Semiconductor light source using a primary and secondary heat sink combination

• US 20030039120A1
• Filed: 08/24/2001
• Published: 02/27/2003
• Est. Priority Date: 08/24/2001
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: CAO Group, Inc.
• Inventors: Cao, Densen
• Granted Patent: US 6,634,771 B2
• Time in Patent Office: Days
• US Class Current: 362/227
• 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 3/04 characterised by materials, surface treatments or 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 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• 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 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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: Y10S 362/80 Light emitting diode

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,

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,

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.

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

3. A devices 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 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.

6. 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.

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

8. A semiconductor light source for creating white 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 mounted on it,

a plurality of primary heat sinks being located on said secondary heat sink, said primary heat sinks being smaller in physical volume than said secondary heat sink,

a well located on at least one of said primary heat sinks,

a semiconductor chip being capable of emitting light located in said well,

a transparent material located in said well and covering said chip, said transparent material being capable of converting monochromatic light emitted by said chip to white light, and

a dome located over said primary heat sink.

9. A device as recited in claim 8 further comprising a wall in said well, said wall serving to reflect light emitted by said chip to said dome.

10. A device as recited in claim 8 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.

11. A device as recited in claim 9 further comprising a quantity of light reflective adhesive located between said chip and said primary heat sink.

12. A device as recited in claim 10 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.

13. A semiconductor light source for creating white 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 heat sink located in said interior volume, said secondary heat sink being capable of drawing heat from one or more semiconductors devices mounted on it,

a plurality of vertical cavity surface emitting laser chips capable of emitting light mounted on said heat sink,

said vertical cavity surface emitting laser chips including

a substrate,

a plurality of epitaxial layers of semiconductor materials,

panel of a conductive material located on said semiconductor materials, and

a plurality of apertures in said panel, said apertures being formed to permit light to pass therethrough,

and

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

14. A device as recited in claim 13 wherein said panel of conductive material includes a material selected from the group consisting of Au/Ge and Au/Zn.

15. A devices as recited in claim 13 further comprising a primary heat sink mounted on said heat sink, said primary heat sink having one of said vertical cavity surface emitting laser chips mounted on it.

16. A device as recited in claim 15 further comprising a dome covering said chip mounted on said primary heat sink.