High power LED lamp structure using phase change cooling enhancements for LED lighting products

• US 6,452,217 B1
• Filed: 06/30/2000
• Issued: 09/17/2002
• Est. Priority Date: 06/30/2000
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Minnear, William P., Wojnarowski, Robert J.
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): MONDT, JOHANNES P
• Application Number:
  US09/607,700
• Time in Patent Office: 809 Days
• Field of Search: 257/88, 257/98, 257/99, 257/100, 362/555, 362/339, 362/296, 362/241, 362/252, 362/341, 362/327, 362/329, 362/800, 362/293, 362/260, 362/294, 362/7
• US Class Current: 257/99
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21L 4/027 the light sources being a LED
• CPC Class Codes: F21V 29/87 Organic material, e.g. filled polymer composites; Thermo-conductive additives or coatings therefor
• CPC Class Codes: F21W 2111/10 for personal use, e.g. hand-held
• 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: H01L 2224/05553 being rectangular
• CPC Class Codes: H01L 2224/48091 Arched
• 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: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 33/642 characterized by the shape
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

High power LED lamps for use in lighting products, such as flashlights and the like, are formed of a plurality of LED die arranged in a multi-dimensional array, each of the LED die having a gallium nitride semiconductor layer and phosphor material for creation of white light. Each of the LED die emits light from the top, bottom and sides of the die and is arranged on the multi-dimensional array so that the emitted light from each of the die does not contact another die. A reflector gathers and focuses the light from each of the die to approximate a high power LED lamp. A thermally conducting, electrically insulating material or phase change material is incorporated into the lamp to act as a source of heat removal.

Claims

1. An LED lamp comprising:

a plurality of LED die arranged in a multi-dimensional array, each of the LED die having a transparent substrate and a semiconductor material deposited on a surface of the substrate, each of the LED die emitting light in a plurality of directions including from the sides of the die, each of the LED die arranged on the multi-dimensional array so that the emitted light from the sides of each of the LED die does not contact another of the LED die; and

at least one reflecting surface arranged relative to the plurality of LED die comprising the multi-dimensional array such that the arrangement of the LED die and the at least one reflecting surface cooperate to direct light emitted from the sides of the LED die outward from the LED lamp;

wherein the multi-dimensional array is formed in a three-dimensional trapezoidal shape.

2. The LED lamp of claim 1 wherein the reflector is formed of a polymer having a lower optical index than that of the transparent substrate.

3. The LED lamp of claim 1 wherein the reflector has a mirrored surface.

4. The LED lamp of claim 1 wherein the LED die are attached to the multi-dimensional array using a solder or a silver-filled epoxy.

5. The LED lamp of claim 1 wherein the transparent substrate is sapphire (Al₂O₃).

6. The LED lamp of claim 1 wherein at least one of the LED die comprises wire bonds for attachment of the LED die to the multi-dimensional array.

7. The LED lamp of claim 1 wherein at least one of the LED die is formed in a flip chip arrangement.

8. The LED lamp of claim 1 wherein the LED die are in a wire-bonded format, a flip chip format or a combination thereof.

9. The LED lamp of claim 1 wherein the multi-dimensional array is comprised of a thermally conducting, electrically insulating epoxide.

10. The LED lamp of claim 1 further comprising a molded insert formed of a thermally conducting, electrically insulating material, the reflector formed on a surface of the molded insert, the molded insert serving as a source of heat removal from the LED lamp.

11. The LED lamp of claim 10 wherein the multi-dimensional array is attached to a surface of the molded insert.

12. The LED lamp of claim 10 wherein the molded insert is formed of a phase change material.

13. The LED lamp of claim 1 wherein each of the LED die further comprises fluorescent or phosphorescent material disposed over the LED die.

14. The LED lamp of claim 13 wherein the LED die emit light at predetermined wavelengths which is partially converted by the fluorescent or phosphorescent material into another wavelength to provide a white light.

15. The LED lamp of claim 13 further comprising an RTV layer disposed over the fluorescent or phosphorescent material.

16. The LED lamp of claim 1 wherein each of the LED die is deenergized in a predetermined order to effect dimming of the lamp.

17. The LED lamp of claim 1 for use in a flashlight.

18. The LED lamp of claim 1 wherein the semiconductor material deposited on a surface of the substrate includes:

semiconductor material deposited in the form of one or more odd-sided polygons including fewer than ten sides each.