JPH08220340A - Color filter and its production - Google Patents

Abstract

PURPOSE: To prevent production of a rugged state on the upper surface of a color filter and to prevent disconection and pinholes in electrodes or dielectric layers to be formed in the succeeding processes by disposing a dye part in an overcoat layer formed on a substrate. CONSTITUTION: The color filter consists of a substrate 10, dye part 12 arranged by patterning at a specified position, and overcoat layer 13 to cover the dye part 12. The substrate 10 is a glass substrate such as soda lime glass, borosilicate glass and the like. As for the dye part 12, pigments are mainly used, and especially inorg. pigments are preferable. As for the material for the overcoat layer 13, a low melting point glass or inorg. oxides are preferably used. Since the obtd. color filter has a flat surface of the overcoat layer 13 which covers the dye part 12, production of pinholes in electrodes or dielectric material to be formed on the filter can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter which is provided in various display devices such as a plasma display and a liquid crystal display and a solid-state image pickup device and is used for reducing reflectance, color synthesis or color separation, and a manufacturing method thereof. .

[0002]

2. Description of the Related Art For example, in a color liquid crystal display,
A color filter for displaying in color is required.
Therefore, as described in a known document (for example, Tani et al., Technical Report of the Television Society, IDY94-112 (1
994)), a color filter produced by a method such as a dyeing method or a pigment dispersion method is used. This is to color a resin layer with an organic dye or an organic pigment to form a color filter. Also in the plasma display,
It has been proposed to use a color filter to improve the contrast when displaying an image (Wazu, Nikkei Electronics, November 8, 1993 (No. 59).
4) pp. 215). As described above, in some display devices, a color filter is indispensable for color display and improving image quality.

By the way, in the case of a plasma display,
The manufacturing process includes a process of firing at about 600 ° C. If a color filter for a liquid crystal display is diverted to a color filter for a plasma display, a material such as an organic material is included, so that a reaction such as combustion or decomposition occurs in the plasma display manufacturing process, and the color filter is Cannot be obtained.

As a solution to this problem, it has been proposed to use a low melting glass in which an inorganic pigment is dispersed as a color filter (Sakai et al., Technical Report E D993 IPD113-8 of the Television Society).
6) etc.). This is because a paste obtained by kneading a low-melting glass and an inorganic pigment with an appropriate binder resin and a solvent is patterned on a predetermined substrate by a method such as screen printing, and then baked to remove the binder resin and the solvent. A filter in which an inorganic pigment is dispersed in a low melting point glass is obtained. In this case, since the color filters are all made of an inorganic material, they can withstand the high temperature process involved in plasma display fabrication.

[0005]

In view of the structure of the plasma display, electrodes and dielectrics are formed on this color filter. Therefore, it is important to prevent the disconnection and the pinhole, and for that purpose, it is desirable that the irregularities on the substrate due to the filter layer be small and as flat as possible.

However, according to the above method, as shown in FIG. 5, since the low melting point glass 11 containing the pigment 12 is formed on the substrate 10 only at a predetermined position, the low melting point glass is formed. The low-melting-point glass 1 is formed in the place where 11 is formed and the place where it is not formed.
The unevenness is generated by the thickness of 1. The depth H of the unevenness may reach about 10 μm, and this unevenness may cause disconnection of the electrode formed thereon or pinhole of the dielectric.

The present invention has been made to solve the above problems, and provides a color filter in which unevenness on the upper surface is reduced and a manufacturing method thereof.

[0008]

A color filter according to claim 1, wherein a substrate, a flat upper surface and a transparent overcoat layer formed on the substrate, and a dye disposed at a predetermined position in the overcoat layer. And a section.

At this time, it is desirable that the dye portion is made of an inorganic pigment.

The invention according to claim 3 is the color filter according to claim 1 or 2, characterized in that the overcoat layer is made of a low melting point glass or a transparent inorganic oxide.

