JPH0361902A - Production of color filter - Google Patents

Abstract

PURPOSE:To improve the yield at the time of producing color filters by forming dummy patterns adjacent by to the ends of normal patterns and the circumferences of alignment marks, thereby selectively generating void defects in the dummy pattern parts. CONSTITUTION:The dummy patterns 3D are formed adjacently to the normal patterns and alignment marks 3 in the process for producing the color filters to form the accurate patterns on a substrate by using printing means. The void defects which are liable to arise as the supply, drying condition, etc., of ink are unstable are, therefore, selectively generated in the dummy pattern parts 3D adjacent to the normal patterns 3 and the dummy patterns 7 and the normal patterns 3 and the alignment mark 7 are always normally printed and formed. The generation of the defects inconvenient for forming the accurate patterns on the substrate is obviated in this way and the yield is improved.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for manufacturing a color filter, and more particularly to an improvement in a method for manufacturing a fine pattern using printing means.

[Conventional technology]

Color filters used in LCD displays, etc.
Red, green, and blue areas 1R are placed on a transparent substrate made of glass, etc.
It is often manufactured by repeatedly and continuously forming thin lines consisting of the three primary colors GB. Intaglio or intaglio offset printing is often used as a means to form continuous lines, but in the case of color filters, the lines formed must not be disordered, and the ink must not be printed in pinholes. It is also not acceptable to have so-called white spots. Even if a pinhole-like white spot is a physical defect, when used as a liquid crystal display, the backlight directly enters the eye and appears white, so it cannot be used as a product. In the case of color filters used in recent liquid crystal displays that require particularly high resolution, 50μ-
A fine pattern is required in which extremely thin lines are repeatedly formed, but as the pattern becomes finer, it is difficult to uniformly supply ink to the line grooves provided on the printing plate, and the drying speed of the ink is limited. As the speed increases overall, the above-mentioned white spot defects tend to occur frequently. Therefore, in the current manufacturing process, in order to improve the product yield,
A repair process is in place.

[Problem to be solved by the invention]

For example, apply red ink onto the printing plate and use a squeegee (
(not shown), excess ink 3R is scraped off with a doctor, and ink is supplied to the printing grooves. Then, the plate cylinder blanket is brought into contact with the surface of the printing plate while rotating, and the ink supplied to the printing grooves is transferred to the surface of the plate cylinder blanket. Furthermore, the printing plate cylinder blanket is brought into rotational contact with the smooth printing surface of the glass substrate, and the ink is transferred to transfer the printing pattern of the printing plate onto the glass substrate. It slides in the direction of the line grooves to scrape off excess ink supplied to the printing plate. Since the surface tension acts to draw out the remaining ink only from the side of the ink that has been pushed in the direction of travel, a sufficient amount of ink cannot remain in the image grooves that are first scraped off. In intaglio offset printing performed using a printing plate in which ink is supplied to the image grooves in this manner, defects in the form of blank spots due to insufficient supply of ink selectively occur. However, repairing fine patterns is an extremely delicate task that requires handwriting while observing under a microscope, so there is a problem in that efficiency is not high enough to require manual labor. Therefore, in order to fundamentally solve the problems of the prior art, the present invention aims to provide a printing means that does not generate defects in the process of forming fine patterns on a substrate.

[Means to solve the problem]

The present invention has been made to solve the problems of the prior art described above, and in a method of manufacturing a color filter in which a fine pattern is formed on a substrate using printing means, This is a method of manufacturing a color filter characterized by forming a dummy pattern. It is natural for regular lines to have defects, such as defects, which occur in white areas, but defects in alignment marks can also cause misalignment defects and other defects. Cause. In particular, alignment marks are often formed apart from other regular print lines, and the above-mentioned problems are likely to occur no matter which direction the ink is scraped off with a doctor. Therefore, the means of the present invention can also be used for such alignment marks in a different sense.

[Effect]

According to the color filter manufacturing method of the present invention, white stripe-like defects that tend to occur due to unstable ink supply and drying conditions can be avoided in the dummy pattern area adjacent to the regular pattern or alignment mark. Occurs selectively in
Regular patterns and alignment marks are printed and formed normally. Next, the present invention will be explained in detail based on illustrated embodiments.

