JPS61281220A - Production of color filter - Google Patents

Abstract

PURPOSE:To dispose many color patterns on a common electrode without separating a transparent electrode by forming selectively color patterns on a sheet of the transparent electrode with a resist film as a mask by using an electrodeposition method. CONSTITUTION:The resist film is coated and deposited on the transparent electrode film 2 and is patterned by exposing and developing to obtain the resist film pattern 30 from which the resist film at the segment points to be disposed with a red filter is removed. The film 2 is thereafter subjected to an electrodeposition treatment in an aq. high-polymer resin soln. dispersed with a red pigment, for example, an aq. melamine resin soln. added with a carboxyl group with said film as a positive electrode and a counter electrode N as a negative electrode, then the red filter R consisting of the high-polymer resin film incorporated therein with the red pigment is deposited and formed on the surface of the electrode 2 at the points exposed from the resist film pattern 30 as a mask. Such substrate 1 is dried by heating to bake and fix the high-polymer resin of the red filter R and thereafter the pattern 30 is stripped therefrom. A green filter G and blue filter B are thereafter formed in the same manner.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for manufacturing color filters used in liquid crystal color television panels and the like.

((b) Conventional technology) Conventionally, in the case of LCD color television panels, as disclosed in the article ``Commercialized LCD pocket color television'' of ``Nikkei Electronics'' published on September 10, 1984. In addition, display of a color image is realized by employing color filters in which red, green, and blue filter segments (R), (G), and (B) are arranged in a mosaic pattern as shown in FIG.

Conventionally, such color filters have been manufactured using a dyeing method that dyes an organic film such as gelatin, or a printing method that prints a coloring agent, but this dyeing method requires many steps and is expensive to manufacture. Not only does this increase the filter area, but it also makes it difficult to apply a uniform film, and in the case of printing, the colorant bleeds easily, making it unsuitable for forming fine filter patterns.

Therefore, in recent years, a new method for manufacturing color filters has been developed to replace the dyeing and printing methods described above, by applying the phenomenon in which water-soluble polymers are electrochemically insolubilized and deposited on electrodes. Attempts have been made to adopt an electrodeposition method in which a colored polymer resin layer can be formed on an electrode by dispersing a coloring agent into the molecules.
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A conventional manufacturing method for manufacturing a color filter as shown in FIG. 2 by employing such an electrodeposition method is shown in FIGS. 3(a) to 3(a).
The explanation will be based on the manufacturing process diagram in e) and the electrode pattern diagrams in FIGS. 4(a) and 4(b).

First, a transparent electrode film (2) made of ITO was formed on one glass substrate (1) of a sandwich-structured liquid crystal panel (Fig. 3 (a)), and then this electrode film (2) was patterned with a resist. FIG. 4(2L): Etching is performed to separate each segment as shown in FIG. 3(b).

At this time, the segment-separated transparent electrode film...
Among the separated transparent electrode films on which the same color filter is to be formed, adjacent ones are electrically connected by thin line patterns (21) as shown in Fig. 4(b). need to be done.

After that, electrodeposition was performed in a polymer aqueous solution in which red pigment was dispersed, using the separated transparent electrode to form the red filter (R) as the positive electrode and the counter electrode (N) as the negative electrode, and then electricity was applied. Separated transparent electrode (201...A polymer resin film mixed with a red pigment is formed on the surface, and this is heated and dried to obtain a red filter (R)... (Fig. 3 (C)).Then, the same A green filter 0 made of a polymer resin film mixed with a green pigment by electrodeposition is attached to a predetermined electrode ■...
Then, a blue filter (B) made of a polymeric resin film mixed with blue pigment is obtained on the predetermined electrode (Fig. 3(d)) by the same electrodeposition process. .

e→ Problems to be Solved by the Invention The drawbacks of the conventional color filter manufacturing method as shown in FIG. 3 are listed below.

■ As shown in Figure 4, the electrical resistance at the - of the thin line pattern connecting each separated transparent electrode film on which the same color filter is to be deposited becomes high, so during the electrodeposition process. When power is applied to the separated transparent electrode film, the color filters are also separated into segments, creating gaps between filters of different colors, and light from this gear lip is also separated. This causes the quality of the displayed image to deteriorate in the liquid crystal color television panel.

The three primary color filters (l) are directly applied to the common transparent electrode film of an Actebuma I-IJ type liquid crystal panel, in which a large number of segment electrode films are opposed to a common transparent electrode film, and liquid crystal material is filled between these electrode films. (XGXB) was difficult to deposit.

B) Means for Solving the Problems The method for manufacturing a color filter of the present invention is to sequentially form color filters of at least two colors on a single sheet of transparent electrode, and the color filters of at least one color are The formation of the resist film includes a step of depositing a resist film on the transparent electrode, a step of removing a predetermined portion of the resist film, and a step of electrodepositing the transparent electrode in a solution containing a colorant. The process of attaching coloring agent to the exposed area from the removed part, *
#The step of peeling off the resist film on the transparent electrode after the electrodeposition process is a process consisting of 1 piece, 1 piece, and 1 piece of paper.

