Method for patterning a multilayered conductor/substrate structure

• US 6,602,790 B2
• Filed: 11/13/2001
• Issued: 08/05/2003
• Est. Priority Date: 02/14/2001
• Status: Expired due to Term

• Current Assignee: Liberty Patents LLC
• Original Assignee: Avery Dennison Corporation
• Inventors: Heydarpour, Ramin, Kian, Kouroche
• Primary Examiner(s): TSAI, H JEY
• Application Number:
  US10/008,808
• Publication Number:
  US 20030092267A1
• Time in Patent Office: 630 Days
• Field of Search: 438/30, 438/690, 438/737, 438/618-647, 438/663, 438/463, 438/940
• US Class Current: 438/690
• 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: G02F 1/136 Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit G02F1/135 takes precedence
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 59/80517 Multilayers, e.g. transparent multilayers
• CPC Class Codes: H10K 59/873 Encapsulations
• CPC Class Codes: H10K 71/60 Forming conductive regions or layers, e.g. electrodes
• 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: Y10S 438/94 Laser ablative material removal
• CPC Class Codes: Y10T 428/24917 including metal layer
• CPC Class Codes: Y10T 428/31507 Of polycarbonate

Abstract

A method for patterning a multilayered conductor/substrate structure includes the steps of: providing a multilayered conductor/substrate structure which includes a plastic substrate and at least one conductive layer overlying the plastic substrate; and irradiating the multilayered conductor/substrate structure with ultraviolet radiation such that portions of the at least one conductive layer are ablated therefrom. In a preferred embodiment, a projection-type excimer laser system is employed to rapidly and precisely ablate a pattern from a mask into the at least one conductive layer. Preferably, the excimer laser is controlled in consideration of how well the at least one conductive layer absorbs radiation at particular wavelengths. Preferably, a fluence of the excimer laser is controlled in consideration of an ablation threshold level of at least one conductive layer. According to a preferred method, the excimer laser is employed and controlled to ablate portions of the at least one conductive layer without completely decomposing the at least one functional layer therebeneath.

Claims

1. A method for patterning a multilayered conductor/substrate structure comprising the steps of:

(a) providing a multilayered conductor/substrate structure which includes a plastic substrate and at least one conductive layer overlying the plastic substrate; and

(b) irradiating the multilayered conductor/substrate structure with ultraviolet radiation such that portions of the at least one conductive layer are ablated therefrom to pattern the multilayered conductor/substrate structure.

2. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the ultraviolet radiation is spatially incoherent.

3. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the ultraviolet radiation has a wavelength in the mid-UV range.

4. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the irradiating step comprises employing an excimer laser to ablate portions of the at least one conductive layer.

5. The method for patterning a multilayered conductor/substrate structure of claim 4 wherein the step of employing the excimer laser comprises controlling the excimer laser in consideration of how well the at least one conductive layer absorbs radiation at particular wavelengths.

6. The method for patterning a multilayered conductor/substrate structure of claim 4 wherein the step of employing the excimer laser comprises controlling the excimer laser to image a pattern from a mask onto the at least one conductive layer.

7. The method for patterning a multilayered conductor/substrate structure of claim 6 wherein the pattern includes a line gap which is no larger than about 10 μ

m.

8. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the multilayered conductor/substrate structure further comprises at least one functional layer located between the at least one conductive layer and the plastic substrate, the at least one functional layer comprising an insulating material.

9. The method for patterning a multilayered conductor/substrate structure of claim 8 wherein the irradiating step comprises employing and controlling an excimer laser to irradiate a portion of the at least one conductive layer such that a portion of the at least one functional layer therebeneath heats and swells to a desired degree.

10. The method for patterning a multilayered conductor/substrate structure of claim 9 wherein the step of controlling the excimer laser comprises controlling a fluence of the excimer laser in consideration of an ablation threshold level of the at least one conductive layer.

11. The method for patterning a multilayered conductor/substrate structure of claim 8 wherein the irradiating step comprises employing and controlling an excimer laser to ablate portions of the at least one conductive layer without completely decomposing the at least one functional layer therebeneath.

12. The method for patterning a multilayered conductor/substrate structure of claim 4 wherein the excimer laser is part of a projection-type ablation system.

