JP2010225853A - Method of forming pattern on flexible board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming a pattern which can improve dimensional stability when a color filter and a TFT are pattern-formed on a flexible board. <P>SOLUTION: The method of forming the pattern includes a temporary joint step A of temporarily joining a flexible board 3 to a dimensionally stable hard board 1 using a temporary joint agent, an anneal processing step B of anneal-treating the flexible board 3 at a temperature equal to or higher than a glass transition temperature of the temporary joint agent and a temperature equal to or lower than a glass transition temperature of a polymer constituting the flexible board 3, a pattern forming step C of forming a pattern on the flexible board 3 by photolithography, and a lifting step D of lifting the pattern-formed flexible board 3 from the hard board 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for forming a pattern on a flexible substrate, which can improve dimensional stability when a color filter or TFT is formed on the flexible substrate.

  Flat panel displays such as liquid crystal display devices and organic electroluminescence (organic EL) display devices are widely used as thin and space-saving display devices. Among these display devices, most of those that perform color display (particularly most of liquid crystal display devices) are colored by RGB color filters corresponding to pixels formed using a glass substrate. A substrate on which three primary color patterns are formed is generally called a color filter.

  In recent years, an attempt has been made to use a plastic film instead of glass for a substrate in order to further reduce the thickness and weight of a display device for a portable device such as a mobile phone. As the kind of the plastic film, in addition to thermoplastic films such as polyethylene terephthalate, polycarbonate and polyethersulfone, crosslinkable resins such as epoxy resins have been proposed.

  By the way, when using a colored resist when manufacturing a color filter using a plastic film, patterning is performed by photolithography and a heat treatment step of about 200 ° C. is required. When this step is performed three times for each of the red, green, and blue colored portions, or when a resin black matrix is formed between the colored portions, at least four heat treatment steps are required. When a plastic film is used for the substrate, the heat treatment process is repeated a plurality of times. For example, in the case of a thermoplastic resin, deformation may occur in the process when, for example, an external force such as a tension is applied during transportation, and particularly in the case of a stretched film, shrinkage due to relaxation occurs. Even in the case of a crosslinkable resin, curing shrinkage occurs due to thermal history. Since the heat treatment process is repeated, a dimensional change due to such deformations occurs, and there is a problem that the dimensional accuracy deviates from the design value when a glass substrate is used.

In order to solve the above problem, for example, in Patent Document 1, after forming a substrate by providing a transparent ceramic layer on one side of the transparent plastic film, heat treatment may be performed at a temperature higher than the glass transition temperature of the transparent plastic film material. Proposed. However, in this proposal, there is a problem that the flexibility of the transparent plastic film is impaired by providing the transparent ceramic layer.
Further, in Patent Document 2, in a color filter for a display device having a color filter layer formed by heat treatment on a plastic film, the temperature is equal to or higher than the heat treatment temperature at the time of forming the color filter layer before the formation of the color filter layer. A color filter for a display device in which a plastic film is heated has been proposed. However, if only the flexible substrate is used as in this proposal, the substrate may be slightly warped due to the heat treatment at the time of manufacturing the color filter, and the dimensional stability may be lowered.

JP 2003-292657 A JP 2006-99016 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention can improve the dimensional stability during pattern formation on a flexible substrate, and can be applied to a flexible substrate that can form a color filter pattern and a TFT pattern on the flexible substrate with high dimensional stability. An object is to provide a pattern forming method.

  As a result of intensive studies by the present inventors in order to solve the above-mentioned problems, the dimensions when forming a pattern on a flexible substrate by temporarily retaining the flexible substrate with a temporary anchoring agent on a hard substrate with little dimensional change due to temperature Stability can be improved. In addition, after temporarily fixing the flexible substrate on the hard substrate with a temporary fixative, annealing is performed at a temperature not lower than the glass transition temperature of the temporary fixative and not higher than the glass transition temperature of the polymer constituting the flexible substrate. It has been found that the dimensional stability of the flexible substrate after peeling from the substrate is improved, the flexible substrate can be stuck on the substrate while being smooth, and the workability is improved.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A temporary holding step of temporarily fixing a flexible substrate to a dimensionally stable hard substrate with a temporary holding agent;
An annealing treatment step of annealing the flexible substrate at a temperature not lower than the glass transition temperature of the temporary binder and not higher than the glass transition temperature of the polymer constituting the flexible substrate;
A pattern forming step of forming a pattern by photolithography on the flexible substrate;
And a peeling step of peeling the patterned flexible substrate from the hard substrate.
<2> The pattern forming method according to <1>, wherein in the peeling step, the patterned flexible substrate is peeled from the hard substrate by immersing the laminate of the patterned flexible substrate and the hard substrate in hot water. It is.
<3> The pattern forming method according to any one of <1> to <2>, wherein the pattern to be formed is any one of a color filter and a TFT.
<4> The pattern forming method according to any one of <1> to <3>, wherein the polymer constituting the flexible substrate is polyethylene naphthalate (PEN).

