Light emitting device

• US 10,615,308 B2
• Filed: 06/01/2015
• Issued: 04/07/2020
• Est. Priority Date: 06/01/2015
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Noichi, Takuya, Kageyama, Hiroaki
• Primary Examiner(s): Gebremariam, Samuel A
• Assistant Examiner(s): Beardsley, Jonas T
• Application Number:
  US14/726,641
• Publication Number:
  US 20160351756A1
• Time in Patent Office: 1,772 Days
• CPC Class Codes: H01L 33/38 with a particular shape

Abstract

A light emitting device includes a base structure and a light emitting element. The light emitting element includes a first electrode and a second electrode. The first electrode includes a first electrode surface. The second electrode is separately provided from the first electrode. The second electrode includes a second electrode surface. The second electrode surface is spaced apart from the first electrode surface in a second direction different from a first direction. The second electrode surface includes a first part and a second part. The first part extends in a third direction different from each of the first direction and the second direction. The second part extends from the first part in the second direction. At least part of the second part has a curved profile extending from the first part when viewed in the first direction.

Claims

1. A light emitting device comprising:

a base structure including a first base surface and a second base surface opposite to the first base surface in a first direction, wherein the base structure includes a base member; and

a light emitting element configured to emit light, the light emitting element comprising;

a first electrode including a first electrode surface exposed from the second base surface to an outside of the light emitting device; and

a second electrode separately provided from the first electrode, wherein the base member includes an intermediate portion provided between the first electrode and the second electrode, wherein the second electrode includes a second electrode surface, wherein the second electrode surface is spaced apart from the first electrode surface in a second direction different from the first direction, the second electrode surface comprising;

a first part extending longitudinally in a third direction different from each of the first direction and the second direction, the first part of the second electrode surface extends within an opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device; and

a second part extending longitudinally from the first part in the second direction, at least part of the second part having a curved profile extending from the first part when viewed in the first direction, the second part of the second electrode surface extends within the opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device,

wherein the base member forms the second base surface, and wherein the base member at the second base surface includes a light reflection material to reflect light emitted from the light emitting element so that light emitted from the light emitting element is emitted out of the light emitting device through the first base surface,

wherein the second part extends from the first part toward the first electrode surface in the second direction, and

wherein the entire first electrode surface has a substantially rectangular shape defined by four sides when viewed in plan view.

2. The light emitting device according to claim 1, wherein

the second part includes extending portions extending from the first part in the second direction,

the extending portions are spaced apart from each other in the third direction,

the second electrode surface includes at least one curved edge defining at least part of the curved profile and extending from the first part, and

the at least one curved edge is provided between an adjacent two of the extending portions.

3. The light emitting device according to claim 2, wherein

the extending portions extend from the first part toward the first electrode surface in the second direction.

4. The light emitting device according to claim 2, wherein

the first part has a first length defined in the second direction,

the extending portions respectively have second lengths defined in the second direction, and

at least one of the second lengths is longer than the first length.

5. The light emitting device according to claim 4, wherein

at least two of the second lengths of the extending portions are substantially equal to each other.

6. The light emitting device according to claim 4, wherein

at least one of the second lengths of the extending portions longer than a minimum distance between the first electrode surface and the second electrode surface in the second direction.

7. The light emitting device according to claim 4, wherein

at least one of the second lengths of the extending portions is longer than a maximum distance between adjacent two of the extending portions in the third direction.

8. The light emitting device according to claim 2, wherein

the first part has a third length defined in the third direction,

the extending portions respectively have a plurality of fourth lengths in the third direction, and

the fourth lengths are shorter than the third length.

9. The light emitting device according to claim 2, wherein

the extending portions respectively has fourth lengths in the third direction, and

the fourth lengths are substantially equal to each other.

10. The light emitting device according to claim 2, wherein

at least one of the extending portions includes a larger width portion and a smaller width portion,

the larger width portion has a first width defined in the third direction,

the smaller width portion has a second width defined in the third direction, and

the first width of the larger width portion is larger than the second width of the smaller width portion.

11. The light emitting device according to claim 2, wherein

the extending portions includes a first extending portion, a second extending portion, and at least one third extending portion,

the at least one third extending portion is provided between the first extending portion and the second extending portion in the third direction,

the first extending portion has a first width defined in the third direction,

the second extending portion has a second width defined in the third direction,

the at least one third extending portion has a third width defined in the third direction, and

the third width is larger than the first width and the second width.

12. The light emitting device according to claim 1, wherein

the first part has a first length defined in the second direction,

the second part has a second length defined in the second direction, and

the second length is longer than the first length.

13. The light emitting device according to claim 12, wherein

the second length is longer than a minimum distance between the first electrode surface and the second electrode surface in the second direction.

14. The light emitting device according to claim 2, wherein

the second base surface includes at least one intermediate area provided between the adjacent two of the extending portions in the third direction when viewed from the first direction, and

the at least one intermediate area includes a substantially round end defined by the at least one curved edge.

