JP2003292657A - Substrate and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate and a color filter causing no shrinkage and permitting retention of pattern precision when heated. <P>SOLUTION: The substrate is formed by making a transparent ceramic layer 2 on one side of a transparent plastic film 1 to form a substrate and heat- treating the substrate. The heat-treating temperature, Ta°C, is lower than the glass transition temperature, Tg°C, of the material of the film. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic substrate, a color filter provided with the plastic substrate, a display device and the like, and a method for manufacturing them.

[0002]

2. Description of the Related Art Currently, glass substrates are mainly used in liquid crystal display devices, but they are thin, lightweight, and have improved impact resistance.
From the viewpoint of reducing manufacturing costs, the use of plastic as a substrate material is being considered.

[0003]

However, since the baking treatment (post-baking treatment) after patterning each pixel of the color filter, the TFT and the like on the substrate is performed at a high temperature of about 200 ° C., the plastic is used as the substrate. When used as, the plastic substrate contracts when it is cooled after heating, and there is a problem that the accuracy of the pattern formed intentionally at this site cannot be maintained. For example, in the case of forming a color filter by the colored photosensitive material method, after the first color pattern is exposed and developed, the first color is baked at about 200 ° C., and then cooled to cause planar shrinkage of the substrate film. Then, there is a problem that the pattern position of the second color is displaced.

Therefore, according to the present invention, the shrinkage does not occur even when heated, and the pattern accuracy can be maintained.
It is an object to provide a substrate and a color filter.

[0005]

The means used in the present invention to solve the above problems will be described below. In addition, in order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are added in parentheses, but the present invention is not limited to the illustrated forms.

A first aspect of the present invention is a method for producing a heat-treated substrate, which comprises forming a substrate by providing a transparent ceramic layer (2) on one side of a transparent plastic film (1) and then heat treating the substrate. The heat treatment temperature Ta ° C. is set within the range of Ta <Tg when the glass transition temperature of the transparent plastic film material is set to Tg ° C., thereby providing a method for manufacturing a heat treatment substrate, and solving the above problems. . "Plastic" here consists of an organic compound with a large molecular weight,
Normally, the final state is solid, but a group of materials that can be freely molded by being fluidized by the action of heat or pressure on the way to the solid state is collectively referred to. "Ceramic" refers to a material made by sintering or burning a non-metallic inorganic material. The term "transparent" refers to the property of allowing light to pass through the material, and the degree of transmissivity to be transparent should be reasonably determined depending on the intended use of the heat-treated substrate. . Further, the "heat treatment" means holding the substrate under a predetermined atmosphere at a predetermined temperature for a predetermined time. Further, it may include a temperature raising process from room temperature to a predetermined temperature and a temperature lowering process from a predetermined temperature to room temperature. Further, the glass transition temperature is a temperature at which a partially crystallized amorphous region of a polymer changes from a viscous or elastic state to a hard and relatively brittle state.

According to the method for manufacturing a heat-treated substrate of the first aspect, the plastic substrate undergoes heat history by heat treatment and expands and contracts on the basis of the same size even if the subsequent heating-cooling cycle is repeated. repeat. Further, since the transparent ceramic layer formed on the one surface side has a strong backing due to the anchoring effect, further dimensional stability and shape stability can be achieved. In addition, since the heat treatment of the transparent plastic film is performed below the glass transition temperature of the plastic material forming the film,
Since there is no large change in the state of viscosity or elasticity in the amorphous region of the plastic film, it is possible to prevent excessive heat history from being applied to the substrate.

In the method for manufacturing a heat-treated substrate according to the above aspect, the heat treatment temperature Ta ° C. may be in the range of Ta <Td when the heat resistant temperature of the transparent plastic film material is Td ° C. Here, the “heat resistant temperature” refers to the maximum operating temperature based on UL746B.
The "UL" standard is based on Underwriters Laboratories In
It is a standard related to safety and testing established by c.
"746" is a standard for performance evaluation relating to ignition resistance, thermal deterioration, electrical properties and other properties of the resin material, among which UL746B is a standard for heat resistance.

In this case, the heat treatment of the transparent plastic film is carried out at a temperature lower than the heat resistant temperature of the material plastic constituting the film, so that the heat treatment is carried out in a temperature range where it is hard to be deformed by an external load. Excessive heat history is prevented from being applied to.

In the method for manufacturing a heat-treated substrate of the above aspect, the material of the transparent plastic film is PES,
The temperature of the heat treatment may be 160 to 185 ° C.

The term "PES" as used herein means polyether sulfone, which is transparent and has a high glass transition temperature and a high heat resistance temperature. Therefore, by forming a transparent plastic film with PES, it is possible to provide a method for manufacturing a heat-treated substrate that can withstand pattern baking at high temperature. In addition, since the heat treatment is performed just below the glass transition temperature (225 ° C.) and the heat resistant temperature of PES, it is possible to prevent an excessive heat history from being applied to the substrate, while the subsequent heating is performed during subsequent heating.
Even if the cooling cycle is repeated, it is possible to receive a thermal history capable of repeating expansion and contraction based on the same size.

