LIGHT EMITTING DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20120248483A1
• Filed: 03/23/2012
• Published: 10/04/2012
• Est. Priority Date: 03/24/2011
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Noichi, Takuya, Beppu, Suguru
• Granted Patent: US 8,835,957 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light emitting device includes a substrate having a conductive portion; a light emitting element having one or more electrodes on a lower surface side thereof, the electrodes being positioned on the conductive portion of the substrate; a phosphor layer disposed on a surface of the light emitting element and on a peripheral surface area of the conductive portion next to the light emitting element; and a reflection layer covering a part of the phosphor layer disposed on the peripheral surface area of the conductive portion.

Claims

1. A light emitting device, comprising:

a substrate having a conductive portion;

a light emitting element having one or more electrodes on a lower surface side thereof, the electrodes being positioned on the conductive portion of the substrate;

a phosphor layer disposed on a surface of the light emitting element and on a peripheral surface area of the conductive portion next to the light emitting element; and

a reflection layer covering a part of the phosphor layer disposed on the peripheral surface area of the conductive portion.

2. The light emitting device according to claim 1, wherein the reflection layer is positioned lower than an upper surface of the light emitting element.

3. The light emitting device according to claim 1, wherein the reflection layer covers an outer side of the part of the phosphor layer disposed on the peripheral surface area of the conductive portion.

4. The light emitting device according to claim 1,

wherein:

the conductive portion has an opening surrounding at least a portion of the light emitting element, the substrate being exposed at the opening,

the part of the phosphor layer disposed on the peripheral surface area of the conductive portion is separated from a part of the phosphor layer disposed on the surface of the light emitting element by the opening, and

the reflective layer covers an exposed area of the substrate at the opening.

5. The light emitting device according to claim 1, wherein:

the light emitting element further comprises a luminescent layer, and

the reflection layer is positioned lower than the luminescent layer.

6. The light emitting device according to claim 1, wherein an upper surface of the reflection layer is positioned higher than a lower surface of a semiconductor layer of the light emitting element.

7. The light emitting device according to claim 1, wherein an upper surface of the reflection layer is positioned higher than an upper surface of a semiconductor layer of the light emitting element.

8. The light emitting device according to claim 1, wherein the reflection layer covers an entirety of the part of the phosphor layer disposed on the peripheral surface area of the conductive portion.

9. A method for manufacturing a light emitting device, the method comprising:

connecting one or more electrodes of a light emitting element to a conductive portion of a substrate;

forming a phosphor layer on at least the light emitting element on the substrate; and

forming a reflection layer on a part of the phosphor layer around a periphery of the light emitting element.

10. The method for manufacturing the light emitting device according to claim 9, wherein:

the phosphor layer is formed on a surface of the light emitting element and on a peripheral surface area of the conductive portion next to the light emitting element, and

the reflection layer is formed on a part of the phosphor layer formed on the peripheral surface area of the conductive portion.

11. The method for manufacturing the light emitting device according to claim 9, wherein the phosphor layer is formed by an electrodeposition method or an electrostatic coating method.

12. The method for manufacturing the light emitting device according to claim 9, wherein the reflection layer is formed by an electrodeposition method or an electrostatic coating method.

13. The method for manufacturing the light emitting device according to claim 12, further comprising:

forming a covering layer having conductivity on the surface of the light emitting element before forming the phosphor layer, the phosphor layer being formed on a surface of the covering layer and on a peripheral surface area of the conductive portion next to the light emitting element; and

reforming the covering layer so as to have an insulating property after forming the phosphor layer, the reflection layer being formed on a part of the phosphor layer formed on the peripheral surface area of the conductive portion.

14. The method according to claim 9, wherein the reflection layer is positioned lower than an upper surface of the light emitting element.

15. The method according to claim 9, wherein the reflection layer is formed so as to cover an outer side of the part of the phosphor layer formed on the peripheral surface area of the conductive portion.

16. The method according to claim 9, wherein:

the conductive portion has an opening surrounding at least a portion of the light emitting element, the substrate being exposed at the opening,

the part of the phosphor layer formed on the peripheral surface area of the conductive portion is separated from a part of the phosphor layer formed on the surface of the light emitting element by the opening, and

the reflective layer is formed so as to cover an exposed area of the substrate at the opening.

17. The method according to claim 9, wherein:

the light emitting element further comprises a luminescent layer, and

the reflection layer is positioned lower than the luminescent layer.

18. The method according to claim 9, wherein an upper surface of the reflection layer is positioned higher than a lower surface of a semiconductor layer of the light emitting element.

19. The method according to claim 9, wherein an upper surface of the reflection layer is positioned higher than an upper surface of a semiconductor layer of the light emitting element.

20. The method according to claim 9, wherein the reflection layer is formed so as to cover an entirety of the part of the phosphor layer formed on the peripheral surface area of the conductive portion.