LCD polymerized column spacer formed on a modified substrate, from an acrylic resin, on a surface having hydrophilic and hydrophobic portions, or at regular spacings

• US 5,739,882 A
• Filed: 05/19/1994
• Issued: 04/14/1998
• Est. Priority Date: 11/18/1991
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Konuma, Toshimitsu, Nishi, Takeshi, Shimizu, Michio
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Malinowski, Walter J.
• Application Number:
  US08/246,241
• Time in Patent Office: 1,426 Days
• Field of Search: 359/62, 359/80, 359/81, 359/51, 359/52, 359/74, 349/86, 349/92, 349/93, 349/94, 349/123, 349/153, 349/155, 349/156, 349/124
• US Class Current: 349/123
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence

Abstract

A liquid crystal electro-optical device is fabricated by holding a mixture of a liquid crystal material and an uncured resin between a pair of substrates, precipitating the uncured resin from the mixture in the form of columns, and curing the thus precipitated columns of uncured resin. wherein a ultraviolet-curable resin is used as the sealing material and the uncured resin to cure the both by irradiating an ultraviolet radiation thereto. In this manner, the curing of the sealing material and the resin columns can be completed in a single process. Also, in a liquid crystal electro-optical device comprising a pair of substrates in which one of them is a light-transmitting substrate, a fabricating process comprises precipitating an uncured resin from a mixture of a liquid crystal material and a resin curable by either or both of ultraviolet radiation and heating, and curing the precipitated resin by irradiating an ultraviolet radiation and heating. Furthermore, the surface state of the plane of at least one of the substrates to be in contact with the liquid crystal mixture is partially modified or rendered hydrophobic and/or hydrophilic to control the precipitation position of the resin.

Claims

1. A method for fabricating a liquid crystal electro-optical device, the method comprising the steps of:

partially modifying a state of a surface of at least one of first and second substrates to have hydrophobic and hydrophilic portions wherein the surface is in contact with a mixture of a liquid crystal material, an uncured resin and a sealing material so that the uncured resin is precipitated at a desired position;

placing said mixture of the liquid crystal material, said uncured resin and said sealing material on a first substrate;

adhering said second substrate on the surface of the first substrate onto which the mixture is placed;

precipitating the uncured resin from the mixture; and

simultaneously curing the sealing material and the precipitated uncured resin so that polymerized spacers are formed using the cured resin,

wherein said uncured resin is precipitated at regular spacing along both a transverse and longitudinal direction within said liquid crystal material.

2. A method of claim 1, wherein the sealing material has an ultraviolet-curable material, the uncured resin has an ultraviolet-curable material and the sealing material and the uncured resin are cured by ultraviolet radiation.

3. A method of claim 1, wherein the sealing material and the uncured resin are cured by heat.

4. A method for fabricating a liquid crystal electro-optical device comprising a pair of substrates facing each other and one of the substrates having a light shield film, the method comprising the steps of:

holding between the pair of substrates, a mixture of liquid crystal material and an uncured resin curable by ultraviolet radiation or heat, the uncured resin comprising an acrylic modified epoxy resin;

precipitating the uncured resin from the mixture; and

curing the precipitated uncured resin by ultraviolet radiation or heat to form polymerized spacers.

5. A method for fabricating a liquid crystal electro-optical device, the method comprising the steps of:

partially modifying a state of a surface of at least one of a pair of substrates wherein the surface is in contact with a mixture of a liquid crystal material and an uncured resin, to precipitate the uncured resin at a desired position;

holding the mixture between the pair of substrates;

precipitating the uncured resin from the mixture; and

curing the precipitated uncured resin.

6. A method of claim 5, wherein the uncured resin is cured by a ultraviolet radiation.

7. A method of claim 6, wherein the uncured resin is cured by heat.

8. A method for fabricating a liquid crystal electro-optical device, the method comprising the steps of:

partially modifying a state of a surface of at least one of a pair of substrates wherein the surface is in contact with a mixture of a liquid crystal material and an uncured resin by pressing a plate for screen printing against the surface, to precipitate the uncured resin at a desired position;

holding the mixture between the pair of substrates;

precipitating the uncured resin from the mixture; and

curing the precipitated uncured resin.

