Light emitting device

• US 9,166,116 B2
• Filed: 03/15/2013
• Issued: 10/20/2015
• Est. Priority Date: 05/29/2012
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Formosa Epitaxy Incorporated (Ennostar, Inc.)
• Inventors: Pu, Chi-Chih, Yeh, Shih-Yu, Cheng, Wei-Kang, Pan, Shyi-Ming, Hong, Siang-Fu, Huang, Chih-Shu, Wang, Tzu-Hsiang, Tang, Shih-Chieh, Yang, Cheng-Kuang, Lee, Chen-Hong
• Primary Examiner(s): Patel, Ashok
• Application Number:
  US13/834,246
• Publication Number:
  US 20130320373A1
• Time in Patent Office: 949 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21V 17/10 characterised by specific fastening means or way of fastening F21V17/02 - F21V17/08 take precedence
• CPC Class Codes: F21V 21/00 Supporting, suspending, or attaching arrangements for lighting devices F21V17/00, F21V19/00 take precedence; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q, stands for supporting apparatus or articles in general F16M11/00; Hand grips
• CPC Class Codes: F21V 21/14 Adjustable mountings
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 29/85 characterised by the material liquid coolants F21V29/56
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21Y 2107/00 Light sources with three-dimensionally disposed light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/1403 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 2224/14051 Bump connectors having different shapes
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• 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 2224/48227 : connecting the wire to a bond pad of the item
• 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 2224/49107 : on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73204 : the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/83385 : Shape, e.g. interlocking features
• CPC Class Codes: H01L 2224/8592 : Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 24/14 : of a plurality of bump connectors
• CPC Class Codes: H01L 24/16 : of an individual bump connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• 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 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 33/007 : comprising nitride compounds
• CPC Class Codes: H01L 33/44 : characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/486 : adapted for surface mounting
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/508 : having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

The present invention relates to a light emitting device comprising a transparent substrate which light can pass through and at least one LED chip emitting light omni-directionally. Wherein the LED chip is disposed on one surface of the substrate and the light emitting angle of the LED chip is wider than 180°, and the light emitted by the LED chip will penetrate into the substrate and at least partially emerge from another surface of the substrate. According to the present invention, the light emitting device using LED chips can provide sufficient lighting intensity and uniform lighting performance.

Claims

1. A light emitting device, comprising:

a sapphire substrate, having a support surface, the thickness of said sapphire substrate being greater than or equal to 200 μ

m; and

at least one light emitting diode chip comprising a plurality of light emitting surfaces, disposed on said support surface of said substrate, one of said light emitting surfaces and said support surface forming a first main surface;

wherein a light emitting angle of said light emitting diode chip is wider than 180°

, and the light emitted by said light emitting diode chip penetrates into said substrate from said support surface and at least partially emerges from a second main surface corresponding to said first main surface of said sapphire substrate, the transmittance of said sapphire substrate is greater than or equal to 70% when the wavelength of the light is greater than or equal to 420 nm and less than or equal to 470 nm.

2. A light emitting device as claimed in claim 1, further comprising:

at least one diamond-like carbon film, disposed on said substrate.

3. The light emitting device of claim 1, wherein the difference between the color temperature of said first main surface and the color temperature of said second main surface is equal to or less than 1500K.

4. The light emitting device of claim 1, further comprising a wavelength conversion layer disposed on said first main surface and said second main surface, wherein said wavelength conversion layer receives at least a portion of the light emitted by said light emitting diode chip and converts the wavelength thereof.

5. The light emitting device of claim 4, wherein said wavelength conversion layer directly contacts said light emitting diode chip.

6. The light emitting device of claim 4, wherein said wavelength conversion layer does not contact said light emitting diode chip.

7. The light emitting device of claim 4, wherein said wavelength conversion layer is disposed on said first main surface and said second main surface, and the ratio of the fluorescent powder contained in said wavelength conversion layer located on different surfaces ranges from 1:

0.5 to 1;

3.