According to a second aspect of the present invention, a step of forming a substrate by providing a transparent ceramic layer on one side of a transparent plastic film, a step of subjecting the substrate to heat treatment to produce a heat treated substrate, and a step of forming the transparent ceramic layer And a step of forming a pattern portion on the other surface of the heat-treated substrate which is located on the side opposite to the formed surface. Here, the "pattern part" means
For example, the black matrix of the color filter, "R",
"G" and "B" color pixel parts, elements such as circuits, TFTs, LSIs, etc., which have been formed into a predetermined pattern by photolithography or the like, and then baked for the purpose of hardening treatment. Say. Therefore, the "formation of the pattern portion" here is a concept including firing of the pattern portion. According to this substrate manufacturing method, since the substrate is heat-treated in advance, even if firing is performed thereafter, the dimensions of the substrate do not significantly change before and after firing. Therefore, it is possible to form an accurate pattern.

In the above method for producing a substrate, when the glass transition temperature of the transparent plastic film material is Tg ° C., the heat treatment temperature is Ta ° C., and the calcinable minimum temperature is Tb ° C., the relationship of Tb <Ta <Tg is established. Alternatively, the heat treatment may be performed.
Here, the “minimum calcinable temperature” refers to the lowest temperature at which the material forming the pattern portion begins to cure when the pattern portion formed of a resist or the like is subjected to a film hardening treatment by a photolithography method or the like.

In such a structure, the heat treatment of the transparent plastic film is performed below the glass transition temperature of the material plastic forming the film, so that excessive heat history is prevented from being applied to the substrate. ,
Since the heat treatment is performed at a temperature higher than the minimum calcinable temperature, a thermal history is added to the extent that dimensional reproducibility is not lost when the calcining is actually performed. Therefore, when the substrate is cooled to room temperature after firing, the dimensions of the substrate can return to those before firing. Therefore, an accurate pattern can be formed.

In the above method of manufacturing a substrate, when the heat resistant temperature of the transparent plastic film material is Td ° C., the heat treatment temperature is Ta ° C., and the calcinable minimum temperature is Tb ° C., Tb <Ta <Td. Heat treatment may be performed.

In this case, the transparent plastic film is heat-treated at a temperature lower than the heat-resistant temperature of the plastic material of which the film is made. Since the heat treatment is performed at a temperature higher than the lowest possible temperature, when the firing is actually performed, a thermal history is added to the extent that dimensional reproducibility is not lost even at that temperature. Therefore, when the substrate is cooled to room temperature after firing, the dimensions of the substrate can return to the dimensions before firing, and accurate pattern formation can be performed.

In the above substrate manufacturing method, the material of the transparent plastic film may be PES, and the heat treatment temperature may be 160 to 185 ° C.

With this structure, PES can be used in the method of manufacturing a substrate according to the second aspect. PE
S is transparent and has a high glass transition temperature and a flexural load temperature. Therefore, by forming a transparent plastic film with PES, it is possible to provide a method for manufacturing a substrate that can withstand pattern baking at high temperature. In addition, since the heat treatment is performed just below the glass transition temperature (225 ° C.) and the heat resistant temperature of PES, it is possible to prevent an excessive heat history from being applied to the substrate, while heating / cooling in the subsequent firing. Even if the cycle is repeated, it is possible to receive a thermal history capable of repeating expansion and contraction based on the same size. Therefore, an accurate pattern can be formed.

A third aspect of the present invention is to provide a transparent ceramic layer on one side of the transparent plastic film to form a substrate, heat-treat the substrate to produce a heat-treated substrate, and form the transparent ceramic layer. Patterning a black matrix on the other surface of the heat-treated substrate located on the side opposite to the formed surface, and patterning an area of "R", "G", or "B" between the black matrices. The step of firing after forming is referred to as “R”,
And a step of repeating each color of "G" and "B". Here, "R", "G", and "B" represent the colors "red", "green", and "blue" of each pixel of the color filter, and more specifically, in the resist that constitutes each pixel. 3 shows the color of the pigment dispersed in.

According to the method of manufacturing the color filter of this aspect, since the transparent plastic is heat-treated in advance, the black matrix, “R”, “G”,
Even if the "B" pixel portion of each color is baked, the pattern when cooled after baking does not deviate from the position at the time of exposure. Therefore, each pattern can be formed at an accurate position even if exposure and baking are repeated.

In the color filter manufacturing method of the above aspect, when the glass transition temperature of the transparent plastic film material is Tg ° C., the heat treatment temperature is Ta ° C., and the minimum calcinable temperature is Tb ° C., the relationship of Tb <Ta <Tg is satisfied. The heat treatment may be performed based on the above.

In such a structure, the heat treatment of the transparent plastic film is performed below the glass transition temperature of the material plastic material forming the film, so that excessive heat history is prevented from being applied to the substrate. ,
Since the heat treatment of the resist containing the pigment constituting the color filter is performed at a temperature higher than the minimum temperature at which baking is possible,
When firing is actually performed, a thermal history is added to the substrate to the extent that dimensional reproducibility is not lost even at that temperature. Therefore, when the substrate is cooled to room temperature after firing, the dimensions of the substrate can return to those before firing. Therefore, an accurate pattern can be formed for each color of "R", "G", and "B".