13. The method for patterning a multilayered conductor/substrate structure of claim 12 wherein the projection-type ablation system is configured to project a broadened laser beam.

14. The method for patterning a multilayered conductor/substrate structure of claim 13 wherein the projection-type ablation system is configured to project the broadened laser beam onto a patterned mask positioned over but not touching the at least one conductive layer.

15. The method for patterning a multilayered conductor/substrate structure of claim 14 wherein the broadened laser beam irradiates about a 50 mm²-sized portion of the patterned mask.

16. The method for patterning a multilayered conductor/substrate structure of claim 4 wherein the excimer laser is configured to emit light at a discrete characteristic wavelength.

17. The method for patterning a multilayered conductor/substrate structure of claim 16 wherein the characteristic wavelength is 308 nm.

18. The method for patterning a multilayered conductor/substrate structure of claim 16 wherein the characteristic wavelength is 248 nm.

19. The method for patterning a multilayered conductor/substrate structure of claim 4 wherein the excimer laser is part of an ablation system configured to facilitate a roll-to-roll production process.

20. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the plastic substrate comprises polyethylene terephthalate (PET), polyethylenenapthalate (PEN), polyethersulphone (PES), polycarbonate (PC), polysulfone, a phenolic resin, an epoxy resin, polyester, polyimide, polyetherester, polyetheramide, cellulose acetate, aliphatic polyurethane, polyacrylonitrile, polytetrafluoroethylenes, polyvinylidene fluorides, polytetrafluoroethylenes, HDPEs, poly(methyl α

-methacrylates), or a cyclic or acyclic polyolefin.

21. The method for patterning a multilayered conductor/substrate structure of claim 20 wherein the plastic substrate comprises a cyclic polyolefin material.

22. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer comprises an oxide layer.

23. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer comprises an indium tin oxide (ITO) layer.

24. The method for patterning a multilayered conductor/substrate structure of claim 23 wherein the ITO layer is polycrystalline.

25. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer comprises an alloy.

26. The method for patterning a multilayered conductor/substrate structure of claim 25 wherein the alloy is an indium tin oxide (ITO) alloy.

27. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer comprises a metal-based layer.

28. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer comprises a silver-based layer.

29. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer comprises silver and gold.

30. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer is a multilayered conductive film.

31. The method for patterning a multilayered conductor/substrate of claim 30 wherein the multilayered conductive film comprises:

(i) a silver-based layer formed of a silver-based metallic material having first and second surfaces;

(ii) a first transparent oxide layer provided on the first surface of the silver-based layer; and

(iii) a second transparent oxide layer provided on the second surface of the silver-based layer;

the first and second transparent oxide layers being independently formed of a compound oxide material of indium oxide with at least one secondary metal oxide whose metallic element has substantially no solid solubility in silver.

32. The method for patterning a multilayered conductor/substrate structure of claim 31 wherein the metallic element having substantially no solid solubility in silver is selected from the group consisting of titanium, zirconium, tantalum, niobium, hafnium, cerium, bismuth, germanium, silicon, chromium, and a combination of two or more of these elements.

33. The method for patterning a multilayered conductor/substrate structure of claim 32 wherein the silver based layer is an alloy of silver with gold and copper and the first and second transparent oxide layers comprise indium oxide with cerium oxide.

34. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer, where it has not been etched, has a thickness between around 10 nm and around 120 nm.

35. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer has a resistivity of no greater than 80 Ω

/square.

36. The method for patterning a multilayered conductor/substrate structure of claim 35 wherein the at least one conductive layer has a resistivity of no greater than 30 Ω

/square.

37. The method for patterning a multilayered conductor/substrate structure of claim 36 wherein the at least one conductive layer has a resistivity of no greater than 20 Ω

/square.

38. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the at least one conductive layer has a transmissivity of at least 80%.

39. The method for patterning a multilayered conductor/substrate structure of claim 8 wherein the at least one functional layer comprises a protective layer which serves to protect layers beneath the protective layer from laser irradiation.

40. The method for patterning a multilayered conductor/substrate structure of claim 39 wherein the layers beneath comprise a barrier layer which serves to protect the plastic substrate from environmental damage.

41. The method for patterning a multilayered conductor/substrate structure of claim 39 wherein the layers beneath include the plastic substrate.

