LED integrated heat sink

• US 6,517,218 B2
• Filed: 12/01/2000
• Issued: 02/11/2003
• Est. Priority Date: 03/31/2000
• Status: Expired due to Term

• Current Assignee: Relume Technologies, Inc. (Revolution Lighting Technologies, Inc.)
• Original Assignee: Relume Corporation
• Inventors: Hochstein, Peter A.
• Primary Examiner(s): HUSAR, STEPHEN F
• Application Number:
  US09/727,726
• Publication Number:
  US 20010030866A1
• Time in Patent Office: 802 Days
• Field of Search: 362/294, 362/373, 362/800, 362/555, 362/545, 257/712, 361/704, 361/705, 361/712
• US Class Current: 362/294
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 45/48 with means for conducting heat from the inside to the outside of the lighting devices, e.g. with fins on the outer surface of the lighting device
• CPC Class Codes: F21V 19/001 the light sources being semiconductors devices, e.g. LEDs
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/713 in direct thermal and mechanical contact of each other to form a single system
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21W 2131/10 Outdoor lighting
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/3011 Impedance
• 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
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

An electrically driven light emitting diode (LED) assembly comprising a light emitting diode (12), first (14) and second (16) electrical leads for conducting electricity to and from the light emitting diode (12), and a heat sink (18). The assembly is characterized by the first lead (14) including the heat sink (18) for conducting electricity and heat from the light emitting diode (12) through the heat sink (18). In other words, the diode (12) conducts electricity through a heat sink (18) allowing the diode (12) to be in electrical conductivity with the heat sink (18).

Claims

1. An electrically driven light emitting diode (LED) assembly comprising;

a light emitting diode (12),

first (14) and second (16) electrical leads for conducting electricity to and from said light emitting diode (12),

a heat sink (18) having an extension (25),

said first lead (14) including said heat sink (18) for conducting electricity and heat from said light emitting diode (12) through said heat sink (18), and

an electrical insulator (28) surrounding said extension (25) for conducting thermal energy from said heat sink (18) to a heat dissipater (30) in contact with said insulator (28).

2. An assembly as set forth in claim 1 wherein said first lead (14) conducts thermal energy away from said light emitting diode (12) at a greater rate than said second lead (16).

3. An assembly as set forth in claim 1 wherein said first lead (14) has a greater capacity for thermal energy than said second lead (16).

4. An assembly as set forth in claim 1 wherein said first lead (14) has a greater cross-sectional area than said second lead (16).

5. An assembly as set forth in claim 1 wherein said first lead (14) comprises a material having a greater thermal capacity than the material comprising said second lead (16).

6. An assembly as set forth in claim 1 wherein said light emitting diode (12) is disposed on said heat sink (18), said first lead (14) being in electrical contact with said heat sink (18) and said second lead (16) being in electrical contact with said light emitting diode (12).

7. An assembly as set forth in claim 6 including an electrically and thermally conductive adhesive (22) securing said light emitting diode (12) to said heat sink (18).

8. An assembly as set forth in claim 6 including an optical body (24) encapsulating said light emitting diode (12) and at least a portion of said leads and said heat sink (18).

9. An assembly as set forth in claim 8 wherein said body (24) includes a lens (26) for transmitting light generated by said light emitting diode (12).

10. An assembly as set forth in claim 8 wherein said extension (25) extends from said body (24).

11. An assembly as set forth in claim 8 including a circuit board (32) and circuit traces (34) thereon, said leads (14 and 16) being in electrical contact with said traces (34), said circuit board (32) having an opening (36) therein, said heat sink (18) having an extension (25) extending through said opening (36) and in spaced relationship to said to said circuit board (32).

12. An assembly as set forth in claim 11 including a heat dissipater (30) disposed adjacent said circuit board (32), a thin electrical insulator (28) surrounding said extension (25) and contacting said heat dissipater (30) for conducting thermal energy from said heat sink (18) to a heat dissipater (30) and for preventing electrical conduction between said heat sink (18) and said heat dissipater (30).

13. A method of fabricating an electrically driven light emitting diode (LED) assembly including a light emitting diode (12) with first (14) and second (16) electrical leads for conducting electricity to and from said light emitting diode (12) and a heat sink (18), said method comprising the steps of;

disposing the heat sink (18) in electrical series with the first lead (14) for conducting electricity and heat from said light emitting diode (12) through the heat sink (18), and

extending the heat sink (18) and disposing an electrical insulator (28) on the extension (25) for conducting thermal energy from the heat sink (18) to a heat dissipater (30) in contact with said insulator (28) while preventing electrical conductivity between the heat sink (18) and the heat dissipater (30).

14. A method as set forth in claim 13 including disposing the light emitting diode (12) on the heat sink (18), disposing the first lead (14) in electrical contact with the heat sink (18) and disposing the second lead (16) in electrical contact with the light emitting diode (12).

15. A method as set forth in claim 14 including securing the light emitting diode (12) to the heat sink (18) by an electrically and thermally conductive adhesive (22).

16. A method as set forth in claim 15 including encapsulating the light emitting diode (12) and at least a portion of the leads (14 and 16) and the heat sink (18) in an optical body (24).

17. A method as set forth in claim 16 including forming a lens (26) in the optical body (24) for transmitting light generated by the light emitting diode (12).

18. A method as set forth in claim 16 including disposing the leads (14 and 16) in electrical contact with traces (34) on a circuit board (32) having an opening (36) therein with the extension (25) extending through the opening (36) and in spaced relationship to the to the circuit board (32).

19. A method as set forth in claim 18 including disposing a heat dissipater (30) adjacent the circuit board (32), disposing a thin electrical insulator (28) between the extension (25) and the heat dissipater (30) for conducting thermal energy from the heat sink (18) to the heat dissipater (30) for preventing electrical conduction between the heat sink (18) and the heat dissipater (30).