Semiconductor light source using a heat sink with a plurality of panels

• US 6,465,961 B1
• Filed: 08/24/2001
• Issued: 10/15/2002
• Est. Priority Date: 08/24/2001
• Status: Expired due to Term

• Current Assignee: CAO Lighting, Inc. (CAO Group, Inc.)
• Original Assignee: CAO Group, Inc.
• Inventors: Cao, Densen
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Clinger, James
• Application Number:
  US09/939,340
• Time in Patent Office: 417 Days
• Field of Search: 315/58, 315/185, 313/512, 362/83.1, 362/800, 362/293, 362/230, 362/231, 362/235, 362/246, 362/249, 250/339.13
• US Class Current: 315/58
• 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 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 29/677 the fans being used for discharging
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/89 Metals
• 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 3/10 characterised by coatings
• CPC Class Codes: F21Y 2107/40 on the sides of polyhedrons, e.g. cubes or pyramids
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• 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

Abstract

A semiconductor light source for illuminating a physical space has been invented. In various embodiments of the invention, a semiconductor such as and LED chip, laser chip, LED chip array, laser array, an array of chips, or a VCSEL chip is mounted on a heat sink. The heat sink may have multiple panels for mounting chips in various orientations. The chips may be mounted directly to a primary heat sink which is in turn mounted to a multi-panel secondary heat sink. A TE cooler and air circulation may be provided to enhance heat dissipation. An AC/DC converter may be included in the light source fitting.

Claims

1. A semiconductor light source for emitting light to illuminate a space used by humans, the semiconductor light source comprising:

an enclosure, said enclosure being fabricated from a material substantially transparent to white light,

an interior volume within said enclosure,

a heat sink located in said interior volume,

said heat sink being capable of drawing heat from one or more semiconductors devices,

said heat sink having a plurality of panels on it suitable for mounting semiconductor devices thereon,

said panels on said heat sink being oriented to facilitate emission of light from the semiconductor light source in desired directions around the semiconductor light source,

at least one semiconductor chip capable of emitting light mounted on one of said panels,

said semiconductor chip being capable of emitting monochromatic light,

said semiconductor chip being selected from the group consisting of light emitting diodes, light emitting diode arrays, laser chips, LED modules, laser modules, and VCSEL chips, and

a coating for converting monochromatic light emitted by said chip to white light.

2. A device as recited in claim 1 wherein said coating is located on the interior of said enclosure.

3. A device as recited in claim 1 wherein said coating is located on said chip.

4. A device as recited in claim 1 further comprising a power module for powering the light source, said power module including a fitting for installation in a traditional light bulb socket and an AC/DC converter for converting AC power from traditional building wiring to DC power usable by a semiconductor devices.

5. A device as recited in claim 1 further comprising a quantity of heat conductive adhesive located between said chip and said heat sink and serving to conduct heat from said chip to said heat sink.

6. A device as recited in claim 1 further comprising a quantity of light reflective adhesive located between said chip and said heat sink.

7. A device as recited in claim 1 wherein said chip includes

a substrate on which epitaxial layers are grown,

a buffer layer located on said substrate, said buffer layer serving to mitigate differences in material properties between said substrate and other epitaxial layers,

a first cladding layer serving to confine electron movement within the chip, said first cladding layer being adjacent said buffer layer,

an active layer, said active layer emitting light when electrons jump to a valance state,

a second cladding layer, said second cladding layer positioned so that said active layer lies between cladding layers, and

a contact layer on which an electron may be mounted for powering said chip.

8. A device as recited in claim 7 further comprising a first and a second reflective layers, each of said first and second reflective layers being located on opposite sides of said active layer, said reflective layers serving to reflect light emitted by said active layer.

9. A device as recited in claim 8 wherein said reflective layers include multiple quantum wells.

15. A device as recited in claim 1 further comprising a quantity of heat conductive adhesive located between said chip and said primary heat sink and serving to conduct heat from said chip to said primary heat sink.

16. A device as recited in claim 1 further comprising a quantity of light reflective adhesive located between said chip and said primary heat sink.

