LED lamps

• US 8,399,903 B2
• Filed: 04/25/2011
• Issued: 03/19/2013
• Est. Priority Date: 11/19/1997
• Status: Expired due to Fees

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Salam, Hassan P A
• Primary Examiner(s): STARK, JARRETT J
• Application Number:
  US13/064,899
• Publication Number:
  US 20110241062A1
• Time in Patent Office: 694 Days
• Field of Search: 257/94, 257/99, 257/E33.062
• US Class Current: 257/99
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements

Abstract

A high power LED lamp has a GaN chip placed over an AlGaInP chip. A reflector is placed between the two chips. Each of the chips has trenches diverting light for output. The chip pair can be arranged to produce white light having a spectral distribution in the red to blue region that is close to that of daylight. Also, the chip pair can be used to provide an RGB lamp or a red-amber-green traffic lamp. The active regions of both chips can be less than 50 microns away from a heat sink.

Claims

1. An LED lamp for producing incoherent visible light comprising:

an LED semiconductor structure comprising an n-layer and a p-layer overlying most of the n-layer;

first and second terminals; and

a plurality of spaced conductors on said LED semiconductor structure, each for energizing an associated underlying portion of said n-layer, the associated underlying portion being electrically common to neighboring light-generating portions of the semiconductor structure that are on opposite sides of the spaced conductor;

said plurality of spaced conductors being connected to said first terminal; and

wherein a light-generating portion of the semiconductor structure extends continuously from a vicinity of one of said spaced conductors to a vicinity of another of said spaced conductors, and

wherein, for each of said plurality of spaced conductors, there is an adjacent light-generating portion of the semiconductor structure that extends from one side of the spaced conductor to an opposite side of the spaced conductor, and

wherein, for each of at least two of said plurality of spaced conductors, p-layer parts of neighboring light generating portions of the semiconductor structure that are on opposite sides of the spaced conductor are connected to said second terminal.

2. The LED lamp according to claim 1, wherein said semiconductor structure has four light-generating outer corners;

each devoid of conductor that energizes the n-layer.

3. The LED lamp according to claim 1, wherein said p-layer is a single sheet that extends to four outer sides of said semiconductor structure.

4. The LED lamp according to claim 1, wherein said plurality of spaced conductors comprise a meandering track.

5. The LED lamp according to claim 4, wherein said n-layer has a plurality of oblique surfaces positioned between a pair of said spaced conductors, each of said oblique surfaces being in contact with non-semiconductor material and oblique to a plane that is generally parallel to said n layer.

6. The LED lamp according to claim 5, wherein said non-semiconductor material is light-passing.

7. The LED according to claim 1, wherein said spaced conductors are metallic.

8. The LED lamp according to claim 1, wherein there is a conductor contacting substantially all of the p-layer.

9. The LED lamp according to claim 1, wherein said semiconductor structure has been formed over sapphire.

10. An LED lamp for producing incoherent visible light comprising:

an LED semiconductor structure comprising an n-layer and a p-layer overlying most of the n-layer;

first and second terminals;

a plurality of spaced conductors on said LED semiconductor structure, each for energizing an associated underlying portion of said n-layer, the associated underlying portion being electrically common to neighboring light-generating portions of the semiconductor structure that are on opposite sides of the spaced conductor;

more than one of said plurality of spaced conductors being connected to said first terminal; and

wherein a first light-generating portion of the semiconductor structure lies between a pair of said spaced conductors, and

wherein, for each of at least two of said plurality of spaced conductors, p-layer parts of neighboring light generating portions of the semiconductor structure that are on opposite sides of the spaced conductor are connected to said second terminal, and

wherein the semiconductor structure has a first group of light generating portions that are connected in parallel, and a second ground of light generating portions that are connected in parallel, said first group connected in series with said second group.

11. The LED lamp according to claim 10, wherein said n-layer has a plurality of oblique surfaces positioned between a pair of said metallic conductors, each of said oblique surfaces being in contact with non-semiconductor material and oblique to a plane that is generally parallel to said n layer.

12. The LED lamp according to claim 10, wherein at least one spaced conductor is provided along a boundary between said first light generating portion and a directly adjacent second light generating portion provided on an opposite side of said at least one spaced conductor from said first light generating portion.

13. An LED lamp for producing incoherent visible light comprising:

an LED semiconductor structure comprising an n-layer and a p-layer overlying the n-layer;

first and second terminals; and

a plurality of spaced conductors on said LED semiconductor structure, each of said plurality of spaced conductors being configured to energize an associated underlying portion of said n-layer, the associated underlying portion being electrically common to neighboring light-generating portions of the semiconductor structure, said plurality of spaced conductors being connected to said first terminal,

wherein a light-generating portion of the semiconductor structure extends continuously from a vicinity of one conductor of said spaced conductors to a vicinity of another conductor of said spaced conductors,

wherein, for said one conductor, there is an adjacent light-generating portion of the semiconductor structure that extends from one side of said one conductor to an opposite side of said one conductor, and

wherein, for said one conductor, p-layer parts of neighboring light generating portions of the semiconductor structure that are on opposite sides of said one conductor are connected to said second terminal.

14. An LED lamp comprising:

an LED semiconductor structure comprising an n-layer and a p-layer overlying the n-layer;

a first terminal;

a second terminal;

a plurality of n-layer conductors connected to said first terminal, said plurality of n-layer conductors extending along said n-layer to define a plurality of light emitting element areas; and

a plurality of p-layer conductors connected to said second terminal, said plurality of p-layer conductors extending along said p-layer,

wherein a first light emitting element area is provided with a first n-layer conductor extending along a side thereof and a second n-layer conductor extending along an opposite side thereof,

wherein said first n-layer conductor is provided along a boundary between said first light emitting element area and a directly adjacent second light emitting element area provided on an opposite side of said first n-layer conductor from said first light emitting element area; and

wherein a light-generating portion of said first light emitting element area extends continuously from a vicinity of said first n-layer conductor to a vicinity of said second n-layer conductor.

15. The LED lamp according to claim 14,

wherein each light emitting element area of said plurality of light emitting element areas has an n-layer conductor extending along at least two sides thereof, and

wherein each light emitting element area of said plurality of light emitting element areas has a p-layer conductor extending through said light emitting element area.

16. The LED lamp according to claim 14,

wherein said first light emitting element area has a p-layer conductor extending therethrough, and

wherein said light-generating portion of said first light emitting element area extends from one side of said p-layer conductor to an opposite side of said p-layer conductor.

17. The LED lamp according to claim 14,

wherein said plurality of n-layer conductors are formed of a conductive material provided within a plurality of linear trenches formed within said n-layer.

18. The LED lamp according to claim 17,

wherein said plurality of linear trenches have side walls that are at an obtuse angle with respect to an upper surface of said n-layer.