Tiles for solid state lighting panels

• US 20070115670A1
• Filed: 11/17/2006
• Published: 05/24/2007
• Est. Priority Date: 11/18/2005
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Roberts, John, You, Chenhua, Sims, Paul
• Granted Patent: US 7,993,021 B2
• Time in Patent Office: Days
• US Class Current: 362/367
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133613 characterized by the sequence of light sources
• CPC Class Codes: G09F 9/35 being liquid crystals G09F9/302 takes precedence; liquid crystal materials C09K19/00; liquid crystal panels comprising a number of electrodes in a single cell per se G02F1/13
• CPC Class Codes: H01L 2224/45014 Ribbon connectors, e.g. rectangular cross-section
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/85205 Ultrasonic bonding
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/206 Length ranges
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05K 1/142 Arrangements of planar printed circuit boards in the same plane, e.g. auxiliary printed circuit insert mounted in a main printed circuit
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 3/0058 Laminating printed circuit boards onto other substrates, e.g. metallic substrates H05K1/0281 takes precedence
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A solid state lighting tile includes a substrate and a plurality of lighting element clusters on a surface of the substrate. Respective ones of the plurality of lighting element clusters include first and second mounting positions configured to receive solid state light emitting devices, and at least first and second ones of the solid state lighting element clusters may be electrically connected in series. The tile further includes a plurality of solid state light emitting devices configured to emit a first color light, and respective ones of the solid state light emitting devices may be mounted in respective ones of the plurality of solid state lighting element clusters. One of the first color light emitting devices is mounted in the first mounting position of the first solid state lighting element cluster and a second of the first color light emitting devices is mounted in the second mounting position of the second solid state lighting element cluster.

Claims

1. A solid state lighting tile, comprising:

a substrate;

a plurality of lighting element clusters on a surface of the substrate, wherein respective ones of the plurality of lighting element clusters include first and second mounting positions configured to receive solid state light emitting devices, wherein at least first and second ones of the lighting element clusters are electrically connected in series;

a plurality of solid state light emitting devices configured to emit a first color light, wherein respective ones of the solid state light emitting devices are mounted in respective ones of the plurality of lighting element clusters, and wherein one of the first color light emitting devices is mounted in the first mounting position of the first lighting element cluster and a second of the first color light emitting devices is mounted in the second mounting position of the second lighting element cluster.

2. The solid state lighting tile of claim 1, further comprising:

a third lighting element cluster connected in series with the first and second lighting element clusters;

wherein respective ones of the lighting element clusters include a third mounting position configured to receive a solid state light emitting device; and

wherein a third of the first color light emitting devices is mounted in the third mounting position of the third lighting element cluster.

3. The solid state lighting tile of claim 2, wherein the first, second and third of the first color light emitting devices are electrically connected in series.

4. The solid state lighting tile of claim 1, wherein the first mounting position of a lighting element cluster is rotationally offset from the second mounting position of the lighting element cluster relative to a center of the lighting element cluster.

5. The solid state lighting tile of claim 4, wherein the respective ones of the lighting element clusters include a third mounting position configured to receive a solid state light emitting device.

6. The solid state lighting tile of claim 5, wherein the third mounting position of the lighting element cluster is rotationally offset from the first and second mounting positions relative to the center of the lighting element cluster.

7. The solid state lighting tile of claim 1, further comprising a reflector panel on the surface of the substrate, the reflector panel including a plurality of apertures aligned with respective ones of the plurality of lighting element clusters.

8. The solid state lighting tile of claim 7, wherein the reflector panel comprises a diffuse reflector.

9. The solid state lighting tile of claim 8, wherein the reflector panel comprises MCPET.

10. The solid state lighting tile of claim 1, wherein respective ones of the lighting element clusters comprise an encapsulant dome over the solid state lighting devices.

11. The solid state lighting tile of claim 10, wherein respective ones of the mounting positions comprise a mounting pad and an electrical lead extending away from the mounting pad, wherein respective ones of the lighting element clusters further comprise a solder mask exposing the mounting positions of the respective lighting element clusters, and wherein the encapsulant dome of a respective lighting element cluster covers the mounting pads and the electrical leads of the lighting element cluster.

12. The solid state lighting tile of claim 10, further comprising electrical test pads adjacent one of the lighting element clusters, the electrical test pads configured to permit individual testing of the light emitting devices of the one of the lighting element clusters.

13. The solid state lighting tile of claim 1, wherein the first and second lighting element clusters are connected in series in a first path extending from a first end of the substrate to a second end of the substrate opposite from the first end, the lighting panel further comprising third and fourth lighting element clusters connected in series in a second path and extending parallel to the first string from the second end of the substrate to the first end of the substrate.

14. The solid state lighting tile of claim 13, further comprising a retention hole therethrough, the retention hole being located near the center of a triangle formed by the first and second lighting element clusters in the first string and one of the third or fourth lighting element clusters of the second string.

15. The solid state lighting tile of claim 1, further comprising:

a third lighting element cluster defining a triangle on the tile together with the first and second lighting element clusters;

wherein respective ones of the first, second and third lighting element clusters include a third mounting position configured to receive a lighting element cluster; and

wherein a third of the first color light emitting devices is mounted in the third mounting position of the third lighting element cluster.

16. The solid state lighting tile of claim 15, wherein the first, second and third lighting element clusters are arranged to form an equilateral triangle.

