Light emitting device

• US 8,344,601 B2
• Filed: 01/21/2010
• Issued: 01/01/2013
• Est. Priority Date: 01/21/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Baek, Joong-Hyun, Lee, Hee-Jin
• Primary Examiner(s): Mai, Anh T.
• Assistant Examiner(s): COUGHLIN, ANDREW J
• Application Number:
  US12/691,156
• Publication Number:
  US 20100181887A1
• Time in Patent Office: 1,076 Days
• Field of Search: 313/11, 313/45, 313/46, 313/498
• US Class Current: 313/46
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• 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 2224/48247 connecting the wire to a bond pad of the item
• 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 2924/01066 Dysprosium [Dy]
• 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
• CPC Class Codes: H01L 33/642 characterized by the shape
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

A light emitting device with improved heat dissipation is provided. The light emitting device includes a first lead frame, a second lead frame, a light emitting element and a housing. The first lead frame includes a light emitting element mounting portion, a first heat dissipation portion extending from the light emitting element mounting portion in a first direction, and second and third heat dissipation portions extending from the light emitting element mounting portion in a second direction opposite to the first direction. The second lead frame extends in the second direction and is disposed between and spaced apart from the second and third heat dissipation portions. The light emitting element is mounted on the light emitting element mounting portion and is electrically coupled to the first and second lead frames. The housing encapsulates the first and second lead frames. The second and third heat dissipation portions have a first width and the second lead frame has a second width the same as or different from the first width.

Claims

1. A light emitting device comprising:

a first lead frame comprising a light emitting element mounting portion, a first heat dissipation portion that extends from the light emitting element mounting portion in a first direction, second and third heat dissipation portions that extend from the light emitting element mounting portion in a second direction different from the first direction, and a first protrusion disposed perpendicular to, and extending from a middle portion of, at least one of the second heat dissipation portion and the third heat dissipation portion;

a second lead frame that extends in the second direction and is disposed between and spaced apart from the second and third heat dissipation portions;

a light emitting element that is disposed on the light emitting element mounting portion and electrically coupled to the first and second lead frames; and

a housing that encapsulates the first and second lead frames,

wherein each of the second and third heat dissipation portions has a first width, and the second lead frame has a second width the same as or different from the first width.

2. The light emitting device of claim 1, wherein the first direction is opposite to the second direction.

3. The light emitting device of claim 2, wherein the second width is less than the first width.

4. The light emitting device of claim 1, wherein a ratio of the first width to the second width is in a range between 1:

1 and 4;

1.

5. The light emitting device of claim 1, wherein the first heat dissipation portion, the light emitting element, and the second lead frame are coplanar with one another.

6. The light emitting device of claim 1, wherein the first lead frame further comprises a second protrusion that is disposed perpendicular to the first heat dissipation portion.

7. The light emitting device of claim 1, wherein the second lead frame includes an extension having the second width and a power applying part connected to the extension and having a third width.

8. The light emitting device of claim 7, wherein the third width is less than the second width.

9. The light emitting device of claim 7, wherein the extension is disposed closer to the first heat dissipation portion than the power applying part.

10. The light emitting device of claim 1, wherein the first heat dissipating portion has a fourth width that is less than the first width.

11. The light emitting device of claim 1, wherein the first heat dissipating portion has a fourth width that is greater than or equal to the first width.

12. The light emitting device of claim 1, wherein the light emitting element mounting portion, the first heat dissipation portion, the second heat dissipation portion, and the third heat dissipation portion have a substantially equal thickness.

13. The light emitting device of claim 12, wherein at least one of the first, second, and third heat dissipation portions include portions having different heights, and at least one of the first, second, and third heat dissipation portions include a portion that is exposed to a bottom surface of the housing.

14. The light emitting device of claim 13, further comprising an internal heat dissipation unit that is disposed within the housing, wherein the internal heat dissipation unit contacts the first lead frame and is exposed to the bottom surface of the housing.

15. The light emitting device of claim 14, further comprising a circuit board having heat conductive vias formed thereon and an external heat dissipation unit connected to the heat conductive vias, wherein the first and second lead frames are coupled to the heat conductive vias.

16. The light emitting device of claim 13, further comprising a circuit board having heat conductive vias formed thereon and an external heat dissipation unit connected to the heat conductive vias, wherein the first and second lead frames are coupled to the heat conductive vias.

17. The light emitting device of claim 12, wherein each of the first, second, and third heat dissipating portions comprises an extending part that extends from the light emitting element mounting portion, a height adjusting part that extends from the extending part, and an exposed heat dissipation part that extends from the height adjusting part.

18. The light emitting device of claim 17, wherein the extending parts of the first, second, and third heat dissipating portions have a different height from the exposed heat dissipation parts of the first, second and third heat dissipating portions, respectively.

19. The light emitting device of claim 18, wherein the exposed heat dissipation part of each of the first, second, and third heat dissipating portions is exposed to a bottom surface of the housing.

20. The light emitting device of claim 1, wherein at least one of the first lead frame and the second lead frame extends outside of the housing.

21. The light emitting device of claim 1, wherein each of the light emitting element mounting portion, the first heat dissipation portion, the second heat dissipation portion, and the third heat dissipation portion includes a planar part and an exposed part that extends from the planar part toward a bottom surface of the housing and is exposed to the bottom surface of the housing.

22. A light emitting apparatus comprising:

a transparent substrate;

a plurality of light emitting devices that is disposed on the transparent substrate in a line type structure;

a phosphor layer and a transparent resin that are arranged in a line type structure and enclose the plurality of light emitting devices;

wherein each light emitting device of the plurality of light emitting devices comprises;

a first lead frame comprising a light emitting element mounting portion, a first heat dissipation portion that extends from the light emitting element mounting portion in a first direction, second and third heat dissipation portions that extend from the light emitting element mounting portion in a second direction different from the first direction, and a first protrusion disposed perpendicular to, and extending from a middle portion of, at least one of the second heat dissipation portion and the third heat dissipation portion;

a second lead frame that extends in the second direction and is disposed between and spaced apart from the second and third heat dissipation portions;

a light emitting element that is disposed on the light emitting element mounting portion and electrically coupled to the first and second lead frames; and

a housing that encapsulates the first and second lead frames,

wherein each of the second and third heat dissipation portions has a first width, and the second lead frame has a second width the same as or different from the first width.

23. A light emitting apparatus comprising:

a transparent substrate;

a plurality of light emitting devices disposed on the transparent substrate in a dot type structure;

a plurality of phosphor layers and a plurality of transparent resins arranged in a dot type structure, wherein each phosphor layer of the plurality of phosphor layers and each transparent resin of the plurality of transparent resins enclose a corresponding light emitting device of the plurality of light emitting devices;

wherein each light emitting device of the plurality of light emitting devices comprises;

a first lead frame comprising a light emitting element mounting portion, a first heat dissipation portion that extends from the light emitting element mounting portion in a first direction, second and third heat dissipation portions that extend from the light emitting element mounting portion in a second direction different from the first direction, and a first protrusion disposed perpendicular to, and extending from a middle portion of, at least one of the second heat dissipation portion and the third heat dissipation portion;

a second lead frame that extends in the second direction and is disposed between and spaced apart from the second and third heat dissipation portions;

a light emitting element that is disposed on the light emitting element mounting portion and electrically coupled to the first and second lead frames; and

a housing that encapsulates the first and second lead frames,

wherein each of the second and third heat dissipation portions has a first width, and the second lead frame has a second width that is the same as or different from the first width.