Color filter and manufacturing method therefor

• US 6,630,274 B1
• Filed: 08/16/2000
• Issued: 10/07/2003
• Est. Priority Date: 12/21/1998
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Takizawa, Keiji, Kiguchi, Hiroshi, Shimizu, Masaharu, Katagami, Satoru, Kuno, Tadaaki, Fujimori, Natsuo
• Primary Examiner(s): McPherson, John A.
• Application Number:
  US09/622,368
• Time in Patent Office: 1,147 Days
• Field of Search: 430/7, 349/106, 347/106
• US Class Current: 430/7
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02B 5/223 containing organic substances, e.g. dyes, inks or pigments
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133516 Methods for their manufacture, e.g. printing, electro-deposition or photolithography
• CPC Class Codes: G03F 7/0007 Filters, e.g. additive colour filters; Components for display devices

Abstract

The color filter of the present invention comprises ink films colored by ink drops 140 inside openings 111 enclosed by banks 112 demarcated and formed on a substrate 110. The banks 112 have a laminar structure comprising a metal film 120 and a photosensitive organic thin film 130 from the substrate 110 side. The inks should contain a solvent having a high boiling point. The bank layer may also be configured so that the peripheral edges of the bottom surface thereof are positioned inside from the peripheral edges of the light blocking layers, so that the light blocking layers have exposed surfaces on the upper surface thereof where the bank layer is not superimposed. Thus color filters can be provided which exhibit outstanding contrast without coloring irregularities.

Claims

1. A color filter comprising ink films colored by inks, inside openings enclosed by banks demarcated and formed on a substrate, wherein a contact angle between said banks and said inks is 30 degrees or greater but 60 degrees or less, and

said banks have a laminar structure comprising a metal film and a photosensitive organic thin film.

2. The color filter according to claim 1, wherein said photosensitive organic thin film is of a resist for etching said metal film.

3. The color filter according to claim 1, wherein said photosensitive organic thin film is either a polyimide film, an acrylic resin film, a polyhydroxy styrene film, a novolac resin film, a polyvinyl alcohol film, or a cardo resin film.

4. The color filter according to claim 1, wherein said photosensitive organic thin film is a thin film to which a fluorine-based surfactant has been added.

5. The color filter according to claim 4, wherein said fluorine-based surfactant has a structure having a fluorine-containing group that is perfluoroalkyl or derivative thereof, fluorobenzene, difluorobenzene, trifluorobenzene, perfluorobenzene, or fluorophenol or derivative thereof.

6. The color filter according to claim 1, wherein said photosensitive organic thin film is a thin film into which a fluorine-based polymer has been mixed.

7. The color filter according to claim 6, wherein said fluorine-based polymer is one polymer selected from among silicone rubber, vinylidene polyfluorides, fluoroolefins, vinyl ether-based copolymers, ethylene trifluoride, vinylidene fluoride copolymers, polytetrafluoroethylenes, perfluoroethylene propyline resins, and perfluoroalcoxy resins.

8. The color filter according to claim 1, wherein said photosensitive organic thin film is a thin film wherein a plurality of photosensitive organic thin films is laminated.

9. The color filter according to claim 1, wherein said metal film is a black matrix.

10. The color filter according to claim 1, wherein said metal film is either chromium or nickel or tungsten or tantalum or copper or aluminum.

11. The color filter according to claim 1, comprising a protective film that covers said banks and ink films, wherein said protective film has a composition that is the same as that of said organic thin film.

12. The color filter according to claim 11, wherein said protective film is either bisphenol A or bisphenol fluorolene.

13. The color filter according to claim 1, wherein contact angle between said substrate and said inks is 30 degrees or less.

14. A liquid crystal display element comprising a color filter according to claim 1.

15. An electro-optical device comprising:

a color filter cited in claim 1;

an opposing panel deployed at a prescribed interval with said color filter; and

an electro-optical material layer deployed between said color filter and said opposing panel.

16. The electro-optical device according to claim 15, wherein said electro-optical material layer is a liquid crystal material layer.