17. A backlight for an LCD display including a solid state lighting tile as recited in claim 1.

18. A solid state luminaire including a solid state lighting tile as recited in claim 1.

19. A solid state lighting tile, comprising:

a substrate;

a plurality of lighting element clusters on a surface of the substrate, wherein respective ones of the plurality of lighting element clusters include first, second and third mounting positions configured to receive solid state light emitting devices;

a plurality of first solid state light emitting devices configured to emit a first color light, a plurality of second solid state light emitting devices configured to emit a second color light, and a plurality of third solid state light emitting devices configured to emit a third color light, wherein respective ones of the first, second and third solid state light emitting devices are mounted in respective ones of the plurality of lighting element clusters so that respective ones of the lighting element clusters include a first solid state light emitting device, a second solid state light emitting device, and a third solid state light emitting device;

wherein the lighting element clusters are configured such that the mounting positions of respective first, second and third light emitting devices in the lighting element clusters are not repeated in neighboring lighting element clusters.

20. The solid state lighting tile of claim 19, wherein the first mounting position of a lighting element cluster is rotationally offset from the second mounting position of the lighting element cluster relative to a center of the lighting element cluster.

21. The solid state lighting tile of claim 20, wherein the third mounting position of the lighting element cluster is rotationally offset from the first and second mounting positions relative to the center of the lighting element cluster.

22. The solid state lighting tile of claim 19, wherein the plurality of lighting element clusters comprise a first group of lighting element clusters arranged along a first line and a second group of lighting element clusters arranged along a second line that is parallel to the first line, wherein the second group of lighting element clusters is laterally offset from the first group of lighting element clusters.

23. The solid state lighting tile of claim 22, wherein the second group of lighting element clusters is offset from the first group of lighting element clusters by a distance d that is about half the spacing between adjacent ones of the lighting element clusters in the first group of lighting element clusters.

24. A backlight for an LCD display including a solid state lighting tile as recited in claim 19.

25. A solid state luminaire including a solid state lighting tile as recited in claim 19.

26. A solid state lighting tile, comprising:

a substrate;

a lighting element cluster on a surface of the substrate, the lighting element cluster comprising;

first and second die attach pads configured to receive solid state light emitting devices;

first and second wire bond pads associated with the respective first and second die attach pads;

first and second electrical traces extending away from the respective first and second die attach pads on a first side of the lighting element cluster; and

third and fourth electrical traces extending away from the respective first and second wire bond pads on a second side of the lighting element cluster opposite the first side;

wherein the second electrical trace is nearer a third side of the lighting element cluster between the first and second sides of the lighting element cluster than the first electrical trace, and the third electrical trace is nearer the third side of the lighting element cluster than the fourth electrical trace.

27. The solid state lighting tile of claim 26, wherein the lighting element cluster further comprises:

a third die attach pad configured to receive solid state a light emitting device;

a third wire bond pad associated with the third die attach pad;

a fifth electrical trace extending away from the third die attach pad on the first side of the lighting element cluster; and

a sixth electrical trace extending away from the third wire bond pads on the second side of the lighting element cluster;

wherein the fifth electrical trace is between the first and second electrical traces on the first side of the lighting element cluster, and wherein the third electrical trace is between the fourth and sixth electrical traces on the second side of the lighting element cluster.

28. The solid state lighting tile of claim 27, wherein the first die attach pad is rotationally offset from the second die attach pad relative to a center of the lighting element cluster.

29. The solid state lighting tile of claim 28, wherein the third die attach pad is rotationally offset from the first and second die attach pads relative to the center of the lighting element cluster.

30. A backlight for an LCD display including a solid state lighting tile as recited in claim 26.

31. A solid state luminaire including a solid state lighting tile as recited in claim 26.

32. A method of forming a solid state lighting tile, comprising:

defining a plurality of lighting element cluster locations on the tile, the lighting element cluster locations including first, second and third die attach pads in first, second and third mounting positions, respectively;

mounting a first light emitting device configured to emit a first color of light in a first mounting position of a first lighting element cluster location; and

mounting a second light emitting device configured to emit a color of light different than the first color of light in the first mounting position of a second lighting element cluster location neighboring the first lighting element cluster location.

33. The method of claim 32, further comprising:

mounting a third light emitting device configured to emit the first color of light in a mounting position of the second lighting element cluster location other than the first mounting position.

34. The method of claim 32, wherein the first, second and third mounting positions of respective lighting element cluster locations are rotationally offset from one another.

35. The method of claim 32, wherein defining the lighting element cluster locations comprises arranging the lighting element cluster in an array of triangles on the tile.

36. The method of claim 35, further comprising forming a retention hole positioned at the center of one of the triangles of the array of triangles.

37. The method of claim 33, further comprising:

connecting the first light emitting device in series with the third light emitting device.

38. A solid state lighting tile, comprising:

a plurality of lighting element clusters on a surface of the tile, each of which is configured to receive a plurality of different color LEDs, wherein at least two of the lighting element clusters are configured to receive the different color LEDs at different mounting positions therein.

39. The solid state lighting tile of claim 38, each of the lighting element clusters include first and second mounting positions, wherein the first mounting position of a lighting element cluster is rotationally offset from the second mounting position of the lighting element cluster relative to a center of the lighting element cluster.

40. The solid state lighting tile of claim 39, wherein each of the lighting element clusters includes a third mounting position configured to receive a solid state light emitting device, and wherein the third mounting position of the lighting element cluster is rotationally offset from the first and second mounting positions relative to the center of the lighting element cluster.