Light emitting device and method for manufacturing the same

• US 9,899,576 B2
• Filed: 08/07/2014
• Issued: 02/20/2018
• Est. Priority Date: 03/24/2011
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Beppu, Suguru, Noichi, Takuya
• Primary Examiner(s): Wright, Tucker J
• Application Number:
  US14/454,492
• Publication Number:
  US 20140346548A1
• Time in Patent Office: 1,293 Days
• 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 light emitting element having electrodes on a lower surface side thereof; a phosphor layer covering a surface of the light emitting element; a transparent covering member disposed on at least one side surface of the light emitting device; and a reflection member that covers the covering member.

Claims

1. A light emitting device, comprising:

a light emitting element having an upper surface, a lower surface opposed to the upper surface and lateral surfaces extending from the upper surface to the lower surface, the light emitting element including electrodes located at the lower surface side thereof;

a transparent covering member that continuously and directly covers the upper surface of the light emitting element and on at least one lateral surface of the light emitting element but is separated from the electrodes, the transparent covering member being made of an insulating material;

a phosphor layer covering at least the upper surface of the light emitting element via the transparent covering member; and

a reflection member extending around a portion of lateral surfaces of the transparent covering member, the reflection member comprising a transparent material and a plurality of insulating reflective particles disposed in the transparent material, and

wherein a width of the reflection member, measured from an inner periphery of the reflection member to an outer periphery of the reflection member, is smaller than an outer width of the light emitting element.

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

3. The light emitting device according to claim 2, wherein the phosphor layer has a rectangular shape in a plan view of the light emitting device.

4. The light emitting device according to claim 2, wherein the phosphor layer has a uniform thickness.

5. The light emitting device according to claim 2, wherein the reflection member extends in an outward direction from the phosphor layer and the transparent covering member in a plan view of the light emitting device.

6. The light emitting device according to claim 2, wherein the reflection member has a shape of a quadrilateral in a plan view of the light emitting device.

7. The light emitting device according to claim 2, wherein a lower surface of the transparent covering member is positioned higher than a lowermost surface of the reflection member.

8. The light emitting device according to claim 1, wherein the phosphor layer has a rectangular shape in a plan view of the light emitting device.

9. The light emitting device according to claim 1, wherein the phosphor layer has a uniform thickness.

10. The light emitting device according to claim 1, wherein a thickness of the phosphor layer is in a range of about 0.1 μ

m to about 100 μ

m and a thickness of the reflection member is in a range of about 0.1 μ

m to about 100 μ

m.

11. The light emitting device according to claim 1, wherein a width of each electrode of the light emitting element, in a direction extending between the lateral surfaces of the light emitting element, is smaller than a width of the light emitting element in that same direction.

12. The light emitting device according to claim 1, wherein the reflection member extends in an outward direction from the phosphor layer and the transparent covering member in a plan view of the light emitting device.

13. The light emitting device according to claim 1, wherein the reflection member has a shape of a quadrilateral in a plan view of the light emitting device.

14. The light emitting device according to claim 1, wherein a lower surface of the transparent covering member is positioned higher than a lowermost surface of the reflection member.

15. The light emitting device according to claim 1, wherein the light emitting element comprises a semiconductor layer, and the electrodes are located directly on a surface of the semiconductor layer.

16. The light emitting device according to claim 1, wherein an overall outer width of the reflection member is larger than the outer width of the light emitting element.

17. The light emitting device according to claim 1, wherein the phosphor layer includes a first portion that directly covers an upper surface of the transparent covering member, a second portion that is continuous with the first portion and directly covers at least one lateral surface of the transparent covering member, and a third portion that is continuous with the second portion and directly covers a portion of the lower surface of the light emitting element.

18. The light emitting device according to claim 17, where the third portion of the phosphor layer also directly covers lateral surfaces of the electrodes.

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

providing a light emitting element having an upper surface, a lower surface opposed to the upper surface and lateral surfaces extending from the upper surface to the lower surface, the light emitting element including electrodes;

positioning the light emitting element such that the electrodes of the light emitting element are located at the lower surface side of the light emitting element;

forming a transparent covering member that continuously and directly covers the upper surface of the light emitting element and on at least one lateral surface of the light emitting element;

forming a phosphor layer such as to cover the upper surface of the light emitting element via the transparent covering member; and

forming a reflection member so as to extend around a portion of lateral surfaces of the transparent covering member, the reflection member comprising a transparent material and a plurality of insulating reflective particles disposed in the transparent material,

wherein the transparent covering member is formed such that the electrodes are separated from the transparent covering member,

wherein a width of the reflection member, measured from an inner periphery of the reflection member to an outer periphery of the reflection member, is smaller than an outer width of the light emitting element, and

wherein, in the manufactured light emitting device, the transparent covering member is made of an insulating material.

20. The method according to claim 19, wherein the phosphor layer has a rectangular shape in a plan view of the light emitting device.

21. The method according to claim 19, wherein an upper surface of the reflection member is positioned lower than an upper surface of the phosphor layer.

22. The method according to claim 21, wherein forming the transparent covering member is carried out before forming the reflection member.

23. The method according to claim 19, wherein the phosphor layer has a uniform thickness.

24. The method according to claim 19, wherein forming the transparent covering member is carried out before forming the reflection member.

25. The method according to claim 19, wherein a thickness of the phosphor layer is in a range of about 0.1 μ

m to about 100 μ

m and a thickness of the reflection member is in a range of about 0.1 μ

m to about 100 μ

m.

26. The method according to claim 19, wherein a width of each electrode of the light emitting element, in a direction extending between the lateral surfaces of the light emitting element, is smaller than a width of the light emitting element in that same direction.

27. The method according to claim 19, wherein the light emitting element comprises a semiconductor layer, and the electrodes are located directly on a surface of the semiconductor layer.

28. The method according to claim 19, wherein an overall outer width of the reflection member is larger than the outer width of the light emitting element.

29. The method according to claim 19, wherein the phosphor layer includes a first portion that directly covers an upper surface of the transparent covering member, a second portion that is continuous with the first portion and directly covers at least one lateral surface of the transparent covering member, and a third portion that is continuous with the second portion and directly covers a portion of the lower surface of the light emitting element.

30. The method according to claim 29, where the third portion of the phosphor layer also directly covers lateral surfaces of the electrodes.