JP5110015B2 - Manufacturing method of color filter - Google Patents

Description

  The present invention relates to a case where a patterning substrate is manufactured by ejecting ink or the like into a predetermined opening using an ink jet method or the like, and mainly relates to a patterning substrate and a patterning printing exposure process in an electronic / optical component. Specific examples include color filters for liquid crystal panels, organic EL elements, wiring for semiconductor circuits, and cell culture substrates.

  For example, a color filter for a liquid crystal panel is an optical element having a fine black, red, green, blue pattern or the like.

  As its manufacturing method, there are a photolithographic method, a printing method, an ink jet method and the like, or a combination thereof, but the photolithographic method is generally applied at present.

  In the photolithography method, first, a polymer solution of a photosensitive resin composition containing a pigment or the like is uniformly coated on a substrate such as glass, and then the solvent is removed using an apparatus such as a vacuum drying apparatus. Next, an exposure process is performed to expose the necessary dye pattern. The exposure step is a step of irradiating an electromagnetic wave of a certain wavelength range such as ultraviolet rays through a photomask on which a desired pattern is drawn as an opening / light-shielding portion, and curing the desired pattern on the substrate. This is one of the important processes that influence the shape of the pattern.

  Furthermore, the development process is performed using a developing solution etc., and the unnecessary photosensitive resin composition is removed from the said base material. Thereafter, using a baking device such as an oven device or a hot plate device, baking is performed at a high temperature (for example, about 230 ° C.) to completely remove the solvent remaining in the photosensitive resin composition, and the polymer in the photosensitive resin composition Is cured at a high temperature to cure the dye pattern. As a result, it is possible to give various characteristics such as adhesion strength, durability, chemical resistance, etc. to the glass substrate of the dye pattern, which is usually required for a color filter. As a result, a high quality color filter could be manufactured as a result.

  However, the photolithographic method requires an expensive coating device, exposure device, and developing device for each color, and there is a problem that the cost of introducing the equipment becomes enormous as the required substrate size increases.

  Therefore, at present, an ink jet method is attracting attention as a method for producing a color filter instead of the photolithography method.

  Since the inkjet method can draw the number of colors required for the color filter on the substrate at the same time, and the photolitho method does not require the exposure and development processes that are essential, the production lines for these processes should be deleted. This is expected to reduce initial capital investment.

  Furthermore, in the photolithographic method, it was necessary to peel off the unnecessary photosensitive resin composition in the development process, and waste was generated correspondingly. However, in the ink jet method, only the ink necessary for the product is shot on the substrate. The material cost can be reduced compared to the photolitho method.

  In addition, increasing the number of nozzles and increasing the number of scans can easily cope with an increase in size, which meets the needs of the world.

When producing a color filter by an inkjet method, it is required to accurately eject a very small amount of ink into a colored layer region determined from a minute hole.

  Therefore, in general, an ink having a low solid content concentration is used as the ink-jet ink. However, when the ink is ejected alone on the substrate, it spreads on the substrate and causes “color mixing”. As it is, a necessary pattern cannot be formed.

Therefore, in order to prevent the occurrence of the “mixed color” defect, a method of making the structure of the black matrix into a multi-layered structure having a layer having affinity for ink and a layer having non-affinity is examined. (Patent Document 1).
However, in this method, it is necessary to make the black matrix multi-layered, and therefore it is necessary to perform the photolithography process a plurality of times. As a result, there is a problem that the process is complicated and the cost is increased.

  Further, as another method for preventing the “color mixing” defect, a material approach may be considered in which the amount of the ink repellent agent itself contained is increased and more ink repellent agent is transferred to the black matrix surface. However, in general, increasing the amount of ink repellent agent has led to an increase in material costs, and this has been a problem as an ink jet technique in which low cost is an advantage among color filter production techniques. Furthermore, if the amount of the ink repellent agent is excessively increased in order to eliminate the “color mixing” defect, the liquid repellency becomes excessively high. When the ink is repelled more than necessary, a defect called “white spot” in which the color ink partially escapes from the pixel and is biased toward one side of the pixel may occur.