  According to the present invention, conventional problems can be solved, dimensional stability in pattern formation on a flexible substrate can be improved, and color filter patterns and TFT patterns can be formed on a flexible substrate with high dimensional stability accuracy. The pattern formation method to the flexible substrate which can provide the pattern formation method to the flexible substrate which can be formed can be provided.

FIG. 1 is a process diagram showing a pattern forming method (production of a color filter) on a flexible substrate of the present invention. FIG. 2 is a plan view of a flexible substrate (plastic film) on which a black matrix pattern is formed. FIG. 3 is a plan view of a flexible substrate (plastic film) on which a black matrix pattern and a RED coloring pattern are formed. FIG. 4 is a cross-sectional view illustrating an example of a color filter.

  The pattern forming method on the flexible substrate of the present invention includes a temporary holding process, an annealing process, a pattern forming process, and a peeling process, and further includes other processes as necessary.

<Temporary distillation process>
The temporary anchoring step is a step of temporarily fixing the flexible substrate to a dimensionally stable hard substrate with a temporary anchoring agent.

As long as the flexible substrate has flexibility, the shape, material, size, shape, structure and the like are not particularly limited and can be appropriately selected according to the purpose. Examples of the structure include a single layer structure and a laminated structure.
Examples of the material include polyethylene terephthalate (PET), polyethylene, polypropylene, polyester, polyolefin, polyacrylonitrile, ethylene vinyl acetate copolymer (EVA), cellulose triacetate (TAC), polyethylene naphthalate, polycarbonate, polyphenylene sulfide, polyimide. , Polyvinyl chloride, polyethersulfone, polyamideimide, polyamide, polyethylene naphthalate (PEN), polyethersulfone (PES), and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, polyethylene naphthalate (PEN) is particularly preferable because it is highly transparent and suitable for an optical material, and heat shrinkage due to a heating and cooling process is small.
The flexible substrate preferably has a thickness of 0.1 mm to 0.5 mm.

  The dimensionally stable hard substrate is not particularly limited as to the material, size, shape, structure, etc. as long as the dimensional change due to heat treatment is small, and can be appropriately selected according to the purpose, for example, a glass substrate, A quartz plate, a sapphire plate, an aluminum plate, an iron plate, a duralumin plate, etc. are mentioned. Among these, a glass substrate is particularly preferable in that it is inexpensive and is stable without being affected by chemicals.

The temporary entraining agent is not particularly limited as long as it can temporarily hold a flexible substrate and a hard substrate and both can be peeled in the peeling step, and can be appropriately selected according to the purpose, for example, an acrylic polymer, Examples include polyvinyl alcohol, vinyl acetate polymer, starch paste, and the like.
As the temporary retention agent, a suitably synthesized product or a commercially available product may be used. Examples of the commercially available products include Photo Bond 800 (manufactured by Sunrise MSI Co., Ltd.), Photo Bond 810 (manufactured by Sunrise MSI Co., Ltd.), Photo Bond 830 (manufactured by Sunrise MSI Co., Ltd.), and Photo Bond 840 (manufactured by Sunrise MSI Co., Ltd.). PVA-103 (manufactured by Kuraray Co., Ltd.), PVA-105 (manufactured by Kuraray Co., Ltd.), PVA-107 (manufactured by Kuraray Co., Ltd.), PVA-117 (manufactured by Kuraray Co., Ltd.), PVA-203 (manufactured by Kuraray Co., Ltd.) , PVA-205 (manufactured by Kuraray Co., Ltd.), PVA-210 (manufactured by Kuraray Co., Ltd.), PVA-403 (manufactured by Kuraray Co., Ltd.), PVA-405 (manufactured by Kuraray Co., Ltd.), PVA-420 (manufactured by Kuraray Co., Ltd.) , Etc.