(e) Function: According to the method for manufacturing a color filter of the present invention, even though electrodeposition is used, a color pattern can be selectively formed on a single transparent electrode using the resist film as a mask. (It is possible to arrange many color patterns on a common transparent electrode.)

(f) Example Figures 1 (a) to (h) show manufacturing process diagrams of the method for manufacturing a color filter of the present invention, and the process for manufacturing a three-primary color filter as shown in Figure 2 according to the same figure. A specific example will be explained in detail. First, a transparent electrode film (2) made of ITO is formed on one substrate (1) of the liquid crystal panel (Fig. 1 (2)).
). Note that one substrate (1) is provided with this single transparent electrode film (2), and the other substrate is provided with a large number of segment electrode films connected to switching transistors in a matrix in segment units. By interposing a liquid crystal substance between the two, an active matrix type liquid crystal panel is constructed. Next, a resist film is coated on the transparent electrode film (2), and patterned by exposure and development to form a resist film pattern (■) in which the resist film is removed from the segment location where the red filter is to be placed. (Fig. 1(b)). Thereafter, electrodeposition is performed using the transparent electrode film (2) as a positive electrode and the counter electrode (N) as a negative electrode in an aqueous polymer resin solution in which a red pigment is dispersed, for example, in an aqueous solution of melanin resin to which a carboxyl group has been added. Transparent mold m of the exposed area from the resist film pattern gloss
(A red filter (R) consisting of a polymer resin film mixed with a red pigment is deposited on the surface of 21 (Fig. 1 (C)
). At this time, since the transparent electrode film (2) is composed of one sheet,
Since it is controlled by a potential difference of, for example, 30V with this electrode film (2), the thickness of this film is uniform, for example, about 2 μm.

Next, 20 mm of the substrate (1) is peeled off at a temperature of 200 DEG C. in an electric furnace (FIG. 1 (ψ)).

Transparent electrode (2) with red filter (R) formed in this way
On the top, a resist film is applied, exposed, and developed in the same manner as in the previous case to obtain a glossy resist film pattern that will serve as a mask for electrodeposition of the green filter (G) (Fig. 1 (C)).
. At this time, in the resist film pattern (to), the resist film at the segment location of the already formed red filter (R) and the segment location where the green filter (G) is to be formed has been removed. Thereafter, the same electrodeposition process as described above is performed, but the pigment in this case is a green pigment, and a green filter (G) made of a polymer resin film containing this green pigment is placed on the exposed part of the transparent electrode (21). The electrodeposition voltage at this time is the same voltage as when forming the red filter (R), so the green filter 0 is further deposited on the red filter (R) that has already been formed. There is no risk that the green filter (G) will be precipitated and formed.After the green filter (G) is subjected to the same heating and drying treatment as described above, the resist film pattern (2) is peeled off (FIG. 1(g)).

Finally, in the exposed segment on the transparent electrode (2), 0 has already been formed on the color filters of the other two of the three primary colors, so these filters (R) (G)
There is no need for a resist film pattern since it acts as a mask.

In the above embodiments, pigments were used as coloring agents in the electrodeposition process, but the present invention is not limited to this, and dyes or the like may also be used.

In addition, there are two types of pigments: atomite-based pigments and organic-based pigments. In the case of organic pigments, if they are ionized in a suitable solvent, polymers as a carrier for the above-mentioned dispersed pigments can be used. No resin solution is required.

(G) Effects of the Invention According to the method for manufacturing a color filter of the present invention, a color filter can be selectively formed on a single transparent electrode using a resist film as a mask, even though the electrodeposition method is used. It becomes possible to arrange many color patterns on a common transparent electrode without separating them. Therefore, the electrodeposition voltage can be kept constant by using a common transparent electrode that does not have any difference, and it is possible to form filters of the same color with a uniform thickness, and as a result, there is no fluctuation in light transmittance. Furthermore, since each color filter can be formed successively, the gap between different color filters can be eliminated, and a color filter without light leakage can be realized.

Therefore, such a color filter can be employed in an active matrix type liquid crystal color television panel in which a color filter is formed on a common transparent electrode that is not separated, and high-quality display images can be realized due to the above-mentioned advantages. .

[Brief explanation of the drawing]

Figures 1 (λ) to (h) are cross-sectional views showing the manufacturing method of the color filter of the present invention in the order of steps, Figure 2 is a plane pattern diagram of the color filter, and Figures 3 (a) to (e) are conventional Figures 4(2) and 4(b) are diagrams of the manufacturing process of the color filter, and Figures 4(2) and 4(b) are diagrams of electrode patterns used in conventional color filters and their essential parts. (1)...-Glass substrate, (2)...Transparent electrode, ■■
...Resist, (R)...Red filter, (C)
・Green filter, (B)...Blue filter.

Claims (1)

[Claims] 1) A method for manufacturing a color filter in which color filters of two or more colors are sequentially formed on a single transparent electrode, wherein at least one color filter is formed by forming a resist film on the transparent electrode. a step of depositing a predetermined portion of the resist film; a step of electrodepositing the transparent electrode in a colorant-containing solution, and adhering the colorant to the portion exposed from the removed portion of the resist film; A method for manufacturing a color filter, characterized in that it is formed in the following steps: a step of peeling off the resist film on the transparent electrode after the electrodeposition treatment.