JP3098562B2 - Manufacturing method of color filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter and a method of manufacturing a color filter, and more particularly to a color filter used for a color liquid crystal display device and the like, which has a feature in forming an inorganic blocking layer.

[0002]

2. Description of the Related Art A liquid crystal display device, which is used in various devices instead of a CRT as a small display device, has a transparent substrate made of glass or the like provided with a transparent electrode layer provided with a gap of about several μm therebetween. A liquid crystal material is sealed, and the liquid crystal is oriented in a certain direction by a voltage applied between the electrodes to form a transparent portion and an opaque portion, thereby displaying an image. The color liquid crystal display device has three color filters of red (R), green (G), and blue (B) corresponding to the three primary colors of light on any transparent electrode substrate.

A color filter for a color liquid crystal display device is composed of a transparent substrate, a colored layer, a protective layer, a transparent conductive film, and the like. Several μm
, And a liquid crystal material is sealed to form a liquid crystal display device.

There are various color display methods using a liquid crystal display device. At present, three colors of red (R), green (G) and blue (B) corresponding to the three primary colors of light are provided on a transparent electrode substrate. Color filter, and the liquid crystal RG
A method using a color filter for controlling the amount of light transmission corresponding to B is mainly used.

[0005] The color filter used for such a purpose includes red (R), which corresponds to the three primary colors of light, on a transparent electrode substrate in order to control transmitted light by a light modulation effect of liquid crystal.
Three colored layers of green (G) and blue (B), a protective layer of the colored layer,
A transparent electrode layer for driving a liquid crystal is formed. The color filter forms a liquid crystal display device by enclosing a liquid crystal material between an electrode facing a position of the three primary colors of RGB of the colored layer or a transparent substrate on which an active element is formed.

[0006]

A color filter is formed on a transparent substrate such as glass by a pigment dispersion method, a dyeing method, an electrodeposition method, or the like.
A colored layer having a predetermined shape of the three primary colors R, G and B is formed by a printing method or the like, and a protective layer is formed on the colored layer for the purpose of physically and chemically protecting the colored layer and smoothing the surface of the colored layer. Is formed. The protective layer is made of a transparent polymer composition such as an acrylic or novolak.

When the protective layer is formed on the entire surface of the color filter, the adhesion between the substrate of the color filter and the transparent electrode layer is not sufficient, or when the color filter and the counter electrode are bonded with an adhesive. It is desirable that the protective layer formed on the color filter be limited on the color filter because a high adhesion strength cannot be obtained. In order not to form the protective layer on the outer periphery of the color filter, a colored layer is formed. Various measures such as applying a photocurable resin on the substrate and providing a photomask that limits the light irradiation area to the colored layer, and exposing the area outside the colored layer to remove the resin during development. Has been made.

A color filter is manufactured by forming a transparent electrode film of ITO composed of indium oxide and tin oxide directly on the surface of the protective layer. It is preferable to form a transparent inorganic inorganic blocking layer made of silicon oxide for protection from heat or chemicals during the manufacturing process of the liquid crystal display device.

However, even if an inorganic blocking layer is formed on the surface of the protective layer, if the bonding strength between the inorganic blocking layer and the glass substrate at the portion where the protective layer is not formed around the color filter is small, the inorganic blocking layer may be damaged. Peeling from the glass substrate may occur, causing a serious problem for the color filter, such as a chemical penetrating the coloring layer from the peripheral portion or peeling of the transparent electrode layer formed on the inorganic blocking layer.

When the cause of the peeling of the inorganic blocking layer was seriously examined, various organic substances such as coloring materials and photosensitive resin used in forming the colored layer and the protective layer were left on the substrate on the outer peripheral portion of the color filter. It is inevitable to adhere as, and even if the amount of such organic residue in the outer peripheral portion is extremely small, it affects the adhesion strength of the inorganic blocking layer,
It has been found that a situation that seriously affects the reliability of the liquid crystal display device, such as disconnection or peeling of the electrode take-out portion, occurs.

[0011]

The inventors of the present invention have studied means for solving the above-mentioned problems, and as a result, have found that silicon oxide is formed on a color filter in which a protective layer is formed on a colored layer formed on a transparent substrate. By forming the discharge gas during sputtering as a specific component when forming the inorganic blocking layer by sputtering, the color filter for forming the inorganic blocking layer can be formed with the glass substrate without performing any special pretreatment before sputtering. It has been found that an inorganic blocking layer having a large adhesive force is formed.

That is, when a color filter having a protective layer formed on a colored layer is sputtered using a silicon dioxide target, a small amount of oxygen is added to argon to form a discharge gas.

It is well known that plasma using oxygen as a discharge gas is used for ashing of organic substances and the like, but in the case of a mixed gas used in the present invention, it is formed on a colored layer. This makes it possible to increase the adhesion of the inorganic blocking layer around the colored layer without adversely affecting the protective layer made of an organic substance.

As an example of the composition of the discharge gas used in the present invention, oxygen having a partial pressure of 3 × 10 ⁻⁵ torr to 5 × 10 ⁻⁴ torr is mixed with argon having a partial pressure of 3 × 10 ⁻³ torr. A gas having such a composition is used as a discharge gas to form an inorganic blocking layer of silicon oxide by high frequency sputtering using a silicon dioxide target, and a transparent electrode film of ITO is formed on the formed inorganic blocking layer. A film is formed by sputtering or the like.

[0015]

The color filter obtained by the present invention is
In the method of forming a transparent electrode film on a substrate having an organic film formed thereon, a transparent electrode was formed after forming an inorganic blocking layer made of silicon oxide by sputtering in a discharge gas containing argon and oxygen. As a result, it is possible to obtain an extremely large adhesive force between the inorganic blocking layer and the transparent electrode film without adversely affecting the protective layer.

