JP2002333516A - Transparent substrate and method for manufacturing transparent substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent substrate having high reliability without discontinuity in lines or peeling in the patterning step of a transparent conductive film, and to provide a manufacturing method threfor. SOLUTION: In the transparent substrate on which at least an organic polymer thin film layer is formed, the surface of the organic polymer thin film layer shows <=50 deg. contact angle with water and 0.1 nm to 5.0 nm center line average roughness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color filter used in a color liquid crystal display device and a method of manufacturing the color filter.

[0002]

2. Description of the Related Art In a color filter manufacturing process, a chromium film is formed on a transparent substrate such as glass using a vacuum film forming method or the like, a photoresist is applied, a photomask is arranged, and exposure, development, and the like are performed. Chromium etching and photoresist stripping are performed to form a patterned black light-shielding layer. Particularly in recent years, in consideration of the influence on the global environment, a resin black matrix (BM) using a light-shielding resin as a black light-shielding layer without using harmful chromium has been developed and manufactured. In addition, a color filter of a type in which a colored layer is formed by overlapping a colored layer without providing a black light-shielding layer has been developed and manufactured. Next, after applying the first color photosensitive material from above the black light shielding layer, a photomask is arranged and exposed,
After that, development is performed to form a first color pattern,
Similarly, the second and subsequent color patterns are formed. Finally, a color filter is completed through a step of forming a transparent conductive film layer used as an electrode for driving a liquid crystal on the color pattern. At this time, an overcoat layer made of an organic polymer material may be formed between the color pattern and the transparent conductive film layer for the purpose of protecting pixels and flattening the color pattern. By the way, high light transmittance and low resistance are required for the transparent conductive film layer, and in view of these points, indium oxide (ITO) to which tin oxide is added is widely used as a suitable material. ing. As a method of forming the ITO film, methods such as sputtering, ion plating, and vacuum deposition are known, but all require heating the substrate under a reduced pressure atmosphere. In many cases, a sputtering method is used which can obtain a high light transmittance and a low resistance value at a relatively low temperature. The thickness of the ITO film is preferably larger from the viewpoint of the resistance value, but as the film thickness increases, there is a disadvantage that the transparency deteriorates and the transmittance of the color filter decreases. Therefore, the thickness of the ITO film is 0.1 μm or more.
A thickness of about 0.4 μm is generally adopted.

There are various types of color liquid crystal display systems, but there are two main types, a TFT system and an STN system, and the required characteristics of a color filter are different depending on the system. In particular, as a required characteristic of a color filter for STN, it is necessary to reduce the level difference of the colored layer. Therefore, it is general to form an overcoat layer to reduce the level difference. In addition, good etching processability of the ITO film formed on the overcoat layer is also a required characteristic of a color filter for STN. this is,
This is because in the STN method, the ITO film formed on the color filter needs to be patterned because it is used as a scanning electrode for driving liquid crystal. Generally, as a method of forming an electrode pattern, a photoresist is coated on an ITO film formed on the entire surface of a color filter, a photomask is arranged, and a predetermined pattern is formed through exposure, development, etching, and photoresist peeling. A lithography method is employed.

However, in the etching process of the ITO film, the pattern is broken due to partial excessive side etching of the ITO film, or the pattern is caused by erosion of the etching solution at the interface between the overcoat layer and the ITO film. Is peeled off, and there is a risk that the driving characteristics and display characteristics of the color liquid crystal display device are seriously affected.

To solve the above problem, for example,
(1) JP-A-62-153826 and JP-A-6-153826
ITO disclosed in Japanese Patent Application Laid-Open No. 3-44627.
A method of improving the etching processability by forming an inorganic intermediate film such as SiO ₂ between the film and the color filter and improving the adhesion has been proposed. A process of forming an ITO film after forming an inorganic intermediate film such as ₂ is widely and generally used. For example, for example, (2)
Japanese Patent Application Laid-Open No. 65902/65 proposes a method of reducing the apparent stress and improving the etching processability by making the ITO film a laminated film of a film exhibiting a compressive stress and a film exhibiting a tensile stress. ing.