On the other hand, when the shape of the black matrix is round and rounded as shown in FIG. 3, even if the black matrix has sufficient liquid repellency, the shape of the black matrix is sufficient to function as a weir. In some cases, a “mixed color” defect could occur. Therefore, it has been studied to increase the liquid repellency of the black matrix excessively. However, when the color ink is ejected into the black matrix pattern using the ink jet device, the central portion of the color ink pattern rises and the color of the outer peripheral portion becomes extremely thin,
It became a quality problem.
From the above, it has been very difficult to obtain a black matrix having the performance and shape necessary for producing a high-quality color filter using an inkjet method.

JP-A-11-271753

  The present invention relates to the best shape of a black matrix, its production method, and the liquid repellency required for a black matrix when a substrate (referred to as a “black matrix substrate”) patterned with a black matrix as a base material is produced by a photolithography method. It is an object to propose a magnitude of sex and a method of providing it.

  Moreover, this invention makes it a subject to propose producing a color filter using the black matrix which has the said shape and the said liquid repellency. A color filter can be produced by applying other colors other than the black matrix by using an inkjet method. Of course, the coating may be performed by a method other than the inkjet method, for example, a printing method.

This invention is made | formed in view of the said subject, The invention is shown below.
[Claim 1]
A color filter manufacturing method of forming a black matrix pattern by photolithography method on the substrate, a photosensitive resin composition comprising a compound having liquid repellency on which was coated on the substrate, in the pattern exposure step A method for producing a color filter , characterized in that a black matrix pattern is formed by performing exposure with different number of irradiations depending on a place with a constant exposure amount in a substrate .

[Claim 2]
A method for producing a color filter , wherein a black matrix pattern is formed by the method for producing a color filter according to claim 1 , and a plurality of colors of ink are respectively ejected into openings of the black matrix, and formed.
While making the exposure total amount irradiated to the photosensitive resin composition in the exposure step constant,
A method for producing a color filter, wherein the number of exposures to the photosensitive resin composition is changed depending on a place.

  The present invention can provide a black matrix having excellent straightness and sufficient liquid repellency. Furthermore, by adopting the black matrix, it was possible to easily produce a high-quality color filter free from defects such as “mixed colors” and “white spots”.

It is a figure which shows the black matrix cross section of a taper shape with a long eagles. It is a figure which shows the taper-shaped black matrix cross section of this invention with a short loop. It is a figure which shows the black matrix cross-section of a kamaboko shape. It is a figure which shows the black matrix cross section of an overhang shape.

  The best mode for carrying out the present invention will be described below in detail with reference to FIGS.

The patterning substrate and the manufacturing method of the present invention will be described along the respective steps of the black matrix substrate for a color filter which is the basis of the present invention.
(1) Coating process First, a photosensitive resin composition for a black matrix containing an ink repellent agent capable of imparting liquid repellency to a substrate placed on a parallel surface plate is applied with a coating nozzle. Apply evenly. The substrate is usually glass or the like, but depending on the process, a transparent film material, a resin material, a synthetic fiber material or the like can be used. As described above, the ink repellent agent is a photosensitive material for black matrix in order to prevent the desired color ink ejected to the black matrix pattern opening by the inkjet method from entering the adjacent pixels with the black matrix as a boundary. There is no particular limitation on the material of the resin composition as long as it can achieve the purpose. Typical examples include silicone-based and fluorine-based ones.
Silicone resins and silicone rubbers containing a siloxane component, and other examples include, but are not limited to, vinylidene fluoride, vinyl fluoride, ethylene trifluoride, etc., and fluorine resins such as copolymers thereof. It is not something. There is no particular limitation on the coating nozzle, and a suitable one may be selected as appropriate. Further, with respect to the configuration, only one or a plurality of similar or different nozzles may be used in succession.
(2) Vacuum drying and pre-baking step Next, vacuum drying is performed with a vacuum drying device to remove the solvent contained in the coated photosensitive resin composition for black matrix. At this time, there is no restriction | limiting in the vacuum drying method, What is necessary is just to select the method according to the objective suitably, and may use the apparatus of 1 unit | set or several units | sets continuously. However, in order to prevent final shortage of the product from drying, it is desirable that the first pressure reduction pressure condition is 1500 Pa or less. Furthermore, it is preferable to perform pre-baking using a hot plate apparatus or the like. At this time, there is no limitation on the apparatus and method to be used, and a method suitable for the purpose may be selected as appropriate.
(3) Exposure process In the exposure process, electromagnetic waves such as ultraviolet rays or electron beams in a certain wavelength range were applied in the (1) coating process through a photomask on which openings and light-shielding parts were drawn. Irradiation to the photosensitive resin composition is performed to cure (bake) a desired pattern. Therefore, it is a particularly important process that influences the patterning shape of the black matrix among the processes. A high-quality color filter can be produced by accurately exposing and developing a desired pattern in these steps. The exposure method is roughly classified into a proximity exposure method and a projection exposure method. However, in the present invention, no limitation is imposed on the apparatus and method used. What is necessary is just to select the method suitable for the objective suitably.