42. The method for patterning a multilayered conductor/substrate structure of claim 8 wherein the at least one functional layer comprises a layer of acrylic which abuts the at least one conductive layer.

43. The method for patterning a multilayered conductor/substrate structure of claim 8 wherein the at least one functional layer comprises a barrier layer which serves to protect the plastic substrate from environmental damage.

44. The method for patterning a multilayered conductor/substrate structure of claim 43 wherein the barrier layer is inorganic.

45. The method for patterning a multilayered conductor/substrate structure of claim 43 wherein the barrier layer has an oxygen transmission rate (OTR) no greater than 0.1 cc/m²/day.

46. The method for patterning a multilayered conductor/substrate structure of claim 43 wherein the barrier layer has a water vapor transmission rate (WVTR) no greater than 0.1 g/m²/day.

47. The method for patterning a multilayered conductor/substrate structure of claim 43 wherein the barrier layer comprises a layer of SiO_x which abuts the plastic substrate.

48. The method for patterning a multilayered conductor/substrate structure of claim 8 wherein the multilayered conductor/substrate further comprises an additional functional layer abutting a side of the plastic substrate that faces away from the at least one conductive layer, the additional functional layer serving to provide structural protection and/or environmental protection for the plastic substrate.

49. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the multilayered electrode/substrate structure is an OLED.

50. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the multilayered electrode/substrate structure is a PLED.

51. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the multilayered electrode/substrate structure has surface roughness of less than about 8 nm.

52. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the multilayered electrode/substrate structure has a driving voltage of less than about 20 volts.

53. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the conductive material of the multilayered electrode/substrate structure comprises a light-emitting polymer.

54. The method for patterning a multilayered electrode/substrate structure of claim 53 wherein the light-emitting polymer is selected from the group consisting of poly(p-phenylenevinylene) (PPV), poly(dialkoxyphenylenevinylene), poly(thiophene), poly(fluorene), poly(phenylene), poly(phenylacetylene), poly(aniline), poly(3-alkylthiophene), poly(3-octylthiophene), and poly(N-vinylcarbazole).

55. The method for patterning a multilayered electrode/substrate structure of claim 54 wherein the light-emitting polymer is poly(p-phenylenevinylene) (PPV).

56. The method for patterning a multilayered electrode/substrate structure of claim 54 wherein the light-emitting polymer is polyfluorene.

57. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the conductive material comprises a luminescent organic or organometallic material.

58. The multilayered electrode/substrate structure of claim 57 wherein the luminescent organic or organometallic material is selected from the group consisting of metal ion salts of 8-hydroxyquinolate, trivalent metal quinolate complexes, trivalent metal bridged quinolate complexes, Schiff base divalent metal complexes, tin (IV) metal complexes, metal acetylacetonate complexes, metal bidentate ligand complexes incorporating organic ligands such as 2-picolylketones, 2-quinaldylketones, 2-(o-phenoxy) pyridine ketones, bisphosphonates, divalent metal maleonitriledithiolate complexes, molecular charge transfer complexes, rare earth mixed chelates, (5-hydroxy) quinoxaline metal complexes, and aluminum tris-quinolates.

59. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the interlayer adhesion of the multilayered electrode/substrate structure is sufficiently great to survive a 180°

peel adhesion test.

60. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the Young'"'"'s modulus of the multilayered electrode/substrate structure is at least 1200 MPa.

61. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the tensile elongation of the multilayered electrode/substrate structure is <

1% when subject to 1 lb/in at 23°

C.

62. The method for patterning a multilayered electrode/substrate structure of claim 4 wherein the excimer laser has a fluence of from about 320 mJ/cm² to about 800 mJ/cm².

63. The method for patterning a multilayered electrode/substrate structure of claim 62 wherein the excimer laser has a fluence of from about 320 mJ/cm² to about 400 mJ/cm².

64. The method for patterning a multilayered electrode/substrate structure of claim 1 wherein the method further comprises a step of cleaning debris from at least one surface of the multilayered electrode/substrate structure subsequent to ablation.

65. The method for patterning a multilayered electrode/substrate structure of claim 64 wherein the step of cleaning debris from at least one surface of the multilayered electrode/substrate structure subsequent to ablation comprises cleaning with dry carbon dioxide.