  There is no restriction | limiting in particular as a method of temporarily fixing the flexible substrate to a dimensionally stable hard substrate, and it can be appropriately selected according to the purpose. For example, (1) applying a temporary agent on the hard substrate (2) A temporary substrate is applied on the hard substrate, and the flexible substrate is stacked on the temporary agent layer. And a method of curing by heating, (3) a method of applying a temporary binder on a hard substrate, overlaying a flexible substrate on the temporary binder layer, and press-bonding.

<Annealing process>
The annealing treatment step is a step of annealing the flexible substrate at a temperature not lower than the glass transition temperature of the temporary retention agent and not higher than the glass transition temperature of the polymer constituting the flexible substrate. By annealing the flexible substrate, the internal stress is usually reduced and the heat-stable state is obtained.

The temperature of the annealing treatment is not lower than the glass transition temperature of the temporary retention agent and not higher than the glass transition temperature of the polymer constituting the flexible substrate, and is preferably 40 ° C to 200 ° C. If the temperature of the annealing treatment is lower than the glass transition temperature of the temporary retention agent, the effect of annealing may not be noticeable and dimensional stability may not be improved, and the polymer constituting the flexible substrate may not be seen. When the glass transition temperature is exceeded, the flexible substrate may be softened and it may be difficult to maintain the shape.
It is preferable that the temporary transition agent has a glass transition temperature of 40 ° C to 100 ° C.
It is preferable that the glass transition temperature of the polymer which comprises the said flexible substrate is 50 to 200 degreeC.
The glass transition temperature of the polymer constituting the flexible substrate is preferably higher than the glass transition temperature of the temporary retention agent.

  The annealing treatment method is not particularly limited as long as the flexible substrate can be heat-treated at a temperature not lower than the glass transition temperature of the temporary holding agent and not higher than the glass transition temperature of the polymer constituting the flexible substrate, and can be appropriately selected according to the purpose. For example, heating and air cooling in an oven, heating and air cooling using a hot plate, heating and air cooling using infrared heating, and the like can be given.

<Pattern formation process>
The pattern forming step is a step of forming a pattern on the flexible substrate by photolithography. In this invention, workability | operativity improves by performing pattern formation in the temporary holding state with high dimensional stability.

  The pattern formed in the pattern forming step is preferably either a color filter or a TFT.

  Hereinafter, a method of forming a color filter composed of a black matrix and a coloring pattern using RGB colorants on the surface of a flexible substrate (plastic film) temporarily retained on a glass substrate and annealed will be described.

  The black matrix and the RGB coloring pattern can be formed by photolithography, and can be performed in a single sheet (cut sheet form) or in a continuous roll-to-roll process. In particular, when it is carried out in a roll-to-roll continuous process, productivity is high.

  Here, the black matrix and the colorant are either a photosensitive composition for forming a black matrix and a composition for forming a colored pattern, which are directly coated on a plastic film and patterned and heat cured, or separately. This photosensitive composition is applied onto a base film and dried to form a dry film, which is laminated on a plastic film as a substrate, transferred, patterned, and thermally cured.

The photosensitive composition contains (A) a colorant, (B) an alkali-soluble resin, (C) a polyfunctional monomer, and (D) a photopolymerization initiator. Contains ingredients.
The colorant (A) is a material for color-displaying each colored pattern or shielding a black matrix pattern when the color filter is irradiated with transmitted light. For example, a red organic pigment, Examples of the green organic pigment, the blue organic pigment, and the light shielding material include carbon black pigment.
The alkali-soluble resin (B) is a material for dissolving the layer during development and removing the layer made of the photosensitive composition, and examples thereof include benzyl methacrylate / methacrylic acid copolymer.
The polyfunctional monomer (C) is a material for polymerizing a layer made of a photosensitive composition during exposure to form an insoluble pattern during development. For example, dipentaerythritol Examples include hexaacrylate.
The photopolymerization initiator (D) is a material for polymerizing a polyfunctional monomer during exposure, such as 2-benzyl-2-dimethylamino-1- (4-monofoliophenyl) butanone. -1 or the like.
By using such a photosensitive composition, a high-resolution colored pattern and a black matrix pattern can be formed on a roll-to-roll, and a flexible pattern following the flexibility of the plastic film can be formed.

