LED lamps

• US 7,947,998 B2
• Filed: 06/27/2006
• Issued: 05/24/2011
• Est. Priority Date: 11/19/1997
• Status: Expired due to Fees

• Current Assignee: Epistar Corporation
• Original Assignee: Unisplay S.A.
• Inventors: Salam, Hassan P. A.
• Primary Examiner(s): Stark; Jarrett J
• Application Number:
  US11/475,021
• Publication Number:
  US 20060237738A1
• Time in Patent Office: 1,792 Days
• Field of Search: None
• 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;

a plurality of spaced metallic conductors on said LED semiconductor structure, each of said metallic conductors having respective neighbouring light-generating portions of the semiconductor structure on opposite sides thereof;

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

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

wherein a pair of said metallic conductors are spaced apart by a light-generating portion of the semiconductor structure as viewed normal to said layers; and

wherein, for each of at least two of said plurality of spaced metallic conductors, p-layer parts of neighboring light-generating portions of the semiconductor structure that are on opposite sides of a respective metallic conductor are interconnected by metal that is over the p-layer, said interconnecting metal being metallically connected to said second terminal.

2. The LED lamp according to claim 1, wherein said n-layer has a plurality of oblique surfaces positioned between a pair of said metallic conductors as viewed normal to said n-layer, each of said oblique surfaces being in contact with light-passing non-semiconductor material and oblique to a plane that is generally parallel to said 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 semiconductor structure has been formed on sapphire.

5. The LED lamp according to claim 1, wherein said semiconductor structure comprises a plurality of light-generating sections that are electrically connected in series.

6. The LED lamp according to claim 1, wherein said semiconductor structure has four light-generating outer corners, each devoid of conductor that energises the n-layer.

7. The LED lamp according to claim 1, wherein said metal that is over the p-layer has been formed at a wafer manufacturing stage.

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

an LED semiconductor structure that has been formed over sapphire and comprising an n-layer and a p-layer overlying most of the n-layer;

first and second terminals;

a plurality of spaced metallic conductors on a top surface of said LED semiconductor structure, each of said metallic conductors having respective neighboring light-generating portions of the semiconductor structure on opposite sides thereof;

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

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

wherein a pair of said metallic conductors are spaced apart by a light-generating portion of the semiconductor structure as viewed normal to said layers; and

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

9. The LED lamp according to claim 8, wherein there are first and second elongate conductors on the n-layer.

10. The LED lamp according to claim 9, wherein said first and second elongate conductors are oblique to each other.

11. The LED lamp according to claim 8, wherein said n-layer has a plurality of oblique surfaces positioned between a pair of said metallic conductors as viewed normal to said n-layer, each of said oblique surfaces being in contact with light-passing non-semiconductor material and oblique to a plane that is generally parallel to said n layer.