Transparent conductive film for flat panel displays

• US 7,217,344 B2
• Filed: 11/01/2002
• Issued: 05/15/2007
• Est. Priority Date: 06/14/2002
• Status: Expired due to Term

• Current Assignee: Xylon LLC (Intellectual Ventures LLC)
• Original Assignee: Streaming Sales LLC (Intellectual Ventures LLC)
• Inventors: He, Xiao-Ming, Sasaki, Yukihiko
• Primary Examiner(s): Lavilla; Michael E.
• Application Number:
  US10/286,205
• Publication Number:
  US 20040086717A1
• Time in Patent Office: 1,656 Days
• Field of Search: 427/126.1, 427/123, 427/126.3, 427/74, 427/75, 427/124, 427/125, 427/255.5, 204/192.1, 204/192.11, 204/192.12, 204/192.14, 204/192.26, 204/192.27, 204/192.29, 204/192.38, 349/147, 349/139
• US Class Current: 204/192.26
• CPC Class Codes: C23C 14/025 Metallic sublayers
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/205 by cathodic sputtering
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 50/816 Multilayers, e.g. transparent multilayers
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/80517 Multilayers, e.g. transparent multilayers
• CPC Class Codes: H10K 59/80524 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31942 Of aldehyde or ketone condensation product

Abstract

Substrates having films are used to produce flat panel displays and similar devices. Various embodiments of transparent conductive films and methods for the same for flat panel displays and similar devices are disclosed herein.

Claims

1. A method for forming a composite film comprising:

(a) providing a flexible plastic substrate; and

(b) depositing a multi-layered conductive metallic film continuously on the flexible plastic substrate by a thin-film deposition technique, the multi-layered conductive metallic film comprising two layers of indium cerium oxide (InCeO), each InCeO layer having a thickness from about 30 nm to about 45 nm, and a layer of an alloy of silver, palladium, and copper (Ag/Pd/Cu) having a thickness from about 12 nm to about 16 nm and deposited by sputtering a target including 98.0 atomic % silver, 0.5 atomic % palladium, and 1.5 atomic % copper, with the two layers of InCeO surrounding the layer of Ag/Pd/Cu and the composite film having a transmittance of at least about 90% at 550 nm.

2. The method of claim 1 wherein the InCeO layers are deposited by DC magnetron sputtering performed at a sputter power setting of from about 300 watts to about 2000 watts.

3. The method of claim 1 wherein the InCeO layers are sputtered by DC magnetron sputtering at a sputter power of from about 600 watts to about 800 watts, and the Ag/Pd/Cu layer is sputtered at a sputter power of from about 70 watts to about 90 watts.

4. The method of claim 1 wherein the deposition technique for making the InCeO layers is sputttering in an atmosphere containing argon and oxygen.

5. The method of claim 4 wherein the flow rate of oxygen is from about 0.2 to about 2.0 standard cubic centimillitor.

6. The method of claim 1 further comprising the step of collecting the composite films in continuous rolls using a line speed during deposition of up to about 4 feet/min.

7. The method of claim 6 wherein the line speed during deposition of the InCeO layers is from about 0.3 feet/min to about 1 .2 feet/min.

8. The method of claim 7 wherein the line speed during deposition of the InCeO layers is from about 0.7 feet/mm to about 0.8 feet/min.

9. The method of claim 6 wherein the line speed during deposition of the layer of an alloy of silver, palladium, and copper is about 0.7 to about 0.8 feet/min.

10. The method of claim 1 further comprising the step of purging the surface of the flexible plastic substrate prior to film deposition, to enhance the adhesion of the film to the substrate.

11. The method of claim 10 wherein the step of purging the surface of the flexible plastic substrate prior to film deposition is performed with a plasma selected from the group consisting of the group of Ar+O₂, Ar, and Ar+N_2.

12. The method of claim 11 wherein the step of purging the surface of the flexible plastic substrate prior to film deposition is performed with an Ar+O₂ plasma.

13. The method of claim 1 wherein the flexible plastic substrate is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC), polysulfone, a phenolic resin, an epoxy resin, polyester, polyimide, polyetherester, polyetheramide, cellulose acetate, aliphatic polyurethanes, polyacrylonitrile, polytetrafluoroethylenes, polyvinylidene fluorides, poly(methyl a-methacrylates) and an aliphatic or cyclic polyolefin.

