JPH0727082B2 - Method for manufacturing color filter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a color filter used for multicoloring a display element such as a liquid crystal.

[Outline of Invention]

The present invention is a method for forming a color filter on the surface of a substrate constituting a display device, in which a positive photosensitive film is formed on the substrate, and exposure, development and electrodeposition are repeated to form a desired array shape. A color filter for a multicolor display element is formed.

[Prior art]

The following three methods are generally well known as main methods of forming a color filter on the substrate surface of a display device. (I) A method in which a polymer film of gelatin or the like is provided on the surface of the substrate and the film is dyed. (Ii) By offset printing,
A method of printing ink directly on the substrate surface. (Iii) A method of electrodepositing a polymer in which a dye is dispersed on a patterned conductive film on a substrate.

The method (i) is the most general and has an advantage that a fine pattern can be formed with high precision, but the process is complicated and the cost is high. (Ii) is very cheap in terms of cost and mass-produced,
At present, it is difficult to print ink with high accuracy on glass, and thus it is not suitable for producing a filter having a fine shape. The method by electrodeposition of (iii) is described in, for example, Japanese Patent Laid-Open No.
As described in detail in Japanese Patent Laid-Open No. 9-114572, the number of steps is smaller than that of the method (i), the cost is advantageous, and fine processing is possible.

FIG. 2 shows a color filter for a typical matrix liquid crystal display device manufactured by a conventional electrodeposition method.
2 (a) is a plan view thereof, and FIG. 2 (b) is a sectional view taken along the line BB ′ of FIG. 2 (a).

Next, the manufacturing method will be briefly described. A transparent conductive film 2 for driving a liquid crystal is formed on the substrate 1 and patterned in a line shape. The first colored layer (for example, red) in the transparent conductive film 2
Only those desired to be formed are connected to a power source, and the first colored layer 4a is formed by energizing in the electrodeposition bath.
Hereinafter, the same method is repeated to obtain the second colored layer 4b.
The color filter of FIG. 2 is manufactured by sequentially forming (for example, green) and the third colored layer 4c (for example, blue).

[Problems to be Solved by the Invention]

However. The conventional method of manufacturing a color filter by electrodeposition has a problem that the arrangement shape of the colored layer is limited depending on the type of the display element, or the number of steps is increased.

For example, consider the case of a color filter for a simple matrix type liquid crystal display device. In order to drive the liquid crystal by the simple matrix method, it is necessary to arrange the transparent conductive film 2 for driving in a line. Therefore, if an attempt is made to produce a color filter by electrodeposition using the conductive film 2, only a so-called stripe array color filter in which each colored layer is arranged in a line can be produced (see FIG. 2 (a) above). (See (b)). That is, the conductive film 2
Since the arrangement of each colored layer is limited by the shape, there is a drawback that even if an attempt is made to make a color filter such as a mosaic arrangement which is advantageous for color mixing, it cannot be made.

Next, a color filter for a so-called active matrix type liquid crystal display device in which a TFT (thin film transistor) is formed on one substrate will be described. In this type of liquid crystal display element, the potential of the substrate facing the TFT needs to be kept constant at all times, so it suffices if a transparent conductive film is formed on the entire surface of the substrate, and patterning of the conductive film is generally unnecessary. . However, in the case of producing a color filter on this counter substrate by electrodeposition, a step of first patterning a conductive film, electrodepositing each colored layer, and then electrically connecting the conductive films again is required. . That is, there is a drawback in that the number of whole steps is significantly increased.

[Means for Solving the Problems]

The present invention provides a means for forming a color filter by forming a positive photosensitive film on a substrate and repeating exposure, development, and electrodeposition in order to solve problems such as arrangement limitation and complicated steps. It was adopted.

[Work]

In the present invention, the position of electrodeposition is determined by exposure and development using a positive photosensitive film. Therefore, it is possible to manufacture a color filter having a free color arrangement without the arrangement of each colored layer being influenced by the shape of the conductive film. Further, the color filter for active matrix does not require the step of patterning the conductive film and the step of connecting after electrodeposition.