  Here, a mode in which a black matrix is laminated on a plastic film from a dry film will be described. The dry film for black matrix used here is a base film formed by applying the black matrix-forming composition in a wet state using a die coat and drying to form a layer comprising the photosensitive composition, and then laminating the cover film. Can be obtained.

  As a coating method of the photosensitive composition, there are gravure coating, gravure reverse coating, slit reverse coating, micro gravure coating, comma coating, slide coating, spray coating, curtain coating and the like in addition to die coating.

  The thickness of such a base film is preferably 2.5 μm to 100 μm, more preferably 6 μm or more in order to improve the transportability of the film, and 50 μm or less in order to increase the followability to the unevenness of the substrate to be transferred. Is more preferable.

  The cover film is previously peeled from the dry film thus obtained, and the base film is laminated so that the layer made of the photosensitive composition faces the gas barrier layer on the plastic film as the base material. A layer composed of the photosensitive composition is subjected to heat and pressure treatment with a pressure and heating roller, and continuously transferred to prepare a laminated original fabric.

  Here, for the heat and pressure treatment, a general pressure and heat roller can be used. Specifically, the film can be sandwiched between two upper and lower rolls, and the other roll is heated by one roll. It has a structure that receives pressure. A material whose surface is mainly covered with heat-resistant rubber is used for one roll, and a chromium roll-treated metal roll is used for the other. Thus, pressurization can be made uniform by using one as a rubber roll and the other as a metal roll.

The conditions of the pressure heat treatment are such that the roller pressure is 0.5 kg / cm ^{2 to} 10 kg / cm ² , the heating temperature is 50 ° C. to 150 ° C., and the conveyance speed is 100 mm / min to 2,000 mm / min. Thus, the transfer quality can be improved. The reason for this is that if the roller pressure and heating temperature are low, the adhesion between the transfer layer and the substrate to be transferred becomes insufficient and defects in the transfer are likely to occur, and conversely if it is high, the transfer layer, the non-transfer substrate and the base film For example, deformation or the like may occur due to the influence of heat pressure on the toner, resulting in a decrease in transfer quality. If the conveying speed is low, the throughput is lowered and the transfer quality is deteriorated due to heat pressure. If it is fast, the heat pressure is insufficient at the time of transfer, and the transfer is not performed accurately.

  Next, an exposure treatment is performed on the layer of the photosensitive composition with the base film peeled off as necessary with respect to the heated and pressure-treated laminated original fabric.

  When the black matrix forming composition is applied directly on a plastic film, all the above steps are omitted, or after application, a base film is laminated to produce a laminated original, and the base film is applied to the laminated original. You may perform an exposure process in the state attached on the layer which consists of a photosensitive composition.

  In the step of exposing to the photosensitive composition, an exposure unit having an exposure stage for exposing light from a light source to be described later, an unwinding device on the upstream side, and a downstream side for introducing the photosensitive composition into the exposure unit In addition, the lamination raw material obtained above is passed through an exposure apparatus equipped with a winding device and a pair of nip rolls on the inlet side and the outlet side, and the nip roll pair is driven to convey the continuous laminated raw material to the exposure unit. Then, the laminated raw material is sucked and fixed on the exposure table by the exposure unit, and the laminated raw material is exposed by proxy exposure.

  It is preferable that the driving of the nip roller is stopped while the laminated raw material is adsorbed and fixed on the exposure table. In addition, with respect to the tension applied to the original fabric during conveyance, from the viewpoint that if the strength is weak, the meandering of the original fabric is likely to occur due to poor conveyance, and if the tension is strong, the elongation of the original fabric is affected. The width is preferably 300 mm.

  In the above-described raw material conveyance mode, the apparatus for performing the black matrix coating or the patterning process using the base film, the apparatus for performing the exposure / development process, and the baking apparatus described later are separate apparatuses. The unwinding and winding device is necessary, but in the case of a continuous device configuration, the idea of winding in each device is not necessarily required.

