JPH05333329A - Formation of electrodeposition type color filter - Google Patents

Abstract

PURPOSE:To decrease the number of stages and process time by forming the electrodeposition type color filter of a color liquid crystal display device in such a manner that the large effective utilization area of glass substrates can be taken in the method for formation of the color filter. CONSTITUTION:Masking parts 12a to 12c having opening holes 11 a 11c shifted in positions by respective colors; R (red), G (green), B (blue) on transparent electrodes of ITO formed on the glass substrates are provided and silver paste is applied to silver paste lines 13a to 13c by each color to short circuit the respective transparent electrodes 1. Electrodeposition is executed by selectively connecting the silver paste of the respective colors to the electrodes for electrodeposition, by which the color filters of the respective colors are successively electrodeposited and formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an electrodeposition type color filter in a manufacturing process of a color liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, when a color filter is formed on a transparent electrode of an LCD or the like by an electrodeposition method, the length of the electrode terminal of the transparent electrode is formed in multiple stages for each color and the electrode terminal for each color is formed by silver paste or the like. Are selectively short-circuited to perform electrodeposition to sequentially form color filters of each color.

3 and 4 are views showing the principle of forming a color filter by such an electrodeposition method.

First, as shown in FIG. 3 (a), a polymer resin containing a pigment of a predetermined color in water and an organic solvent is placed in an electrodeposition tank in which an anode plate and a cathode plate are arranged. Put it in.
At this time, the polymer resin has a large number of carboxyl groups and is neutralized with an organic amine in a solvent to form a salt.
Then, as shown in FIG. 3 (b), when a DC power source is connected to the anode plate and the cathode plate, the polymer resin neutralized into a salt is ionized in water to be in a dissociated state, resulting in an electrochemical reaction. On the electrode. As a result, the color filter of the predetermined color is formed. The precipitation mechanism at this time is represented by the following reaction formula.

2H ₂ O → 2OH + 2H + 2e 2OH → H ₂ O + O 2 O → O ₂ ↑ R-COO + H → R-COOH That is, the above reaction shows an anion electrodeposition type deposition mechanism. FIG. 4A and FIG. 4B show how the polymer resin containing the pigment is deposited.

Next, based on the above principle, R (red), G
A case of manufacturing color filters of the three primary colors of (green) and B (blue) will be described.

In this case, as shown in FIG. 5, the outermost end (electrode lead-out portion for electrodeposition) of the transparent electrode made of, for example, ITO on a glass substrate has three stages. Then, first, as shown in FIG. 5A, a silver paste is applied so as to short-circuit the outermost transparent electrode for red (the electrode of R shaded), and electrodeposition is performed to make the first color. An R color filter is formed.

Next, after temporarily drying the color filter of the first color to form an insulating film, as shown in FIG.
A silver paste is applied so as to short-circuit the green transparent electrode for the green color (the G electrode with the mesh) and electrodeposition is performed to form a G color filter for the second color. At this time, the electrode terminal for R of the first color is not electrodeposited because the color filter is already an insulating film. Hereinafter, the third color B color filter is similarly formed. FIG. 6 is a cross-sectional view taken along the line AA of FIG. 5B, showing how the above-described color filter is formed.

Here, a drive circuit connecting portion for connecting to a liquid crystal drive circuit (not shown) for driving liquid crystal after forming a liquid crystal cell using the color filter substrate formed as described above is 1 Masking is performed before the color filter of the third color is formed, and the transparent electrode of the drive circuit connecting portion is prevented from being electrodeposited to form the color filter of the third color. Therefore, by removing the masking portion after electrodeposition, the drive circuit connecting portion formed of the transparent electrode is not electrodeposited.

When forming a liquid crystal cell, the liquid crystal is formed so that the liquid crystal is injected into the portion corresponding to the effective display portion of the transparent electrode, and the unnecessary electrodeposition electrode extraction portion is cut off.

In addition to the above-mentioned color filter forming method, a masking portion having a step of a predetermined length for each color is provided on the electrode terminal of the electrodeposition substrate, and the electrode terminal is short-circuited at each stage to electrodeposition. The inventors of the present invention have proposed a method for sequentially forming color filters of each color by performing the above (Japanese Patent Application No.
-301142).

This color filter forming method enables chip-on-glass, and as shown in FIG. 7, the first electrode, the second color, and the third color have steps of a predetermined length at the end of the transparent electrode 1. The masking portions 2 and 3 described above are provided, and silver paste, which is a conductive material, is applied to each stage of the masking portions to sequentially form color filters of each color.