[Example 1] The printing plate 1 used in the method of manufacturing a color filter according to the present invention has at least one regular printing groove 11a at one end of a plurality of regular printing grooves 11a having a desired thickness and length. This is a printing plate in which dummy image grooves lid are formed adjacent to each other. The normal image line groove 11a is formed into a thin line (for example, thickness 100μ) required by the standard of the color filter to be a product, and is formed on one side of the glass substrate 2 in red, green, and blue areas 1fRG.
In order to form the desired regular pattern 3 by repeatedly and continuously forming the regular print lines 3r13g and 3b of the B three primary colors, the regular print grooves 11a are spaced apart by an interval twice the thickness (in this case, 200 μm). are placed in parallel. or,
The dummy image groove lid is also provided parallel to and spaced apart from the regular image groove 11a at the end by the same distance. It should be noted that the printing plate 1 is made by conventional means such as photolithography, which is well known to those skilled in the art, and the method of intaglio offset printing using the printing plate 1 is also well known to those skilled in the art.
To omit the explanation of the inside of the film and to explain in detail only the constituent elements of the present invention, for example, red ink 3R is supplied onto the printing plate 1, and after leveling it with a squeegee (not shown), the excess is removed with a doctor 4. Scrape off ink 3R and regular printing groove 1
Ink 3R is supplied to each of 1a and the dummy printing groove lid. Then, the plate cylinder blanket 5 is brought into contact with the surface of the printing plate 1 while being rotated, and the ink 3R supplied to each of the regular print grooves 11a1 and the dummy print grooves lid is transferred to the surface of the plate cylinder blanket 5. Further, the print cylinder blanket 5 is brought into rotational contact with the smooth printing surface 21 of the glass substrate 2, and the ink 3R is transferred to transfer the printing pattern of the printing plate 1 onto the glass substrate 2. 4 slides from the dummy drawing groove lid side of the printing plate 1 in the direction of the regular drawing groove 11a (from left to right in the drawing) to scrape off excess ink 3R supplied to the printing plate 1. , when scraping off the excess, the ink 3R remaining in the dummy print groove lid is pulled out with surface tension only from the ink 3R side that was pushed by the doctor 4 to the regular print line Jlla side on the right side of the drawing. Therefore, a sufficient amount of ink 3R is applied to the dummy printing groove 11d.
cannot be left behind. On the other hand, the regular drawing groove 11a
Regarding the dummy image [111d
Since surface tension acts from both the ink 3R remaining in the ink 3R and the excess ink 3R pushed to the right side of the drawing by the doctor 4, a sufficient amount of ink 3R remains, so that all other regular printing grooves 11a A sufficient amount of ink 3R is also supplied for each. In intaglio offset printing performed using the printing plate 1 in which a sufficient amount of ink 3R is uniformly supplied to all the regular print grooves 11a in this way, the red regular print lines 3r are in an extremely good condition. The white stripe-like defect 6 selectively occurs on the dummy lines 3 and 1 which are printed and formed and to which a sufficient amount of ink 3R is not supplied. Also, dummy drawing! 13r' Adjacent regular print lines 3r tend to have less ink 3R than regular print lines 3r in other parts,
In particular, compared to the regular drawing line 3r at the opposite end, the drying speed is faster in terms of the amount of ink, which tends to cause white spot defects 6, but the ink supplied to the adjacent dummy drawing groove 11d Due to the vapor pressure of the solvent evaporated from 3R, the normal streak 3r
Since the drying of the white spots is suppressed, the occurrence of white spot defects 6 is effectively prevented. One dummy drawing line 3r is created on the glass substrate 2 by the above method.
' and a large number of regular objects 3r are successively formed at intervals of 200μ■, then the printing plate 1 is shifted to the right side of the drawing by 100μ■ and the green dummy object line 31 and the regular object line 3 are followed by the same method.
g, and then print and form a blue dummy object line 3b' and a regular object line 3b shifted by 100 μm in the same direction, a regular object line 3rx3 of the three primary colors of RGB with a width of 100 μm is obtained.
A dummy pattern 3D is formed by continuously printing dummy lines 3r', 3g' and 3b' adjacent to the desired regular pattern 3 formed by repeatedly printing dummy lines 3r', 3g' and 3b'. The color filter in which the regular pattern 3 and the dummy pattern 3D are formed adjacent to each other on one side of the glass substrate 2 in this way is similar to conventional color filters, and the printed surface is polished or rolled as necessary. After smoothing, etc., electrodes are arranged and liquid crystal is encapsulated to create a liquid crystal display. Note that the dummy pattern formed adjacent to the regular pattern 3 is formed adjacent to the regular drawing groove 11a on the scraping start side when the direction in which excess ink is scraped off by the doctor 4 is known as described above. However, if the direction of scraping by the doctor 4 is unknown at the time of preparing the printing plate 1, it may be formed adjacent to the regular pattern 3 on all sides. For this purpose, dummy drawing grooves 11d as shown in the embodiment are provided adjacent to both ends of the regular drawing groove 11a, and the regular drawing groove 11a and the dummy drawing groove lid are arranged in the vertical direction of the drawing. , the length may be longer than the specified length required for liquid crystal displays, etc. Regular pattern 3 and dummy pattern 3D
may be formed in a stripe shape or in a dot shape, and only one dummy image groove 11d may be provided, or two or more dummy image grooves may be provided in parallel. In addition, the dummy pattern is not only the regular pattern 3 that becomes the display part of a liquid crystal display, but also adjacent to the regular pattern of the alignment mark 7 formed at the end of the glass substrate 2 for positioning during manufacturing, and has the same effect. You can also get .