  Here, the temperature of the exposure unit of the exposure apparatus is set to 20 ° C. ± 0.1 ° C. to 25 ° C. ± 0 in consideration of the temperature during exposure of the apparatus, the air temperature that is the fluctuation range of the humidity condition, and the atmospheric stability of the humidity. It is preferable that the humidity is 50% ± 1% to 65% ± 1% in consideration of the stability of each material and the hygroscopicity of the material at this temperature.

  In addition, the gap (gap) between the layer made of the base film of the laminated film or the photosensitive composition for forming the black matrix and the pattern (photomask) is automatically adjusted every time so as to be constantly constant. In this case, the gap amount takes into account the resolution of the pattern to be formed. That is, if the gap amount is too large, the resolution is lowered, and if it is closer, the resolution is improved, and adhesion of dust and dirt to the photomask increases. Therefore, 5 μm to 200 μm is preferable.

  In addition, the exposure position of the pattern of the laminated film is automatically detected from the distance from the end surface of the laminated film, and exposure is performed after automatic adjustment so that the photomask pattern position is a fixed distance from the laminated film according to the detection result. . At this time, it is preferable to prepare an alignment mark for aligning an exposure position when forming a colored pattern of each color of RGB described later.

  Examples of the light source used in the exposure process include a high-pressure mercury lamp, a DEEP UV lamp, a metal halide lamp, a low-pressure mercury lamp, and a halogen lamp. When the above-described photosensitive composition for forming a black matrix is used. In particular, exposure using a wavelength of 350 to 450 nm is preferable from the viewpoint of sensitivity and resolution.

  Subsequently, development processing and post-baking processing are performed. The development process is performed by a developing device installed on the downstream side of the exposure machine. Specifically, the layered film after exposure is conveyed at a constant speed and the base film is peeled off while developing on the surface of the peeled plastic film. By discharging the liquid in a spray form at room temperature, a composite film in which a black matrix having a predetermined pattern is laminated on a plastic film can be obtained. In addition, when the exposure is performed with the base film attached, the developer is applied after the base film is peeled off and developed. Thereafter, the composite film is passed through a baking furnace while being conveyed at a constant speed in a continuous baking furnace, and subjected to baking treatment, whereby the resin pattern of the black matrix can be thermally cured. Here, the baking temperature is preferably 120 ° C. to 250 ° C., if the temperature is too low, heat curing is insufficient, and if the temperature is high, the resin is yellowed.

FIG. 2 is a plan view of the plastic film on which the black matrix pattern thus obtained is formed.
According to FIG. 2, the black matrix pattern 5 is formed in a lattice shape on the plastic film.

  Subsequently, after forming a black matrix pattern, an RGB coloring pattern is formed. When the RGB color pattern is transferred using a dry film as described above, the corresponding colorant dry film of each RGB color can also be produced in the same manner as in the case of the black matrix described above.

  For example, in order to pattern red (RED) in a black matrix, a plastic film having a black matrix formed thereon is prepared, and then a RED dry film having a cover film previously peeled off is applied to the coating composition layer on the plastic film side. It is possible to produce a laminated original fabric by laminating so as to face each other and continuously transferring a layer of a photosensitive composition for forming a colored pattern corresponding to RED by a pressure heating roller. The transfer process of the colored pattern by the pressure heating roller can be performed by the same apparatus and conditions as the black matrix formation described above.

  Next, in the exposure process for the transferred RED coloring pattern, alignment is performed using an alignment mark patterned simultaneously with the black matrix. Thereafter, an exposure process, a development process, and a post-bake process are performed in the same manner as in the case of the black matrix, and a heat-cured colored pattern can be formed on the plastic film on which the black matrix is formed.

  In addition, it can carry out similarly to the case of black matrix formation also by apply | coating the photosensitive composition for coloring pattern formation directly on the plastic film in which the black matrix was formed.

FIG. 3 is a plan view of the plastic film on which the black matrix pattern and the RED coloring pattern thus obtained are formed.
According to FIG. 3, red patterns 4 that are RED coloring patterns are formed at predetermined intervals in a square area surrounded by a black matrix pattern 5 formed in a lattice shape.

