JPH02157802A - Production of color filter - Google Patents

Abstract

PURPOSE:To substantially decrease the errors of inter-color distances to zero by printing abscissa register lines and ordinate register lines in monitor regions simultaneously with printing of respective color patterns and successively regulating the patterns of the 1st color, the 2nd color and the 3rd color at the time of forming the color filters for liquid crystal display by printing. CONSTITUTION:The R, G, B color filters 25 are printed on a transparent substrate 24 consisting of glass, etc., and the register lines 26 are simultaneously printed successively by colors to the margin parts of the substrate 24. The register lines 26 are provided at two points and the axis misalignment in the vertical and horizontal directions is observed by these two register lines 26, 26'. The observation of the deviation in the rotating direction is enabled as well. The matching of the 1st color is executed in a 1st printing stage in such a manner, then the matching of the 2nd color and the 3rd color is executed in the 2nd and 3rd printing stages. Then the registration of the respective color patterns is surely executed with about 5mum accuracy. The error even when the color patterns are printed at 50 to 300mum inter-color distance is confined within about 0 to 2% of the inter-color distance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method of manufacturing a color filter for a liquid crystal display device, and particularly to alignment of color patterns, so-called color matching.

(Prior technology) Conventionally used color filters for liquid crystal display devices (
A color filter (hereinafter referred to as a color filter) is a black matrix formed by a light-shielding film formed on a transparent substrate such as a glass plate using photolithography to improve the contrast ratio. Patterns of each color are formed. Since the performance of color filters largely depends on accurate alignment of the three color patterns, highly accurate alignment methods have been studied for some time. Note that the alignment between each color pattern is also simply called "color alignment."

Generally, in multicolor printing, each printing plate is provided with registration marks (hereinafter referred to as registration marks) in order to correctly overprint two or more colors on the same substrate and obtain the perfect printing effect. This register is generally in the shape of a cross, and its positioning accuracy is about 200 μm, and is usually called a "register mark." In the conventional method for manufacturing color filters, the above-mentioned "region marks" are formed simultaneously with the black matrix-like light-shielding film by photolithography, and color matching is performed using this as a target. The accuracy of the "region marks" obtained by the photolithography method was as high as about 2 μm, and there were no particular problems.

However, with the development of panel technology, it has become possible to obtain a sufficient contrast ratio without using a black matrix. Therefore, in order to reduce production costs,
It is desired to develop a color filter that does not use a black matrix but only has a color pattern. However, in the past, color matching was performed using a register formed at the same time as a black matrix, so highly accurate registers made using photolithography cannot be used for color matching of color filters that do not use a black matrix. A problem arose. Therefore, it has been desired to develop a new register and color matching means. (Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a color filter that is equipped with a color matching means for color filters that does not use a black matrix. do.

(Means for Solving the Problems) An object of the present invention is to provide a method for manufacturing color filters using a printing method, in which each color pattern is printed on a filter area of a substrate, and at the same time, a predetermined monitor area is also printed for color matching. A rectangular pattern with a width slightly narrower than the intercolor distance (P) in the horizontal axis direction is used as the register mark, and a mark with an acute-angled tip is used in the vertical axis direction. This can be achieved by a method for manufacturing a color filter characterized by the following.

Note that the intercolor distance (P) is the distance between mutually adjacent color patterns, and refers to the distance between the center lines of each color pattern (see FIG. 1C (a)).

(Function) In the present invention, two types of registers are printed on the monitor area at the same time as printing each color pattern, namely, a register used for color matching in the horizontal axis direction (hereinafter referred to as horizontal axis register) and a register mark in the vertical axis direction. The colors of the color filters are matched using the register used for color matching (hereinafter referred to as the vertical axis register).

The horizontal axis target and the vertical axis target are set so that the distance between the center lines is twice and three times the intercolor distance (P), respectively. As a result, when the first color pattern is printed, the first color register defines the position where the two color mouth pattern is to be printed.

When a two-color pattern is printed based on this,
The two-color register mark that is formed is a register mark that confirms that the two-color register pattern is printed at the position specified by the first color register mark, and a register mark that specifies the position where the three-color register pattern should be printed. Provide a target mark to be used. Then, when the three-color pattern is printed, a three-color pattern is formed to confirm that the three-color pattern is printed at the position defined by the first or second color pattern. This method allows color matching of color filters.