  However, in the present invention, the process conditions are limited so that the total exposure amount required in the exposure step is irradiated in several times.

  Normally, when a black matrix is produced using a photolithographic method, the number of exposures is only one in consideration of tact and the like. Even when the required exposure dose is divided into several exposures, the performance and shape of the black matrix depend on the total exposure dose, and it has been thought that there is no difference from the time of one exposure.

  However, in the experiment conducted by the present inventor, it was found that the liquid repellency of the black matrix is higher than that at the time of single exposure and the “mixed color” defect is difficult to occur when the same portion is exposed by dividing the exposure amount into several times. It was.

  On the other hand, when considering the shape of a black matrix in which “color mixing” defects are unlikely to occur, the cross section shown in FIG. 1 can be divided into an upper part (17) and a lower part (18), and an upper part (17). It is better to have a shape that protrudes outward from the lower part (18). At this time, the height of the upper portion (17) of the black matrix is preferably 40% or less of the entire black matrix. Also, the angle (12) between the side surface of the black matrix lower part and the substrate is 90 degrees or less (hereinafter referred to as a taper shape from the vertical), and further, from the point (16) where the bottom of the black matrix side surface and the substrate contact each other. It has a comb-like portion (11) (hereinafter referred to as “hisashi”) extending in a lateral direction from a point (13) (hereinafter referred to as “side apex”) where a line extending vertically upward intersects the surface of the black matrix. Better. In the case of such a shape, the color ink ejected during the patterning of the black matrix has the function of a weir as compared with the case of the black matrix whose cross-sectional view shown in FIG. Therefore, wetting and spreading of ink can be prevented. As a result, it is possible to suppress the occurrence of “color mixing” defects without excessively increasing the liquid repellency of the black matrix. Even if each color ink is ejected onto the black matrix patterning using an inkjet device, each color pattern It is possible to obtain a high quality color filter without causing the color of the outer periphery of the film to become extremely thin.

  On the contrary, as shown in FIG. 4, even if the angle (41) formed between the side surface of the black matrix and the base material is larger than 90 degrees, the shape of the overhang that cannot separate the upper part and the lower part is used. It can play the same role as Hisashi as a weir. However, in order to realize such a shape, it is common to take a long development time with respect to the exposure amount. However, the black matrix ends protruding laterally in the cross section are discontinuous in the development process. As a result, the straightness tends to deteriorate. Further, there may be a problem that the brightness of the color ink portion is lowered, and such a shape is a problem in quality.

  Therefore, it can be said that the ideal cross-sectional shape of the black matrix is a taper shape from the vertical with a ridge.

  However, the longer the longer the distance (15) between the end (14) and the side apex (13) of the hook portion in FIG. Missing is likely to occur, and as a result, the straightness of the black matrix tends to deteriorate.

  Therefore, the present inventor conducted an experiment, and the cross-sectional shape of the black matrix not only has the eagles but also has the elongate length (23) as shown in FIG. 2 of 1.5 μm or less. It was confirmed that a black matrix with a taper shape from the vertical is more ideal.

  However, it is very difficult to process such a black matrix having a length of 1.5 μm or less and a taper shape from the vertical. For example, as a method for shortening the length of the cypress, process conditions such as taking a longer development time were examined. In that case, the ink repellent contained in the black matrix was excessively eluted in the developer during the development process. As a result, the necessary liquid repellency cannot be obtained, resulting in a “color mixing” defect.

  However, in experiments conducted by the present inventors, it has been found that the length of the eagles can be shortened by irradiating the total exposure amount in several times.