A method for manufacturing a color filter according to a fourth aspect is characterized in that after a dye portion is formed at a predetermined position on a substrate, a transparent overcoat layer covering the dye portion and having a flat upper surface is laminated. To do.

According to a fifth aspect of the present invention, in the method of manufacturing a color filter, a pigment medium containing a pigment is formed at a predetermined position on a substrate, and the pigment medium is removed by firing to cover the pigment portion of the remaining pigment. As described above, an overcoat medium containing an overcoat material made of low-melting glass or a transparent inorganic oxide is laminated on a substrate and baked to remove the overcoat medium to form a flat overcoat layer on the upper surface. It is characterized by that.

The invention according to claim 6 is the method for producing a color filter according to claim 5, characterized in that a blade coat is used for laminating the overcoat layer.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a color filter, in which a pigment medium containing a pigment is formed at a predetermined position on a substrate, and further, an overcoat material made of low melting point glass or a transparent inorganic oxide is contained. After laminating the overcoat medium, the dye medium and the overcoat medium are removed by firing, and an overcoat layer made of a pigment dye portion and an overcoat material covering the dye portion is formed on a substrate. Is.

The invention according to claim 8 is the method for manufacturing a color filter according to claim 7, wherein the overcoat medium is an organic binder.

According to a ninth aspect of the invention, in the color filter according to the fourth aspect, any one of a printing method, a photolithography method, an electrophotographic method, and an electrodeposition method is used as a method for forming the dye portion. It is a manufacturing method.

The invention according to claim 10 is the method for manufacturing a color filter according to claim 4, wherein a coating method by a liquid phase method or a vapor phase method is used as a method for forming the overcoat layer.

[0018]

The present invention will be described in detail below. As shown in FIG. 1, the color filter of the present invention is configured to include a substrate 10, a dye portion 12 patterned and arranged at a predetermined position, and an overcoat layer 13 that covers the dye portion 12. As the substrate, one used for a general color filter can be applied, and there is a glass plate made of soda lime glass, borosilicate glass, or the like. A pigment is mainly applied to the dye portion 12 arranged at a predetermined position on the substrate, but among them,
Inorganic pigments are preferred. Examples of inorganic pigments include Fe ₂ O ₃ as a red pigment and TiO ₂ —Co as a green pigment.
O-NiO-ZnO, as a blue pigment CoO-Al ₂
O _{3 and the} like can be used, but the present invention is not limited thereto. Further, pigments of other colors may be used depending on the application.

As the overcoat material forming the overcoat layer 13, a transparent material is applied, and low melting point glass or inorganic oxide is preferable. As the low melting point glass, lead borosilicate glass or the like can be used, but the low melting point glass is not limited thereto. Also, as a transparent inorganic oxide, S
It is possible to use iO _2, or a composite oxide of SiO ₂ and TiO ₂ , but not limited to these. As shown in FIG. 1, this overcoat 13 is applied to each dye portion 12
Is formed not only on the upper part of the dye, but also between the dye parts, and the upper surface thereof is flat.

In this color filter, since the upper surface of the overcoat layer that covers the dye portion is formed flat, there is no unevenness on the upper portion thereof, and there are no breaks in the electrodes formed thereon or pinholes in the dielectric. Can be suppressed.

According to the method of manufacturing a color filter of claim 4, first, the dye portion is formed at a predetermined position on the substrate, and then the overcoat layer including the dye portion is laminated on the substrate, Flatten its top surface. Various methods can be applied to the formation of the dye portion on the substrate, and above all,
It is desirable to use any one of a printing method, a photolithography method, an electrophotographic method and an electrodeposition method. In the case of the printing method, a screen printing method, a lithographic offset printing method, or the like can be used, but the printing method is not limited thereto.

