Light emitting diode lamp with low thermal resistance

• US 8,278,677 B2
• Filed: 03/31/2008
• Issued: 10/02/2012
• Est. Priority Date: 03/30/2007
• Status: Expired due to Fees

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Alexander, Zhbanov
• Primary Examiner(s): Tran, Long
• Assistant Examiner(s): KLEIN, JORDAN M
• Application Number:
  US12/059,284
• Publication Number:
  US 20080237625A1
• Time in Patent Office: 1,646 Days
• Field of Search: 257/666, 257/676, 257/692, 257/696, 257/E23.043, 257/E23.045, 257/79, 257 98-100, 257/675, 257431-433
• US Class Current: 257/99
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/12041 LED
• CPC Class Codes: H01L 2924/181 Encapsulation
• 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

Disclosed is a light emitting diode lamp that has low resistance to heat emitted therefrom. The LED lamp may include a heat coupling member thermally coupling a top part of a first lead to a top part of a second lead. The LED lamp may further include one or more top parts for lowering thermal resistance of the LED lamp. This configuration facilitates heat transfer from the first lead having an LED chip mounted thereon to the top part of the second lead and/or to the other top parts, lowering resistance to heat emitted from the LED lamp.

Claims

1. A light emitting diode lamp, comprising:

a first lead having a first top part and a leg extending from the first top part;

a second lead spaced apart from the first lead, and having a second top part adjacent to the top part of the first lead and a leg extending from the second top part;

a light emitting diode mounted on the first top part;

a bonding wire connecting the light emitting diode to the second top part;

an encapsulating material surrounding the light emitting diode and the first and second top parts;

a heat coupling member thermally coupling the first top part to the second top part, the heat coupling member being formed of an insulating material having a higher thermal conductivity than the encapsulating material; and

a third top part disposed adjacent to the first top part, the third top part being spaced apart from at least one of the first and second top parts within the encapsulating material, wherein the third top part is electrically insulated from all leads in the light emitting diode lamp, and wherein the entire surface of the third top part is within the encapsulating material.

2. The light emitting diode lamp according to claim 1, wherein the heat coupling member is disposed between the first and second top parts.

3. The light emitting diode lamp according to claim 1, wherein the heat coupling member surrounds side surfaces of the first and second top parts.

4. The light emitting diode lamp according to claim 1, wherein the first top part comprises:

an upper surface having an elongated rectangular shape, the upper surface having the light emitting diode mounted thereon;

first opposite side surfaces connected to shorter edges of the upper surface and having smaller surface areas;

second opposite side surfaces connected to longer edges of the upper surface and having larger surface areas; and

a lower surface connected to the first and second opposite side surfaces.

5. The light emitting diode lamp according to claim 4, wherein the second top part is disposed adjacent to one of the first opposite side surfaces having the smaller surface areas.

6. The light emitting diode lamp according to claim 4, wherein the second top part is disposed adjacent one of the second opposite side surfaces having the larger surface areas.

7. The light emitting diode lamp according to claim 6, wherein the second top part includes side surfaces having smaller surface areas and side surfaces having larger surface areas, one of the larger side surfaces being disposed to face one of the second side surfaces of the first top part.

8. The light emitting diode lamp according to claim 7, wherein the heat coupling member is interposed between the side surfaces of the first and second top parts facing each other.

9. The light emitting diode lamp according to claim 7, wherein one of the legs extending from the first and second top parts has a twisted portion.

10. The light emitting diode lamp according to claim 1, wherein the heat coupling member thermally couples at least one of the first and second top parts to the third top part.

11. The light emitting diode lamp according to claim 1, further comprising:

a fourth top part disposed adjacent to the first top part, the fourth top part being spaced apart from at least one of the first and second top parts within the encapsulating material.

12. The light emitting diode lamp according to claim 11, wherein the first and second top parts are disposed between the third and fourth top parts.

13. The light emitting diode lamp according to claim 12, wherein the heat coupling member thermally couples the first to fourth top parts.

14. A light emitting diode lamp, comprising:

a first lead having a first top part and a leg extending from the first top part;

a second lead spaced apart from the first lead, and having a second top part adjacent to the top part of the first lead and a leg extending from the second top part;

a third top part disposed adjacent to the first top part while being spaced apart from at least one of the first and second top parts;

a light emitting diode mounted on the first top part;

a bonding wire connecting the light emitting diode to the second top part; and

an encapsulating material entirely surrounding the light emitting diode and the first to third top parts,

wherein the third top part is electrically insulated from all leads in the light emitting diode lamp.

15. The light emitting diode lamp according to claim 14, further comprising:

a heat coupling member thermally coupling at least one of the first and second top parts to the third top part.

16. The light emitting diode lamp according to claim 14, further comprising:

a fourth top part disposed adjacent to the first top part while being spaced apart from at least one of the first and second top parts, wherein the first and second top parts are disposed between the third and fourth top parts.

17. The light emitting diode lamp according to claim 16, further comprising:

a heat coupling member thermally coupling at least one of the first and second top parts to the forth top part.

18. The light emitting diode lamp of claim 14, wherein the first top part comprises an upper surface having an elongated rectangular shape, the light emitting diode being mounted on the upper surface.

19. A light emitting diode lamp, comprising:

a first lead having a first top part and a leg extending from the first top part, the first top part comprising an upper surface having an elongated rectangular shape, first opposite side surfaces connected to shorter edges of the upper surface, second opposite side surfaces connected to longer edges of the upper surface and having larger surface areas than the first opposite side surfaces, and a lower surface connected to the first opposite side surfaces and the second opposite side surfaces;

a second lead spaced apart from the first lead, and having a second top part disposed adjacent to one of the second opposite side surfaces and a leg extending from the second top part;

a light emitting diode mounted on the elongated rectangular shaped upper surface of the first top part;

a bonding wire connecting the light emitting diode to the second top part; and

an encapsulating material surrounding the light emitting diode, and the first and second top parts.

20. The light emitting diode lamp according to claim 19,

wherein the second top part comprises an upper surface having an elongated rectangular shape, first opposite side surfaces connected to shorter edges of the upper surface and having smaller surface areas, second opposite side surfaces connected to longer edges of the upper surface and having larger surface areas, and a lower surface connected to the first and second opposite side surfaces;

and

wherein one of the second side surfaces of the second top part is disposed to face one of the second side surfaces of the first top part, the leg of the second lead extends from the lower surface of the second top part, the bonding wire is bonded to the upper surface of the second top part, and one of the legs extending from the first top part and the second top part has a twisted portion.

21. The light emitting diode lamp of claim 19, further comprising a heat coupling member connecting the first top part to the second top part, the heat coupling member comprising an insulating material having a higher thermal conductivity than the encapsulating material.

22. The light emitting diode lamp of claim 19, further comprising a third top part, wherein the entire surface of the third top part is within the encapsulating material.