[0006]

However, (1)
The method of forming an inorganic intermediate film such as SiO ₂ requires a decompression equipment for film formation, and it is strongly desired to omit it from the viewpoints of cost, yield, productivity, maintainability and the like. Further, in the method (2) in which the ITO film is used as a laminated film, if one apparatus is used, it is necessary to change the conditions after the formation of the first layer to form the second layer. There is a problem of spoiling.

The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to improve the adhesion of an ITO film by modifying the surface of an overcoat layer.
The present invention aims to improve the reliability of a color liquid crystal display device by improving the occurrence of disconnection and peeling of an ITO electrode pattern generated in the etching process of a TO film, and to provide a highly reliable color filter and a method of manufacturing the same. is there.

[0008]

The present inventors have pursued the cause of the disconnection and peeling of the pattern, and as a result, have found that the cause is that the adhesion between the transparent conductive film and the overcoat layer made of an organic polymer material is low. The conclusion has been reached. Furthermore, it has been found that when the surface properties of the overcoat layer are in an appropriate state, the adhesiveness of the transparent conductive film is improved, and sufficient etching processability can be obtained without interposing an inorganic intermediate film. Also,
By the proper size of the transparent conductive film grains,
It has been found that the adhesion of the transparent conductive film is further improved, and the etching processability is dramatically improved.

That is, the transparent substrate of the present invention has the following configuration. (1) In a transparent substrate having at least an organic polymer thin film layer formed thereon, the contact angle of water on the surface of the organic polymer thin film layer is 5
A transparent substrate, which is not more than 0 ° and has a center line average roughness Ra of 0.1 nm to 5.0 nm. (2) The transparent substrate according to (1), wherein the transparent substrate has at least a colored layer, and the organic polymer thin film layer is an overcoat layer that protects the colored layer. (3) the organic polymer thin film layer is a polyimide resin, a silicone resin obtained by condensation polymerization of an organosilane, an imide modified silicone resin obtained by condensation polymerization of an organosilane and a compound having an imide group, an acrylic resin; The transparent substrate according to claim 1, wherein the transparent substrate is formed of at least one selected from an epoxy resin or a mixture thereof. (4) In the transparent substrate on which at least the organic polymer thin film layer is formed, the organic polymer thin film layer is exposed to plasma under atmospheric pressure, (1) to (3).
The transparent substrate according to any one of the above. (5) The transparent substrate according to any one of Claims 1 to 4, wherein the transparent conductive film formed on the organic polymer thin film layer has a grain size of 1.0 µm or less. (6) The transparent substrate according to any one of (1) to (5), wherein the transparent conductive film is annealed at a temperature of 180 to 280 ° C. after formation. (7) After the formation of the transparent conductive film, the transparent conductive film is patterned by etching.
The transparent substrate according to any one of (6). (8) The transparent substrate according to any one of (1) to (7), wherein the transparent conductive film is a compound of indium oxide and tin oxide. (9) A color filter formed from the transparent substrate according to any one of (1) to (8) and a method of manufacturing the color filter.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a transparent substrate on which an organic polymer thin film layer is formed, wherein the contact angle of water on the surface of the organic polymer thin film layer is 50 ° or less, and the center line average of the surface is reduced. A first characteristic feature of the transparent substrate is that the roughness Ra is 0.1 nm to 5.0 nm. A transparent substrate according to a second feature is that a transparent conductive film formed on the organic polymer thin film layer has a grain size of 1.0 μm or less. Embodiments of the present invention will be described below.

The organic polymer thin film layer in the present invention is not particularly limited as long as it is formed on a transparent substrate. For example, a black matrix layer, a colored layer, an overcoat layer constituting a color filter, and a color filter are formed on the transparent substrate. Orientation film, which is suitably used as a sealing material,
It is more suitable as an overcoat layer for protecting the colored layer and reducing the level difference.

The substrate used in the present invention is not particularly limited as long as it is transparent, and a glass having high light transmittance, excellent mechanical strength and dimensional stability is optimal, and soda glass, alkali-free glass, low alkali Glass, borosilicate glass, quartz glass, and the like are often used. Other polyimide resin,
A plastic plate or a transparent film made of an acrylic resin, a polyester resin, a polycarbonate resin or the like can also be used. Alternatively, SiO ₂ , Al, A
A type coated with an inorganic film of g, Ni, Cr or the like is also used. When used for a color filter having a color pattern of one or more colors, various plastic and inorganic thin films satisfying the required characteristics of the color filter are patterned on glass, plastic, or a transparent film. A laminated composite is used.

