Method for patterning a multilayered conductor/substrate structure

• US RE44,071 E1
• Filed: 07/13/2006
• Issued: 03/12/2013
• Est. Priority Date: 02/14/2001
• Status: Expired due to Term

• Current Assignee: Liberty Patents LLC
• Original Assignee: Streaming Sales LLC (Intellectual Ventures LLC)
• Inventors: Heydarpour, Ramin, Kian, Kouroche
• Primary Examiner(s): Tran, Binh X
• Application Number:
  US11/487,577
• Time in Patent Office: 2,434 Days
• Field of Search: 438/706, 438/707, 438/714, 438/717, 438/720, 438/725, 438/690, 349/56, 349/64, 349/89
• US Class Current: 438/690
• CPC Class Codes: B23K 26/364 for making a groove or trench, e.g. for scribing a break initiation groove
• 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: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H01L 51/5206 Anodes, i.e. with high work-function material
• CPC Class Codes: H05K 3/027 the conductive material being removed by irradiation, e.g. by photons, alpha or beta particles

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:

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;

wherein the irradiating step comprises employing an excimer laser of a projection-type ablation system to ablate portions of the at least one conductive layer by illuminating a mask with a collimated laser beam and

employing projection optics positioned between the mask and the at least one conductive layer to project a pattern from the mask onto the at least one conductive layer.

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 step of employing the excimer laser comprises selecting the excimer laser depending upon radiation absorption of the at least one conductive layer at particular wavelengths.

5. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the pattern includes a line gap 10 μ

m or smaller.

6. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the steps of providing and irradiating the multilayered conductor/substrate structure are part of a roll-to-roll production process.

7. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the plastic substrate comprises, polyethylenenapthalate (PEN), or polyethersulphoflc (PES).

8. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the plastic substrate comprises a polyolefin material.

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

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

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

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

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

14. 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.

15. 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.

16. 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%.

17. 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.

18. The method for patterning a multilayered conductor/substrate structure of claim 17 wherein the ITO layer is polycrystalline.

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

20. The method for patterning a multilayered conductor/substrate structure of claim 19 wherein the alloy is an indium tin oxide (ITO) alloy.

21. The method for patterning a multilayered conductor/substrate structure of claim 1 wherein the excimer laser is selected to emit light at a discrete characteristic wavelength.

22. The method for patterning a multilayered conductor/substrate structure of claim 21 wherein the characteristic wavelength is 308 nm.

23. The method for patterning a multilayered conductor/substrate structure of claim 21 wherein the characteristic wavelength is 248 nm.

24. 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 intermediate the at least one conductive layer and the plastic substrate, the at least one functional layer comprising an insulating material.

25. The method for patterning a multilayered conductor/substrate structure of claim 24 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.

26. The method for patterning a multilayered conductor/substrate structure of claim 24 wherein the at least one functional layer comprises a layer of actylic which abuts the at least one conductive layer.

27. The method for patterning a multilayered conductor/substrate structure of claim 24, further comprising:

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.

28. The method for patterning a multilayered conductor/substrate structure of claim 24 wherein the irradiating step comprises employing and controlling the 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 via thermal conduction through the at least one conductive layer and swells to assist in ablating the portion of the at least one conductive layer.

29. The method for patterning a multilayered conductor/substrate structure of claim 28 wherein the step of controlling the excimer laser comprises controlling a fluence.

30. The method for patterning a multilayered conductor/substrate structure of claim 24 wherein the at least one functional layer comprises a protective layer which serves to protect layers beneath the protective layer from laser irradiation.

31. The method for patterning a multilayered conductor/substrate structure of claim 30 wherein the layers beneath comprise a barrier layer which serves to protect the plastic substrate from environmental damage.

32. The method for patterning a multilayered conductor/substrate structure of claim 30 wherein the layers beneath include the plastic substrate.

33. The method for patterning a multilayered conductor/substrate structure of claim 24 wherein the at least one functional layer ocmprises a barrier layer which serves to protect the plastic substrate from enviornmental damage.

34. The method for patterning a multilayered conductor/substrate structure of claim 33 wherein the barrier layer is inorganic.

35. The method for patterning a multilayered conductor/substrate structure of claim 33 wherein the barrier layer has an oxygen transmission rate (OTR) no greater than 0.05 cc/m²/day.

36. The method for patterning a multilayered conductor/substrate structure of claim 33 wherein the barrier layer has a water vapor transmission rate (WVTR) no greater than 0.05 g/m²/day.

37. The method for patterning a multilayered conductor/substrate structure of claim 24, further comprising:

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.