10. A semiconductor light source for emitting light to illuminate a space used by humans, the semiconductor light source comprising:

an enclosure, said enclosure being fabricated from a material substantially transparent to white light,

a base to which said enclosure is mounted,

an interior volume within said enclosure,

a secondary heat sink located in said interior volume,

said secondary heat sink being capable of drawing heat from one or more semiconductors devices,

said secondary heat sink having a plurality of panels on it suitable for mounting primary heat sinks thereon,

said panels on said secondary heat sink being oriented to facilitate emission of light from the semiconductor light source in desired directions around the semiconductor light source,

a plurality of primary heat sinks mounted on said secondary heat sink, each of said primary heat sinks being smaller than said secondary heat sink,

a semiconductor chip capable of emitting light mounted on one of said primary heat sinks, said semiconductor chip being capable of emitting monochromatic light, said semiconductor chip being selected from the group consisting of light emitting diodes, light emitting diode arrays, laser chips, and VCSEL chips,

a coating for converting monochromatic light emitted by said chip to white light.

11. A device as recited in claim 10 wherein said coating is located on the interior of said enclosure.

12. A devices as recited in claim 10 wherein said coating is located on said chip.

13. A device as recited in claim 10 further comprising a power module for powering the light source, said power module including a fitting for installation in a traditional light bulb socket and an AC/DC converter for converting AC power from traditional building wiring to DC power usable by a semiconductor devices.

14. A device as recited in claim 10 wherein at least one of said heat sink includes a material selected from the group consisting of include copper, aluminum, silicon carbide, boron nitride natural diamond, monocrystalline diamond, polycrystalline diamond, polycrystalline diamond compacts, diamond deposited through chemical vapor deposition and diamond deposited through physical vapor deposition.

17. A semiconductor light source for emitting light to illuminate a space used by humans, the semiconductor light source comprising:

an enclosure, said enclosure being fabricated from a material substantially transparent to white light,

an interior volume within said enclosure,

a heat sink located in said interior volume,

said heat sink being capable of drawing heat from one or more semiconductors devices,

said heat sink having a plurality of panels on it suitable for mounting semiconductor devices thereon,

said panels on said heat sink being oriented to facilitate emission of light from the semiconductor light source in desired directions around the semiconductor light source,

at least one semiconductor chip module capable of emitting light mounted on one of said panels,

said semiconductor chip module including a module heat sink, a semiconductor chip mounted to said module heat sink, and a cover covering said semiconductor chip,

said semiconductor chip module being capable of emitting monochromatic light.

18. A device as recited in claim 17 wherein said chip includes a substrate on which epitaxial layers are grown,

a buffer layer located on said substrate, said buffer layer serving to mitigate differences in material properties between said substrate and other epitaxial layers,

a first cladding layer serving to confine electron movement within the chip, said first cladding layer being adjacent said buffer layer,

an active layer, said active layer emitting light when electrons jump to a valance state, and

a second cladding layer, said second cladding layer positioned so that said active layer lies between cladding layers.

19. A device as recited in claim 17 wherein at least one of said heat sinks includes a material selected from the group consisting of include copper, aluminum, silicon carbide, boron nitride, natural diamond, monocrystalline diamond, polycrystalline diamond, polycrystalline diamond compacts, diamond deposited through chemical vapor deposition and diamond deposited through physical vapor deposition.

20. A semiconductor light source for emitting light to illuminate a space used by humans, the semiconductor light source comprising:

an enclosure, said enclosure being fabricated from a material substantially transparent to white light,

an interior volume within said enclosure,

a heat sink located in said interior volume,

said heat sink being capable of drawing heat from one or more semiconductors devices,

said heat sink including a material selected from the group consisting of include copper, aluminum, silicon carbide, boron nitride, natural diamond, monocrystalline diamond, polycrystalline diamond, polycrystalline diamond compacts, diamond deposited through chemical vapor deposition and diamond deposited through physical vapor deposition,

said heat sink having a plurality of panels on it suitable for mounting semiconductor devices thereon,

said panels on said heat sink being oriented to facilitate emission of light from the semiconductor light source in desired directions around the semiconductor light source,

at least one semiconductor chip capable of emitting light mounted on one of said panels,

said semiconductor chip being capable of emitting monochromatic light,

said semiconductor chip being selected from the group consisting of light emitting diodes, light emitting diode arrays, laser chips, LED modules, laser modules, and VCSEL chips,

said chip including

a substrate on which epitaxial layers are grown,

a buffer layer located on said substrate, said buffer layer serving to mitigate differences in material properties between said substrate and other epitaxial layers,

a first cladding layer serving to confine electron movement within the chip, said first cladding layer being adjacent said buffer layer,

an active layer, said active layer emitting light when electrons jump to a valance state,

a second cladding layer, said second cladding layer positioned so that said active layer lies between cladding layers, and

a coating for converting monochromatic light emitted by said chip to white light.