In the color filter manufacturing method of the above aspect, the heat resistant temperature of the transparent plastic film material is set to Td.
℃, the temperature of heat treatment is Ta ℃, the lowest temperature that can be fired is Tb ℃
In this case, the heat treatment may be performed under the relationship of Tb <Ta <Td.

In such a structure, the heat treatment of the transparent plastic film is carried out at a temperature lower than the heat resistant temperature of the material plastic constituting the film, so that an excessive heat history is prevented from being applied to the substrate. Since the heat treatment of the resist containing the pigment that constitutes the color filter is performed at a temperature higher than the minimum temperature at which baking is possible, the dimensional reproducibility will not be lost even if the temperature is reached when the baking is actually performed. The thermal history of is added to the substrate. Therefore, when the substrate is cooled to room temperature after firing, the dimensions of the substrate can return to those before firing. Therefore, it is possible to form an accurate pattern for each color of “R”, “G”, and “B”.

In the color filter manufacturing method of the above aspect, the material of the transparent plastic film may be PES, and the heat treatment temperature may be 160 to 185 ° C.

In this way, PES can be used in the method of manufacturing the color filter of the third aspect. PE
S is transparent and has a high glass transition temperature and heat resistant temperature. Therefore, by forming a transparent plastic film with PES, it is possible to provide a method for manufacturing a color filter that can withstand pattern baking at high temperature. In addition, since the heat treatment is performed just below the glass transition temperature (225 ° C.) and the heat resistant temperature of PES, it is possible to prevent an excessive heat history from being applied to the substrate, while heating / cooling in the subsequent firing. Even if the cycle is repeated, it is possible to receive heat history enough to repeat expansion and contraction based on the same size.
Therefore, an accurate pattern can be formed for each color of "R", "G", and "B".

A fourth aspect of the present invention is a heat-treated substrate obtained by heat-treating a substrate having a transparent ceramic layer on one side of a transparent plastic film, the side opposite to the side on which the transparent ceramic layer is formed. The heat-treated substrate is characterized in that a pattern portion that has been baked is formed on the other surface.

According to the heat treatment substrate of the fourth aspect, the plastic substrate undergoes heat history by heat treatment, and even if the subsequent heating-cooling cycle is repeated, expansion and contraction are repeated based on the same size. Further, since the transparent ceramic layer formed on the one surface side has a strong backing due to the anchoring effect, further dimensional stability and shape stability can be achieved. In addition, since pattern formation can be performed on a substrate that has been heat-treated in advance, and then firing can be performed, there is no significant change in the dimensions of the substrate before and after firing. Therefore, it is possible to obtain a substrate on which an accurate pattern is formed.

In the above embodiment, the transparent ceramic
The layers are ITO, SnO_Two, In_TwoO _Three, SiO_Two, Ti
O, Al_TwoO_Three, C (diamond)
One or a combination of a plurality of these
It may be done. Here, "ITO" and "Sn"
O_Two, "In_TwoO_Three, "SiO_Two, "TiO",
"Al_TwoO_Three", And" C (diamond) "is that
"Indium tin oxide", "Tin oxide", "Acid"
Indium chloride ”,“ silicon oxide ”,“ titanium oxide ”,
"Aluminum oxide" and "diamond crystalline carbon"
(The same shall apply hereinafter.).

When configured as described above, the IT
O, SnO ₂ , In ₂ O ₃ , SiO ₂ , TiO, Al ₂
The heat-treated substrate of the above aspect can be obtained by utilizing O ₃ , C (diamond) or the like.

Further, in the above structure, the material of the transparent plastic film may be PES.

By doing so, since "PES" is transparent and has a high heat resistance temperature, by providing a transparent plastic film with PES, a heat-treated substrate that can withstand pattern baking at high temperature is provided. can do.

A fifth aspect of the present invention comprises a heat-treated substrate obtained by heat-treating a substrate having a transparent ceramic layer on one side of a transparent plastic film, which is located on the opposite side of the surface on which the transparent ceramic layer is formed. On the other side of the heat-treated substrate, a black matrix and "R" that has been baked,
The color filter (4) is characterized in that pixel pattern portions of "G" and "B" colors are formed so as to be repeatedly arranged in order in a black matrix.

According to the color filter of the fifth aspect,
Even if the plastic substrate undergoes heat history due to heat treatment and then repeatedly undergoes heating-cooling cycles, expansion and contraction are repeated based on the same size. In addition, the anchoring effect of the transparent ceramic layer formed on the one surface provides a strong backing, so that further dimensional stability and shape stability are achieved. Therefore, even if the pattern formation by exposing the black matrix and each of the “R”, “G”, and “B” pixels and firing are repeated, the position of the pattern may shift during the second and subsequent exposures. What happens is avoided.

In the above embodiment, the transparent ceramic layer is
ITO, SnO_Two, In_TwoO_Three, SiO_Two, TiO, A
l_TwoO_Three, One of C (diamond)
It may be configured by the following. Alternatively, transparent cell
Mick layer is ITO, SnO _Two, In_TwoO_Three, Si
O_Two, TiO, Al_TwoO_ThreeOut of C (diamond)
From any of the
You may.

When configured as described above, the IT
O, SnO ₂ , In ₂ O ₃ , SiO ₂ , TiO, Al ₂
The color filter of the above embodiment can be obtained by using O ₃ , C (diamond), or the like.