14. The method of claim 13 wherein the flexible plastic substrate is a cyclic polyolefin.

15. The method of claim 14 wherein the cyclic polyolefin is poly(bis(cyclopentadiene)).

16. The method of claim 13 wherein the flexible plastic substrate is a polyester.

17. The method of claim 16 wherein the polyester is an aromatic polyester.

18. The method of claim 13 wherein the flexible plastic substrate is reinforced with a hard coating.

19. The method of claim 18 wherein the hard coating is an acrylic coating.

20. The method of claim 18 wherein the hard coating improves the adhesion and smoothness of the composite film to the flexible plastic substrate.

21. The method of claim 1 wherein the method further comprises a post-deposition annealing step at ambient conditions.

22. The method of claim 21 wherein the post-deposition annealing step comprises annealing the film at a temperature of between about 130°

C. to about 250°

C. for from about 0.5 hour to about 2 hours.

23. The method of claim 21 wherein the post-deposition annealing step enhances the adhesion and smoothes the surface of the films, and induces the reduction of sheet resistance and the increase of both transmittance and brightness of the films.

24. The method of claim 1 wherein the flexible plastic substrate and the multi-layered conductive metallic film have a composition and a thickness adapted to produce a composite film having a brightness of at least about 80%.

25. The method of claim 1 wherein the flexible plastic substrate and the multi-layered conductive metallic film have a composition and a thickness adapted to produce a composite film having an electrical resistance of no greater than about 20 Ω

/square.

26. The method of claim 25 wherein the flexible plastic substrate and the multi-layered conductive metallic film have a composition and a thickness adapted to produce a composite film having an electrical resistance of no greater than about 10 Ω

/square.

27. The method of claim 26 wherein the flexible plastic substrate and the multi-layered conductive metallic film have a composition and a thickness adapted to produce a composite film having an electrical resistance of no greater than about 5 Ω

/square.

28. The method of claim 1 wherein the multi-layered conductive metallic film has a root-mean square roughness of no greater than about 2.5 nm.

29. The method of claim 28 further comprising a post-deposition annealing step and wherein multi-layered conductive metallic film has a root-mean-square roughness of no greater than about 1.5 nm.

30. The method of claim 1 wherein the flexible plastic substrate and the multi-layered conductive metallic film have a composition and a thickness adapted to produce a composite film being stable to a 500-hour exposure at 60°

C. and 90% relative humidity.

31. The method of claim 1 wherein the flexible plastic substrate and the multi-layered conductive metallic film have a composition and a thickness adapted to produce a composite film having an interlayer adhesion sufficiently great to pass an ASTM 3359B standard 180°

C. peel adhesion test.

32. The method of claim 1 wherein the flexible plastic substrate and the multi-layered conductive metallic film have a composition and a thickness adapted to produce a composite film being wet and dry etchable.

33. The method of claim 1 further comprising depositing a hard coating having a composition and a thickness adapted to produce a composite film being laser etchable.

34. The method of claim 1 wherein the flexible plastic substrate and the multi-layered conductive metallic film have a composition and a thickness adapted to produce a composite film having a brightness L of at least about 80.0%, a red to green shift a of between about 0 and about 7.00 and a blue to yellow shift b of between about 0 and about 7.00.

35. The method of claim 1 wherein the sputtering is the sputtering is the DC magnetron sputtering.

36. The method of claim 35 wherein said sputtering is at a sputter power of from about 60 watts to about 100 watts.

37. The method of claim 35 wherein the deposition distance for DC magnetron sputtering is from about 2 inches to about 12 inches.

38. The method of claim 37 wherein the deposition distance for DC magnetron sputtering is from about 9 inches to about 11 inches.

39. The method of claim 35 wherein the DC magnetron sputtering is performed in an atmosphere that contains argon.

40. The method of claim 39 wherein the flow rate of argon is from about 5.0 to about 20.0 standard cubic centimillitor.

41. The method of claim 40 wherein the flow rate of argon is about 10.0 standard cubic centimillitor.