At this time, first, silver paste is applied to both the first lead portion C1 of the lead area C and the short lead portion D1 of the first color so as to be substantially orthogonal to the transparent electrode 1, and the α electrodeposition lines 4 and β are formed. The electrodeposition line 5 is formed. And FIG.
As shown in, the lead portion C1 of the first color (α electrodeposition line 4) is connected to the anode side of the DC power supply 6, and the short lead portion D1 (β electrodeposition line 5) of the first color and the counter electrode 7 are connected to the cathode side. And voltage is applied to perform electrodeposition of the first color. At this time, the first color short lead portion D1 of the β electrodeposition line 5 has the same potential as the counter electrode 7, that is, the transparent electrode of the first color is covered with the masking portion 3, and the transparent electrodes of the second and third colors are β.
Since it is connected by the electrodeposition line 5 and the β electrodeposition line 5 has the same potential as the counter electrode 7 which is an anode,
The transparent electrodes of the first and third colors are not electrodeposited, and only the transparent electrodes of the first color are electrodeposited and colored.

In FIG. 7, I is an electrodeposition electrode extraction portion, II is a drive circuit connection portion, and III is an effective display portion (electrodeposition colored portion). Further, in FIG. 8, 8 is an electrodeposition tank, and 9 is an electrode terminal.

[0015]

By the way, in the conventional method of forming the color filter of the LCD device as described above, for example, in the method of making the length of the transparent electrode multistage for each color, the drive circuit connection of the transparent electrode is performed. Since it is necessary to arrange the electrode for electrodeposition on the outer side of the portion, the effective use area of the glass substrate is reduced accordingly, and there is a problem that the cost is increased particularly in the case of multi-chambering.

Further, the method of applying masking in multiple stages has an excellent effect that the effective use area of the glass substrate can be made large, but the application of the conductive material such as silver paste and the drying of each color can be performed. Both steps are required, and even when the non-electrodeposited portion has the same potential as the counter electrode, the conductive material needs to be applied for each color, and the number of steps increases.

The present invention has been made by paying attention to the above-mentioned problems, and it is possible to make the effective use area of the glass substrate larger, reduce the number of steps, and shorten the step time. It is an object of the present invention to provide a method of forming a possible electrodeposition type color filter.

[0018]

According to the method of forming an electrodeposition type color filter of the present invention, a plurality of color filter ITs are used.
In a method of forming a color filter for each color on a transparent substrate on which transparent electrodes such as O are formed by an electrodeposition method, a masking portion having openings that are misaligned for each color on the transparent electrode of the transparent substrate. Is provided, and transparent electrodes are short-circuited for each opening hole for each color to selectively perform electrodeposition,
The color filters of the respective colors are sequentially formed by electrodeposition.

Further, at the time of the electrodeposition, the counter electrode and the transparent electrode which is not electrodeposited are made to have the same potential and electrodeposition is performed.

[0020]

In the method for forming the electrodeposition type color filter of the present invention, since the transparent electrode is provided with the masking portion having the opening for electrodeposition to perform electrodeposition, it is necessary to specially provide the electrodeposition electrode extraction portion. Therefore, the effective use area of the glass substrate can be increased accordingly. Moreover, the electroconductive material for electro-deposition is applied only once, and the drying is also required only once.

[0021]

FIG. 1 is a diagram showing an embodiment of the present invention,
FIG. 8 shows a process of forming color filters of three primary colors of R, G, and B in an LCD device using the chip-on-glass technique as in FIG. 7. In the figure, reference numeral 1 denotes an ITO transparent electrode formed on a transparent glass substrate. On the transparent electrode 1, there are openings 11a,
Masking portions 12a, 12b having 11b, 11c,
12c is provided. Reference numerals 13a, 13b and 13c are silver paste lines to which silver paste is applied independently for each of the opening holes 11a, 11b and 11c for each color.

FIG. 2 is a plan view of the glass substrate 14 on which the transparent electrode 1 is formed, and FIG. 1 is an enlarged view of the masking portion X of FIG.

Next, a method for forming a color filter according to this embodiment will be described. First, as shown in FIG. 1, the above-mentioned opening hole 11 is formed in the drive circuit connecting terminal portion of the transparent electrode 1.
Masking portions 12a, 12 having a, 11b, 11c
b, 12c, that is, a perforated resist film having a step for each color is formed. Next, a silver paste is applied on this along the lines 13a, 13b, 13c to form an electrodeposition film on the transparent electrode 1. And the opening hole 11 for each color
The transparent electrode 1 is short-circuited for each of a, 11b, and 11c to selectively perform electrodeposition, and the color filters of each color are sequentially electrodeposited.

The method of forming the color filter has been described above. Next, details of a specific forming process will be described step by step.

(A) First, I is determined by the photolithography method.
The glass substrate 14 with TO is etched to form the transparent electrode 1.

(B) As shown in FIG. 1, a photoresist film is formed as masking portions 12a, 12b, 12c.

(C) Next, the photoresist film is baked at a temperature of 150 ° C. to 300 ° C. By this process,
The dissolution of the photoresist film by the solvent contained in the silver paste in the next step is prevented.