In the color filter of the above aspect, the material of the transparent plastic film may be PES.

As described above, PES is transparent and has a high heat resistant temperature. Therefore, by forming a transparent plastic film with PES, it is possible to provide a color filter that can withstand pattern baking at high temperature.

According to a sixth aspect of the present invention, a color filter according to any one of the above aspects is provided on one surface side and a substrate is provided on the other one surface side, and an electro-optical element is provided between the color filter and the substrate. The display device is sandwiched. A seventh aspect of the present invention is provided with a color filter according to any one of the above aspects on one surface side and a drive circuit board on the other one surface side, and a liquid crystal layer is provided between the color filter and the drive circuit board. The display device (100) is sandwiched.

According to these display devices, the advantages of the color filters of the above aspects can be utilized in the display device.

The operation and gain of the present invention will be apparent from the embodiments described below.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to an embodiment shown in the drawings by taking a manufacturing process of a color filter and a display device constituted by using the color filter as an example.

<Substrate Material> In the present embodiment, a plastic substrate is used in place of the conventional glass substrate from the viewpoints of thinning and weight reduction, impact resistance improvement, and the like. As the material of the plastic substrate here, PES (polyether sulfone) is used from the viewpoint of being transparent and having heat resistance. PES is "Sumika Excel (registered trademark) PES" of Sumitomo Chemical Co., Ltd. in the city.
As such, it is possible to obtain several grades depending on the molecular weight. The basic physical properties are shown in Table 1 below.

[0044]

[Table 1]

As is clear from Table 1, PES has a high heat resistance temperature and a glass transition temperature as a transparent plastic material. In particular, the glass transition temperature does not depend on the grade (molecular weight) and is always a constant value of 225 ° C. As such, PES is a plastic material that can potentially replace glass substrates as substrates used in displays. In the present embodiment, as shown in FIG.
A PES film 1 having a thickness of 0.1 mm is cut into a predetermined size to obtain a thin plate-shaped substrate.

<Heat Treatment Substrate> PES is a plastic material having a possibility of substituting a glass substrate as a substrate used in a display device as described above. However, since PES is a plastic material, it can be used alone as a heat-resistant temperature or glass. When heated to a temperature near the transition temperature, warpage and irreversible expansion and contraction easily occur. For example, when a pigment-dispersed color resist pattern-formed on a substrate by a photolithography method is subjected to a film hardening treatment (post-baking), this may cause a serious problem. Here, when the film plane direction is XY and the thickness direction is Z, "warpage" means deformation in the Z direction, and "irreversible expansion and contraction" means that the film is in the XY direction at room temperature before and after heating. It means that the length of the changes.

In order to solve this irreversible expansion and contraction defect, in this embodiment, the ITO layer 2 is formed on one side of the PES film 1 as shown in FIG. Heat treatment is applied to. In this application,
A substrate that has been subjected to heat treatment is referred to as a “heat treated substrate”. The ITO layer 2 is formed to a thickness of about 0.1 μm by the low temperature sputtering method. Thus, by forming the ITO layer 2 on one surface side of the PES film 1 and applying heat treatment under predetermined conditions, it is possible to prevent the length in the XY direction from changing before and after heating such as firing to be performed later. You can Regarding heat treatment conditions, especially how to set the temperature, see P
The baking temperature (post-baking) of the resist patterned on the PES film 1 has a close relationship with the heat resistance characteristics of the ES itself (for example, the glass transition temperature and the heat resistance temperature). This will be described in detail later.

Since this ITO layer 2 is considered to function as a reinforcing member of the PES film 1, so to speak, I
Instead of TO, another transparent ceramic material such as SnO
₂ , In ₂ O ₃ , SiO ₂ , TiO, Al ₂ O ₃ , C
(Diamond) or the like can be used alone or in combination (including ITO). However, from the perspective of avoiding static electricity generated during the manufacturing process and causing problems due to contaminants,
It is preferable to use a transparent ceramic material having conductivity such as ITO, SnO ₂ , In ₂ O ₃ .

The change in the length in the XY directions due to heating can be solved by forming a transparent ceramic layer on one surface side of the PES film 1 and applying a predetermined heat treatment as described above. However, deformation (warpage) in the Z direction often occurs. This problem can be solved by the method shown in FIG. That is, the polyimide sheet 6 is arranged between the base 7 on which the substrate 5 is placed during heating and the substrate. By doing this,
Warpage of the PES film in the Z direction can be prevented. Further, instead of polyimide, PEEK (polyether ether ketone), PTFE (tetrafluoroethylene resin), P
FA (perfluoroalkoxyl alkane) or the like may be used alone or in combination (may include polyimide) to form a sheet. According to the knowledge of the inventor of the present application, it has been confirmed that in the case of a polyimide sheet, a warp in the Z direction does not occur when the film thickness is 70 μm. As described above, the method of arranging the polyimide sheet between the substrate and the base to prevent the deformation (warpage) in the Z direction is not limited to the case of heat-treating the heat-treated substrate, but also the resist patterned on the heat-treated substrate. It is also effective in the case of baking treatment of.