〔Example〕

(Example 1) FIGS. 1A to 1F are views in the order of steps showing a method for producing a color filter of the present invention. Hereinafter, FIG. 1 (a)-
The steps up to (f) will be described in detail. The positive photosensitive film 3 is applied to the substrate 1 having the conductive film 2 formed on the entire surface, and exposed and developed to form only the photosensitive film 3 on the conductive film 2 where the first colored layer is to be formed. To remove (first
(See FIG. (A)).

The first colored layer 4a is electrodeposited by energizing the conductive film 2 in the electrodeposition bath (see FIG. 1 (b)). The portion of the photosensitive film 3 where the second colored layer is to be formed on the conductive film 2 is removed by exposure and development (see FIG. 1 (c)). Second colored layer
4b is electrodeposited (see FIG. 1 (d)). Third on the conductive film 2
The portion of the photosensitive film 3 on which the colored layer is desired to be formed is exposed and developed to be removed (see FIG. 1 (e)). After the third coloring 4c is electrodeposited, the remaining photosensitive coating 3 is removed, and the coloring layers 4a to
4c is heat-cured (see FIG. 1 (f)).

Normally, in the display element, the colored layer 4 has three colors, but when four or more colors are required, the above exposure, development and electrodeposition may be repeated.

By the method described above, a color filter having a colored layer having a desired arrangement shape can be manufactured on a substrate on which the conductive film 2 is formed. When this filter was combined with a substrate provided with a TFT to fabricate an active matrix type liquid crystal display device, good color display was realized.

Example 2 An example of applying the present invention to a simple matrix type liquid crystal display device is shown in FIGS. 3 (a) and 3 (b).

FIG. 3 (a) is a plan view of a color filter produced by the method of the present invention, and FIG. 3 (b) is A- of FIG. 3 (a).
It is sectional drawing which followed the A'line. Since it is a simple matrix type, the conductive film 2 is arranged in a line.

Development, exposure, and electrodeposition are repeated on the conductive film 2 by the same procedure as the method described in the first embodiment to obtain the colored layer 4
A, 4b, and 4c were formed in a mosaic shape. The mosaic color filter can be formed on the line-shaped conductive film, which was impossible with the conventional method.

A simple matrix type liquid crystal display device was manufactured using the color filters shown in FIG. 3, and compared with the conventional color filter shown in FIG. 2, the appearance of various mixed colors became clearer and the display characteristics were improved. Has improved. In addition, although an example in which the colored layers are arranged in a mosaic pattern has been described in this embodiment, it goes without saying that other arrangements such as a triangle can be freely manufactured by the completely same method.

The present invention utilizes a positive photosensitive film, but in principle a negative type is also possible. Further, the present invention is not limited to a color filter for a liquid crystal display element, and is a manufacturing method which is always effective when a colored layer is formed on the surface of a conductor by electrodeposition.

〔The invention's effect〕

As described above, according to the method of the present invention, a color filter having a desired color arrangement can be manufactured without being influenced by the pattern shape of the conductive film.

[Brief description of drawings]

1 (a) to 1 (f) are views showing a manufacturing process sequence of a color filter according to the present invention, FIG. 2 (a) is a plan view of a conventional color filter by electrodeposition, and FIG. 2 (a) is a sectional view taken along the line BB ', FIG. 3 (a) is a plan view of a color filter manufactured according to the present invention, and FIG.
FIG. 3B is a sectional view taken along the line AA ′ of FIG. 1 ... Substrate 2 ... Conductive film 3 ... Positive photosensitive film 4a, 4b, 4c ... Colored layer

Claims (1)

[Claims] 1. A method of manufacturing a color filter, comprising: a) forming a conductive film on the entire surface of a substrate or in a desired shape; and b) forming a positive photosensitive film on the entire surface of the substrate. c) exposing and developing the photosensitive coating into a desired shape to expose a part of the conductive film, and d) forming a colored layer on the exposed part of the conductive film by electrodeposition, and c). A method for producing a color filter, wherein the step d) is repeated twice or more.