38. A composite structure, comprising:

a substrate having an upper surface and a lower surface opposite the upper surface;

a barrier layer comprising an inorganic oxide disposed on the upper surface of the substrate;

a protective layer comprising acrylic disposed on the barrier layer such that the barrier layer is disposed between the protective layer and the substrate, wherein the protective layer is configured to protect the substrate from an excimer laser; and

a conductive layer disposed on the protective layer such that the protective layer is disposed between the conductive layer and the barrier layer.

39. The composite structure of claim 38, wherein the protective layer is configured to swell in response to heat generated from ablating at least a portion of the conductive layer with an excimer laser.

40. The composite structure of claim 38, wherein the conductive layer has a visible-light transmission of at least 80% and a resistivity between 1 ohm/square and 80 ohm/square.

41. The composite structure of claim 38, wherein the conductive layer has sufficient flexibility to support patterning of the conductive layer during a roll-to-roll process.

42. The composite structure of claim 38, wherein the protective layer is further configured to protect the barrier layer from the excimer laser.

43. The composite structure of claim 38, wherein the barrier layer is in direct contact with the upper surface of the substrate, the protective layer is in direct contact with the barrier layer, and the conductive layer is in direct contact with the protective layer.

44. The composite structure of claim 38, wherein the conductive layer is patterned into display device electrodes.

45. The composite structure of claim 38, wherein the substrate comprises a polymeric material.

46. The composite structure of claim 45, wherein the substrate comprises heat-stabilized polyethylene terephthalate.

47. The composite structure of claim 38, wherein the barrier layer further comprises a first barrier layer, and wherein the composite structure further comprises a second barrier layer disposed on the lower surface of the substrate such that the substrate is disposed between the second barrier layer and the first barrier layer.

48. The composite structure of claim 47, wherein the protective layer further comprises a first protective layer, and wherein the composite structure further comprises a second protective layer disposed on the lower surface of the substrate such that the substrate is disposed between the second protective layer and the barrier layer.

49. The composite structure of claim 38, wherein the conductive layer comprises a material selected from the group consisting of an oxide, a metal-based material, an alloy, and a doped material.

50. The composite structure of claim 49, wherein the oxide comprises indium tin oxide.

51. The composite structure of claim 49, wherein the oxide comprises a metal oxide.

52. The composite structure of claim 51, wherein the metal oxide is selected from the group consisting of indium oxide, titanium dioxide, cadmium oxide, gallium indium oxide, niobium pentoxide, and tin dioxide.

53. The composite structure of claim 51, wherein the metal oxide is selected from the group consisting of an oxide of cerium, an oxide of titanium, an oxide of zirconium, an oxide of hafnium, and an oxide of tantalum.

54. The composite structure of claim 51, wherein the metal oxide is selected from the group consisting of zinc peroxide, zinc stannate, cadmium stannate, zinc indium oxide, magnesium indium oxide, and gallium oxide-indium oxide.

55. A display system, comprising:

a first composite structures including;

a substrate having an upper surface and a lower surface opposite the upper surface;

a barrier layer comprising an inorganic oxide disposed on the upper surface of the substrate;

a protective layer comprising acrylic disposed on the barrier layer such that the barrier layer is disposed between the protective layer and the substrate, wherein the protective layer is configured to protect the substrate from an excimer laser; and

a conductive layer disposed on the protective layer such that the protective layer is disposed between the conductive layer and the barrier layer;

a second composite structure; and

a liquid-crystal material disposed between the first composite structure and the second composite structure.

56. The display system of claim 55, wherein the first composite structure comprises a plurality of electrodes patterned in the conductive layer.

57. The display system of claim 55, wherein the liquid crystal material comprises a cholesteric liquid crystal material.

58. The display system of claim 55, wherein the display device comprises a fast multistable liquid crystal display device.

59. The display system of claim 55, wherein the system is a selected one of a computer, an instrument panel, a video game machine, a videophone, a mobile phone, a personal digital assistant, an e-book, a camcorder, a satellite navigation system, a pricing system, a highway sign, a smart card, an informational display, and a toy.

60. The display system of claim 55, wherein the barrier layer is in direct contact with the upper surface of the substrate, the protective layer is in direct contact with the barrier layer, and the conductive layer is in direct contact with the protective layer.

61. The display system of claim 55, wherein the conductive layer comprises a first conductive layer, wherein the second composite structure comprises a second conductive layer, and wherein the liquid crystal material is sandwiched between the first conductive layer and the second conductive layer.

62. The display system of claim 55, wherein the barrier layer is in direct contact with the upper surface of the substrate, the protective layer is in direct contact with the barrier layer, and the conductive layer is in direct contact with the protective layer.

63. The display system of claim 62, wherein the first composite structure further comprises a first plurality of electrodes patterned in the first conductive layer, and wherein the second composite structure comprises a second plurality of electrodes patterned in the second conductive layer.