Light emitting device and fabricating method thereof

• US 8,946,987 B2
• Filed: 12/28/2012
• Issued: 02/03/2015
• Est. Priority Date: 11/07/2007
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chiang, Ya-Hui, Hsu, Chen-Peng, Hu, Hung-Lieh, Hsieh, Chia-Fen, Lu, Chien-Chun
• Primary Examiner(s): Hollweg, Thomas A
• Application Number:
  US13/730,787
• Publication Number:
  US 20130126918A1
• Time in Patent Office: 767 Days
• Field of Search: 257/80, 257/98, 257/99, 313/498, 313/501, 313/503
• US Class Current: 313/512
• 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 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• 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 33/60 Reflective elements
• CPC Class Codes: H05B 33/10 Apparatus or processes specially adapted to the manufacture of electroluminescent light sources

Abstract

A light emitting device and a fabricating method thereof are described, wherein the light emitting device includes a substrate, a wall, a first LED chip and a light conversion filling. The first LED chip is disposed on a surface of the substrate. The wall is disposed on the surface of the substrate, and surrounds the first LED chip. A first angle between a central axis of the wall and an inner surface of the wall is 0 degree or is acute, a second angle between the central axis of the wall and an outer surface of the wall is 0 degree or is acute, and the outer surface of the wall and the substrate has a space therebetween. The light conversion filling is surrounded by the light conversion wall, and is disposed on the first LED chip.

Claims

1. A light emitting device, comprising:

a substrate;

a first light emitting diode (LED) chip, disposed on a surface of the substrate;

a wall, disposed on the surface of the substrate, and surrounding the first LED chip, wherein

a first angle between a central axis of the wall and an inner surface of the wall is 0 degree or is acute,

a second angle between the central axis of the wall and an outer surface of the wall is 0 degree or is acute,

the outer surface of the wall and the substrate has a space therebetween, and

the wall partially covers a top surface of the first LED chip; and

a light conversion filling, disposed on the first LED chip and surrounded by the wall, wherein

light is emittable from both the wall and the light conversion filling, the light emitted from the wall being of a first color temperature, and the light emitted from the light conversion filling being of a second color temperature, and

the first color temperature is higher than the second color temperature.

2. The light emitting device according to claim 1, wherein the wall comprises a first fluorescent material, the light conversion filling comprises a second fluorescent material, a first wavelength of light emitted by the first fluorescent material is different from a second wavelength of light emitted by the second fluorescent material.

3. The light emitting device according to claim 1, wherein the wall comprises a first fluorescent material, the light conversion filling comprises a second fluorescent material, the first fluorescent material and the second fluorescent material are the same, and a concentration of the first fluorescent material is different from a concentration of the second fluorescent material.

4. The light emitting device according to claim 1, wherein the light conversion filling has an average width and an average height, and a ratio of the average width and the average height is 0.1:

10.

5. The light emitting device according to claim 1, wherein a refractive index of the light conversion filling is different from a refractive index of the wall.

6. The light emitting device according to claim 1, wherein the light conversion filling partially covers the substrate surrounded by the wall.

7. The light emitting device according to claim 1, further comprising:

a reflection layer, formed on at least one of an outer surface of the wall and an interface of the wall and the light conversion filling.

8. The light emitting device according to claim 1, further comprising:

a light diffusion layer, covering the first LED chip, covered by the light conversion filling, and surrounded by the wall.

9. The light emitting device according to claim 8, further comprising:

a plurality of second LED chips, disposed on the surface of the substrate, covered by the light diffusion layer, and a wavelength of light emitted by the plurality of second LED chips being different from a wavelength of light emitted by the first LED chip.

10. The light emitting device according to claim 1, further comprising:

a plurality of second LED chips, disposed on the surface of the substrate, and covered by the wall.

11. The light emitting device according to claim 10, wherein a wavelength of light emitted by the first LED chip is different from a wavelength of light emitted by the plurality of second LED chips.

12. The light emitting device according to claim 1, wherein a width of the wall is reduced gradually from the substrate toward outside along a normal of the substrate.

13. The light emitting device according to claim 1, wherein a surface of the light conversion filling protrudes away from the substrate or recesses toward the substrate.

14. A fabricating method of a light emitting device, comprising:

disposing a first LED chip on a surface of a substrate;

forming a wall on the surface of the substrate, such that

the wall surrounds the first LED chip, and partially covers a top surface of the first LED chip, and

an outer surface of the wall and the substrate have a space therebetween, light emitted from the wall being of a first color temperature; and

forming a light conversion filling in a space surrounded by the wall, and on the first LED chip, light emitted from the light conversion filling being of a second color temperature that is lower than the first color temperature.

15. The fabricating method according to claim 14, wherein a first angle between a central axis of the wall and an inner surface of the wall is 0 degree or is acute, a second angle between the central axis of the wall and the outer surface of the wall is 0 degree or is acute.

16. The fabricating method according to claim 14, wherein the light conversion filling partially covers the substrate surrounded by the wall.

17. The fabricating method according to claim 14, further comprising:

forming a plurality of second LED chips on the surface of the substrate, wherein the wall covers the plurality of second LED chips.

18. The fabricating method according to claim 17, wherein a wavelength of light emitted by the first LED chip is different from a wavelength of light emitted by the plurality of second LED chips.

19. The fabricating method according to claim 14, wherein the wall comprising a first fluorescent material, the light conversion filling comprising a second fluorescent material, a first wavelength of light emitted by the first fluorescent material is different from a second wavelength of light emitted by the second fluorescent material.

20. The fabricating method according to claim 14, wherein the wall comprising a first fluorescent material, the light conversion filling comprising a second fluorescent material, the first fluorescent material and the second fluorescent material are the same, and a first concentration of the first fluorescent material is different from a second concentration of the second fluorescent material.

21. The fabricating method according to claim 14, wherein a refractive index of the light conversion filling is different from a refractive index of the wall.

22. The fabricating method according to claim 14, wherein the light conversion filling has an average width and an average height, and a ratio of the average width and the average height is 0.1:

10.

23. The fabricating method according to claim 14, further comprising:

forming a reflection layer on at least one of an outer surface of the wall and an interface of the wall and the light conversion filling.

24. The fabricating method according to claim 14, further comprising:

forming a light diffusion layer on the first LED chip, wherein the light diffusion layer is surrounded by the wall and is covered by the light conversion filling.

25. The fabricating method according to claim 24, further comprising:

forming a plurality of second LED chips on the surface of the substrate, wherein the light diffusion layer covers the plurality of second LED chips, and a wavelength of light emitted by the plurality of second LED chips is different from a wavelength of light emitted by the first LED chip.

26. The fabricating method according to claim 14, wherein a width of the wall is reduced gradually from the substrate toward outside along a normal of the substrate.

27. The fabricating method according to claim 14, wherein a surface of the light conversion filling protrudes away from the substrate or recesses toward the substrate.