The black matrix layer is not particularly limited, but may be an inorganic material such as chromium or a multilayer film of chromium and chromium oxide or chromium nitride, acrylic resin, or the like.
Carbon, titanium, titanium oxide, polyimide resin, etc.
An organic material in which a black pigment composed of the above is dispersed is used. Both inorganic and organic systems are preferably used in the present invention, but it is more advantageous to use an organic system which is more advantageous in terms of manufacturing cost than an inorganic system which requires a complicated vacuum system for film formation and has less influence on the global environment. preferable. Alternatively, the black matrix layer may be formed by overlapping the colored layers. Although the thickness of the black matrix layer is not particularly limited, an inorganic type having a thickness of 0.1 to 0.3 μm and an organic type having a thickness of 0.5 to 2 μm are often used. Although the black matrix layer is not particularly limited, a predetermined pattern is formed by a method such as a photolithography method, an inkjet method, and a printing method.

The coloring layer is not particularly limited, but a layer in which a pigment is dispersed in a resin or the like is used. As the resin, a material that does not soften, decompose, or discolor even when subjected to annealing at 180 ° C. or higher can be used. Epoxy resin, urethane resin, urea resin, acrylic resin, polyvinyl alcohol resin, melamine resin, polyamide resin, polyamideimide Resins, polyimide resins and mixtures thereof are preferably used. Among these, a polyimide resin having excellent heat resistance is more preferable. The thickness of the coloring layer is not particularly limited, but is generally in the range of 0.1 μm to 5 μm.

The overcoat layer is preferably excellent in chemical resistance, and is not particularly limited.
Silicone resin obtained by polycondensation of organosilane,
An imide-modified silicone resin obtained by polycondensation of an organosilane and a compound having an imide group, an acrylic resin,
Epoxy resins and the like are preferably used. The thickness of the overcoat layer is not particularly limited, but is generally 5 μm or less.

In the present invention, the contact angle of water on the surface of the organic polymer thin film layer is 50 ° or less. For example, when an organic polymer thin film layer is used as an overcoat layer, if the contact angle of water on the surface is large, the adhesion to the transparent conductive film decreases, and as a result, the etching processability deteriorates. for that reason,
The contact angle of water on the surface of the overcoat layer is preferably 50
゜ or less, more preferably 40 ° or less, and even more preferably 20 ° or less. If the contact angle of water exceeds 50 °, disconnection and peeling of the pattern of the transparent conductive film layer occurs.

The definition of the contact angle of water at this time is shown in FIG.
As shown in FIG. 5, the angle 1 is formed when water 4 is placed on the surface of the organic polymer thin film 3 formed on the substrate 2 and the water 4 does not spread but forms droplets in an equilibrium state. At this time, the forces acting on the corner interface between water 4, organic polymer thin film 3, and atmosphere 5 are balanced by the relational expression of Expression (1) derived by Young.

Γ _SV −γ _SL = γ _LV cos θ (1) where, γ _SV : energy of the surface of the organic polymer thin film 6 γ _SL : energy of the organic polymer thin film / water interface 7 γ _LV : water surface Energy 8θ: angle 1 to be formed.

In the present invention, the center line average roughness Ra of the surface of the organic polymer thin film layer is in the range of 0.1 nm to 5.0 nm. For example, when the organic polymer thin film layer is an overcoat layer, if fine irregularities are formed on the surface, the contact area between the overcoat layer and the transparent conductive film layer is increased, and the anchor of the transparent conductive film is increased. The effect of suppressing the shear stress by the effect also works, and the adhesion between the overcoat layer and the transparent conductive film is improved. As a result, the etching processability of the transparent conductive film is also improved. However, if the irregularities are too large, crystallization of the transparent conductive film proceeds with the nuclei as a nucleus, resulting in a film having a large grain size, and disconnection and peeling of the pattern occur. At the same time, local concentration of the residual stress of the transparent conductive film also occurs in the uneven portion, and the film itself cracks. Therefore, it is important that the fine irregularities on the surface are appropriate, and the center line average roughness Ra is preferably in the range of 0.1 nm to 5.0 nm in order to obtain good etching workability, and more preferably 0.1 nm to 5.0 nm. The range is from 3 to 3.5 nm. Outside this range, disconnection and peeling of the pattern occur during etching.