[Example 2] The printing plate used in the second example has a cross-shaped alignment mark 8 outside the original pixel area, and an unrelated dummy pattern 9 is formed adjacent to the cross-shaped alignment mark 8. This is a printed version. The alignment mark 8 is formed into a thin line (for example, 100 μm in thickness) required for the positional accuracy of the color filter as a product. R
The alignment marks 8r, 8g, and 8b of the three primary colors of GB are formed in a cross shape so that the relative positions of the respective colors do not deviate. Further, a dummy pattern 9 is also provided around the pattern so as not to come into mixed contact with the alignment mark 8. Incidentally, since the printing plate 1 is the same as that in Example 1, a description thereof will be omitted. In addition, surface tension acts on both the ink remaining in the dummy pattern and the excess ink pushed to the alignment mark part by the doctor, so a sufficient amount of ink remains on the alignment mark part. A sufficient amount of ink is also supplied to each of the other alignment mark portions. Therefore, printing is performed in an extremely good condition, and no defects such as white spots occur. In addition, if only the alignment mark is used, the amount of ink in that part is particularly small, and the drying speed becomes faster in terms of the amount of ink, which tends to cause white spot defects. The drying of the alignment mark is suppressed by the vapor pressure of the solvent, thereby effectively preventing the occurrence of void-like defects. The shape of the alignment mark and the shape of the dummy pattern may be a cross shape, a circle, an L-shape, a hollow cross, or the like. In addition, the dummy pattern has a square shape, as well as Petter halftone dots,
The shape of the alignment mark, such as a parallel cross or multiple contours, is not critical, and it may be formed on only one of the alignment marks.

【Effect of the invention】

As explained above, the method of manufacturing a color filter according to the present invention is a method of manufacturing a color filter in which a fine pattern is formed on a substrate using printing means. Since the dummy pattern is formed using a dummy pattern, white stripe-like defects, which tend to occur due to unstable ink supply and drying conditions, occur selectively in the dummy pattern area, and do not occur in the regular pattern area or alignment marks. Since no defects occur, the yield when manufacturing color filters has improved dramatically.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the process of manufacturing a color filter by printing means, Fig. 2 is an explanatory diagram of the process of supplying ink to the printing plate, Fig. 3 is an explanatory diagram of the color filter, and Fig. 4 is an illustration of the alignment mark. Enlargement stage 11a... regular drawing groove, lid... dummy drawing groove, 2... glass substrate, 3... regular pattern 3bs 3g% 3r... regular drawing line, 3b', 3g'
, 3 rl... dummy drawing line, 3D... dummy pattern, 3R... ink, 4... doctor, 5... plate cylinder blanket, 6... white spot defect, 7...・Alignment mark, 8... Alignment mark, 9... Dummy pattern.

Claims (3)

[Claims] (1) A color filter manufacturing method in which a fine pattern is formed on a substrate using a printing means, the method comprising forming a dummy pattern adjacent to a regular pattern. (2) A color filter manufacturing method in which a fine pattern is formed on a substrate using a printing means, the method comprising forming a dummy pattern adjacent to an alignment mark. (3) A method for manufacturing a color filter according to claims 1 to 2, in which a dummy pattern is provided in at least one direction of the regular pattern.