15. The light emitting device according to claim 1, wherein

the light emitting element comprises a first semiconductor layer, a light emitting layer, and a second semiconductor layer coupled to the first semiconductor layer via the light emitting layer,

the first electrode includes a first contact surface contacting the first semiconductor layer, and

the second electrode surface is provided to avoid overlapping with an area of the first contact surface when viewed from the first direction.

16. The light emitting device according to claim 1, wherein

the curved profile is spaced apart from the area of the first contact surface when viewed from the first direction.

17. The light emitting device according to claim 16, wherein

the second part includes extending portions extending from the first part in the second direction,

the extending portions are spaced apart from each other in the third direction,

the extending portions are provided to avoid overlapping with an area of the first contact surface when viewed from the first direction, and

at least one of the extending portions is arranged to face the area of the first contact surface the second direction when viewed from the first direction.

18. The light emitting device according to claim 16, wherein

the first contact surface includes first contact parts and second contact parts,

the first contact parts are substantially aligned with each other in the third direction and each contact the first semiconductor layer,

the second contact parts are substantially aligned with each other in the third direction and each contact the first semiconductor layer, and

a total number of the second contact parts is different from a total number of the first contact parts.

19. The light emitting device according to claim 1, wherein

each of the first electrode and the second electrode is partially embedded in the base member.

20. The light emitting device according to claim 19, wherein

the base member includes a base portion and a wall protruding from the base portion in the first direction to surround the light emitting element, and

the base structure includes a light transmissive member provided between the wall and the light emitting element to cover the light emitting element.

21. The light emitting device according to claim 19, wherein

the base structure includes a wavelength conversion member to convert a first wavelength of light emitted from the light emitting element to a second wavelength different from the first wavelength, and

the wavelength conversion member is provided on a side opposite to the second base surface relative to the light emitting element.

22. The light emitting device according to claim 1, wherein

the base structure includes

a first straight side extending in the second direction when viewed from the first direction, and

a second straight side extending in the third direction when viewed from the first direction.

23. The light emitting device according to claim 1, wherein

the second electrode includes a second electrode body that extends through the base member to the opening to form the second electrode surface.

24. The light emitting device according to claim 23, wherein

the first electrode surface extends within an additional opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device, and

the first electrode includes a first electrode body that extends through the base member to the additional opening to form the first electrode surface.

25. The light emitting device according to claim 1, wherein

the first electrode surface has a substantially constant width in the second direction over an entirety of the first electrode surface.

26. A light emitting device comprising:

a base structure including a first base surface and a second base surface opposite to the first base surface in a first direction, wherein the base structure includes a base member; and

a light emitting element configured to emit light, the light emitting element comprising;

a first electrode including a first electrode surface exposed from the second base surface to an outside of the light emitting device; and

a second electrode separately provided from the first electrode, wherein the base member includes an intermediate portion provided between the first electrode and the second electrode, wherein the second electrode includes a second electrode surface and a second contact surface, wherein the second electrode surface is spaced apart from the first electrode surface in a second direction different from the first direction, wherein the second contact surface is opposite to the second electrode surface in the first direction, the second electrode surface comprising;

a first part extending longitudinally in a third direction different from each of the first direction and the second direction, the first part of the second electrode surface extends within an opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device; and

a second part extending longitudinally from the first part in the second direction, the second part overlapping with an area of the second contact surface when viewed from the first direction, the second part of the second electrode surface extends within an opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device,

wherein the base member forms the second base surface, and wherein the base member at the second base surface includes a light reflection material to reflect light emitted from the light emitting element so that light emitted from the light emitting element is emitted out of the light emitting device through the first base surface,

wherein the second part extends from the first part toward the first electrode surface in the second direction, and

wherein the entire first electrode surface has a substantially rectangular shape defined by four sides when viewed in plan view.

27. The light emitting device according to claim 26, wherein

the light emitting element includes a first semiconductor layer, a light emitting layer, and a second semiconductor layer coupled to the first semiconductor layer via the light emitting layer,

the light emitting element includes a second additional electrode contacting the second semiconductor layer, and

the second contact surface contacts the second additional electrode.

28. The light emitting device according to claim 26, wherein

the second contact surface includes at least one third contact part contacting the second additional electrode, and

the second part overlaps with an area of the at least one third contact part when viewed from the first direction.

29. The light emitting device according to claim 28, wherein

the second part includes extending portions extending from the first part in the second direction,

the extending portions are spaced apart from each other in the third direction, and

at least one of the extending portions overlaps with an area of the at least one third contact part when viewed from the first direction.

30. The light emitting device according to claim 28, wherein

the at least one third contact part includes third contact parts each contacting the second additional electrode, and

the third contact parts are arranged in the third direction.

31. The light emitting device according to claim 28, wherein

the second contact surface includes a fourth contact part contacting the second additional electrode,

the fourth contact part is spaced apart from the at least one third contact part, and

the first part overlaps with an area of the fourth contact part when viewed from the first direction.

32. The light emitting device according to claim 26, wherein

each of the first electrode and the second electrode is partially embedded in the base member.

33. The light emitting device according to claim 32, wherein

the base member includes a base portion and a wall protruding from the base portion in the first direction to surround the light emitting element, and

the base structure includes a light transmissive member provided between the wall and the light emitting element to cover the light emitting element.

