Ink-based layer fabrication using halftoning to control thickness

Patent metadata

Field	Value
Publication number	US-8995022-B1
Application number	US-201414458005-A
Country	US
Kind code	B1
Filing date	Aug 12, 2014
Priority date	Dec 12, 2013
Publication date	Mar 31, 2015
Grant date	Mar 31, 2015

Abstract

An ink jet process is used to deposit a material layer to a desired thickness. Layout data is converted to per-cell grayscale values, each representing ink volume to be locally delivered. The grayscale values are used to generate a halftone pattern to deliver variable ink volume (and thickness) to the substrate. The halftoning provides for a relatively continuous layer (e.g., without unintended gaps or holes) while providing for variable volume and, thus, contributes to variable ink/material buildup to achieve desired thickness. The ink is jetted as liquid or aerosol that suspends material used to form the material layer, for example, an organic material used to form an encapsulation layer for a flat panel device. The deposited layer is then cured or otherwise finished to complete the process.

First claim

What is claimed is:

1. A method of forming a layer over a substrate, the method comprising:
receiving data identifying a desired thickness of the layer;
using a processor to generate instructions for a printing mechanism to deposit droplets of ink onto the substrate according to the data, the ink carrying material to form the layer; and
wherein using the processor comprises selecting a halftone pattern in dependence on the desired thickness and generating the instructions dependent on the selected halftone pattern.

2. The method of claim 1 , wherein the data includes at least one thickness value, wherein generating the instructions includes converting the at least one thickness value to a grayscale value for each one of plural print cells and selecting the halftone pattern dependent on the grayscale values for the plural print cells.

3. The method of claim 2 , wherein generating the instructions further comprises adjusting the grayscale value for selective ones of the plural print cells.

4. The method of claim 3 , wherein adjusting the grayscale value for selective ones of the plural print cells includes doing so dependent on proximity to an edge of the layer.

5. The method of claim 1 , wherein using the processor includes dividing a substrate deposition area into plural deposition regions and selecting a halftone pattern for each of the plural deposition regions, and wherein the halftone patterns for adjacent ones of the plural deposition regions are selected to have complementary droplet patterns.

6. The method of claim 1 , wherein the method further comprises using the printing mechanism to jet droplets of a liquid to deposit the layer, including jetting substantially like-sized droplets at variable spatial frequency to influence the desired thickness.

7. The method of claim 1 , wherein:
the layer is a first layer;
the substrate comprises at least one active element and an underlying support surface;
the at least one active element includes a second layer having a first face abutting the first layer, a second face on a side of the second layer opposite the first layer, and lateral edges; and
the method further comprises using the printing mechanism to deposit the first layer as an encapsulation layer that encloses the first face, the second face and the lateral edges relative to the underlying support surface, to enclose the second layer against an external atmosphere.

8. The method of claim 7 , wherein using the printing mechanism comprises controlling an atmosphere containing the substrate during deposition of the encapsulation layer.

9. The method of claim 1 , wherein:
the layer is an encapsulation layer;
the substrate comprises a target region that is to be covered with the encapsulation layer and an exposed region that is not to be covered with the encapsulation layer; and
the method further comprises using the printing mechanism comprises to deposit the encapsulation layer in the target region but not the exposed region according to the halftone pattern.

10. The method of claim 9 , wherein:
the substrate further comprises a border region of the target region proximate to the exposed region; and
using the processor comprises adjusting a grayscale value for a print cell representing a subset of the substrate, where the print cell corresponds to the border region.

11. The method of claim 9 , wherein
the substrate further comprises a border region of the target region proximate to the exposed region; and
using the processor further comprises selecting a halftone pattern for at least one print cell corresponding to the border region that emphasizes density of droplets at a periphery of the target region which abuts the exposed region.

12. The method of claim 9 , applied as a method of fabricating a device, wherein the substrate supports active electronic elements within the target region that are to be encapsulated by the encapsulation layer, electrical contacts in the exposed region that are not to be encapsulated by the encapsulation layer, and conductive paths coupling the electrical contacts with respective ones of the active electronic elements.

13. The method of claim 9 , wherein:
using the printing mechanism comprises controlling an atmosphere containing the substrate during deposition of the encapsulation layer; and
the method further comprises forming, prior to using the printing mechanism to deposit the encapsulation layer, the electronic devices, also in presence of a controlled atmosphere, wherein the forming and the using are performed in a manner uninterrupted by exposure to an uncontrolled atmosphere.

14. The method of claim 13 , wherein the atmosphere containing the substrate during deposition and the controlled atmosphere are different.

15. The method of claim 9 , wherein:
the encapsulation layer is an organic encapsulation layer; and
using the printing mechanism to deposit the organic encapsulation layer comprises using an ink jet printing mechanism to deposit the material to form the layer, the material comprising at least one of a liquid monomer, a liquid polymer or a solvent having an organic material suspended therein.

16. The method of claim 1 , wherein the method further comprises analyzing a prior layer formation, comparing the prior layer formation with a target layer thickness, responsively updating at least one of grayscale values for plural print cells or the halftone pattern dependent on a result of the comparing, and storing an updated halftone pattern in machine-readable memory.

17. The method of claim 1 , embodied as a method of fabricating a flat panel television.

18. The method of claim 1 , embodied as a method of fabricating a solar panel.

19. The method of claim 1 , wherein:
using the processor includes
dividing an area representing the substrate into print cells, and
assigning a grayscale value to each of the print cells; and

selecting the halftone pattern comprises selecting the halftone pattern dependent on plural ones of the print cells to deposit ink at a density dependent on the grayscale values for the plural ones of the print cells.

20. The method of claim 1 , further comprising retrieving nozzle-specific droplet ejection parameters from machine-readable memory and adjusting a print pattern in dependence on the retrieved nozzle-specific droplet ejection parameters.

21. The method of claim 1 , wherein receiving the data further comprises receiving layout data, the layout data including the data identifying the desired thickness as well as data defining contours of the layer.

22. A method of forming a flat panel display, the method comprising:
receiving data identifying a desired thickness of a layer to be deposited over a substrate, the layer to form part of the flat panel display;
using a processor to select a halftone pattern dependent on the desired thickness, the halftone pattern representing a relatively more dense droplet pattern for a relatively thicker layer and a relatively less dense droplet pattern for a relatively thinner layer; and
causing an ink jet printing mechanism to deposit droplets of ink onto the substrate according to the halftone pattern, the ink carrying material to form the layer.

23. The method of claim 22 , wherein the ink comprises an organic material.

24. The method of claim 22 , wherein causing the ink jet printing mechanism to deposit droplets of ink includes controlling the ink jet printing mechanism to deposit the droplets

Assignees

• Kateeva Inc

Inventors

• Vronsky Eliyahu
• Harjee Nahid

Classifications

• H10P74/238

  comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement · CPC title

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P72/0441

  Apparatus for sealing, encapsulating, glassing, decapsulating or the like · CPC title

• H10P14/6346

  using printing, e.g. ink-jet printing · CPC title

• B41J2/21

  for multi-colour printing · CPC title