  Therefore, as in the present invention, limiting the process conditions to irradiate ultraviolet rays and the like by dividing the exposure amount required in the exposure process into several times simultaneously and appropriately controls the liquid repellency of the black matrix and the length of the comb. It can be said that it is an effective means for doing.

  Furthermore, if irradiation with ultraviolet rays or the like is performed at different exposure times depending on the location in the substrate, the required liquid repellency can be imparted to each location in the same substrate.

  For example, if the required discharge amount differs for each color ink due to the difference in solid content, etc., the black matrix pattern portion where the color ink required for the discharge amount is higher than that for other colors has higher liquid repellency than other locations. Needed. In such a place requiring high liquid repellency, the total exposure amount may be set to be the same as that in the other place and the number of times of irradiation with ultraviolet rays or the like may be set to be larger than that in the other place.

In this way, optimum liquid repellency can be imparted to the necessary portions.
(4) Development Step In the development step, development work may be performed in the same manner as in a normal photolithography method. The method and apparatus are not particularly limited, and a method suitable for the purpose may be selected as appropriate.
(5) Precure and firing step The developed substrate is fired at a high temperature to complete a black matrix. At this time, the corners of the black matrix may be sagged by the flow due to heat (hereinafter referred to as heat sagging), and may have a kamaboko shape as shown in FIG.

  Such a shape causes quality problems as described above. Therefore, pre-cure work such as applying ultraviolet rays or electron beams to the front surface or back surface of the substrate before the firing step is performed to lower the temperature during the firing step to 200 ° C. or lower. It ’s better to prevent drooling.

  Through the steps (1) to (5), the length of the scissors is 1.5 μm or less and the contact angle with water is 105, which is necessary for producing a high-quality color filter using an ink jet method. It is possible to produce a black matrix of the present invention that is at least the same degree.

  After that, using the existing ink jet device, the color ink is ejected to the opening of the black matrix, and the color filter of the present invention is completed through prebaking and baking processes.

  A black matrix resist containing an ink repellent agent mainly composed of a fluororesin was applied on a glass substrate (base material), and then dried under reduced pressure at an ultimate pressure of 150 Pa. Further, pre-baking was performed using a hot plate set at 120 ° C.

  Then, the exposure process was performed using the projection exposure machine. At that time, the illuminance was set to 156 (mW / cm 2), the number of exposures was twice at the same location, and the exposure amount was set to 50 (mJ / cm 2) in total.

  Next, development was performed using an inorganic alkali developer, precure was performed using an ultraviolet lamp, and then baking was performed at 160 ° C. to complete a black matrix substrate.

  As a result, as shown in Tables 1 to 3, the contact angle of the black matrix was 108 degrees, and sufficient liquid repellency was obtained as an inkjet black matrix. The length of the black matrix has about 1.4 μm, and the straightness was good. Furthermore, when red, blue, and green inks are ejected onto the black matrix pattern using an ink jet device, no defects such as color mixing or repelling occur, and the outer periphery of the color ink pattern does not become extremely light. As a result, a high-quality color filter was obtained.

  A black matrix substrate was prepared in the same manner as in Example 1 except that the total exposure was 30 (mJ / cm 2).

  As a result, as shown in Tables 1 to 3, the contact angle of the black matrix was 105 degrees, and sufficient liquid repellency as an inkjet black matrix could be obtained. The length of the black matrix has about 1.4 μm, and the straightness was good. Furthermore, when red, blue, and green inks are ejected onto the black matrix pattern using an ink jet device, no defects such as color mixing or repelling occur, and the outer periphery of the color ink pattern does not become extremely light. As a result, we were able to obtain a high-quality color filter.

  A black matrix substrate was prepared in the same manner as in Example 1 except that the total exposure was 60 (mJ / cm 2).

  As a result, as shown in Tables 1 to 3, the contact angle of the black matrix was 108 degrees, and sufficient liquid repellency as an inkjet black matrix could be obtained. The length of the black matrix has about 1.5 μm, and the straightness was good. Furthermore, when red, blue, and green inks are ejected onto the black matrix pattern using an ink jet device, no defects such as color mixing or repelling occur, and the outer periphery of the color ink pattern does not become extremely light. As a result, we were able to obtain a high-quality color filter.