  Furthermore, GREEN and BLUE can be formed in the same manner on a plastic film on which a black matrix and RED are formed. A transparent overcoat layer may be provided on these layers. Furthermore, the order of forming the black matrix and the RGB colorant can be arbitrarily determined. Two or more layers may be continuously formed in a roll-to-roll process of unwinding, film formation, and winding.

FIG. 4 is a cross-sectional view of the main part of the plastic film on which the black matrix pattern and the colored pattern of each color of RED thus obtained are formed.
According to FIG. 4, the red pattern 4, the green pattern 6, and the blue pattern 7 are periodically formed in each square area surrounded by the black matrix pattern 5 formed in a lattice shape.

Further, a transparent conductive layer or a column spacer may be provided on the black matrix pattern 5 and the RGB colored patterns 4, 6, 7 formed on the plastic film 3.
The transparent conductive layer is formed by, for example, roll-to-roll sputtering or vapor deposition. Examples of the transparent conductive layer include thin films formed of thin films such as indium tin oxide (ITO), zinc oxide, tin oxide, and indium zinc oxide (IZO), but the material is not limited thereto.

<Peeling process>
The peeling step is a step of peeling the patterned flexible substrate from the hard substrate.

In the peeling step, by immersing a laminate composed of a patterned flexible substrate and a hard substrate in hot water, a difference in thermal expansion coefficient occurs, and the temporary adhesive layer is distorted, thereby forming a patterned flexible substrate. Can be easily peeled from the hard substrate. The temperature of the hot water is preferably 50 ° C to 100 ° C.
By this peeling step, a patterned flexible substrate is obtained.

Here, FIGS. 1A to 1D are process diagrams showing a pattern forming method (production of a color filter) on a flexible substrate of the present invention.
As shown in FIG. 1 (A), a temporary suspension is applied on the hard substrate 1 to form the temporary retention agent layer 2, and a flexible substrate (plastic film) 3 is stacked on the temporary retention agent layer 2. In addition, the hard substrate (glass substrate) 1 and the flexible substrate 3 are temporarily held by being irradiated with ultraviolet rays.
Next, as shown in FIG. 1B, the flexible substrate 3 temporarily retained on the hard substrate 1 is annealed at a temperature not lower than the glass transition temperature of the temporary retention agent and not higher than the glass transition temperature of the polymer constituting the flexible substrate. Process.
Next, as shown in FIG. 1C, a black matrix (BM) pattern 5 and RGB patterns 4, 6, and 7 are formed on the flexible substrate 3 by photolithography.
Next, the laminated body of the patterned flexible substrate and the hard substrate was immersed in hot water to peel from the patterned flexible substrate and the hard substrate. As described above, a flexible color filter can be produced.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
On a glass substrate having a thickness of 0.7 mm, a temporary holding agent (Photo Bond 830, a solution obtained by adding 1% by mass of acrylic acid to Sunrise MSI Co., Ltd., glass transition temperature after curing = 98 ° C.) was applied. A glass substrate is obtained by overlaying a polyethylene naphthalate (PEN) film (Teonex (registered trademark), manufactured by Teijin DuPont Co., Ltd., glass transition temperature = 156 ° C.) with a thickness of 0.1 μm on the agent layer and irradiating with ultraviolet rays. And a polyethylene naphthalate (PEN) film were temporarily fixed.
Next, the polyethylene naphthalate (PEN) film temporarily retained on the glass substrate was annealed at 150 ° C. for 30 minutes using an oven (clean oven DT410, manufactured by Yamato Scientific Co., Ltd.).

Next, a black matrix (BM) pattern was formed on the polyethylene naphthalate (PEN) film by photolithography as follows.
A black resist solution (CK-8400, manufactured by Fuji Film Electromaterials Co., Ltd.) was applied on a glass substrate using a spin coater so that the dry film thickness was 1.0 μm, and dried at 120 ° C. for 2 minutes. A black coating was formed.

Next, using an exposure apparatus, the coating film was irradiated with an exposure dose of 200 mJ / cm ² through a 100 μm mask at a wavelength of 365 nm. After the irradiation, development was performed at 26 ° C. for 100 seconds using a 1.0% CDK-1 (manufactured by Fuji Film Electromaterials) developer. Subsequently, after rinsing with running water for 20 seconds, drying was performed with an air knife, and heat treatment was performed at 180 ° C. for 30 minutes to form a black pattern image (BM matrix).