17. An electronic device comprising an electro-optical device cited in claim 15.

18. The color filter according to claim 1, wherein said banks have a trapezoidal cross-section.

19. A method of manufacturing a color filter comprising ink films, colored by inks, in openings enclosed in banks demarcated and formed on a substrate, wherein a contact angle between said banks and said inks is 30 degrees or greater but 60 degrees or less, and

a first step for forming a metal film on said substrate;

a second step for forming said banks by forming a photosensitive organic thin film on said metal film; and

a third step for forming said ink films by filling said openings with said inks.

20. The color manufacturing method according to claim 19, wherein said second step also etches said metal film using said photosensitive organic thin film as a resist.

21. The color filter manufacturing method according to claim 19, wherein said photosensitive organic thin film is either a polyimide film, an acrylic resin film, a polyhydroxy styrene film, a novolac resin film, a polyvinyl alcohol film, or a cardo resin film.

22. The color filter manufacturing method according to claim 19, wherein said photosensitive organic thin film is a thin film to which a fluorine-based surfactant has been added.

23. The color filter manufacturing method according to claim 22, wherein said fluorine-based surfactant has a structure having a fluorine-containing group that is perfluoroalkyl or derivative thereof, fluorobenzene, difluorobenzene, trifluorobenzene, perfluorobenzene, or fluorophenol or derivative thereof.

24. The color filter manufacturing method according to claim 19, wherein said photosensitive organic thin film is a thin film into which a fluorine-based polymer has been mixed.

25. The color filter manufacturing method according to claim 24, wherein said fluorine-based polymer is one polymer selected from among silicone rubber, vinylidene polyfluorides, fluoroolefins, vinyl ether-based copolymers, ethylene trifluoride, vinylidene fluoride copolymers, polytetrafluoroethylenes, perfluoroethylene propyline resins, and perfluoroalcoxy resins.

26. The color filter manufacturing method according to claim 19, wherein said second step is a step that forms said banks by laminating a plurality of photosensitive organic thin films on said metal film.

27. The color filter manufacturing method according to claim 26, wherein the method further comprises, between said second step and said third step, a step for imparting ink affinity to surface of said substrate by performing a plasma process using oxygen gas as induction gas, and a step for imparting ink repellency to said banks by performing a plasma process using a fluorine-based compound as induction gas.

28. The color filter manufacturing method according to claim 27, wherein said fluorine-based compound is carbon tetrafluoride gas, or nitrogen trifluoride gas, or sulfur hexafluoride gas.

29. The color filter according to claim 19, wherein said banks have a trapezoidal cross-section.

30. A color filter manufacturing method comprising:

forming a metal thin film matrix pattern that is a light blocking layer on a transparent substrate;

forming matrix pattern banks, with a resin on the metal thin film light blocking layer; and

applying inks in gaps in said matrix pattern wherein a contact angle between said banks and said inks is 30 degrees or greater but 60 degrees or less.

31. The color filter manufacturing method according to claim 30, wherein said step for forming said metal thin film matrix pattern is a step for patterning, by a photoresist process, a metal thin film having a thickness of 0.1 μ

m to 0.5 μ

m.

32. The color filter manufacturing method according to claim 30, wherein said step for forming said resin matrix pattern is a step for patterning a photosensitive resin composition by a photoresist process so as to roughly be superimposed on said thin film metal matrix pattern.

33. The color filter manufacturing method according to claim 30, wherein a height of said banks in said resin matrix pattern are 1.5 μ

m to 5 μ

m.

34. The color filter manufacturing method according to claim 30, wherein a difference in contact angle for water between the resin configuring said resin matrix pattern and the surface of substrate in matrix gaps is 15 degrees or greater.

35. The color filter manufacturing method according to claim 30, wherein a surface of said resin matrix pattern and substrate surface in matrix gaps are subjected to dry etching prior to deployment of inks.

36. The color filter manufacturing method according to claim 30, wherein said step for deploying inks in gaps in said resin matrix pattern is performed using an ink jet printing head.

37. The color filter manufacturing method according to claim 30, wherein said step for deploying inks in gaps in said resin matrix pattern discharges extremely minute ink drops of 6 picoliters to 30 picoliters from a printing head while controlling said discharge.