In the photolithography method, a paste in which a pigment is kneaded with an appropriate photosensitive resin is applied onto a substrate, and the paste is exposed using a predetermined photomask, and then developed and patterned, or a method of applying a pigment is used. After coating on a substrate, a photosensitive resin is coated on this pigment, exposed by using a predetermined photomask, and then developed and etched, followed by patterning, or a resin having photoadhesiveness. Is applied on the substrate, exposed using a predetermined photomask, to make only the portion to which the pigment adheres sticky, and then the pigment is sprayed and the pigment is fixed on the sticky layer to be patterned. It is possible, but not limited to these.
In electrophotography, a known resin may be used as a pigment to form a toner, which is attached to a selenium photoreceptor on which a latent image is formed in advance, and then transferred to a substrate for patterning, but the present invention is not limited thereto.

Further, in the electrodeposition method, a pigment is dispersed in water with an alkyd resin or the like to prepare an electrodeposition coating material, and a substrate on which a transparent conductive film such as a patterned ITO film is provided is immersed in the electrodeposition coating material. It is possible to pattern on the transparent conductive film by energizing, but not limited to this.

For forming the overcoat layer, a coating method by a liquid phase method or a gas phase method is suitable. The liquid phase method may be, but not limited to, a method in which a metal alkoxide is applied by a screen printing method, a dip coating method, a spin coating method, and then this is baked. Further, the vapor phase method for forming the overcoat layer may be a vapor deposition method, a sputtering method, or the like, but is not limited thereto.

When it is difficult for the overcoat material to enter between the dye portions previously formed on the substrate, or when the upper surface is unlikely to be flat, blade coating using a doctor blade may be used.

According to a fifth aspect of the present invention, in the method of producing the color filter according to the fourth aspect, a pigment medium containing a pigment is used to form the pigment portion, and an overcoat layer is formed. It is characterized by using an overcoat medium containing a low melting point glass or an inorganic oxide. That is, a predetermined pigment is once dispersed in the medium,
The dye medium is arranged at a predetermined position by the above-mentioned arbitrary forming method, and then this is baked to remove the medium, and only the remaining pigment is formed on the substrate. This dye medium needs to be one that can be removed by firing, and for example, ethyl cellulose, acrylic resin or the like is applied. Similarly, when forming the overcoat layer,
The overcoat material is once dispersed in the medium, the overcoat medium is laminated by any of the above-mentioned forming methods, and then the medium is removed by firing it to form only the remaining overcoat material on the substrate. Of. The overcoat medium needs to be one that can be removed by firing, and for example, an organic binder such as ethyl cellulose or acrylic resin is applied.

According to a seventh aspect of the present invention, a dye medium containing a pigment is formed at a predetermined position on a substrate, an overcoat medium containing an overcoat material is subsequently formed, and then the dye medium is baked to form a dye medium and The overcoat medium is removed together, and a dye portion made of a pigment and an overcoat layer covering the dye portion are formed on the substrate. That is, unlike the invention of claim 5, the pigment medium and the overcoat medium are removed by one-time baking, and only the pigment and the overcoat material which are not removed by the baking remain, and the overcoat material is not on the pigment. Of course, each of the above media can be applied to the dye medium and the overcoat medium in which a layer having a flat upper surface is formed on the substrate. With this manufacturing method, since the number of firing steps is small, the manufacturing steps can be simplified, and the manufacturing time and manufacturing cost can be shortened.

[0028]

The present invention will be described below with reference to examples.
It goes without saying that the present invention is not limited to these. Further, in the following description, a blue dye portion is applied as the dye portion for description, but it is not always required to be blue, and since it is a color filter, it is usually three colors (blue, red, green). It is well known that each of the dye portions of) is arranged at a predetermined position.

Example 1 First, 5 parts of a blue pigment (manufactured by Asahi Kasei Co., Ltd .: "Asahi Super Blue CR") was used as a medium, and α- of ethyl cellulose (manufactured by Kanto Chemical Co., Ltd.) was used.
Terpineol (Kanto Chemical Co., Inc.) 5% by weight solution 50
In addition to the parts, a paste was prepared by kneading this with a three-roll mill. Then, as shown in FIG. 2, the blue pigment paste 14 was applied onto the glass substrate 10 using a screen printing plate of 300 mesh to have a width of 100 μm and a length of 4 mm.
Printed on the pattern.