(D) As shown in FIG. 2, the silver paste is applied to each of the silver paste lines 13a, 13b, 13c independently. Then, in order to remove the solvent of the silver paste, it is dried at a temperature of about 40 ° C. to 80 ° C. for about 30 minutes.

(E) With respect to the glass substrate manufactured as described above, an anode is connected to the silver paste in the silver paste line 13a, a cathode is connected to the counter electrode, and the glass paste is immersed in the electrodeposition tank. Then, a DC voltage is applied between the anode and the cathode for electrodeposition to form a color filter for the first color.

(F) Next, it is washed with water and dried, and thereafter, as in (e), the anode is connected to the silver paste in the silver paste line 13b, and a DC voltage is applied to carry out electrodeposition to carry out the second color filter. To form. Then, after washing with water and drying, a third color filter is formed in the same process.

The color filters of the three primary colors of R, G, and B can be formed as described above, but as another method in the above steps (e) and (f), a silver paste line is applied to a glass substrate. When the anode is connected to any one of the silver pastes 13a, 13b, and 13c, the cathode is connected to the remaining two lines of silver paste to perform electrodeposition, and the remaining electrodeposition is similarly performed after washing and drying. You may do it. Also, the order of electrodeposition, that is, the silver paste lines 13a, 13
The selection order of b and 13c is not limited to the above example, and the selection order can be arbitrary.

The resist as a masking material usually has a poorer adhesion to the substrate on the base glass as compared with ITO, and peeling of the masking material immediately causes electrodeposition short-circuit failure. Therefore, as shown in FIG. 1, the masking portion 12a,
It is preferable that the edges of the opening holes 11a, 11b, and 11c of the holes 12b and 12c be placed on ITO having good adhesion.

Here, in the above-mentioned forming method, the selectivity of each color for forming the color filter by applying the electrodeposition voltage is given not by the step difference in the length of the electrode end of the transparent electrode but by the masking. The effective use area of the glass substrate can be increased. Moreover, since the masking pattern is a perforated pattern for each color line, there is no need to specially provide the electrodeposition electrode lead-out portion on the transparent electrode, and it can be used as the drive circuit lead-out portion, and the effective use area of the glass substrate can be improved. Can be made large, and since there is no limitation for electrodeposition, the shape of the electrode end of the transparent electrode can be freely set.

Further, as shown in FIG. 2, the silver paste can be applied at the same time, and the silver paste lines 13a, 13 can be applied.
The conductive material may be applied to b and 13c only once, and may be dried once. Therefore, the number of steps is reduced and the process time can be shortened.

Further, since the counter electrode and the transparent electrode which is not electrodeposited can be electrodeposited at the same time during electrodeposition, the dye of the color filter by electrodeposition adheres to another non-electrodeposited substrate. Can be completely prevented. Also in this case, the steps of applying and drying the silver paste are required only once.

[0036]

As described above, according to the present invention, a masking portion having openings that are misaligned for each color is provided on a transparent electrode, and the transparent electrode is short-circuited for each color and the transparent electrode is selected. Since the electrodeposition is performed selectively, it is not necessary to provide the electrodeposition electrode extraction portion on the transparent electrode, the effective use area of the glass substrate can be made larger, and the shape of the transparent electrode end portion can be freely set. There is an effect that you can.

Further, since the conductive material for electrodeposition is applied only once and the drying step is also required only once, the number of steps can be reduced and the process time can be shortened.

Furthermore, by setting the counter electrode and the non-electrodeposition electrode at the same potential during electrodeposition, it is possible to completely prevent the dye due to electrodeposition from adhering to another electrodeposition substrate.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a plan view of a glass substrate on which the transparent electrode of FIG. 1 is formed.

FIG. 3 is an explanatory diagram showing a principle of forming a color filter by an electrodeposition method.

FIG. 4 is an explanatory diagram showing the principle of forming a color filter by an electrodeposition method.

FIG. 5 is an explanatory diagram showing a conventional example.

6 is a sectional view taken along line AA of FIG.

FIG. 7 is an explanatory diagram showing another conventional example.

FIG. 8 is a plan view showing the arrangement of electrodes.

[Explanation of symbols]

 1 Transparent electrodes 11a, 11b, 11c Opening holes 12a, 12b, 12c Masking part

Claims (2)

[Claims] 1. A method for forming a color filter in which a plurality of color filters are formed for each color on a transparent substrate on which a transparent electrode such as ITO is formed by an electrodeposition method, wherein each color is formed on the transparent electrode of the transparent substrate. Another feature is that a masking portion having misaligned opening holes is provided, transparent electrodes are short-circuited for each opening hole for each color, and selective electrodeposition is performed, and color filters for each color are sequentially formed by electrodeposition. Method for forming electrodeposition type color filter. 2. The method for forming an electrodeposition type color filter according to claim 1, wherein the electrodeposition is carried out by equipping the counter electrode and the transparent electrode which is not electrodeposited at the same potential during electrodeposition.