Hereinafter, embodiments of the present invention will be shown and described in further detail.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an apparatus for carrying out the method according to the invention. In the sputtering apparatus 1, a target 2 made of silicon dioxide, an anode 3 facing the target, and a color filter 4 on which an inorganic blocking layer is to be formed are provided on the anode. Apply high frequency current.

In the sputtering, after the inside of the apparatus is sufficiently evacuated to a reduced pressure, argon and oxygen are supplied so as to have a predetermined partial pressure, and discharge is performed until an inorganic blocking layer having a specified thickness is obtained.

FIG. 2 is a cross-sectional view of a color filter manufactured by applying the method of the present invention. The color filter 4 has a protective layer 7 on a colored layer 6 and an inorganic blocking layer 8.
Further, a transparent electrode film 9 is formed, and the inorganic blocking layer is firmly bonded to the substrate 11 at the peripheral portion 10.

Example 1 A glass substrate (AL material manufactured by Asahi Glass Co., Ltd.) having a size of 300 mm × 350 mm and a thickness of 1.1 mm was sufficiently washed, and a red photosensitive resin having a thickness of 1.2 μm was further placed thereon. And then dried in an oven at a temperature of 70 ° C. for 30 minutes, exposed with a mercury lamp, spray-developed with water for 1 minute, and a red relief is formed in the area where a red pixel is to be formed. An image was formed and heat-cured at 150 ° C. for 30 minutes.

By repeating the same steps, a green relief pixel was formed in a region where a green pixel was to be formed, and a blue relief pixel was formed in a region where a blue pixel was to be formed, thereby forming a colored layer.

Subsequently, bisphenol A acrylate (molecular weight 1500) was used as a photocurable acrylate oligomer.
To 2000), 50 parts by weight of trimethylolpropane triacrylate (TMPTA manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional polymerizable monomer, and Irgacure 651 (manufactured by Ciba Geigy) as a polymerization initiator. The mixture obtained by mixing 2 parts by weight was dissolved in 200 parts by weight of ethyl cellosolve acetate, and 10 g of the solution was applied to the color layer with a spin coater to a thickness of 2.0 μm using a spin coater. A photomask was placed in contact with the coating film, and only the colored layer was irradiated with ultraviolet light for 10 seconds by a super high pressure mercury lamp of 2.0 KW. Subsequently, 1% in a developer consisting of 1,1,2,2-tetrachloroethane at a temperature of 25 ° C.
The coating was immersed for a minute to remove only the uncured portion of the coating film.

Next, the obtained substrate on which the protective layer was formed was placed in a reaction chamber in a high-frequency sputtering apparatus at 1 × 10 5
After reducing the pressure to ^-6 torr, the partial pressure of argon in the apparatus was set to 3 × 10 ^-3 torr, and the partial pressure of oxygen was set to 3 × 10 ^-5 torr.
The sputtering was performed at a frequency of 13.56 MHz and a target power density of 1.5 W / cm ^{2 using} silicon dioxide as a target while changing the temperature between r and 8 × 10 ⁻⁴ torr to obtain an inorganic blocking layer having a thickness of 500 nm. Was.

A transparent electrode film of ITO having a thickness of 200 nm was formed on the obtained inorganic blocking layer by DC magnetron sputtering.

The adhesion at the periphery of the color filter when the oxygen partial pressure was changed was examined with a scratch tester schematically shown in FIG. Table 1 shows the results.

[0026]

[Table 1]

Comparative Example 1 A color filter was manufactured by performing sputtering in the same manner as in Example 1 except that only argon at a pressure of 3 × 10 ⁻³ torr was used as a reaction gas.

The adhesion at the peripheral portion of the color filter was examined by a scratch tester in the same manner as in the example.
g peeled off the silicon dioxide layer.

[0029]

According to the method of the present invention, there is provided a method of forming a transparent electrode layer on a substrate having an organic film formed thereon, wherein an inorganic blocking layer made of silicon oxide is sputtered in a discharge gas containing argon and oxygen. By forming a transparent electrode after forming a film, the adhesion of the inorganic blocking layer and the transparent electrode film can be extremely increased without adversely affecting the protective layer. can get.

[Brief description of the drawings]

FIG. 1 shows a sputtering apparatus for carrying out the method of the present invention.

FIG. 2 shows a cross-sectional view of a color filter manufactured by the method of the present invention.

FIG. 3 shows an outline of a scratch test.

[Explanation of symbols]

1 ... sputtering apparatus, 2 ... target, 3 ... anode,
4: color filter, 5: high frequency power supply, 6: colored layer,
7 Protective layer 8 Inorganic blocking layer 9 Transparent electrode film 10
... peripheral part, 11 ... substrate

────────────────────────────────────────────────── (5) References JP-A-64-26821 (JP, A) JP-A-58-193370 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/1343 G02B 5/20 101 G02F 1/1335 505

Claims (1)

(57) [Claims] 1. A colored layer, a protective film, an inorganic blocking layer formed of silicon oxide, and a transparent electrode film are sequentially laminated on a transparent substrate, and the inorganic blocking layer is formed on the transparent substrate at a peripheral portion thereof. In a method for producing a color filter formed without a layer, a method for producing a color filter containing argon and oxygen, wherein the partial pressure of argon is 1 × 10 ⁻³ torr to 1 × 10 ⁻² torr.
r, oxygen partial pressure is 1 × 10 ⁻⁵ torr to 1 × 10 ⁻³ t
A method for producing a color filter, comprising forming an inorganic blocking layer made of silicon oxide by performing sputtering in a discharge gas of orr.