Light-emitting diode apparatus

• US 20080258156A1
• Filed: 09/28/2007
• Published: 10/23/2008
• Est. Priority Date: 09/29/2006
• Status: Abandoned Application

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: HATA, Masayuki
• Application Number:
  US11/864,380
• Publication Number:
  US 20080258156A1
• Time in Patent Office: Days
• US Class Current: 257/88
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/05 of an individual bonding area
• 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 2924/12041 LED
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

In a light-emitting diode apparatus, light emitted from a principal plane of an emission layer has a plurality of unequal luminous intensities depending on the in-plane azimuth angle of the principal plane of the emission layer, and at least one of a light-emitting diode chip and a package has a structure of reducing difference in the intensity of light emitted from the package according to variation in the in-plane azimuth angle of a chip-arrangement surface.

Claims

1. A light-emitting diode apparatus comprising:

a light-emitting diode chip including an emission layer having a principal plane; and

a package having a chip-arrangement surface on which said light-emitting diode chip is arranged, wherein

primary light emitted from said principal plane of said emission layer has a plurality of unequal luminous intensities depending on the in-plane azimuth angle of said principal plane of said emission layer, and

at least one of said light-emitting diode chip and said package has a structure of reducing difference in the intensity of secondary light emitted from said package according to variation in the in-plane azimuth angle of said chip-arrangement surface.

2. The light-emitting diode apparatus according to claim 1, wherein

said package is formed in a structure reducing said difference.

3. The light-emitting diode apparatus according to claim 2, wherein

said package includes a reflective surface and a surface of said reflective surface has a corrugated shape.

4. The light-emitting diode apparatus according to claim 3, wherein

the interval between projection portions of said corrugated shape has a size similar to or larger than the wavelength of said primary light.

5. The light-emitting diode apparatus according to claim 3, wherein

said package includes a support member having a recess portion, and

said reflective surface is formed by forming a surface of said recess portion in said corrugated shape and forming a reflective material on said surface of said recess portion.

6. The light-emitting diode apparatus according to claim 2, wherein

anisotropic structure relative to the in-plane direction of said chip-arrangement surface is formed on a light-emission surface of said package, thereby reducing said difference.

7. The light-emitting diode apparatus according to claim 6, wherein

said light-emission surface of said package consists of a light-transmitting member.

8. The light-emitting diode apparatus according to claim 6 wherein

said anisotropic structure has a shape in which shapes along a first direction and a second direction intersecting with said first direction respectively are different in the in-plane direction of said light-emission surface of said package, and said primary light emitted in said first direction and said primary light emitted in said second direction have unequal luminous intensities with respect to the respective in-plane azimuth angles of said principal plane of said emission layer.

9. The light-emitting diode apparatus according to claim 6, wherein

said light-emission surface of said package has a corrugated shape.

10. The light-emitting diode apparatus according to claim 6, wherein

said light-emission surface of said package is so arranged as to substantially perpendicularly extend with respect to said primary light emitted from said principal plane of said emission layer.

11. The light-emitting diode apparatus according to claim 2, wherein

said package includes a lens portion through which said primary light is transmitted, and

said lens portion has a structure in which said primary light is deflected toward the direction of the in-plane azimuth angle of said chip-arrangement surface.

12. The light-emitting diode apparatus according to claim 1, wherein

said light-emitting diode chip has a light-emission surface, and

anisotropic structure relative to the in-plane direction of said light-emission surface is formed on said light-emission surface of said light-emitting diode chip, thereby reducing said difference.

13. The light-emitting diode apparatus according to claim 12, wherein

said anisotropic structure has a shape in which shapes along a first direction and a second direction intersecting with said first direction respectively are different in the in-plane direction of said light-emission surface, and said primary light emitted in said first direction and said primary light emitted in said second direction have unequal luminous intensities with respect to the respective in-plane azimuth angles of said principal plane of said emission layer.

14. The light-emitting diode apparatus according to claim 13, further comprising a semiconductor layer formed on a surface of said emission layer, wherein

said anisotropic structure is formed in a corrugated shape formed on said light-emission surface of said semiconductor layer.

15. The light-emitting diode apparatus according to claim 14, wherein

recess portions and projection portions of said corrugated shape formed on said light-emission surface of said emission layer are so formed as to extend in said second direction.

16. The light-emitting diode apparatus according to claim 14, wherein

an interval between said projection portions of the corrugated shape formed on said light-emission surface of said semiconductor layer has a size similar to or larger than the wavelength of said primary light.

17. The light-emitting diode apparatus according to claim 1, wherein

said light-emitting diode chip includes a first light-emitting diode chip and a second light-emitting diode chip, and

said first light-emitting diode chip and said second light-emitting diode chip are arranged such that a direction of an azimuth angle having a large luminous intensity in the in-plane direction of said principal plane of said emission layer of said first light-emitting diode chip and a direction of an azimuth angle having a large luminous intensity in the in-plane direction of said principal plane of said emission layer of said second light-emitting diode chip are directed to different directions from each other in the in-plane of said chip-arrangement surface of said package, thereby reducing said difference.

18. The light-emitting diode apparatus according to claim 17, wherein

the direction of the azimuth angle having the large luminous intensity in the in-plane direction of said principal plane of said emission layer of said first light-emitting diode chip and the direction of the azimuth angle having the large luminous intensity in the in-plane direction of said principal plane of said emission layer of said second light-emitting diode chip are substantially perpendicular to each other.

19. The light-emitting diode apparatus according to claim 1, wherein

said emission layer consists of either a semiconductor having a wurtzite structure or a —

SiC, and said principal plane of said emission layer includes a plane other than a (0001) plane.

20. The light-emitting diode apparatus according to claim 19, wherein

said principal plane of said emission layer substantially includes a (H,K,−

H−

K,0) plane (H and K are integers, and at least one of H and K is not

     0).

21. The light-emitting diode apparatus according to claim 1, wherein

an oscillator strength of said emission layer with respect to linear polarization of the in-plane direction of said principal plane of said emission layer has a plurality of unequal magnitudes depending on the in-plane azimuth angle of said principal plane of said emission layer.

22. The light-emitting diode apparatus according to claim 1, wherein

appearance of said light-emitting diode chip is formed such that a direction having the largest luminous intensity and a direction having the smallest luminous intensity relative to the in-plane azimuth angles of said light-emitting diode chip can be distinguished.

23. The light-emitting diode apparatus according to claim 22, wherein

an outer shape of an upper surface of said light-emitting diode chip is substantially formed in a rectangle and a long side or a short side of the rectangle substantially coincides with the direction having the largest luminous intensity relative to said in-plane azimuth angle.