9. A method of claim 8, wherein the uncured resin is cured by a ultraviolet radiation.

10. A method of claim 8, wherein the uncured resin is cured by heat.

11. A method for fabricating a liquid crystal electro-optical device, the method comprising the steps of:

screen printing on one of the pair of substrates a sealing material for adhering peripheral portions of the substrates each other;

partially modifying a state of a surface of the other substrate on which the sealing material is not screen printed, to precipitate an uncured resin at a desired position;

holding a mixture of a liquid crystal material and the uncured resin between the pair of substrates;

precipitating the uncured resin in the form of columns from the mixture; and

curing the precipitated uncured resin.

12. A method of claim 11, wherein the uncured resin is cured by ultraviolet radiation.

13. A method of claim 11, wherein the uncured resin is cured by heat.

14. A method for fabricating a liquid crystal electro-optical device, the method comprising the steps of:

preparing at least one of a pair of substrates having a surface to be in contact with a mixture of a liquid crystal material and an uncured resin, the surface having hydrophobic and hydrophilic portions, to precipitate the uncured resin at a desired position;

holding the mixture between the pair of substrates;

precipitating the uncured resin from the mixture; and

curing the precipitated uncured resin.

15. A method of claim 14, wherein the uncured resin is cured by a ultraviolet radiation.

16. A method of claim 14, wherein the uncured resin is cured by heat.

17. A method for fabricating a liquid crystal electro-optical device, the method comprising the steps of:

pressing a substance having a lattice form against a surface of at least one of a pair of substrates wherein the surface is in contact with a mixture of a liquid crystal material and a uncured resin, to precipitate the uncured resin at a desired position;

holding the mixture between the pair of substrates;

precipitating the uncured resin from the mixture; and

curing the precipitated uncured resin.

18. A method of claim 17, wherein the uncured resin is cured by a ultraviolet radiation.

19. A method of claim 17, wherein the uncured resin is cured by heat.

20. A liquid crystal electro-optical device comprising:

a pair of substrates for holding a mixture of a liquid crystal material and an uncured resin, said uncured resin comprising an acrylic modified epoxy resin;

orienting means for uniaxially orienting the liquid crystal material, the orienting means being arranged on at least one of the pair of substrates,

wherein the orienting means has a surface with a partially modified surface state and the surface is in contact with the mixture so that the uncured resin is precipitated from the mixture at a desired position and cured to form polymerized spacers.

21. A device of claim 20, further comprising a pixel electrode wherein the uncured resin is precipitated around the pixel electrode.

22. A device of claim 20, wherein the uncured resin is cured by an ultraviolet radiation.

23. A device of claim 20 wherein the uncured resin is cured by heat.

24. The device of claim 20, said device including polymerized column spacers formed from the precipitated and cured resin wherein said partially modified surface state of the surface of said orienting means provides the site for the precipitation of the resin and polymerized column spacers.

25. A liquid crystal electro-optical device comprising:

a pair of substrates for holding a mixture of a liquid crystal material and an uncured resin, said uncured resin comprising an acrylic modified epoxy resin; and

a pair of pixel electrodes arranged on the substrates,

wherein at least the substrate or the pixel electrode has a surface with a partially modified surface state and the surface is in contact with the mixture so that the uncured resin is precipitated from the mixture at a desired position and cured to form polymerized spacers.

26. A device of claim 25, wherein the uncured resin is precipitated around the pixel electrodes.

27. A device of claim 25, wherein the uncured resin is cured by an ultraviolet radiation.

28. A device of claim 25, wherein the uncured resin is cured by heat.

29. The device of claim 25, said device including polymerized column spacers formed from the precipitated and cured resin wherein said partially modified surface state of the surface of said orienting means provides the site for the precipitation of the resin and polymerized column spacers.

30. A method for fabricating a liquid crystal electro-optical device, the method comprising the steps of:

forming a sealing material on a peripheral portion of a first substrate having a surface;

placing a mixture of a liquid crystal material and an uncured resin on the surface of the first substrate;

adhering a second substrate on a surface of the first substrate onto which the mixture is placed;

precipitating the uncured resin from the mixture; and

curing the sealing material and the precipitated uncured resin to form polymerized spacers,

wherein said uncured resin is precipitated at regular spacing along both a transverse and longitudinal direction within said liquid crystal material.