As shown in FIG. 2, the surface 10 of the overcoat layer 9 usually has some undulation, and when the measurement length 11 is increased when measuring Ra, the undulation is measured as Ra. Of course, from the viewpoint of etching workability, it is preferable to reduce Ra including the undulation. However, in the present invention, the fine unevenness formed on the undulating surface is more important for the etching processability. Therefore, the method of measuring Ra at this time is to measure the measurement length 9 at 0.5 μm or less. Also,
The center line average roughness Ra is ANSI B46.1-1985.
And is calculated by the following equation (2).

[0021]

(Equation 1)

Here, Ra: center line average roughness L: measured length 9 y: distance from the center line to the roughness curve.

The contact angle of water on the surface of the overcoat layer and the center line average roughness of the surface are described above. The contact angle of water after the formation of the overcoat layer is usually 60 ° or more. Ra changes depending on the material of the overcoat layer, application conditions and drying conditions. Therefore, in the present invention, by any means of chemical and mechanical,
It is preferable to modify the surface of the overcoat layer so as not to cause fatal damage to the overcoat layer and the color filter layer. The means is not particularly limited,
For example, the following method can be considered. Low-pressure plasma treatment in which the substrate surface is exposed to plasma under reduced pressure. In addition, an RF treatment for modifying the overcoat surface by applying high-frequency power to the substrate surface under reduced pressure. Alternatively, at atmospheric pressure, atmospheric pressure plasma processing in which the substrate surface is exposed to plasma at atmospheric pressure. UV ozone treatment in which the chemical bond of organic substances is broken using the energy of ultraviolet rays, and the surface is modified by the action of removing organic substances by ozone. As a mechanical method, a polishing process of scrubbing the surface with a resin, a fiber, or the like. Among them,
From the standpoint of quality, uniform processing without damage to the color filter, uniformity can be easily integrated into in-line equipment, productivity that enables high-speed processing, economy without the need for vacuum equipment, and facility maintenance. To atmospheric pressure plasma treatment is preferred.

The temperature during the treatment of the surface of the overcoat is not particularly limited, but is preferably 300 ° C. or lower, more preferably 250 ° C. or lower. Exceeding this may cause damage to the color filters and warp of the color filter substrate.

The method of treating the surface of the overcoat using an atmospheric pressure plasma apparatus is not particularly limited, but the plasma is obtained by applying a high DC voltage or a high frequency voltage to the supplied gas. Raise,
A method of exposing the gas excited by the plasma to the object to be processed or the surface thereof can be preferably used. It is preferable to use an inert gas or a mixed gas of an inert gas and a reaction gas as the supplied gas in order to stabilize discharge.
Helium, argon, neon, krypton and the like can be used as the inert gas, but helium or argon is most preferably used in consideration of discharge stability and economic efficiency. As the reaction gas, an oxidizing gas such as oxygen, air, CO ₂ , N ₂ O, or the like can be arbitrarily used.

The method of exposing the substrate to the atmospheric pressure plasma is not particularly limited. The direct method in which the substrate is directly conveyed into the plasma and the plasma treatment is performed, and the active species generated in the plasma generating unit is applied to the plasma There is an indirect method or the like in which a gas is introduced to a substrate disposed at a position where the substrate is not exposed to water, and the like, and any method can be suitably employed. However, in the former direct method, a strong plasma is generated partially when protrusions or irregularities are present on the substrate surface, or when metal is present inside or on the surface layer, for example, when the black matrix layer is made of chromium. As a result, the processing range varies,
There is a possibility that electrical damage such as discharge marks may occur on the substrate surface. Therefore, when the direct method is adopted, it is preferable to optimize plasma generation conditions such as applied power, introduced gas, electrode structure, electrode-substrate distance, etc., depending on the discharge state and the processing substrate, and furthermore, unevenness of the surface of the substrate to be processed. In order to eliminate projections and the like as much as possible, it is preferable to polish or remove the projections. Of course, it is also preferable to improve the flatness of the treated surface as much as possible by overcoating in order to prevent local plasma damage.