  A black matrix substrate was produced in the same manner as in Examples 1, 2, and 3 except that the illuminance was lowered to 128 (mW / cm 2).

As a result, the contact angles of the black matrix were 108 degrees, 105 degrees, and 108 degrees, respectively, as shown in Tables 1 to 3, and sufficient liquid repellency was obtained as an inkjet black matrix. Further, the length of the black matrix has about 1.4 to 1.5 μm, and the straightness was also good. Furthermore, when red, blue, and green inks are ejected onto the black matrix pattern using an ink jet device, no defects such as color mixing or repelling occur, and the outer periphery of the color ink pattern does not become extremely light. As a result, we were able to obtain a high-quality color filter.
[Comparative Example 1]
A black matrix substrate was produced in the same manner as in Examples 1, 2, and 3 except that the number of exposures was one.

As a result, the length of the eclipse portion of the black matrix was 1.9 μm as shown in Tables 1 to 3, resulting in a black matrix having poor linearity and a quality problem. Furthermore, when the exposure amount is 30 (mJ / cm 2), the contact angle with water is 100 degrees, so that it is impossible to obtain the necessary liquid repellency as a black matrix for ink jet. When each color ink of red, blue and green was used, a “mixed color” defect occurred, and as a result, a high quality color filter could not be obtained.
[Comparative Example 2]
A black matrix substrate was prepared in the same manner as in Example 4 except that the number of exposures was one.

  As a result, the length of the eclipse portion of the black matrix was 1.8 to 1.9 μm as shown in Tables 1 to 3, resulting in a black matrix having poor linearity and a quality problem.

  Further, when the exposure amount was 30 (mJ / cm 2), the contact angle was 102 degrees, and the ink jet black matrix was anxious about liquid repellency. Furthermore, when red, blue, and green inks were ejected onto the black matrix pattern using an inkjet device, a “color mixing” defect occurred partially, and as a result, a high-quality color filter could not be obtained. .

表１から表３は、各実施例、比較例の結果をまとめたものである。

Tables 1 to 3 summarize the results of the examples and comparative examples.

  The upper part of Table 2 shows the length of the horseradish.

“◯” and “X” in the lower part of Table 2 are the results of the quality judgment of “straightness” of the black matrix.
In the present application, the determination of “straightness” was performed as follows.

  When observed from the top of the substrate, when the eaves portion was almost linear, it was evaluated as “◯”.

If the eclipse part does not have a linear shape, it is wavy or partly missing,
".

In Table 3, “◯”, “Δ”, and “×” indicate the presence or absence of the occurrence of color mixing and repelling defects.

  The upper row is the evaluation of color mixing, and the lower row is the evaluation of repelling.

  “X” indicates that many defects occurred.

  “Δ” indicates that a defect has partially occurred.

  “◯” indicates that no defect occurred.

1: Tapered black matrix patterning section with long eclipse 10: Substrate 11: Hedge at the top of black matrix patterning 12: Angle formed by patterning lower side of black matrix and substrate 13: Side apex 14: Hoshi Edge 15: Hedge length 16: Black matrix patterning Lower side contact with substrate 17: Black matrix patterning upper portion 18: Black matrix patterning lower portion 2: Tapered black matrix with short hoop Patterning section 20: Substrate 21: Black matrix patterning upper portion 22: Hedge end 23: Hedge length 24: Black matrix patterning Lower side surface and contact point of substrate 3: Kamaboko-shaped black Trix patterning section 30: base material 4: overhang of the black matrix pattern section 40: substrate 41: an angle patterning the lower side surface and the base material of the black matrix form

Claims (2)

A color filter manufacturing method of forming a black matrix pattern by photolithography method on the substrate, a photosensitive resin composition comprising a compound having liquid repellency on which was coated on the substrate, in the pattern exposure step A method for producing a color filter , characterized in that a black matrix pattern is formed by performing exposure with different number of irradiations depending on a place with a constant exposure amount in a substrate .
A method for producing a color filter , wherein a black matrix pattern is formed by the method for producing a color filter according to claim 1 , and a plurality of colors of ink are respectively ejected into openings of the black matrix, and formed.
While making the exposure total amount irradiated to the photosensitive resin composition in the exposure step constant,
A method for producing a color filter, wherein the number of exposures to the photosensitive resin composition is changed depending on a place.

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