In addition, in the present invention, a shape having an acute-angled tip is particularly used as the vertical axis register. In the case of printing, when considering a rectangular ink pattern, the straight parts in the front and back of the printing direction, that is, the top and bottom edges, cannot be printed clearly, making it difficult to confirm whether the color pattern has been printed accurately. . Therefore, in the present invention, it was decided to use the acute-angled tip portion, which can be printed relatively clearly even when printing, as the vertical axis register. As a result, color matching accuracy has improved dramatically.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

First, the register used in the present invention will be explained.

For the horizontal axis target mark, refer to Figure 1A (a), and for the vertical axis target mark, refer to Figure 1A (b).
) Explain with reference to the figure.

Horizontal axis target Color matching in the horizontal axis direction is confirmed by looking at the gap between the horizontal axis targets. Therefore, in order to perform accurate color matching, it is necessary that the gaps between the register marks clearly appear when the register marks are printed. Therefore, it is preferable to use a rectangular pattern as the horizontal axis target used in the present invention. In addition, the rectangular pattern needs to be large enough to visually confirm the gap between the horizontal axis registration columns, and the horizontal length of the rectangle should be approximately 0.8 to 0.0, 9 times, the length is about 3 to 5
Double is preferred.

According to FIG. 1A (a), three horizontal axis target marks are provided. The distance between the center lines of horizontal axis registers 1 and 2 is set to twice the intercolor distance. Further, the distance between the center lines of the horizontal axis target marks 2 and 3 is set to three times the intercolor distance.

Vertical Axis Registration Color matching in the vertical axis direction is confirmed by checking whether the sharp end portions 21 of the vertical axis register are aligned.

As shown in an enlarged view in FIG. 3, it is also possible to perform color matching in the vertical axis direction using the horizontal axis register portion 23, but in the case of printing, the upper edge straight portions 22 and 23 of the ink pattern are clearly visible. It is difficult to print, and therefore color matching accuracy decreases. In contrast, the sharp tip 21 can be printed relatively clearly. Therefore, it is preferable to use a mark with an acute tip as the vertical register.

Furthermore, according to FIG. 1A (b), there are three vertical axis registers, similar to the horizontal axis registers. Vertical axis register 9 and 1
The distance between the 0 center lines is set to twice the intercolor distance. Further, the distance between the center lines of the vertical axis registers 10 and 11 is set to three times the intercolor distance.

The color matching means of the present invention will be explained below.

As shown in FIG. 2, a color filter 25 is printed and formed on a transparent substrate 24 such as glass. At the same time, the above-mentioned register mark 26 is formed. As described above, the register marks 26 are formed in order for each color. This register 2
6 is provided at two locations as shown. By doing this, it is possible to know not only the deviation in the vertical and horizontal axis directions but also the deviation in the rotational direction by observing the two target marks 26 and 26'.

FIG. 1 is a schematic diagram showing each printing process of the color matching method of the present invention. Here, FIG. 1A shows the color matching of the first color (hereinafter referred to as the first printing process), FIG. 1B shows the color matching of the second color (hereinafter referred to as the second printing process), and FIG.
The figure shows the third color matching (hereinafter referred to as the third printing process)
It represents. In each figure, (a) is the horizontal axis orientation, and (b) is the vertical axis orientation. The plate used in the present invention may be any type of plate, but an intaglio plate or a planographic plate is preferable. Further, as the printing method, intaglio offset printing or lithographic offset printing is preferable.

Hereinafter, the color matching method of the present invention will be explained according to each printing process.

First printing step FIG. 1A is a diagram showing the register formed by printing the first color.

According to this, three horizontal axis registers (a) and three vertical axis registers (b) are printed on the substrate.

As shown, the distance between the center lines of horizontal axis registers 1 and 2 and vertical axis registers 9 and 10 is 2 times the desired intercolor distance.
It is set to double. Further, the distance between the center lines of the horizontal axis registers 2 and 3 and the vertical axis registers 10 and 11 is set to three times the desired intercolor distance. These register marks are printed at the same time as the first color pattern is printed.

The horizontal axis register sources 1 and 2 and the vertical axis registers 9 and 10 of the first color printed in this step define the position of the two-color opening pattern printed in the second printing step. That is, the two-color register printed in the second printing process is formed to match the spaces 17 and 18.

Second printing process FIG. 1B is a diagram showing the state after the two-color opening pattern is printed at the position defined by the first-color register printed in the first printing process.

The two-color mouth register formed in this process is as follows.
It has two functions.