34. The light emitting device according to claim 26, wherein

the base structure includes

a first straight side extending in the second direction when viewed from the first direction, and

a second straight side extending in the third direction when viewed from the first direction.

35. A light emitting device comprising:

a base structure including a first base surface and a second base surface opposite to the first base surface in a first direction, wherein the base structure includes a base member; and

a light emitting element configured to emit light, the light emitting element comprising;

a first electrode including a first electrode surface exposed from the second base surface to an outside of the light emitting device; and

a second electrode separately provided from the first electrode surface, wherein the base member includes an intermediate portion provided between the first electrode and the second electrode, wherein the second electrode includes a second electrode surface provided in the second base surface when viewed from the first direction, wherein the second electrode surface is spaced apart from the first electrode surface in a second direction different from the first direction, the second electrode surface comprising;

a first part extending in a third direction different from each of the first direction and the second direction, the first part of the second electrode surface extends within an opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device; and

a second part including extending portions extending from the first part in the second direction, the extending portions being spaced apart from each other in the third direction, each of the extending portions including a first end having a straight edge, the second part of the second electrode surface extends within an opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device,

wherein the base member forms the second base surface, and wherein the base member at the second base surface includes a light reflection material to reflect light emitted from the light emitting element so that light emitted from the light emitting element is emitted out of the light emitting device through the first base surface,

wherein the second part extends from the first part toward the first electrode surface in the second direction, and

wherein the entire first electrode surface has a substantially rectangular shape defined by four sides when viewed in plan view.

36. The light emitting device according to claim 35, wherein

the base structure includes

a first straight side extending in the second direction when viewed from the first direction, and

a second straight side extending in the third direction when viewed from the first direction.

37. A light emitting device comprising:

a base structure including a first base surface and a second base surface opposite to the first base surface in a first direction, wherein the base structure includes a base member; and

a light emitting element configured to emit light, the light emitting element comprising;

a first semiconductor layer;

a first electrode comprising;

a first electrode surface exposed from the second base surface to an outside of the light emitting device; and

a first contact surface contacting the first semiconductor layer; and

a second electrode provided separately from the first electrode, wherein the base member includes an intermediate portion provided between the first electrode and the second electrode, wherein the second electrode includes a second electrode surface, wherein the second surface is spaced apart from the first electrode surface in a second direction different from the first direction,

the second electrode surface comprising;

a first part extending longitudinally in a third direction different from each of the first direction and the second direction, the first part of the second electrode surface extends within an opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device; and

a second part extending longitudinally from the first part in the second direction, the second part being provided to avoid overlapping with an area of the first contact surface when viewed from the first direction, the second part of the second electrode surface extends within an opening on the second base surface to be exposed from the second base surface to the outside of the light emitting device,

wherein the base member forms the second base surface, and wherein the base member at the second base surface includes a light reflection material to reflect light emitted from the light emitting element so that light emitted from the light emitting element is emitted out of the light emitting device through the first base surface,

wherein the second part extends from the first part toward the first electrode surface in the second direction, and

wherein the entire first electrode surface has a substantially rectangular shape defined by four sides when viewed in plan view.

38. The light emitting device according to claim 37, wherein

the base structure includes

a first straight side extending in the second direction when viewed from the first direction, and

a second straight side extending in the third direction when viewed from the first direction.

39. A light emitting device comprising:

a base structure including a first base surface and a second base surface opposite to the first base surface in a height direction along a height of the light emitting device, the second base surface being divided by a hypothetical straight line into a first part second base surface and a second part second base surface; and

a light emitting element having a light emitting surface and an electrode side opposite to the light emitting surface in the height direction, the light emitting element being provided in the base structure such that the light emitting surface faces toward the first base surface to emit light from the first base surface, the light emitting element comprising;

a first electrode having a first electrode surface within the first part second base surface on the second base surface and provided on the electrode side to pass through the base structure such that the first electrode surface is exposed on the second base surface; and

a second electrode having a second electrode surface within the second part second base surface on the second base surface and provided on the electrode side to pass through the base structure such that the second electrode surface is exposed on the second base surface, the second electrode surface having a shape including projections projecting toward the first electrode surface when viewed in the height direction,

wherein the second part extends from the first part toward the first electrode surface in the second direction, and

wherein the entire first electrode surface has a substantially rectangular shape defined by four sides when viewed in plan view.

40. The light emitting device according to claim 39, wherein the light emitting element comprises

a semiconductor layer, and

contact surfaces separately provided on the semiconductor layer and electrically connected to the first electrode.

41. The light emitting device according to claim 39, wherein the first electrode surface, the second electrode surface, and the second base surface are provided to be substantially flush.

42. The light emitting device according to claim 40, wherein the second electrode surface has the shape including projections projecting not to overlap the contact surfaces when viewed in the height direction.

43. The light emitting device according to claim 40, wherein the first electrode and at least one of the contact surfaces overlap when viewed in the height direction.

44. The light emitting device according to claim 40, Wherein the second electrode surface has the shape including at least one recess between the projections, at least one of the contact faces being arranged in the at least one recess when viewed in the height direction.