Further, since the plastic film has a property of allowing gas and water vapor to pass therethrough at a certain ratio, a barrier layer is provided on at least one surface side of the plastic film in order to prevent these from entering the liquid crystal layer under negative pressure. Is desirable. In this embodiment, the barrier layer 3 is formed on one surface opposite to the surface on which the ITO layer 2 is formed (see FIG. 1C). When a color filter is formed, a black matrix and R, G, and B pixels 4 are formed on the barrier layer 3 side (FIG. 1).
(See (d)). The barrier layer can form a polymer layer by PVA or a copolymer of PE and PVA.
In addition, S is provided between the polymer layer and the plastic film.
A barrier layer having a two-layer structure may be formed by interposing an iO ₂ layer. The polymer layer can be formed by a wet coating method such as slit coating or die coating. Also,
The SiO ₂ layer can be formed by a sputter vapor deposition method.

Example 1 The present inventor conducted the following test in order to confirm the effect of the ITO layer. First,
Square PES film with a side of 10 cm (thickness 0.1 m
m) A test piece was prepared. Two pieces of the sample thus prepared were prepared, and an ITO layer having a thickness of 0.1 μm was formed on one surface side of one of the pieces by a low temperature sputtering method. After that, the above two test pieces are placed in a furnace and heated at 180 ° C for 30
Heat history was added for minutes. After that, remove the sample from the furnace,
It was naturally cooled to room temperature. After confirming that the test piece was completely cooled to room temperature, as shown in FIG. 3, alignment marks were attached to two points near the periphery so that the distance between the marks was the same, and the distance between the marks was set. Was measured. Then, the two test pieces were placed in the furnace again, and a thermal history was applied for 30 minutes at a temperature of 180 ° C. Then, the sample was taken out of the furnace and naturally cooled to room temperature. Then, the distance between the alignment marks was measured again. In the series of tests described above, in order to eliminate the influence of the shape change (warp) in the Z direction, as shown in FIG.
When the film substrate 5) is placed in the furnace, a plastic sheet 6 having a higher glass transition temperature than PES, such as polyimide, may be placed between the base 7 on which the sample 5 is placed and the sample 5. desirable. The results are shown in Table 2.

[0052]

[Table 2]

As is clear from Table 2, once the PES film provided with the ITO layer is subjected to heat history, the dimensions at room temperature before and after heating hardly change even if the PES film is subjected to similar heat history thereafter. On the other hand, a film made of PES alone tends to change its dimensions at room temperature each time it is subjected to heat history.

<Formation of BM> Based on the above test results and the like,
In this embodiment, a heat-treated substrate obtained by heat-treating a PES film having an ITO layer on one surface side at 180 ° C. for 30 minutes is used as a color filter substrate. Also IT
A barrier layer is formed on the surface opposite to the surface on which the O layer is formed.

Although a black matrix is formed on the heat-treated substrate, the black matrix is made of metal (chromium) B.
Instead of M, according to the coloring sensitive material method described below,
As another color “black” in addition to “R”, “G”, and “B”, a colored photosensitive material in which a pigment such as carbon black is dispersed is used.

<Photolithography Process Using Colored Sensitive Material> FIG. 4
3 is a flowchart showing a photolithography process using a colored photosensitive material. By this process, “R”, “G”,
It is possible to form a color filter by forming each pixel of "B" and, as the case may be, a black matrix as described above.

In step S1, the substrate is prepared. In the present embodiment, the PES film is cut into a predetermined size, and the ITO layer is formed on one side and the barrier layer is formed on the other side.

In step S2, a heat-treated substrate is manufactured by subjecting the substrate thus adjusted to heat treatment under predetermined conditions.

In the subsequent step S3, the colored photosensitive material is applied on the heat-treated substrate, and in step S4 prebaking is performed. Pre-baking will be described in detail later. In step S5, exposure through the photomask is performed, and in subsequent step S6, the exposed colored photosensitive material is developed. Next, in step S7, baking called post-baking is performed to cure the colored photosensitive material left after development. In the following step S8,
It is determined whether or not the above steps have been completed for all colors of "R", "G", and "B" (including "black" when the black matrix is also formed in this step). When a negative determination is made in step S8, the process is returned to step S3 and the above process is repeated for another color which has not been processed.

If an affirmative decision is made in step S8, that is, if the processes from S3 to S7 have been completed for all colors, it is decided in the following step S9 whether or not flattening is required for the color filter. If the determination in step S9 is affirmative, that is, if the color filter is required to be flattened, a protective film is formed (step S10), and then an ITO film as a common electrode is formed on the protective film (step S10). S11). When a negative determination is made in step S9, that is, when the color filter is not required to be flattened, the protective film formation (step S10) is skipped and the ITO film is directly formed on each pixel (step S).
11).

FIG. 5 is a diagram specifically showing the step of producing a color filter by the colored photosensitive material method. Here, the black matrix is already formed on the heat-treated substrate (FIG. 5A). First, on the side of the heat-treated substrate on which the black matrix is formed, the first color "R"
The colored photosensitive material in which the pigment is dispersed is applied by the spin coater method (FIG. 5B).

<Pre-baking> Pre-baking is a heat treatment carried out to impart a predetermined hardness to the coated colored light-sensitive material, and the heat-treated substrate is held on a hot plate heated to 80 ° C. for 3 minutes. (B1 in FIG. 5). Since the pre-baking temperature is relatively low compared to the heat resistant temperature and glass transition temperature of PES, the warpage in the Z direction does not occur even if the polyimide sheet is not placed between the base and the base. .

