Process for forming a patterned thin film conductive structure on a substrate

• US 20030203101A1
• Filed: 04/23/2003
• Published: 10/30/2003
• Est. Priority Date: 04/24/2002
• Status: Abandoned Application

• Current Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Hosseini, Abbas, Chaug, Y. S., Wu, Zarng-Arh George, Liang, Rong-Chang, Haubrich, Jeanne E., Gendler, Paul
• Application Number:
  US10/422,557
• Publication Number:
  US 20030203101A1
• Time in Patent Office: Days
• US Class Current: 427/96.9
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: H05K 2201/0317 Thin film conductor layer; Thin film passive component
• CPC Class Codes: H05K 2203/0257 Brushing, e.g. cleaning the conductive pattern by brushing or wiping
• CPC Class Codes: H05K 2203/0264 Peeling insulating layer, e.g. foil, or separating mask
• CPC Class Codes: H05K 2203/0522 Using an adhesive pattern
• CPC Class Codes: H05K 2203/0746 Local treatment using a fluid jet, e.g. for removing or cleaning material; Providing mechanical pressure using a fluid jet
• CPC Class Codes: H05K 3/04 the conductive material being removed mechanically, e.g. by punching
• CPC Class Codes: H05K 3/048 using a lift-off resist pattern or a release layer pattern
• CPC Class Codes: H05K 3/146 By vapour deposition
• CPC Class Codes: H05K 3/16 by cathodic sputtering
• CPC Class Codes: H05K 3/184 using masks
• CPC Class Codes: H05K 3/386 by the use of an organic polymeric bonding layer, e.g. adhesive

Abstract

A process for forming a patterned conductive structure on a substrate is disclosed. A pattern is printed with a material, such as a masking coating or an ink, on the substrate, the pattern being such that, in one embodiment, the desired conductive structures will be formed in the areas where the printed material is not present, i.e., a negative image of conductive structure to be formed is printed. In another embodiment, the pattern is printed with a material that is difficult to strip from the substrate, and the desired conductive structures will be formed in the areas where the printed material is present, i.e., a positive image of the conductive structure is printed. The conductive material is deposited on the patterned substrate, and the undesired area is stripped, leaving behind the patterned electrode structures.

Claims

1. A process for forming a patterned conductive thin film structure on a substrate, comprising:

printing on the substrate a pattern comprised of a printable strippable material, the printed strippable material defining an area on the substrate where the conductive thin film structure is to be formed by comprising a negative image thereof such that the printed strippable material is present in areas on the substrate where the conductive thin film structure is not to be formed and the printed strippable material is substantially not present in the area on the substrate where the conductive thin film structure is to be formed;

depositing a thin film of conductive material on the patterned substrate; and

stripping the strippable material from the substrate;

whereby the strippable material and any conductive material formed thereon are removed by said stripping leaving behind the conductive thin film structure.

2. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the strippable material comprises a strippable ink.

3. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the strippable material comprises a strippable masking coating.

4. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the strippable material is polymer-based.

5. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the strippable material is wax-based.

6. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the strippable material comprises an additive selected from the group consisting of surfactants, fillers, pigments, dyes, curing agents, and plasticizers;

whereby the presence of said additive facilitates the stripping of the strippable material subsequent to the deposition of the conductive thin film.

7. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of stripping comprises using a solvent to remove the strippable material.

8. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 7, wherein the solvent is selected from the group consisting of water, aqueous solutions, alcohols, ketones, esters, ethers, amides, hydrocarbons, alkylbenzenes, pyrrolidones, sulfones, DMSO, and their mixtures and derivatives.

9. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the conductive material is a material selected from the group consisting of metals, metal oxides, and their alloys and multilayer composites.

10. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the conductive material is a metal selected from the group consisting of aluminum, copper, zinc, tin, molybdenum, nickel, chromium, silver, gold, iron, indium, thallium, titanium, tantalum, tungsten, rhodium, palladium, platinum and cobalt.

11. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the conductive material is a metal oxide selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide, gadolinium indium oxide, tin oxide, or fluorine-doped indium oxide.

12. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of depositing a thin film of conductive material comprises sputtering.

13. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of depositing a thin film of conductive material comprises vapor deposition.

14. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of depositing a thin film of conductive material comprises vacuum deposition.

15. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of depositing a thin film of conductive material comprises electroplating.

16. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of depositing a thin film of conductive material comprises electro-less plating.

17. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of depositing a thin film of conductive material comprises electro-forming.

18. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of printing comprises flexographic printing.

19. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of printing comprises driographic printing.

20. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of printing comprises electrophotographic printing.

21. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of printing comprises lithographic printing.

22. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of printing comprises gravure printing.

23. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of printing comprises thermal printing.

24. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of printing comprises inkjet printing.

25. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of printing comprises screen printing.

26. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the substrate comprises a plastic substrate.

27. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 26, wherein the patterned conductive thin film structure comprises a flexible printed circuit board or a portion of a flexible printed circuit board.

28. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 26, wherein the plastic substrate comprises a portion of a roll of plastic substrate.

29. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 28, wherein the process for forming a patterned conductive thin film structure on a substrate is a component part of a roll-to-roll process for fabricating a display.

30. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 29, wherein the display is an electrophoretic display.

31. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 29, wherein the display is a passive matrix electrophoretic display.

32. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 29, wherein the display is an in-plane switching electrophoretic display.

33. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 29, wherein the display is a dual-mode switching electrophoretic display comprising a plurality of electrophoretic cells filled with charged particles and a colored solvent in which the display is configured such that the particles can be driven between the top and bottom of the electrophoretic cells in a first mode and can be driven horizontally (in-plane) in a second mode.

34. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, further comprising laminating the substrate with the conductive thin film structure formed thereon to a display medium layer.

35. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 34, wherein the display medium layer comprises a layer of electrophoretic cells.

36. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 35, wherein said electrophoretic cells are prepared by embossing.

37. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 35, wherein said electrophoretic cells are closed and sealed by a polymeric sealing layer.

38. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the conductive thin film structure comprises an electrode.

39. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 38, wherein the electrode is a segment electrode.

40. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 38, wherein the electrode is a column electrode.

41. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 38, wherein the electrode is a row electrode.

42. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 38, wherein the electrode is a pixel electrode.

43. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the conductive thin film structure comprises a conductive trace.

52. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of stripping comprises using solvent to remove the strippable material.

53. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of stripping comprises using mechanical pressure to remove the strippable material.

54. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein using mechanical pressure comprises brushing.

55. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein using mechanical pressure comprises using a spray nozzle.

56. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of stripping comprises:

applying an adhesive layer having a higher adhesive strength with respect to the metal thin film and/or strippable material than the adhesive strength of the strippable material to the substrate; and

removing the strippable material and any metal thin film formed thereon by peeling off the adhesive layer.

63. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 1, wherein the step of stripping comprises:

applying an adhesive layer to the substrate after the conductor deposition step; and

removing the conductor thin film on the area with the first printed adhesive or adhesion promoting material by peeling off the adhesive layer.

64. The method of claim 63, wherein the cohesion strength of the conductor thin film and the adhesion strength between conductor thin film and the substrate are stronger than any of the three forces:

the cohesion strength of the strippable material, the adhesion strength between the conductor thin film and the strippable material, and the adhesion strength between the strippable material and the substrate.

44. A process for forming a patterned conductive thin film structure on a substrate, comprising:

printing with a printable material on the top surface of the substrate a pattern that defines the area where the conductive thin film structure is to be formed by comprising a positive image thereof such that the printable material is printed in the area where the conductive thin film structure is to be formed;

depositing a conductive thin film layer on the patterned top surface of the substrate, wherein the conductive thin film, the printable material, and the substrate are chosen so that the conductive thin film adheres more strongly to the printable material than to the substrate; and

stripping from the substrate the portions of the conductive thin film formed directly on the substrate using a stripping process that does not strip the conductive thin film from the printable material such that the conductive thin film structure remains formed on the printable material used to define the area in which the conductive thin film structure was to be formed.

45. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein the printable material comprises a primer coating, adhesive, or adhesion promoting material.

46. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein the printable material comprises ink.

47. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein the printable material is radiation curable.

48. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein the printable material is thermal curable.

57. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein the step of stripping comprises using solvent to remove the strippable material.

58. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein the step of stripping comprises using mechanical pressure to remove the strippable material.

59. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein using mechanical pressure comprises brushing.

60. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein using mechanical pressure comprises using a spray nozzle.

61. The process for forming a patterned conductive thin film structure on a substrate as recited in claim 44, wherein the step of stripping comprises:

applying a second adhesive layer to the substrate after the conductor deposition step; and

removing the conductor thin film on the area without the first printed adhesive or adhesion promoting material by peeling off the second adhesive layer.

62. The method of claim 61, wherein the adhesion strength between conductor thin film and the substrate is the weakest as compared to the cohesion strength of the second adhesive layer, the cohesion strength of the first adhesive or adhesion promoting material, the cohesion strength of the metal thin film, the adhesion strength between the metal thin film and the second adhesive layer, and the adhesion between the metal thin film and the first adhesive or adhesion promoting material.

49. A process for forming a patterned conductive thin film structure on a substrate, comprising:

printing with a printable first material on the top surface of the substrate a pattern that defines the area where the conductive thin film structure is to be formed by comprising a positive image thereof such that the printable first material is printed in the area where the conductive thin film structure is to be formed, the printable first material being water repelling and strippable using a solvent other than water;

overcoating the printed top surface of the substrate with a water based second material, such that the second material is repelled by the first material and fills in the areas of the substrate between the areas where the first material has been printed without coating the areas where the first material is present;

stripping the first material away using a process that strips away the first material without stripping away the second material, such that the second material remains coated on the portions of the substrate where the first material was not present, thereby defining the boundaries of the conductive thin film structure by comprising a negative image thereof such that the second material is not present in and the first material has been stripped from the area where the conductive thin film structure is to be formed;

depositing a conductive thin film layer on the patterned top surface of the substrate; and

stripping the second material to form the conductive thin film structure.

50. A process for forming a patterned conductive thin film structure on a substrate, comprising:

printing on a first surface of the substrate a first pattern comprised of strippable material, the first pattern of strippable material defining an area on the first surface of the substrate where a first conductive thin film structure is to be formed;

depositing a thin film of conductive material on the patterned first surface of the substrate;

stripping the first pattern of strippable material from the substrate;

printing on a second surface of the substrate a second pattern comprised of strippable material, the second pattern of strippable material defining an area on the second surface of the substrate where a second conductive thin film structure is to be formed;

depositing a thin film of conductive material on the patterned second surface of the substrate; and

stripping the second pattern of strippable material from the substrate;

whereby the first pattern of strippable material, the second pattern of strippable material, and any conductive material formed on either the first or the second pattern of strippable material are removed leaving behind the first conductive thin film structure on the first surface of the substrate and the second conductive thin film structure on the second surface of the substrate.

51. A process for forming a patterned conductive thin film structure on a substrate, comprising:

printing on a first surface of the substrate a first pattern comprised of strippable material, the first pattern of strippable material defining an area on the first surface of the substrate where a first conductive thin film structure is to be formed;

printing on a second surface of the substrate a second pattern comprised of strippable material, the second pattern of strippable material defining an area on the second surface of the substrate where a second conductive thin film structure is to be formed;

depositing a thin film of conductive material on the patterned first surface and on the patterned second surface of the substrate; and

stripping the first pattern and second pattern of strippable material from the substrate;

whereby the first pattern of strippable material, the second pattern of strippable material, and any conductive material formed on either the first or the second pattern of strippable material are removed leaving behind the first conductive thin film structure on the first surface of the substrate and the second conductive thin film structure on the second surface of the substrate.