On the other hand, when performing the plasma processing by the latter indirect method, the distance between the substrate and the plasma becomes important. Since active species generated by plasma have a lifetime,
If the distance between the substrate and the plasma is too large, the processing ability will be significantly reduced. For this reason, there is a certain restriction on the distance relationship between the substrate and the plasma, and there is no particular limitation, but the distance between the plasma and the substrate is preferably within 30 mm, more preferably within 10 mm.

The method for forming the transparent conductive film is not particularly limited.
It is preferable to use a sputtering method in that a film having a low resistance and a high transparency can be obtained even when the film is formed at a temperature of not more than ° C. Among them, the DC magnetron sputtering method which can obtain a high film forming rate is more preferable.

There are various types of film forming apparatuses such as a batch type, an in-line type, and a single-wafer type. In the prior art, the transparent conductive film of the STN color filter is composed of an overcoat layer and a transparent conductive film. In order to form an inorganic intermediate film such as SiO ₂ between the conductive film and the conductive film, a batch type or a single wafer type is generally used. However, in the present invention, since an inorganic intermediate film is not essential, any type of film forming apparatus can be used, and although not particularly limited, an in-line type is preferable in terms of excellent productivity. In the case of an in-line type, the surface of the overcoat layer can be modified without impairing productivity by providing a processing device before the film formation zone, and productivity can be improved by providing a heat treatment chamber after the film formation zone. Can be performed without impairing the heat treatment.

The transparent conductive film used in the present invention includes:
Although not particularly limited, tin oxide, indium oxide, zirconium oxide, zinc oxide, cadmium oxide, indium oxide (ITO) to which tin oxide is added, and the like are preferable, with ITO being preferred in terms of high transparency and low resistance. IT
The amount of tin oxide added in O is not particularly limited, but is preferably in the range of 5 to 15% by weight for reducing the resistance value, and more preferably 8 to 12%. The sputtering target for sputtering is not particularly limited, but an ITO sintered body target or an indium-tin alloy target can be used.

The smaller the grain size of the transparent conductive film, the better the etching processability. This is because when the crystallization of the transparent conductive film proceeds and the grain size becomes larger than 1.0 μm, the residual stress in the film increases, and the adhesion between the overcoat and the transparent conductive film decreases. Therefore, the grain size of the transparent conductive film in the present invention is preferably 1.0 μm.
m or less, more preferably 0.4 μm or less, and even more preferably 0.2 μm or less. If the grain size exceeds 1.0 μm, disconnection and peeling of the pattern may occur.

The definition of grain in the present invention is as follows.
It is a single crystal portion of the transparent conductive film layer, and the definition of the grain size is the area of the single crystal portion. The grain size is
For example, it can be known by observing the crystal structure of the surface of the transparent conductive film using a scanning electron microscope. There is a grain boundary between the grains and the grains, and each grain can be distinguished.

The film forming temperature is not particularly limited.
The following range is preferable in that the residual stress can be reduced, and more preferably 100 to 170 ° C. For example, in the case where the transparent conductive film is ITO, it is not preferable to form the film at a temperature exceeding 180 ° C. because the crystallization of the film in the process of forming the ITO film is accelerated and the film becomes large in grain size.

The gas introduced during the film formation is not particularly limited.
Simple, or a mixture of argon, helium, nitrogen, oxygen, etc. can be considered.
A mixed gas of argon and oxygen is preferred from the viewpoint of the stability of film characteristics such as transmittance and etching rate. The total pressure at the time of film formation is not particularly limited.
Is more preferable, more preferably 0.4 Pa to 0.6
Pa range. When the pressure is 0.2 Pa or less, the discharge is not stable, and when the pressure exceeds 0.8 Pa, the sputtering rate decreases, which is not preferable. The proportion of oxygen in the deposition gas is not particularly limited, but is preferably 0.8% or less, more preferably 0.3% or less. If the proportion of oxygen in the deposition gas is high, the residual stress of the transparent conductive film increases, which is not preferable.

Although the thickness of the transparent conductive film is not particularly limited,
It varies depending on the required surface resistance value, and is 0.05 to 0.
The range is preferably 60 μm, more preferably 0.10 to 0.30 μm. If the film thickness is too thin, the film will not be uniform and the resistance value will be unstable. On the other hand, if the film thickness is too large, the transparency of the film becomes poor, and the crystallization of the transparent conductive film is accelerated, resulting in a film having a large grain size.