8. A light emitting device as claimed in claim 1, further comprising:

a reflector, disposed on said second main surface of said substrate.

9. The light emitting device of claim 1, wherein said light emitting device further comprising more than one light emitting diode chip, and each of said light emitting diode chips has a light emitting surface;

wherein the area of said first main surface or said second main surface is at least five times the total area of said light emitting surfaces of said light emitting diode chips.

10. A light emitting device, comprising:

a substrate, having a support surface;

at least one light emitting diode chip comprising a plurality of light emitting surfaces, disposed on said support surface of said substrate, one of said light emitting surfaces and said support surface forming a first main surface;

wherein a light emitting angle of said light emitting diode chip is wider than 180°

, and the light emitted by said light emitting diode chip penetrates into said substrate from said support surface and at least partially emerges from a second main surface corresponding to said first main surface of said substrate; and

a wavelength conversion layer disposed on said first main surface and said second main surface, wherein said wavelength conversion layer receives at least a portion of the light emitted by said light emitting diode chip and converts the wavelength thereof;

wherein the ratio of the fluorescent powder contained in said wavelength conversion layer located on different surfaces ranges from 1;

0.5 to 1;

3.

11. The light emitting device of claim 10, wherein the thickness of said substrate is greater than or equal to 200 μ

m.

12. The light emitting device of claim 10, wherein the material of said substrate is selected from the group comprising aluminum oxide, sapphire, glass, plastics, and rubber.

13. The light emitting device of claim 10, wherein the difference between the color temperature of said first main surface and the color temperature of said second main surface is equal to or less than 1500K.

14. The light emitting device of claim 10, wherein said light emitting device further comprises more than one light emitting diode chip, and each of said light emitting diode chips has a light emitting surface;

wherein the area of said first main surface or said second main surface is at least five times the total area of said light emitting surfaces of said light emitting diode chips.

15. A light emitting device as claimed in claim 10, further comprising:

at least one diamond-like carbon film, disposed on said substrate.

16. A light emitting device as claimed in claim 10, further comprising:

a reflector, disposed on a said second main surface of said substrate.

17. A light emitting device, comprising:

a substrate, having a support surface; and

a plurality of light emitting diode chips, disposed on said support surface of said substrate, each said light emitting diode chip comprising a light emitting surface, and said light emitting surfaces and said support surface forming a first main surface;

wherein a light emitting angle of said light emitting diode chip is wider than 180°

;

the light emitted by said light emitting diode chip penetrates into said substrate from said support surface and at least partially emerges from a second main surface corresponding to said first main surface of said substrate; and

the area of said first main surface or said second main surface is at least five times the total area of said light emitting surfaces of said plurality of light emitting diode chips.

18. The light emitting device of claim 17, wherein the material of said substrate is selected from the group comprising aluminum oxide, sapphire, glass, plastics, and rubber.

19. The light emitting device of claim 17, wherein the difference between the color temperature of said first main surface and the color temperature of said second main surface is equal to or less than 1500K.

20. The light emitting device of claim 17, further comprising a wavelength conversion layer disposed on said light emitting diode chip, said first main surface, or said second main surface, wherein said wavelength conversion layer receives at least a portion of the light emitted by said light emitting diode chip and converts the wavelength thereof.

21. The light emitting device of claim 20, wherein said wavelength conversion layer is disposed on said first main surface and said second main surface, and the ratio of the fluorescent powder contained in said wavelength conversion layer located on different surfaces ranges from 1:

0.5 to 1;

3.

22. The light emitting device of claim 17, wherein the thickness of said substrate is greater than or equal to 200 μ

m.

23. A light emitting device as claimed in claim 17, further comprising:

at least one diamond-like carbon film, disposed on said substrate.

24. A light emitting device as claimed in claim 17, further comprising:

a reflector, disposed on a said second main surface of said substrate.