MICRO ASSEMBLED LED DISPLAYS AND LIGHTING ELEMENTS

• US 20150372052A1
• Filed: 06/18/2015
• Published: 12/24/2015
• Est. Priority Date: 06/18/2014
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA)
• Original Assignee: X-Celeprint Limited
• Inventors: Bower, Christopher, Meitl, Matthew, Gomez, David, Bonafede, Salvatore, Kneeburg, David, Fecioru, Alin, Prevatte, Carl
• Granted Patent: US 9,437,782 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 26/04 by periodically varying the intensity of light, e.g. using choppers shutters, diaphragms for cameras G03B9/00; devices for eliminating or reducing the effect of flicker in projection systems G03B21/40
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0264 Details of driving circuits
• CPC Class Codes: G09G 3/22 using controlled light sources
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/18 High density interconnect [HDI] connectors; Manufacturing methods related thereto
• CPC Class Codes: H01L 2224/73267 Layer and HDI connectors
• CPC Class Codes: H01L 2224/92244 the second connecting process involving a build-up interconnect
• CPC Class Codes: H01L 23/4821 Bridge structure with air gap
• CPC Class Codes: H01L 23/5381 Crossover interconnections, e.g. bridge stepovers
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/36 : characterised by the electrodes
• CPC Class Codes: H01L 33/38 : with a particular shape
• CPC Class Codes: H01L 33/385 : the electrode extending at least partially onto a side surface of the semiconductor body
• CPC Class Codes: H01L 33/405 : Reflective materials
• CPC Class Codes: H01L 33/48 : characterised by the semiconductor body packages
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/508 : having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements
• CPC Class Codes: H01L 33/60 : Reflective elements
• 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: H05K 1/0306 : Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/09 : Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 1/181 : associated with surface mounted components
• CPC Class Codes: H05K 1/182 : associated with components mounted in the printed circuit board, e.g. insert mounted components [IMC]
• CPC Class Codes: H05K 2201/0329 : Intrinsically conductive polymer [ICP]; Semiconductive polymer
• CPC Class Codes: H05K 2201/10106 : Light emitting diode [LED]
• CPC Class Codes: H05K 2201/10128 : Display
• CPC Class Codes: H05K 2201/10166 : Transistor
• CPC Class Codes: H05K 5/0017 : with operator interface units

Abstract

The disclosed technology provides micro-assembled micro-LED displays and lighting elements using arrays of micro-LEDs that are too small (e.g., micro-LEDs with a width or diameter of 10 μm to 50 μm), numerous, or fragile to assemble by conventional means. The disclosed technology provides for micro-LED displays and lighting elements assembled using micro-transfer printing technology. The micro-LEDs can be prepared on a native substrate and printed to a display substrate (e.g., plastic, metal, glass, or other materials), thereby obviating the manufacture of the micro-LEDs on the display substrate. In certain embodiments, the display substrate is transparent and/or flexible.

Claims

1. An inorganic light-emitting diode display, the display comprising:

a plurality of inorganic light-emitting diodes assembled in an array on a display substrate non-native to the plurality of light-emitting diodes, wherein each light-emitting diode of the array comprises a first metal terminal on a first side of the corresponding light-emitting diode horizontally separated from a second metal terminal on the first side of the same light-emitting diode by a horizontal distance, wherein the horizontal distance is from 100 nm to 20 microns.

2. The display of claim 1, wherein the display substrate has a thickness from 5 to 10 microns, 10 to 50 microns, 50 to 100 microns, 100 to 200 microns, 200 to 500 microns, 500 microns to 0.5 mm, 0.5 to 1 mm, 1 mm to 5 mm, 5 mm to 10 mm, or 10 mm to 20 mm.

3. The display of claim 1 or 2, wherein each of the plurality of light emitters has a width from 2 to 5 μ

m, 5 to 10 μ

m, 10 to 20 μ

m, or 20 to 50 μ

m.

