Transparent conductive oxides for plastic flat panel displays

• US 20020022156A1
• Filed: 08/24/2001
• Published: 02/21/2002
• Est. Priority Date: 11/02/1998
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Bright, Clark I.
• Granted Patent: US 7,186,465 B2
• Time in Patent Office: Days
• US Class Current: 428/698
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/545 for coating elongated substrates
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/816 Multilayers, e.g. transparent multilayers
• CPC Class Codes: H10K 50/8445 multilayered coatings having a repetitive structure, e.g. having multiple organic-inorganic bilayers
• CPC Class Codes: H10K 77/111 Flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 428/12576 Boride, carbide or nitride component
• CPC Class Codes: Y10T 428/31667 Next to addition polymer from unsaturated monomers, or aldehyde or ketone condensation product
• CPC Class Codes: Y10T 428/31678 Of metal
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31692 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31794 Of cross-linked polyester
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

The present invention employs lightweight, flexible, plastic substrates for constructing flat panel displays, packaging materials and electro luminescence lamps. The display medium must be protected from oxygen and moisture in order to avoid degradation. In the present invention, at least one layer with barrier and electrode characteristics is deposited over the substrate that has both a low enough resistivity to function as an electrode for the display and low oxygen and moisture permeability. If lower permeability and/or higher conductivity is required, multiple alternating layers of barrier materials and conductive materials can be applied. The barrier material includes a thin metallic film, an organic polymer, a thin transparent dielectric, and a thin transparent conductive oxide. The conductive material includes a thin transparent conductive oxide, a thin transparent metallic film, and/or a metal nitride. Preferably there is a Polymer Multi Layer (PML) processed base coat deposited over the substrate. The base coat produces substrate smoothing, and more importantly, in combination with another layer, the base coat has vapor barrier properties. In the preferred embodiment, a PML processed top coat barrier layer is deposited before the coating contacts a surface, such as a roller. The PML processed top coat excludes moisture and atmospheric gases that chemically degrade the device performance.

Claims

1. A composite substrate for use in flat panel displays, packaging or electro luminescence lamps comprising:

a plastic substrate; and

a first conductive barrier material deposited over the plastic substrate, the conductive barrier material including one of a thin transparent conductive oxide, and a metal nitride.

2. The composite substrate of claim 1 further comprising a first organic polymer deposited over the plastic substrate.

3. The composite substrate of claim 1 further comprising a first organic polymer deposited over the conductive barrier layer.

4. The composite substrate of claim 2 further comprising a second organic polymer deposited over the conductive barrier layer.

5. The composite substrate of claim 1 further comprising one or more additional layers of conductive barrier material deposited over the plastic substrate, the additional layers of conductive barrier material having the same material as the first conductive barrier material.

6. The composite substrate of claim 5 further comprising one or more additional layers deposited over the previously deposited conductive barrier material layer, respectively, each additional layer including one of an organic polymer, a thin transparent dielectric, a thin transparent metallic film and a thin transparent conductive oxide.

7. The composite substrate of claim 1 wherein the thin transparent metallic film is aluminum.

8. The composite substrate of claim 1 wherein the thin transparent metallic film is silver.

9. The composite substrate of claim 1 wherein the plastic substrate is one of a polyester and a polyolefin.

10. The composite substrate of claim 1 wherein the transparent conductive oxide coating is tin doped indium oxide.

11. The composite substrate of claim 1 wherein the transparent dielectric barrier is one of silicon oxide and aluminum oxide.

12. The composite substrate of claim 11 wherein the aluminum oxide is deposited by one of evaporation of the aluminum which is then converted to an oxide in an oxygen plasma and electron beam evaporation.

13. The composite substrate of claim 1 wherein the dielectric layer is deposited by a plasma assisted chemical vapor deposition process using one of an oxidizing carrier gas and inert carrier gas.

14. The composite substrate of claim 7 wherein the aluminum layer is deposited by one of vacuum metallizing and sputtering.

15. The composite substrate of claim 1 further comprising multiple alternating layers of vapor deposited crosslinked organic monomer, and transparent conductive oxide.

17. The apparatus of claim 16 wherein the substrate is coated using more than one apparatus.

19. The process of claim 18 further comprising depositing a first organic polymer over the plastic substrate.

20. The process of claim 18 further comprising depositing a first organic polymer over the conductive barrier layer.

21. The process of claim 19 further comprising depositing a second organic polymer over the conductive barrier layer.

22. The process of claim 18 further comprising depositing one or more additional layers of conductive barrier material over the plastic substrate, the additional layers of conductive barrier material having the same material as the first conductive barrier material.

23. The composite substrate of claim 22 further comprising depositing one or more additional layers over the previously deposited conductive barrier material layer, respectively, each additional layer including one of an organic polymer, a thin transparent dielectric, a thin transparent metallic film and a thin transparent conductive oxide.

24. The process of claim 19 further comprising vapor depositing and crosslinking an organic monomer to form the polymer layer.

25. The process of claim 19 further comprising liquid smoothing an organic polymer to form the polymer layer.

26. The process of claim 19 further comprising depositing the polymer layer over the previously deposited layer before the previously deposited layer contacts a surface.

27. The process of claim 18 wherein the thin transparent metallic film is aluminum.

28. The process of claim 18 wherein the thin transparent metallic film is silver.

29. The process of claim 18 wherein the plastic substrate is one of a polyester and a polyolefin.

30. The process of claim 18 wherein the transparent conductive oxide coating is tin doped indium oxide.

31. The process of claim 18 wherein the transparent dielectric barrier is one of silicon oxide and aluminum oxide.

32. The process of claim 31 further comprising depositing the aluminum oxide by one of evaporation of the aluminum which is then converted to an oxide in an oxygen plasma and electron beam evaporation.

33. The process of claim 18 further comprising depositing the dielectric layer by a plasma assisted chemical vapor deposition process using one of an oxidizing carrier gas and inert carrier gas.

34. The process of claim 27 further comprising depositing the aluminum layer by one of vacuum metallizing and sputtering.

35. The process of claim 18 wherein the transparent conductive oxide is deposited by sputtering.

36. The process of claim 35 further comprising providing hydrogen in a plasma of a vacuum chamber used in the sputtering process of the transparent conductive oxide.

37. The process of claim 18 further comprising mildly annealing the substrate before deposition of layers thereon.

38. The process of claim 37 wherein the substrate is annealed to approximately 65°

C.

16. An apparatus for fabricating a composite substrate for use in flat panel display packaging comprising one of a roll coater, a vacuum coater, an in line coating machine and an intermittent motion machine and a Gravure coating machine.

18. A process for fabricating a composite substrate for use in flat panel display packaging comprising:

providing a plastic substrate; and

depositing a first conductive barrier material over the plastic substrate, the conductive barrier material including one of a thin transparent conductive oxide, and a metal nitride.