After the pre-baking, an exposure process is performed through a photomask having a predetermined pattern (FIG. 5).
(C)). A predetermined portion of the colored photosensitive material is exposed by this exposure processing, and a portion corresponding to the "R" pixel pattern is formed by the next development processing (FIG. 5D).

<Post-baking> Post-baking processing (see FIG. 5)
In step B2), the pattern of each of the “R”, “G”, and “B” pixel portions formed by the developing process is cured. In the present embodiment, a post-baking treatment for 30 minutes was performed for each color at a temperature of 180 ° C. using a circulating clean oven. By repeating such processing for each "R", "G", and "B", a color filter having "red", "green", and "blue" pixels repeatedly provided at a predetermined pitch is formed.

<Alignment at the time of pattern formation> After post-baking for “R”, this time, the “G” colored photosensitive material is applied to the upper surface of the heat-treated substrate. Then, based on the alignment mark drawn in advance on the heat-treated substrate,
The position of the photomask corresponding to "G" is determined. As described above, if a predetermined heat history is given to the heat-treated substrate, the dimension in the XY direction of the heat-treated substrate changes before and after the post-baking even if a new heat history is added by the post-baking process (baking). do not do. Therefore, the alignment of the photomask can be accurately performed with reference to the alignment mark, and the "G" pixel pattern can be formed at an appropriate position. Example 2 shown below suggests how to set the temperature regarding the thermal history given to the PES. In particular,
Regarding the relative positional accuracy of the first and second colors, PES
It shows the test results as to how the positional accuracy was affected when the heat treatment temperature of the film was changed.

(Example 2) Similar to the case of Example 1, first, a square PES film having a side of 10 cm (thickness 0.1) was used.
mm) A test piece was prepared. A plurality of test pieces prepared in this manner were prepared, and an ITO layer was formed on one side of all the test pieces and a barrier layer was formed on the other side. The test pieces were placed in a furnace and subjected to a thermal history for 30 minutes at each temperature in increments of 5 ° C between 155 ° C and 200 ° C. Then, the sample was taken out of the furnace and naturally cooled to room temperature. Then, the pattern of the first color was formed by the photolithography method, and the baking treatment was performed. Subsequently, a second color pattern was formed by mask exposure with the alignment mark as a reference by the same procedure, and baked. Then, the positional deviation between the two colors was measured and recorded. Even in this case, in order to eliminate the influence of the shape change (warp) in the Z direction, when mounting the sample in the furnace, a polyimide sheet is placed between the base on which the sample is mounted and the sample. Was placed. Table 3 shows the test results.

[0067]

[Table 3]

As can be seen from Table 3, it can be seen that when PES is used as the substrate, the heat treatment temperature for obtaining dimensional reproducibility in the XY directions may be set to 160 to 185 ° C. In the above test, the degree of deformation (waviness) of each test piece after heat treatment was visually observed.
In the temperature range of 160 to 185 ° C., all were within the allowable range.

<Study of heat treatment temperature optimum temperature range> FIG. 6 shows how to determine the heat treatment temperature of PES when PES is used as a substrate material and a resist having a minimum curable temperature of 160 ° C. is used. FIG. First, it seems that the heat treatment temperature needs to be the same as or higher than the temperature at which the resist patterned on the heat treated substrate is baked. If the temperature is significantly higher than the heat treatment temperature during firing, the heat-treated substrate will be newly subjected to an excessive heat history than the heat history previously received by heat treatment, and there is a high possibility that new dimensional changes and deformation will occur. Because it will be.

On the other hand, the heat treatment temperature is the heat resistant temperature of PES,
When set higher than the glass transition temperature, it is considered that these temperature ranges give a large change that affects the molecular structure itself of PES. At such temperatures,
It is considered that it is difficult to prevent the deformation of the substrate only by providing the ITO layer on one surface side. Therefore, PES
The glass transition temperature (225
It is considered that a temperature lower than around the heat resistant temperature (180 to 185 ° C.) and higher than around the resist curable minimum temperature (160 ° C.) is required. Furthermore, it is considered more desirable to match the baking temperature to actually cure the resist.

<Structure of Display Device> FIG. 7 shows a liquid crystal display device 1 equipped with a color filter made of a heat-treated substrate.
It is a figure which shows the structure of 00. The liquid crystal display device 100 of the present embodiment includes a first substrate 10 mainly including color filters.
And a second substrate 20 mainly including a thin film transistor (TFT) array, and a liquid crystal layer 30 is arranged so as to be sandwiched between the substrates 10 and 20. The observer is located above in the figure, and the backlight 40 of the liquid crystal display device 100 is located below the figure. Polarizing plates 50 and 60 are arranged on the viewer side of the first substrate 10 and on the backlight 40 side of the second substrate 20, respectively.