4. The display of claim 1, wherein each of the plurality of light emitters has a length from 2 to 5 μ

m, 5 to 10 μ

m, 10 to 20 μ

m, or 20 to 50 μ

m.

5. The display of claim 1, wherein each of the plurality of light emitters has with a height from 2 to 5 μ

m, 4 to 10 μ

m, 10 to 20 μ

m, or 20 to 50 μ

m.

6. The display of claim 1, wherein a resolution of the display is 120×

90, 1440×

1080, 1920×

1080, 1280×

720, 3840×

2160, 7680×

4320, or 15360×

8640.

7. The display of claim 1, wherein each light-emitting diode comprises:

a conduction layer;

an inorganic light-emitting layer disposed on a portion of the conduction layer, the conduction layer comprising a cantilever extension extending beyond an edge of the inorganic light-emitting layer, wherein the first metal terminal is disposed on a portion of the inorganic light-emitting layer and the second metal terminal is disposed on the cantilever extension of the conduction layer, wherein a current supplied between the first metal terminal and the second metal terminal causes the inorganic light-emitting layer to emit light.

8. The display of claim 1, wherein the lateral conduction layer comprises at least one member selected from the group consisting of a metal mirror, dielectric mirror, high refractive index semiconductor, and semiconductor substantially transparent to the light emitted from the light-emitting diode, thereby forming an upward emitting display.

9. The display of claim 1, wherein the lateral conduction layer comprises at least one member selected from the group consisting of a semiconductor substantially transparent to the light emitted from the LED, transparent conductive oxide, and thin metal mesh.

12. The display of claim 1, wherein the display is a downward emitting micro-LED display such that a majority of light emitted by the plurality of light-emitting diodes is emitted through the display substrate.

13. The display of claim 12, comprising a plurality of optical reflection structures, each optical reflection structure located on a same side of a corresponding light-emitting diode of the plurality of light-emitting diodes as the first metal terminal.

14. The display of claim 12, wherein the first and second metal terminals are at least partially reflective, thereby allowing light emitted from a respective light-emitting diode to at least partially reflect off the first and second metal terminals and through a second face of each light-emitting diode, opposite the first face.

16. The display of claim 1, wherein the display is an upward emitting micro-LED display such that a majority of light emitted by the plurality of light-emitting diodes is emitted in a direction away from the display substrate.

19. The display of claim 1, comprising:

a plurality of first interconnections each electrically connected to the first metal terminal of a corresponding light-emitting diode; and

a plurality of second interconnections each electrically connected to the second metal terminal of a corresponding light-emitting diode, wherein the plurality of first interconnections and the plurality of second interconnections are on the first face.

20. The display of claim 19, wherein the plurality of first interconnection features and the plurality of second interconnection features are in a single lithography level.

21. The display of claim 20, wherein each of the plurality of first interconnections is electrically coupled to one column electrode of a plurality of column electrodes through a via of a plurality of vias in the insulator, each via associated with a light-emitting diode of the plurality of light-emitting diodes.

22. The display of claim 21, wherein the plurality of column electrodes, the plurality of first interconnections, and the plurality of second interconnections are formed by lithography with a coarser resolution than the lithography used to form the first and second metal terminals.

23. The display of claim 1, wherein each of the light-emitting diodes has a length greater or equal to two times its width.

24. The display of claim 1, wherein, for each light-emitting diode of the plurality of light-emitting diodes, the corresponding first and second metal terminals cover at least half, two-thirds, or three-quarters of the lateral footprint of the corresponding light-emitting diode.

30. The display of claim 1, wherein, for each inorganic light-emitting diode of the plurality of inorganic light-emitting diodes, the horizontal distance is of from 500 nm to 1 μ

m, 1 μ

m to 5 μ

m, 5 μ

m to 10 μ

m, or 10 μ

m to 20 μ

m.

10-11. -11. (canceled)

15. (canceled)

17-18. -18. (canceled)

25-29. -29. (canceled)

31-75. -75. (canceled)