38. The color filter manufacturing method according to claim 30, wherein said inks deployed in said resin matrix pattern gaps comprise a solvent having a boiling point of 150 to 300°

C.

39. The color filter manufacturing method according to claim 30, wherein drying conditions after application of inks deployed in said resin matrix pattern gaps are conditions that, in accordance with properties of said inks, combine either setting in a natural atmosphere or prebaking at 40 to 100°

C. together with final baking at 160 to 300°

C.

40. The color filter manufacturing method according to claim 30, wherein said inks deployed in gaps in said resin matrix pattern, after drying, exhibit a variation in color tone that is a color difference of 3 or less in same pixel, in same chip, and in same substrate.

41. The color filter according to claim 30, wherein said banks have a trapezoidal cross-section.

42. A liquid crystal display device manufacturing method comprising:

forming a light blocking matrix pattern by a thin film metal on a transparent substrate;

forming a resin matrix pattern of banks stacked on that light blocking matrix pattern,

subjecting surface of said resin matrix pattern and substrate surface in matrix gaps to dry etching prior to deploying inks;

deploying inks in said matrix gaps by ink jet, wherein a contact angle between said banks and said inks is 30 degrees or greater but 60 degrees or less;

drying and hardening inks so that film thickness becomes uniform;

applying a transparent overcoat on upper surface of ink after hardening ink;

forming a thin film electrode on top of said transparent overcoat;

deploying color filter substrate obtained by said steps in an opposing substrate having pixel electrodes; and

sealing a liquid crystal composition in gap between said color filter substrate and said opposing substrate.

43. The liquid crystal display device manufacturing method according to claim 42, wherein said step for forming said thin film metal pattern is a metal thin film photoresist etching step.

44. The liquid crystal display device manufacturing method according to claim 42, wherein said step for forming said resin matrix pattern is a step for patterning a photosensitive resin composition by a photoresist process so as to roughly be superimposed on said thin film metal matrix pattern.

45. The liquid crystal display device manufacturing method according to claim 42, wherein a height of said banks in said resin matrix pattern is made 1.5 μ

m to 5 μ

m.

46. The liquid crystal display device manufacturing method according to claim 42, wherein said step for performing said dry etching is a step for performing surface treatment so that difference in contact angle with water between surface of said resin matrix pattern and resin gap surfaces becomes 15 degrees or greater.

47. The liquid crystal display device manufacturing method according to claim 42, wherein said step for deploying inks in gaps in said resin matrix pattern is performed using an ink jet printing head.

48. The liquid crystal display device manufacturing method according to claim 42, wherein said step for deploying inks in gaps in said resin matrix pattern discharges extremely minute ink drops of 6 picoliters to 30 picoliters from a printing head while controlling said discharge.

49. The liquid crystal display device manufacturing method according to claim 42, wherein said inks deployed in gaps in said resin matrix pattern comprise a solvent having a boiling point of 150 to 300°

C.

50. The liquid crystal display device manufacturing method according to claim 42, wherein drying conditions after application of inks deployed in said resin matrix pattern gaps are conditions that, in accordance with properties of said inks, combine either setting in a natural atmosphere or prebaking at 40 to 100°

C. together with final baking at 160 to 300°

C.

51. The liquid crystal display device manufacturing method according to claim 42, wherein said inks deployed in gaps in said resin matrix pattern, after drying, exhibit a variation in color tone that is a color difference of 3 or less in same pixel, in same chip, and in same substrate.

52. The color filter according to claim 42, wherein said banks have a trapezoidal cross-section.

53. A color filter wherein:

light blocking regions and light transmitting regions are arranged in a prescribed matrix pattern on a transparent substrate;

said light blocking regions comprise light blocking layers and a bank layer provided on said light blocking layers, wherein

said light transmitting regions are configured by coloring layers formed by inks and demarcated by said light blocking regions;

peripheral edges of bottom surface of said bank layer are positioned inside from peripheral edges of said light blocking layers;

said light blocking layers have exposed surfaces on upper surface thereof where said bank layer is not superimposed; and

peripheral edges of coloring layers are superimposed on said exposed surfaces of said light blocking layers wherein a contact angle between said banks and said inks is 30 degrees or greater but 60 degrees or less.