Next, this was baked in air at 580 ° C. for 10 minutes to obtain ethyl cellulose and α in the blue pigment paste.
-Terpineol was removed by evaporation or burning, leaving only the pigment 12 on the glass substrate 10, as shown in FIG.

Furthermore, 75 parts of lead borosilicate glass (“GA-9” manufactured by Nippon Electric Glass Co., Ltd.) is used as 2- (2-ethoxyethoxy) of ethyl cellulose (manufactured by Kanto Chemical Co., Inc.).
A glass paste was prepared by adding 25 parts of a 10 wt% solution of ethanol (manufactured by Kanto Chemical Co., Inc.) and kneading the mixture with a three-roll mill. As shown in FIG. 4, a solid pattern is printed on the glass substrate 10 on which the above-prepared pigment 12 is left in a predetermined position by using a 300 mesh screen printing plate, and an overcoat material is obtained. Formed 15.

Then, by baking this in air at 580 ° C. for 10 minutes, ethyl cellulose and 2- (2-ethoxyethoxy) ethanol in the glass paste were evaporated or burned to be removed, and as shown in FIG. An overcoat layer 13 made of low-melting glass on the glass substrate 10.
Was formed, whereby a color filter in which the pigment 12 was fixed on the glass substrate 10 was manufactured.

This color filter was excellent in flatness with irregularities on the upper surface of about 1 μm. The measurement result of the spectral transmittance of this color filter is shown in FIG.

<Example 2> Blue pigment (Asahi Kasei Co., Ltd.)
Made: “Asahi Super Blue CR”) 15 parts, 30 parts of hydroxypropyl cellulose (manufactured by Wako Pure Chemical Industries, Ltd.) as a photosensitive resin and dipentaerythritol hexaacrylate (manufactured by Toagosei Kagaku Co., Ltd .: “Aronix M- 400 ") 30 parts, to which 2-
(2-ethoxyethoxy) ethanol (Kanto Chemical Co., Inc.)
90 parts) and kneaded with a three-roll mill, and then used as a reaction initiator benzyl dimethyl ketal (Toa Gosei Kagaku KK: "Aronix C-101")
A photosensitive blue pigment paste was prepared by adding 5 parts.

The above-prepared photosensitive blue pigment paste was applied to the entire surface of the glass substrate using a 300 mesh screen printing plate, followed by exposure with a high pressure mercury lamp using a predetermined photomask and development with water. Thus, a pattern having a width of 100 μm and a length of 4 mm was obtained.

Then, the glass substrate is baked in air at 580 ° C. for 10 minutes to evaporate or burn off the photosensitive resin, solvent and reaction initiator in the blue pigment paste to remove only the pigment on the glass substrate. It was left.

After that, an overcoat layer was formed in the same manner as in Example 1 to obtain a color filter as shown in FIG. The results of measuring the irregularities on the substrate and the spectral transmittance were the same as in Example 1.

<Example 3> Blue pigment (Asahi Kasei Co., Ltd.)
(Manufactured by: "Asahi Super Blue CR") and 10 parts by weight of 90 parts of a styrene-n-butyl methacrylate copolymer (manufactured by Sanyo Kasei Co., Ltd .: "Heimer SBM-73") while kneading, and after cooling, hammered. The particles were coarsely crushed with a mill, pulverized with a jet mill, and then classified to obtain colored particles having an average particle size of 10 μm, polytrifluoroethyl-α-
Chloroacrylate (manufactured by Toray Industries, Inc.) was adhered by a spray dry method, and this was treated with hot air by a spheroidizing device for thermoplastic particles to obtain a toner.