In the first substrate 10, the ITO layer 11 as a structural material is formed on the upper surface side of the heat-treated PES film 12. A barrier layer 13 is formed on the lower surface side of the PES film 12 to prevent water vapor or gas from entering the liquid crystal layer 30 from the viewer side. On the lower surface of the barrier layer 30, a black matrix and “R”, “G”,
Each “B” pixel layer 14 is formed. Further, an ITO layer 15 as a common electrode is formed on the lower surface thereof. The ITO layer 15 is in contact with the upper surface of the liquid crystal layer 30 via the alignment film 16.

On the other hand, in the second substrate 20, the heat-treated P
ITO layer 2 as a structural material on the lower surface side of ES film 24
5 is formed. Further, the barrier layer 23 is formed on the upper surface side of the PES film 24, and the backlight 4
The entry of water vapor and gas from the 0 side to the liquid crystal layer 30 is blocked. A thin film transistor (TF) is formed on the upper surface of the barrier layer 23.
In addition to T) and transparent electrodes (ITO), wirings such as scanning lines and data lines form the TFT array 22. The TFT array 22 is in contact with the lower surface of the liquid crystal layer 30 via the alignment film 21.

A reference voltage is supplied to the ITO layer 15 (common electrode). A liquid crystal layer 30 is provided between the first substrate 10 and the second substrate 20. Liquid crystals have the property that the orientation of liquid crystal molecules changes according to the applied voltage. A predetermined voltage is applied between the pixel electrode and the common electrode by controlling the on / off of the thin film transistor (TFT) and the voltage supplied to the data line. When the thin film transistor is turned on and a voltage is applied to the liquid crystal layer 30, the liquid crystal layer 30 does not twist in the vibration direction of incident light. On the other hand, when the thin film transistor is turned off and no voltage is applied to the liquid crystal layer 30, the liquid crystal layer 30 gives a predetermined twist in the vibration direction of incident light.

A horizontal polarizing plate 60 is provided below the second substrate 20. The horizontal polarizing plate 60 transmits only the light that oscillates in the horizontal direction among the light that is incident from the backlight 40 side. In this example, the light oscillating in the horizontal direction by the liquid crystal layer 30 to which the voltage is applied is transmitted to the first substrate 10 (color filter 14) side, while the liquid crystal layer 30 to which the voltage is not applied is transmitted. Depending on the vibration direction, light having a predetermined twist from the horizontal direction is transmitted to the first substrate 10 side.

On the other hand, the polarizing plate 50 arranged on the observer side of the first substrate 10 transmits only light having a predetermined twist from the horizontal vibration direction to the observer side. Therefore, while the voltage is applied to the liquid crystal layer 30, light is transmitted while the light is not transmitted when the voltage is applied to the liquid crystal layer 30. With the above configuration, the brightness can be adjusted for each pixel in the flexible liquid crystal display device 100.

Although the present invention has been described above with reference to the most practical and preferred embodiments at the present time, the present invention is limited to the embodiments disclosed in the present specification. However, the invention can be appropriately modified without departing from the scope or spirit of the invention that can be read from the claims and the entire specification, and the substrate and the color filter accompanied by such modifications are also within the technical scope of the invention. Should be understood to be included in.

[0078]

As described above, according to the method for manufacturing a heat-treated substrate according to the first aspect of the present invention, the plastic substrate undergoes heat history by heat treatment, and the subsequent heating-cooling cycle is repeated. However, expansion and contraction are repeated based on the same size. Further, since the transparent ceramic layer formed on the one surface side has a strong backing due to the anchoring effect, further dimensional stability and shape stability can be achieved.

Further, according to the method of manufacturing a substrate of the second aspect of the present invention, since the substrate is heat-treated in advance, even if firing is performed after that, the dimension of the substrate largely changes before and after firing. Does not occur. Therefore, it is possible to form an accurate pattern.

According to the color filter manufacturing method of the third aspect of the present invention, the transparent plastic is heat-treated in advance.
Even if the "R", "G", and "B" color pixel portions are baked, the pattern when cooled after baking does not shift from the position at the time of exposure. Therefore, each pattern can be formed at an accurate position even if exposure and baking are repeated.

According to the heat treatment substrate of the fourth aspect of the present invention,
The plastic substrate undergoes heat history by heat treatment, and even if the subsequent heating-cooling cycle is repeated, expansion and contraction are repeated based on the same size. Further, since the transparent ceramic layer formed on the one surface side has a strong backing due to the anchoring effect, further dimensional stability and shape stability can be achieved.

According to the color filter of the fifth aspect of the present invention, the plastic substrate undergoes thermal history due to heat treatment and expands and contracts on the basis of the same size even if the subsequent heating-cooling cycle is repeated. repeat. Also,
The anchoring effect of the transparent ceramic layer formed on the one surface provides a strong backing, so that further dimensional stability and shape stability are achieved. Therefore, even if the pattern formation by exposing the black matrix and each pixel of “R”, “G”, and “B” and firing are repeated,
It is possible to avoid a situation in which the position of the pattern is displaced during the second and subsequent exposures.

According to the display device of the sixth aspect of the present invention or the display device of the seventh aspect of the present invention, the advantages of the color filters of the above aspects can be utilized in the display device.

[Brief description of drawings]

FIG. 1 is a diagram showing formation of a color filter by a heat treatment substrate.

FIG. 2 is a diagram showing placement of a substrate in a furnace during heat treatment.

FIG. 3 is a diagram showing alignment marks displayed on a substrate.