54. The color filter according to claim 53, wherein said exposed surfaces of said light blocking layers are continuous all around peripheries of said light transmitting regions.

55. The color filter according to claim 53, wherein said exposed surfaces of said light blocking layers have a width of 1 μ

m to 10 μ

m.

56. The color filter according to claim 53, wherein said light blocking layers are configured from metal layers.

57. The color filter according to claim 56, wherein said light blocking layers have a film thickness of 0.1 μ

m to 0.5 μ

m.

58. The color filter according to claim 53, wherein said bank layer has a film thickness of 0.1 μ

m to 5 μ

m.

59. The color filter according to claim 53, wherein said light transmitting regions are such that color tone variation thereof is a color difference of 3 or less in same pixel, in same chip, and in same substrate.

60. The color filter according to any claim 53, wherein said bank layer has a roughly trapezoidal cross-sectional shape in width dimension thereof, that becomes wider in the direction of substrate.

61. The color filter according to claim 53, wherein said banks have a trapezoidal cross-section.

62. A color filter manufacturing method comprising the steps of:

(a) forming light blocking layers having a prescribed matrix pattern on a transparent substrate;

(b) forming a bank layer having a prescribed matrix pattern on said light blocking layers, wherewith peripheral edges of bottom surface of said bank layer are positioned inside outer edges of said light blocking layers, and some of upper surface of those light blocking layers is formed in an exposed condition; and

(c) forming coloring layers by inks in coloring region formation regions demarcated by said light blocking layers and said bank layer, wherewith said coloring layers are formed on said substrate, and peripheral edges thereof are formed in a condition wherein they are superimposed on exposed surfaces on upper surface of said light blocking layers wherein a contact angle between said banks and said inks is 30 degrees or greater but 60 degrees or less.

63. The color filter manufacturing method according to claim 62, wherein said exposed surfaces on upper surface of said light blocking layers are continuous all around peripheries of said light transmitting regions.

64. The color filter manufacturing method according to claim 62, wherein said exposed surfaces on upper surface of said light blocking layers have widths of 1 μ

m to 10 μ

m.

65. The color filter manufacturing method according to claim 62, wherein, in said step (a), said light blocking layers are formed, after a metal layer is formed on said substrate, by patterning that metal layer by photolithography and etching.

66. The color filter manufacturing method according to claim 65, wherein said light blocking layers have a film thickness of 0.1 μ

m to 0.5 μ

m.

67. The color filter manufacturing method according to claims 62, wherein said bank layer has a film thickness of 1 μ

m to 5 μ

m.

68. The color filter manufacturing method according to claims 62, wherein, in said step (b), said bank layer is formed by forming a photosensitive resin layer on substrate whereon said light blocking layers are formed, and then patterning said photosensitive resin layer by photolithography.

69. The color filter manufacturing method according to claims 62, wherein, prior to said step (c), surface treatment is performed bank layer and said substrate relative to ink.

70. The color filter manufacturing method according to claim 62, wherein a difference in contact angle with water between surface of said bank layer and surface of said substrate is 15 degrees or greater.

71. The color filter manufacturing method according to claim 62, wherein, in said step (c), said coloring layers have inks deployed in said coloring layer formation regions using an ink jet printing head.

72. The color filter manufacturing method according to claim 71, wherein said inks are deployed is minute ink drops of 6 to 30 picoliters.

73. The color filter manufacturing method according to claim 62, wherein, in said step (c), said inks for forming said coloring layers comprise a solvent having a boiling point of 150 to 300°

C.

74. The color filter manufacturing method according to claim 62, wherein, in said step (c), said inks for forming said coloring layers, after being deployed in said coloring layer formation regions, in accordance with properties of said inks, either setting in a natural atmosphere or prebaking at 40 to 100°

C., or both, is combined with final baking at 160 to 300°

C.

75. The color filter according to claim 62, wherein said banks have a trapezoidal cross-section.