This tonerized pigment is adhered to a selenium photoreceptor on which a latent image of a predetermined pattern is formed in advance according to a standard method, and the adhered tonerized pigment is heated to 100 ° C.
Then, it was transferred to a glass substrate heated to 100 ° C. and then baked at 580 ° C. for 10 minutes to remove the resin component, so that only the pigment remained on the glass substrate to obtain a pattern of a pigment having a width of 100 μm and a length of 4 mm.

Then, an overcoat layer was formed on the substrate on which the pigment was arranged in the same manner as in Example 1 to obtain a color filter. The results of measuring the irregularities on the substrate and the spectral transmittance were the same as in Example 1.

<Example 4> First, 15 parts of a blue pigment (Asahi Kasei Co., Ltd .: "Asahi Super Blue CR") was added to an aqueous alkyd resin varnish (Dainippon Ink and Chemicals, Inc.).
(Manufactured by: "Watersol S140C") and 45 parts of water to prepare a dispersed electrodeposition coating composition.

According to a conventional method, a glass substrate on which a transparent conductive film having a predetermined pattern has been formed is immersed in this electrodeposition coating material, and the electrodeposition coating material is adhered onto the electrodes by energizing at 60 V for 60 seconds. The substrate was baked at 580 ° C. for 10 minutes to remove the resin component, and only the pigment 12 remained on the glass substrate 10 as shown in FIG. 3 to obtain a pattern of pigment having a width of 100 μm and a length of 4 mm.

An overcoat layer was formed on the substrate on which the pigment 12 was formed in the same manner as in Example 1 to obtain a color filter. The results of measuring the irregularities on the substrate and the spectral transmittance were the same as in Example 1.

Example 5 First, in the same manner as in Example 1, only the pigment 12 was formed on the glass substrate 10. As an overcoat material, a silica coating agent by a sol-gel method (Nippon Soda Co., Ltd .: "Atron NSi 310")
10 parts of ethyl cellulose (manufactured by Kanto Chemical Co., Inc.) α-
Terpineol (Kanto Chemical Co., Inc.) 5% by weight solution 50
In addition to the parts, it was prepared by thoroughly mixing. This was printed on the above substrate in a solid pattern using a 300 mesh screen printing plate.

Then, the glass substrate was baked in air at 580 ° C. for 10 minutes to form an overcoat layer of low melting point glass on the glass substrate, and a color filter in which the pigment was fixed to the glass substrate was obtained. The results of measuring the irregularities on the substrate and the spectral transmittance were the same as in Example 1.

Example 6 In the same manner as in Example 1, after forming only the pigment on the glass substrate, SiO ₂ was formed into a film on the glass substrate by using a vapor deposition apparatus according to a conventional method to form an overcoat layer. The layers were laminated to obtain a color filter in which the pigment was fixed on the glass substrate. The results of measuring the irregularities on the substrate and the spectral transmittance were the same as in Example 1.

<Embodiment 7> After printing the blue pigment paste 14 on the glass substrate 10 in the same manner as in Embodiment 1,
As the overcoat material 15, the glass paste described in Example 1 was laminated and printed. Thereafter, the resin and solvent in the blue pigment paste 10 and the resin and solvent in the overcoat material 15 are removed by baking at 580 ° C. for 10 minutes, and the pigment 12 patterned on the glass substrate 10 is removed.
Then, the overcoat layer 13 made of low-melting glass was formed, whereby the pigment 12 was fixed to the glass substrate 10 to obtain a color filter. The measurement result of the spectral transmittance and the unevenness on the substrate were the same as in Example 1.