FIG. 4 is a flowchart showing a photolithography process using a colored photosensitive material.

FIG. 5 is a diagram showing a step of forming a color filter by a colored photosensitive material method.

FIG. 6 is a diagram for examining an appropriate temperature range of heat treatment temperature.

FIG. 7 is a diagram showing a configuration of a liquid crystal display device using a heat treatment substrate.

[Explanation of symbols]

1 Transparent plastic film (PES) 2 Transparent ceramic layer (ITO) 4 color filters 100 display device (liquid crystal display device)

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) // C08L 101: 00 C08L 101: 00 F term (reference) 2H048 BA03 BA42 BB02 BB15 BB42 2H090 JB03 JD15 JD17 JD19 LA15 2H091 FA02X FA02Y FA02Z GA01 LA04 4F006 AA40 AB74 BA00 CA05 DA01

Claims (17)

[Claims] 1. A method of manufacturing a heat-treated substrate, comprising forming a substrate by providing a transparent ceramic layer on one side of a transparent plastic film, and then heat treating the substrate, wherein the temperature of the heat treatment is Ta ° C. When the glass transition temperature of the film material is Tg ° C., the heat treatment temperature Ta ° C. is in the range of Ta <Tg. 2. The heat treatment substrate according to claim 1, wherein the heat treatment temperature Ta ° C. is within the range of Ta <Td when the heat resistant temperature of the transparent plastic film material is Td ° C. Manufacturing method. 3. The method for manufacturing a heat-treated substrate according to claim 1, wherein the material of the transparent plastic film is PES, and the temperature of the heat treatment is 160 to 185 ° C. 4. A step of forming a substrate by providing a transparent ceramic layer on one surface side of a transparent plastic film, a step of performing heat treatment on the substrate to produce a heat-treated substrate, and a surface on which the transparent ceramic layer is formed. And a step of forming a pattern portion on the other surface of the heat-treated substrate on the opposite side, the method for manufacturing a pattern-formed substrate. 5. When the glass transition temperature of the transparent plastic film material is Tg ° C., the temperature of the heat treatment is Ta ° C., and the calcinable minimum temperature is Tb ° C., the relationship of Tb <Ta <Tg is satisfied. The substrate manufacturing method according to claim 4, wherein heat treatment is performed. 6. When the heat resistant temperature of the transparent plastic film material is Td ° C., the temperature of the heat treatment is Ta ° C., and the calcinable minimum temperature is Tb ° C., the heat treatment is performed under the relationship of Tb <Ta <Td. The method for manufacturing a substrate according to claim 4, wherein the method is performed. 7. The method of manufacturing a substrate according to claim 4, wherein the material of the transparent plastic film is PES, and the temperature of the heat treatment is 160 to 185 ° C. 8. A step of forming a substrate by providing a transparent ceramic layer on one surface side of a transparent plastic film, a step of performing heat treatment on the substrate to produce a heat-treated substrate, and a surface on which the transparent ceramic layer is formed. Forming a black matrix on the other surface of the heat-treated substrate on the opposite side, and "R", "G", "B" between the black matrices.
And a step of repeating the step of patterning any one of the areas and firing the pattern for each of the colors “R”, “G”, and “B”. 9. When the glass transition temperature of the transparent plastic film material is Tg ° C., the temperature of the heat treatment is Ta ° C., and the calcinable minimum temperature is Tb ° C., the relationship of Tb <Ta <Tg is satisfied. The method for manufacturing a color filter according to claim 8, wherein heat treatment is performed. 10. When the heat resistant temperature of the transparent plastic film material is Td ° C., the temperature of the heat treatment is Ta ° C., and the calcinable minimum temperature is Tb ° C., the heat treatment is performed under the relationship of Tb <Ta <Td. The method for producing a color filter according to claim 8, wherein the method is performed. 11. The material of the transparent plastic film is PES, and the temperature of the heat treatment is 160 to 185 ° C.
The method for manufacturing a color filter according to claim 8, wherein 12. A heat-treated substrate obtained by heat-treating a substrate having a transparent ceramic layer on one side of a transparent plastic film, the other side of which is opposite to the side on which the transparent ceramic layer is formed. The heat-treated substrate is characterized in that a baked pattern portion is formed. 13. The transparent ceramic layer comprises ITO, S
nO ₂ , In ₂ O ₃ , SiO ₂ , TiO, Al ₂ O ₃ ,
The heat treatment substrate according to claim 12, wherein any one of C (diamond) or a combination of a plurality of Cs (diamonds) is configured. 14. The material of the transparent plastic film is PES, according to claim 12 or 13.
The heat-treated substrate described in any one of 1. 15. The black matrix and the baked pixel pattern areas of “R”, “G”, and “B” are the black matrix as the pattern section of the heat treatment substrate according to claim 12. A color filter characterized in that it is formed so as to be repeatedly arranged in order between. 16. A color filter according to claim 15 is provided on one surface side, and a substrate is provided on the other surface side, and an electro-optical element is sandwiched between the color filter and the substrate. Display device. 17. A color filter according to claim 15 is provided on one surface side, and a drive circuit board is provided on the other surface side, and a liquid crystal layer is sandwiched between the color filter and the drive circuit board. Display device.