MICRO ASSEMBLED LED DISPLAYS AND LIGHTING ELEMENTS

• US 20150372051A1
• 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, Bonafede, Salvatore, Kneeburg, David, Gomez, David, Fecioru, Alin, Prevatte, Carl
• Granted Patent: US 9,991,423 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. A micro-LED display, comprising:

a display substrate that is at least partially transparent;

an array of color-conversion structures disposed on the display substrate, each color-conversion structure comprising a color-conversion material; and

an array of micro-LEDs separate from the color-conversion structures, each micro-LED in the array of micro-LEDs disposed on a corresponding one of the color-conversion structure in the array of color-conversion structures.

2. The display of claim 1, wherein the display substrate comprises an array of recesses in which the color-conversion material(s) are located.

3. The display of claim 2, wherein the recesses are filled with the color-conversion material(s).

4. The display of claim 1, wherein the micro-LEDs are disposed on the color-conversion material(s) on a side of the color-conversion material(s) opposite the display substrate so that most or all of the light emitted from the micro-LEDs emits downward through the color-conversion material(s) and the display substrate.

5. The display of claim 1, comprising one or more reflective structures substantially covering a side of the micro-LEDs opposite the display substrate, so that the micro-LEDs reflect emitted light toward the display substrates.

6. The display of claim 5, wherein the one or more reflective structures comprise array connection metals or micro-LED contacts.

9. The display of claim 1, wherein the color-conversion material(s) comprise(s) at least one member selected from the group consisting of a phosphor-bearing gel, a phosphor-bearing resin, a phosphor ceramic, and a single-crystal phosphor.

10. The display of claim 1, wherein the color-conversion material(s) are chips of direct band gap semiconductors.

11. The display of claim 1, wherein the color-conversion material(s) at least partially surrounding the micro-LEDs.

12. The display of claim 1, comprising supplementary mirror structures on the display substrate.

13. The display of claim 1, wherein each micro-LED has an LED substrate separate from the display substrate.

14. The display of claim 1, wherein the micro-LEDs are formed in a native substrate distinct and separate from the display substrate.

15. 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.

16. The display of claim 1, wherein each micro-LED 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.

17. The display of claim 1, wherein each micro-LED 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.

18. The display of claim 1, wherein each micro-LED 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.

23. The display of claim 1, wherein each micro-LED has an anode and a cathode disposed on a same side of the respective micro-LED.

24. The display of claim 23, wherein the anode and cathode of a respective light emitter are horizontally separated by a horizontal distance, wherein the horizontal distance is from 100 nm to 500 nm, 500 nm to 1 micron, 1 micron to 20 microns, 20 microns to 50 microns, or 50 microns to 100 microns.

7. A micro-LED display, comprising:

a display substrate;

an array of micro-LEDs on the display substrate; and

an array of color-conversion structures separate from the micro-LED structures, each color-conversion structure in the array of color-conversion structures disposed on a corresponding one of the micro-LEDs in the array of micro-LEDs, wherein each color-conversion structure comprises a color-conversion material.

8. The display of claim 7, wherein the color-conversion material(s) are disposed on top of or at least partially surrounding the micro-LEDs on a side of the micro-LEDs opposite the display substrate.

19-22. -22. (canceled)

25-54. -54. (canceled)