Comparative Example 75 parts of low melting point lead glass (manufactured by Nippon Electric Glass Co., Ltd .: "GA-9") was replaced with 2- (2-ethoxyethoxy) of ethyl cellulose (manufactured by Kanto Chemical Co., Ltd.).
To 25 parts of a 10 wt% solution of ethanol (manufactured by Kanto Chemical Co., Inc.) and kneading this with a three-roll mill, 26 parts of a paste was added, and a blue pigment (Asahi Super Blue CR, manufactured by Asahi Kasei Co., Ltd.) 1 Parts were added, and this was kneaded with a three-roll mill to prepare a paste. This paste was printed on a glass substrate using a 300 mesh screen printing plate to obtain a pattern having a width of 100 μm and a length of 4 mm.

Next, this was baked in air at 580 ° C. for 10 minutes to obtain a color filter in which the pigment was dispersed in the low melting point glass. The top surface of this color filter had irregularities with a depth of about 10 μm. The measurement result of the spectral transmittance is shown in FIG. From the measurement results shown in FIG. 7 and the measurement results shown in FIG. 6, it can be seen that the color filters of Examples 1 to 7 and the color filter of the comparative example show similar spectral transmittances.

[0050]

According to the color filter of the present invention and the manufacturing method of the present invention capable of manufacturing the color filter, it is possible to reduce irregularities formed on the upper surface. For this reason,
Since disconnection and pinholes in electrodes and dielectric layers formed in a later step are less likely to occur, reliability as a display can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a color filter of the present invention.

FIG. 2 is a cross-sectional view showing a state after a pigment paste coating step in a color filter manufacturing example of the invention.

FIG. 3 is a cross-sectional view showing a state after a pigment paste firing step in a color filter manufacturing example of the invention.

FIG. 4 is a cross-sectional view showing a state after a step of applying an overcoat material in a production example of a color filter of the present invention.

FIG. 5 is a cross-sectional view showing a conventional example of a color filter.

FIG. 6 is a graph showing the spectral transmittance measurement results of the color filter of this example.

FIG. 7 is a graph showing a spectral transmittance measurement result of a color filter of a comparative example.

[Explanation of symbols]

 10 Glass Substrate 11 Low Melting Glass 12 Dye Part 13 Overcoat Layer 14 Pigment Paste 15 Overcoat Material

Claims (10)

[Claims] 1. A color filter comprising: a substrate; a flat upper surface and a transparent overcoat layer formed on the substrate; and a dye portion arranged at a predetermined position in the overcoat layer. 2. The color filter according to claim 1, wherein the dye portion is made of an inorganic pigment. 3. The overcoat layer is made of a low melting point glass or a transparent inorganic oxide.
Or the color filter described in 2. 4. A method of manufacturing a color filter, comprising forming a dye portion at a predetermined position on a substrate and then laminating an overcoat layer which covers the dye portion and has a flat upper surface and which is transparent. 5. A low melting point glass or a transparent inorganic material is formed so that a pigment medium containing a pigment is formed at a predetermined position on a substrate, and the pigment medium is removed by baking, and then the pigment portion made of the remaining pigment is covered. A method for manufacturing a color filter, which comprises laminating an overcoat medium containing an overcoat material made of an oxide on a substrate and baking the substrate to remove the overcoat medium to form an overcoat layer having a flat upper surface. . 6. The method of manufacturing a color filter according to claim 5, wherein a blade coat is used for laminating the overcoat layer. 7. A dye medium containing a pigment is formed at a predetermined position on a substrate, and an overcoat medium containing an overcoat material made of low melting glass or a transparent inorganic oxide is further laminated and then baked. And removing the dye medium and the overcoat medium to form a dye portion made of a pigment and an overcoat layer made of an overcoat material covering the dye portion on the substrate. 8. The method of manufacturing a color filter according to claim 7, wherein the overcoat medium is an organic binder. 9. The method for producing a color filter according to claim 4, wherein any one of a printing method, a photolithography method, an electrophotographic method, and an electrodeposition method is used as a method of forming the dye portion. 10. The method of manufacturing a color filter according to claim 4, wherein a coating method by a liquid phase method or a vapor phase method is used as a method of forming the overcoat layer.