Next, an RGB pattern was formed by photolithography as follows.
A green resist solution (CGX-2420, manufactured by Fuji Film Electromaterials Co., Ltd.) was applied on a glass substrate using a spin coater and dried at 100 ° C. for 2 minutes to form a green coating film.
Next, using an exposure apparatus, the coating film was irradiated with an exposure dose of 60 mJ / cm ² through a 100 μm mask at a wavelength of 365 nm. After the irradiation, development was performed at 26 ° C. for 100 seconds using a 1.0% CDK-1 (manufactured by Fuji Film Electromaterials) developer. Subsequently, after rinsing with running water for 20 seconds, it was dried with an air knife and heat-treated to form a green pattern image (green pixel).
This operation is similarly applied to the same glass substrate for the red resist solution (CRX-2420, manufactured by Fujifilm Electromaterials Co., Ltd.) and the blue resist solution (CBX-2420, manufactured by Fujifilm Electromaterials Co., Ltd.). Then, a red pattern image (red pixel) and a blue pattern image (blue pixel) were sequentially formed to produce a color filter.

  Next, the color filter was peeled from the glass substrate by repeating the immersion of the laminate of the color filter and the glass substrate in hot water (70 ° C.) for 3 minutes and in cold water (23 ° C.) for 3 minutes three times. . The flexible color filter of Example 1 was produced by the above.

(Example 2)
A flexible color filter of Example 2 was produced in the same manner as in Example 1 except that the annealing temperature was changed from 150 ° C. to 100 ° C. in Example 1.

(Comparative Example 1)
In Example 1, a flexible color filter of Comparative Example 1 was produced in the same manner as in Example 1 except that temporary retention with a temporary retention agent was not performed.

(Comparative Example 2)
A flexible color filter of Comparative Example 2 was produced in the same manner as in Example 1 except that the annealing temperature was changed from 150 ° C. to 27 ° C. in Example 1.

(Comparative Example 3)
A flexible color filter of Comparative Example 3 was produced in the same manner as in Example 1 except that the annealing temperature was changed from 150 ° C. to 70 ° C. in Example 1.

  Next, for each of the produced flexible color filters, the length change rate after peeling and the amount of warpage were measured as follows. The results are shown in Table 1.

<Measurement of length change rate after peeling process>
Using the design value A (100 mm) of the distance between two predetermined points of the mask used for exposure as a reference, the distance B between the two points in the produced flexible color filter is measured, and the rate of change (% ) [(BA) / A × 100] was calculated.

<Measurement of warpage>
A flexible color filter produced in the center of the substrate was placed on a horizontal plane, and a white plate glass having a 100 mm square and a thickness of 0.7 mm was placed on the upper surface of the color filter. One of the four corners of the white plate glass is fixed on a horizontal plane, the height of the other three corners from the horizontal plane is measured, and the value obtained by subtracting the thickness of the glass from the largest distance from the horizontal plane is the amount of warpage. (Unit: mm).

  Since the pattern formation method of the present invention can improve the dimensional stability during pattern formation on a flexible substrate, it is suitable for forming a functional flexible substrate such as a flexible color filter and TFT. .

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Tempering agent layer 3 Flexible substrate 4 Red pattern 5 Black matrix pattern 6 Green pattern 7 Blue pattern

Claims (4)

A temporary fixing process in which a flexible substrate is temporarily fixed to a dimensionally stable hard substrate with a temporary fixing agent;
An annealing treatment step of annealing the flexible substrate at a temperature not lower than the glass transition temperature of the temporary binder and not higher than the glass transition temperature of the polymer constituting the flexible substrate;
A pattern forming step of forming a pattern by photolithography on the flexible substrate;
And a peeling step of peeling the patterned flexible substrate from the hard substrate.   The pattern forming method according to claim 1, wherein, in the peeling step, the patterned flexible substrate is peeled from the hard substrate by immersing the laminated body of the patterned flexible substrate and the hard substrate in hot water.   The pattern forming method according to claim 1, wherein the pattern to be formed is any one of a color filter and a TFT.   The pattern forming method according to claim 1, wherein the polymer constituting the flexible substrate is polyethylene naphthalate (PEN).