having a plurality of conductive elements disposed thereon, a light-emitting array, and at least one power source. The light-emitting array is disposed over the carrier and includes a plurality of light-emitting strings, each light-emitting string comprising a plurality of unpackaged light-emitting diode (LED) dies electrically connected in series. Each LED die has at least two electrical contacts on one surface thereof, and each electrical contact is electrically connected to a conductive element by a conductive adhesive. The power source provides power to the light-emitting strings.

Claims

1. A lighting system comprising:

an electrically insulating carrier having a plurality of conductive elements disposed thereon;

disposed over the carrier, a light-emitting array comprising a plurality of light-emitting strings, each light-emitting string comprising a plurality of unpackaged light-emitting diode (LED) dies electrically connected in series, each LED die having at least two electrical contacts on one surface thereof, wherein each electrical contact is electrically connected to a conductive element by a conductive adhesive; and

at least one power source for providing power to the light-emitting strings.

2. The system of claim 1, wherein one of the unpackaged LED dies emits radiation at a first wavelength and another one of the unpackaged LED dies emits radiation at a second wavelength different from the first wavelength.

3. The system of claim 1, wherein, within one of the light-emitting strings, one of the unpackaged LED dies emits radiation at a first wavelength and another one of the unpackaged LED dies emits radiation at a second wavelength different from the first wavelength.

4. The system of claim 1, wherein at least one of the unpackaged LED dies is associated with or at least partially covered by at least one light-conversion material.

5. The system of claim 4, wherein the light-conversion material comprises a phosphor.

6. The system of claim 4, wherein the light-conversion material comprises a binder and a phosphor.

7. The system of claim 6, wherein the binder has an index of refraction between about 1.3 and about 1.7.

8. The system of claim 4, wherein at least a first unpackaged LED die is associated with a first light-conversion material and at least a second unpackaged LED die, different from the first unpackaged LED die, is associated with a second light-conversion material different from the first light-conversion material.

9. The system of claim 4, wherein, within one of the light-emitting strings, at least a first unpackaged LED die is associated with a first light-conversion material and at least a second unpackaged LED die, different from the first unpackaged LED die, is associated with a second light-conversion material different from the first light-conversion material.

10. The system of claim 4, wherein (i) at least a first unpackaged LED die within a first light-emitting string is associated with a first light-conversion material, and (ii) at least a second unpackaged LED die within a second light-emitting string, different from the first light-emitting string, is associated with a second light-conversion material different from the first light-conversion material.

11. The system of claim 4, wherein the electrically insulating carrier is reflective to at least one of a wavelength of light emitted by the unpackaged LED dies or a wavelength of light emitted by the light-conversion material.

12. The system of claim 4, further comprising an array of optical elements each associated with at least one unpackaged LED die, the array of optical elements at least one of focusing or shaping light from the unpackaged LED dies to a desired illumination pattern.

13. The system of claim 1, wherein at least one of the unpackaged LED dies comprises a semiconductor material comprising at least one of silicon, SiC, GaAs, Al_xIn_yGa_1-x-yP_zN_tAs_1-t-z, Al_xIn_yGa_1-x-yN, or ZnO.

14. The system of claim 1, wherein the electrically insulating carrier is flexible.

15. The system of claim 1, wherein the electrically insulating carrier comprises at least one of glass, polymer, or metal.

16. The system of claim 1, further comprising, electrically connected to the plurality of light-emitting strings, electrical circuitry for selectively turning off various ones of the light-emitting strings, thereby dimming a light output of the light-emitting array, without altering a level of drive current supplied to the LED dies.

17. The system of claim 1, further comprising, disposed on the electrically insulating carrier, at least one of (i) one or more active circuit elements or (ii) one or more passive circuit elements for controlling current supplied to the unpackaged LED dies.

18. The system of claim 1, further comprising at least one optical element associated with at least one unpackaged LED die, the at least one optical element at least one of focusing or shaping light from the at least one unpackaged LED die to a desired illumination pattern.

19. The system of claim 18, wherein the at least one optical element is optically coupled to the at least one unpackaged LED die with no interface to air therebetween.

20. The system of claim 18, wherein, within one of the light-emitting strings, at least a first unpackaged LED die is associated with an optical element of a first type, and at least a second unpackaged LED die is associated with an optical element of a second type different from the first type.

21. The system of claim 18, wherein (i) at least a first unpackaged LED die within a first light-emitting string is associated with an optical element of a first type, and (ii) at least a second unpackaged LED die within a second light-emitting string, different from the first light-emitting string, is associated with an optical element of a second type different from the first type.

22. The system of claim 1, wherein at least one first light-emitting string emits light having a color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution different from a color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution of at least one second light-emitting string.

23. The system of claim 22, wherein the unpackaged LED dies of the at least one first light-emitting string are substantially identical to the unpackaged LED dies of the at least one second light-emitting string.

24. The system of claim 1, wherein:

the light-emitting array comprises (i) a first group of one or more light-emitting strings, and (ii) a second group of one or more light-emitting strings different from the first group,

activation of the first group and deactivation of the second group produces light having a first color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution, and

activation of the second group and deactivation of the first group produces light having a second color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution different from the first color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution.

25. The system of claim 1, wherein:

the light-emitting array comprises a first group of one or more light-emitting strings and, associated with at least one of the unpackaged LED dies of the first group, a first optical element of a first type,

the light-emitting array comprises a second group, different from the first group, of one or more light-emitting strings and, associated with at least one of the unpackaged LED dies of the second group, a second optical element of a second type different from the first type,

activation of the first group and deactivation of the second group produces light having a first color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution, and

activation of the second group and deactivation of the first group produces light having a second color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution different from the first color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution.

26. The system of claim 1, wherein:

the light-emitting array comprises a first group of one or more light-emitting strings and, associated with at least one of the unpackaged LED dies of the first group, a first light-conversion material having a first optical characteristic,

the light-emitting array comprises a second group, different from the first group, of one or more light-emitting strings and, associated with at least one of the unpackaged LED dies of the second group, a second light-conversion material having a second optical characteristic different from the first optical characteristic,

activation of the first group and deactivation of the second group produces light having a first color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution, and

activation of the second group and deactivation of the first group produces light having a second color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution different from the first color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution.

27. The system of claim 1, wherein each unpackaged LED die comprises a substrate that is substantially transparent to a wavelength of light emitted by the unpackaged LED die.