Micro assembled LED displays and lighting elements

• US 9,520,537 B2
• Filed: 06/18/2015
• Issued: 12/13/2016
• 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
• Primary Examiner(s): Miyoshi, Jesse Y
• Application Number:
  US14/743,981
• Publication Number:
  US 20150372053A1
• Time in Patent Office: 544 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 display comprising:

a display substrate;

a first patterned metal layer on and in direct contact with a surface of the display substrate;

a dielectric layer on and in direct contact with the display substrate and the first patterned metal layer;

a polymer layer on and in direct contact with the dielectric layer, the polymer layer comprising a material different from the dielectric layer;

a plurality of light emitters on and in direct contact with a surface of the polymer layer, each light emitter of the plurality of light emitters having a first electrical connection and a second electrical connection on a same side of the respective light emitter, wherein the display substrate is non-native to the plurality of light emitters;

a plurality of vias formed through the polymer layer and dielectric layer, each via associated with a corresponding light emitter of the plurality of light emitters; and

a second patterned metal layer, the second patterned metal layer comprising a plurality of first interconnections and a plurality of second interconnections in a single layer, each first interconnection electrically connecting a first electrical connection of a corresponding light emitter of the plurality of light emitters to the first patterned metal layer through a corresponding via of the plurality of vias and each second interconnection electrically contacting the second electrical connection of the corresponding light emitter.

2. The display of claim 1, 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.

3. The display of claim 1, wherein the plurality of light emitters comprise a plurality of inorganic light emitting diodes.

4. 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.

5. The display of claim 1, 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.

6. 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.

7. 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.

8. The display of claim 1, wherein display substrate has a transparency greater than or equal to 50%, 80%, 90%, or 95% for visible light.

9. The display of claim 1, wherein the display substrate has a contiguous display substrate area, the plurality of light emitters each have a light-emissive area, and the combined light-emissive areas of the plurality of light emitters is less than or equal to one-quarter of the contiguous display substrate area.

10. The display of claim 9, wherein the combined light-emissive areas of the plurality of light emitters is less than or equal to one eighth, one tenth, one twentieth, one fiftieth, one hundredth, one five-hundredth, one thousandth, one two-thousandth, or one ten-thousandth of the contiguous display substrate area.

11. The display of claim 1, wherein display substrate has a transparency greater than or equal to 50%, 80%, 90%, or 95% for visible light.

12. The display of claim 1, wherein the display substrate is a member selected from the group consisting of polymer, plastic, resin, polyimide, PEN, PET, metal, metal foil, glass, a semiconductor, and sapphire.

13. The display of claim 1, wherein the first patterned metal layer comprises a metal stack.

14. The display of claim 13, wherein the metal stack comprises Aluminum and Titanium.

15. The display of claim 14, wherein the Titanium is on the Aluminum.

16. The display of claim 1, wherein the polymer layer is a photosensitive negative-acting semiconductor-grade epoxy.

17. The display of claim 1, the plurality of light emitters having been micro-transfer printed on the surface of the polymer layer using a print tool.

18. The display of claim 17, wherein the print tool is a viscoelastic elastomer stamp.

19. The display of claim 1, wherein the second patterned metal layer comprises a metal stack.

20. The display of claim 1, wherein the plurality of light emitters comprises a plurality of red light emitters that emit red light, a plurality of green light emitters that emit green light, and a plurality of blue light emitters that emit blue light.