The annealing temperature is preferably in the range of 180 to 280 ° C., more preferably 200 to 260 ° C. If the temperature is lower than 180 ° C., the film is not crystallized, and even if the film is annealed, the resistance value is not lowered to a practical level, and the etching rate of the transparent conductive film is unstable. Further, if the temperature exceeds 280 ° C., the temperature exceeds the heat resistance temperature of the resin or pigment used for the coloring layer, so that the color filter may be uneven or discolored.

Further, the present invention improves the adhesion of a transparent conductive film such as ITO by modifying the surface of an overcoat layer made of an organic polymer material, and is sufficient even without an inorganic interlayer such as SiO _2. Although it is a material that obtains etching workability,
Even when a transparent conductive film is formed on the surface of the overcoat layer of the present invention via an inorganic intermediate film, the adhesiveness between the overcoat layer and the inorganic intermediate film is further improved and a strong film quality is obtained. Can be done.

Further, even when the organic polymer thin film is, for example, a black matrix layer, a coloring layer, an alignment film, or a sealing material, the present invention also improves the adhesion to the film laminated in the next step. Therefore, it can be suitably used.

[0039]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. (Example 1) 5 g of a black pigment composed of carbon black,
25 g of a polyimide precursor solution composed of polyamic acid,
A solvent consisting of 45 g of N-methyl-2-pyrrolidone and 14 g of butyl cellosolve was stirred and mixed to obtain a black color paste. Similarly, red, green, and blue color pastes were obtained using anthraquinone-based red pigments, phthalocyanine-based green pigments, and phthalocyanine-based blue pigments instead of black pigments. Soda glass with SiO ₂ (P070E-D manufactured by Nippon Sheet Glass Co., Ltd.) 400 mm in length and 50 in width
A black color paste was spin-coated on a transparent substrate having a thickness of 0 mm and a thickness of 0.7 mm, and then dried by heating at 110 ° C. for 15 minutes to obtain a polyimide precursor film having a thickness of 1.5 μm. A positive photoresist is spin-coated on this film,
For 20 minutes to obtain a resist film having a thickness of 1.0 μm. Next, after exposing to ultraviolet light through a photomask, unnecessary portions of the photoresist and the polyimide precursor film are removed by etching using a developing solution composed of a 2.4% aqueous solution of tetramethylammonium hydroxide.
The remaining photoresist was removed with methyl cellosolve acetate. This was heated at 300 ° C. for 30 minutes to form a light-shielding layer having a predetermined shape. Next, red, green, and blue pixels having a predetermined shape were formed on the substrate by using a red paste, a green paste, and a blue paste. A transparent acrylic resin was applied thereon so that the thickness after drying became 1.5 μm, and then dried to produce a color filter with an overcoat.

The color filter thus obtained was subjected to an atmospheric pressure plasma processing apparatus (Aiplasm manufactured by Matsushita Electric Works, Ltd.).
(a wide type), the introduced gas is a mixed gas of Ar, He, and O ₂ , the substrate temperature reached during processing is 150 ° C., the applied voltage is 700 kW, and the distance between the plasma outlet and the substrate is 5 m.
Atmospheric pressure plasma processing was performed on the entire surface of the substrate for m and a processing time of 60 seconds.

Thereafter, using an in-line DC magnetron sputtering apparatus, the substrate reached a temperature of 150 ° C. during the film formation, and the introduced gas was a mixed gas of Ar and O _{2 at} a total pressure of 0.6 P
a, An ITO film having a thickness of 0.25 μm is formed under the condition that the ratio of oxygen in the introduced gas is 0.1%, and then an annealing process is performed in an oven at atmospheric pressure at 220 ° C. for 30 minutes to perform ITO. A color filter with a film was obtained.

At this time, the contact angle of water on the overcoat before the formation of the ITO film was measured by a liquid contact angle measuring device (369LCD, manufactured by Elma Corporation) and found to be 18 °. The roughness Ra was measured using an atomic force microscope (AFM, N
nanoScope IIIaAFM Dimension
3000 units: Digital Instrument
ents, scanning range 0.5 μm × 0.5 μm, scanning speed 0.6 Hz), it was 2.0 nm,
The grain size of the obtained ITO film was measured using a scanning electron microscope (FE-SEM, S-4700, manufactured by Hitachi, Ltd.).
Observation with a magnification of 50000) revealed a value of 0.16 μm.

