LED lighting systems and methods

• US 10,334,735 B2
• Filed: 08/22/2012
• Issued: 06/25/2019
• Est. Priority Date: 02/14/2008
• Status: Active Grant

• Current Assignee: MetroSpec Technology LLC
• Original Assignee: MetroSpec Technology LLC
• Inventors: Holec, Henry V., Crandell, Wm. Todd
• Primary Examiner(s): Karimy, Timor
• Application Number:
  US13/592,090
• Publication Number:
  US 20130128582A1
• Time in Patent Office: 2,498 Days
• Field of Search: 257 82, 257 99, 257721, 257724, 257E33075, 257E23099, 438 28
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/09063 Holes or slots in insulating substrate not used for electrical connections
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.

Abstract

Embodiments of the invention include LED lighting systems and methods. For example, in some embodiments, an LED lighting system is included. The LED lighting system can include a flexible layered circuit structure that can include a top thermally conductive layer, a middle electrically insulating layer, a bottom thermally conductive layer, and a plurality of light emitting diodes mounted on the top layer. The LED lighting system can further include a housing substrate and a mounting structure. The mounting structure can be configured to suspend the layered circuit structure above the housing substrate with an air gap disposed in between the bottom thermally conductive layer of the flexible layered circuit structure and the housing substrate. The distance between the layered circuit structure and the support layer can be at least about 0.5 mm. Other embodiments are also included herein.

Claims

1. An LED lighting system comprising:

a flexible layered circuit structure comprising

a top thermally conductive layer;

a middle electrically insulating layer;

a bottom thermally conductive layer;

a plurality of light emitting diodes mounted on the top layer;

a housing substrate;

a mounting structure, the mounting structure comprising an engagement member that grips the flexible layered circuit structure, the mounting structure suspending the layered circuit structure above the housing substrate such that an air gap is disposed in between the bottom thermally conductive layer of the flexible layered circuit structure and the housing substrate, the air gap having a long dimension and a short dimension approximately orthogonal to the long dimension such that the long dimension is longer than the short dimension, where the air gap is open to at least one side of the long dimension of the flexible layered circuit structure, and wherein the distance between the layered circuit structure and the housing substrate is at least about 0.5 mm; and

wherein the mounting structure exerts tension outward on the flexible layered circuit structure along the lengthwise axis of the flexible layered circuit structure away from a middle of the flexible layered circuit structure.

2. The LED lighting system of claim 1, further comprising a plurality of light emitting diodes mounted on the bottom layer.

3. The LED lighting system of claim 1, further comprising an optically translucent material layer disposed over the top thermally conductive layer.

4. The LED lighting system of claim 1, wherein the distance between the layered circuit structure and the housing substrate is between about 0.5 mm and 100 mm.

5. The LED lighting system of claim 1, wherein the distance between the layered circuit structure and the housing substrate is between about 40% and 60% of the width of the flexible layered circuit structure.

6. The LED lighting system of claim 1, the mounting structure comprising a tensioner to apply tension to the flexible layered circuit structure.

7. The LED lighting system of claim 6, the tensioner providing a spring force applied to the flexible layered circuit structure.

8. The LED lighting system of claim 7, wherein the tensioner comprises a first spring and a second spring.

9. The LED lighting system of claim 6, the tensioner configured to maintain a tension force of at least one ounce (0.28 N).

10. The LED lighting system of claim 6, the tensioner configured to maintain a tension force of at least one ounce (0.28 N) despite thermal expansion of the flexible layered circuit structure of up to 1 millimeter per meter in length of the flexible circuit structure.

11. The LED lighting system of claim 1, the mounting structure comprising an item selected from the group consisting of a fastener, a hook, a pin, a clip, a spring clip, a tab, and a tab receptacle.

12. The LED lighting system of claim 1, wherein the flexible layered circuit structure has a first end and a second end, wherein the mounting structure engages the first end and the second end.

13. The LED lighting system of claim 12, wherein the flexible layered circuit structure comprises a U shape such that the first end and the second end are disposed adjacent to one another.

14. The LED lighting system of claim 1, wherein the flexible layered circuit structure has a first lateral side and a second lateral side, wherein the mounting structure engages at least one of the first lateral side and the second lateral side.

15. The LED lighting system of claim 1, the housing substrate comprising a material selected from the group consisting of organic and inorganic structural materials.

16. The LED lighting system of claim 1, wherein the light emitting diodes mounted on the top layer have a power of between 0.25 and 3 watts per inch squared of the surface area of the bottom layer.

17. The LED lighting system of claim 1, wherein the flexible circuit structure sufficient flexibility to achieve bending with a radius of curvature of at least 1 inch.

18. The LED lighting system of claim 1, the flexible layered circuit structure defining apertures, the mounting structure configured to engage the apertures to support the flexible layered circuit structure.

19. The LED lighting system of claim 1, the bottom thermally conductive layer comprising a textured surface having a surface area greater than an equally sized substantially flat surface.

20. The LED lighting system of claim 1, the bottom layer covered with a thermally conductive and emissive material.

21. The LED lighting system of claim 1, the housing substrate coated with a material to enhance heat flow across the air gap.

22. The LED lighting system of claim 1, wherein the top layer includes 0.5 to 4.0 ounces per square foot of copper, the intermediate layer includes fiberglass 0.005 to 0.020 inches thick, and the bottom layer includes 0.5 to 4.0 ounces per square foot of copper.

23. The LED lighting system of claim 1, wherein the top, intermediate, and bottom layers have a thermal resistance of less than 10 degrees Celsius per Watt.

24. The LED lighting system of claim 1, configured to have thermal transfer properties sufficient to allow the system to maintain a thermal equilibrium at or below the critical junction temperatures for the LEDs without the addition of secondary heat sinking.

25. The LED lighting system of claim 1, wherein the flexible layered circuit structure is attached to the mounting structure in a releasable manner.

26. The LED lighting system of claim 1, wherein the flexible layered circuit structure is configured for replacement.

27. The LED lighting system of claim 1, wherein the mounting structure supports the layered circuit structure such that the top surface of the layered circuit structure and the bottom surface of the layered circuit structure are substantially open to surrounding air.

28. An LED lighting system comprising:

a flexible layered circuit structure comprising

a top thermally conductive layer;

a middle electrically insulating layer;

a bottom thermally conductive layer;

a plurality of light emitting diodes mounted on the bottom layer;

a housing substrate;

a mounting structure suspending the layered circuit structure above the housing substrate by connecting to a top layer of the housing substrate and a bottom layer of the flexible layered circuit structure, where the mounting structure supports the layered circuit structure such that the top surface of the layered circuit structure and the bottom surface of the layered circuit structure are substantially open to surrounding air, and where the top layer of the housing substrate and a bottom layer of the flexible layered circuit structure approximately face one another, with an air gap disposed in between bottom thermally conductive layer of the flexible layered circuit structure and the housing substrate, wherein the distance between the layered circuit structure and the housing substrate is at least about 0.5 mm; and

wherein the mounting structure exerts tension on the flexible layered circuit structure in a direction away from the middle of the flexible layered circuit structure along the lengthwise axis of the flexible layered circuit structure such that it is maintained taut.