(1) Function to confirm whether the two-color opening pattern has been printed accurately at the position specified by the register formed in the first printing process (a) Confirmation in the horizontal axis direction Confirmation in the horizontal axis direction ° is performed using the horizontal axis register marks 1 and 2 formed in the first printing process and the horizontal axis register mark 4 formed in the second printing process. Confirmation is performed by checking whether the gap between the horizontal axis target mark 1 and the horizontal axis target mark 4 and the gap between the horizontal axis target mark 4 and the horizontal axis target mark 2 are equally spaced. Since the human eye is very strict in evaluating gaps, it is possible to perform color matching in the horizontal axis direction with high precision.

(b) Confirmation in the vertical axis direction Verification in the vertical axis direction is performed using the vertical axis registers 9 and 10 formed in the first printing process and the vertical axis registers 12 and 13 formed in the second printing process. Let's do it.

Confirmation is performed by checking whether the sharp tips 21 of the vertical axis registers 9, 10, 12 and 13 are aligned.

(2) Function to define the position where the three-color pattern is to be printed The horizontal axis register 3 formed in the first printing process and the second
The horizontal axis register 5 (and the vertical axis registers 11 and 13) formed in the printing process defines the position where the three-color pattern is to be printed. That is, the third
The three-color register printed in the printing process is No. 1A.
It is formed to match the spaces 19 and 20 in the figure.

Third printing process FIG. 1C is a diagram showing the state after the three-color pattern is printed at the position defined by the two-color pattern registered in the second printing process.

Using the register formed in this step, it is confirmed whether the three-color opening pattern has been accurately printed at the position specified in the second printing step.

(a) Confirmation in the horizontal axis direction Confirmation in the horizontal axis direction is performed using the horizontal axis register 3 formed in the first printing process and the horizontal axis register 5 formed in the second printing process,
This is performed using the horizontal axis register 7 formed in the third printing process. Confirmation is performed by checking whether the gap between the horizontal axis target mark 5 and the horizontal axis target mark 7 and the gap between the horizontal axis target mark 7 and the horizontal axis register pattern 3 are equally spaced.

(b) Confirmation of the vertical axis direction Confirmation of the vertical axis direction is performed using the vertical axis register mark formed in the first printing process, the vertical axis register mark formed in the second printing process, and the vertical axis register mark formed in the second printing process.
This is done using vertical axis registers 15 and 16 formed in the printing process. Confirmation is performed by checking whether the acute-angled tip of the already formed vertical axis register and the acute-angled tip of the vertical axis register formed in the third printing process are aligned.

As described above, by the color matching method of the present invention, it is possible to reliably align the blue, green, and red color patterns with an accuracy of about 5 μm. For example, when a color pattern was printed using the present invention with an intercolor distance of 50 to 300 μm,
The error was about 0 to 2% with respect to the intercolor distance.

(Effects of the Invention) According to the present invention, color patterns can be accurately aligned in manufacturing a color filter using a printing method. As a result, it has become possible to manufacture color filters for liquid crystal display devices by directly forming color patterns on substrates such as glass.

[Brief explanation of the drawing]

FIG. 1A is a diagram showing the register mark of the first color. FIG. 1B is a diagram showing the registers of the first color and the second color. FIG. 1C is a diagram showing the registers of the first color, the second color, and the third color. FIG. 2 is a plan view showing an example of a color filter obtained by the manufacturing method of the present invention. FIG. 3 is a partially enlarged view showing the register used in the present invention. 1 to 8...horizontal axis target, 9 to 16...vertical axis target,
21...Acute edge part, 22.23...Ink pattern edge straight part, X...Printing direction Applicant's agent Patent attorney Takehiko Suzue Diagram

Claims (3)

[Claims] (1) In a method of manufacturing a color filter using a printing method, printing each color pattern on a filter area of a substrate and at the same time printing a target mark for color matching in a predetermined monitor area; A method for manufacturing a color filter, characterized in that a rectangular pattern having a width slightly narrower than an intercolor distance (P) is used in the horizontal axis direction, and a mark having an acute-angled tip is used in the vertical axis direction. (2) Three horizontal axis target marks and three vertical axis target marks are provided for the first color, and the distance between the center lines of each target mark is twice and three times the intercolor distance (P). The method for manufacturing a color filter according to claim 1, characterized in that: (3) The method for manufacturing a color filter according to claim 1, wherein the printing method is intaglio offset printing or lithographic offset printing.