A positive photoresist was spin-coated on the color filter thus obtained,
After heating and drying for 0 minutes, a resist film having a thickness of 1.0 μm was obtained. Next, after exposing to ultraviolet light through a photomask, unnecessary portions of the photoresist are removed by etching using a developing solution composed of a 2.4% aqueous solution of tetramethylammonium hydroxide, and then ferric chloride: hydrochloric acid = 1: 1.
After etching at a liquid temperature of 40 ° C. with an etching time of 2 minutes using an ITO etchant consisting of, the remaining photoresist was removed by methyl cellosolve acetate.

As a result of observing the obtained color filter with an optical microscope, it was found that there was no disconnection or peeling of the pattern, and that a good
A color filter with an O-pattern electrode was obtained.
In addition, even when a cross-cut peeling test defined in JIS K5400 was performed, the ITO film was not peeled off, and the evaluation score was 10 points. Example 2 A color filter with an overcoat obtained in the same manner as in Example 1
Was irradiated with ultraviolet light. The irradiation energy was 3.89 mJ, the irradiation time was 360 seconds, and the irradiation amount was 500 mJ.

Thereafter, an ITO film was formed under the same conditions as in Example 1, and annealing was performed under the same conditions as in Example 1 to obtain a color filter with an ITO film.

At this time, the contact angle of water before forming the ITO film is 2
At 0 °, the center line average roughness Ra of the overcoat surface was 3.0 nm. The grain size of the ITO film obtained at this time was 0.18 μm.

The thus obtained color filter was etched with an ITO film in the same manner as in Example 1. As a result, there was no disconnection or peeling of the ITO pattern, and the color filter showed a score of 10 in the cross-cut peeling test. there were. Example 3 A color filter with an overcoat obtained in the same manner as in Example 1 was processed in Example 1 except that the processing time was 20 seconds.
After performing the atmospheric pressure plasma treatment in the same manner as in Example 1, an ITO film was formed in the same manner as in Example 1, and annealing was performed in the same manner as in Example 1 to obtain a color filter with an ITO film.

At this time, the contact angle of water before forming the ITO film is 4
At 5 °, the center line average roughness Ra of the overcoat surface was 0.5 nm. The grain size of the ITO film obtained at this time was 0.15 μm.

The color filter thus obtained was etched with an ITO film in the same manner as in Example 1. As a result, no disconnection or peeling of the ITO pattern occurred, and a score of 10 was obtained in the cross-cut peeling test. there were. Comparative Example 1 An ITO film was formed on a color filter with an overcoat obtained in the same manner as in Example 1 under the same conditions as in Example 1, and annealed under the same conditions as in Example 1 to form an ITO film.
A color filter with a film was obtained.

At this time, the contact angle of water before forming the ITO film was 7
At 8 °, the center line average roughness Ra of the overcoat surface was 0.2 nm. The grain size of the ITO film obtained at this time was 0.13 μm.

The ITO film was etched on the color filter thus obtained in the same manner as in Example 1. As a result, disconnection of the ITO pattern occurred. In the cross-cut peel test, peeling of the ITO film occurred, and the evaluation point was 8 points. (Comparative Example 2) The color filter with overcoat obtained in the same manner as in Example 1 was subjected to atmospheric pressure plasma processing in the same manner as in Example 1 except that the processing time was 360 seconds using atmospheric pressure plasma processing. An ITO film was formed as in Example 1, and annealing was performed as in Example 1 to obtain a color filter with an ITO film.

At this time, the contact angle of water before forming the ITO film was 1
At 0 °, the center line average roughness Ra of the overcoat surface was 5.5 nm. The grain size of the ITO film obtained at this time was 0.25 μm.

As a result of etching the ITO film on the color filter thus obtained in the same manner as in Example 1, disconnection of the ITO pattern occurred. In the cross-cut peeling test, peeling of the ITO film occurred, and the evaluation score was 4 points. (Comparative Example 3) A color filter with an overcoat obtained in the same manner as in Example 1 was treated with UV treatment for 12 hours.
After the UV treatment was performed in the same manner as in Example 2 for 00 seconds,
An ITO film was formed as in Example 1, and annealing was performed as in Example 1 to obtain a color filter with an ITO film.

At this time, the contact angle of water before forming the ITO film was 1
At 0 °, the center line average roughness Ra of the overcoat surface was 6.0 nm. The grain size of the ITO film obtained at this time was 0.26 μm.

As a result of etching the ITO film on the color filter thus obtained in the same manner as in Example 1, disconnection of the ITO pattern occurred. In the cross-cut peeling test, peeling of the ITO film occurred, and the evaluation score was 4 points.

In the above Examples and Comparative Examples, the surface of the overcoat was modified mainly by using atmospheric pressure plasma and UV. However, the same applies to, for example, reduced pressure plasma, reverse sputtering, RF treatment, polishing treatment and the like. It is. In addition, even when an ITO film is formed after forming an inorganic film such as SiO ₂ , Al, Ni, Ag, or Cr as an intermediate film or a reflection film, the present invention improves the adhesion between the overcoat and the inorganic film, ITO etching processability is further improved.
Alternatively, a black matrix layer, a colored layer, an alignment film,
Even for organic polymer thin films other than overcoats such as sealing materials, the adhesion to the laminated film is improved.

[0057]

[Table 1]

In the table, ○ indicates that there was no disconnection or peeling of the ITO film, and X indicates that there was disconnection or peeling of the ITO film.

[0059]

According to the present invention, in a color filter used for a color liquid crystal display device, the occurrence of disconnection and peeling of an ITO pattern in an ITO etching process is economically improved, and a highly reliable color filter is provided. Can be obtained.

[Brief description of the drawings]

FIG. 1 shows the definition of a contact angle.

FIG. 2 is a schematic sectional view illustrating an example of a surface state of an overcoat layer.

[Explanation of Signs] 1: Contact angle (formation angle θ) 2: Substrate 3: Organic polymer thin film 4: Water 5: Atmosphere 6: Organic polymer thin film surface energy (γ _SV ) 7: Organic polymer thin film / water interface Energy (γ _SL ) 8: Water surface energy (γ _LV ) 9: Overcoat layer 10: Overcoat layer surface 11: Measurement length

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayuki Ogawa 1-1-1 Sonoyama, Otsu-shi, Shiga F-term in the Toga Corporation Shiga Plant (reference) 2H048 BA45 BB08 BB37 BB44 2H091 FA02Y FA35Y FB02 FB08 FC25 GA01 GA16 LA30

Claims (9)

[Claims] 1. A transparent substrate on which at least an organic polymer thin film layer is formed, wherein the contact angle of water on the surface of the organic polymer thin film layer is 50 ° or less, and the center line average roughness Ra of the surface is 0.1 mm or less. A transparent substrate having a thickness of 1 nm to 5.0 nm. 2. The transparent substrate according to claim 1, wherein the transparent substrate has at least a colored layer, and the organic polymer thin film layer is an overcoat layer that protects the colored layer. 3. The organic polymer thin film layer, wherein a polyimide resin, a silicone resin obtained by condensation polymerization of an organosilane, an imide modified silicone resin obtained by condensation polymerization of an organosilane and a compound having an imide group, acrylic The transparent substrate according to claim 1, wherein the transparent substrate is formed of at least one selected from a resin and an epoxy resin, or a mixture thereof. 4. The method according to claim 1, wherein the organic polymer thin film layer is exposed to plasma under atmospheric pressure on at least the transparent substrate on which the organic polymer thin film layer is formed. 4. The transparent substrate according to 1. 5. The transparent substrate according to claim 1, wherein the transparent conductive film formed on the organic polymer thin film layer has a grain size of 1.0 μm or less. 6. The method according to claim 1, wherein the transparent conductive film is formed in an amount of 180 to 2 after formation.
The transparent substrate according to claim 1, wherein the transparent substrate has been annealed at a temperature of 80 ° C. 7. 7. The transparent substrate according to claim 1, wherein the transparent conductive film is patterned by etching after being formed. 8. The transparent substrate according to claim 1, wherein said transparent conductive film is a compound of indium oxide and tin oxide. 9. A color filter formed from the transparent substrate according to claim 1 and a method for manufacturing a color filter.