JPH01158401A - Formation of color filter - Google Patents

Abstract

PURPOSE:To enable complete black matrix formation by insulating an area other than display electrodes and forming color filter layers on the display electrodes by an electrodepositing method, and forming light shield layers in other areas. CONSTITUTION:Plural transparent electrodes 2 are formed on a transparent insulating substrate 1 and then an insulating film 5 is formed over the entire surface of the transparent insulating substrate 1 including the transparent electrodes 2. Then the insulating film 5 is removed selectively to expose the display electrode parts of the transparent electrodes 2 and the color filter layers 3 are formed by electrodeposition and set; and then the insulating film 5 is removed to form the color filter layers 3 on the display electrode parts. Then black or dark color light shield layers 6 are formed again by electrodeposition at the parts where the insulating film is removed. Consequently, a complete black matrix is formed.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a method for manufacturing a color filter used in a display panel, and an object thereof is to make it possible to form a complete black matrix that also serves as a spacer without complicating the manufacturing process. For the purpose, a plurality of strip-shaped transparent electrodes are formed on a transparent insulating substrate, an insulating film is formed to cover other parts of the transparent electrodes except for the display electrode part, and then the above-mentioned electrodes are formed by electrodeposition. forming a color filter layer on the exposed portion of the transparent electrode, then removing the insulating film to expose the surface of the underlying transparent electrode;
A light-shielding layer is formed on the exposed surface of the transparent electrode by electrodeposition, then a photosensitive light-shielding resin is applied, and back exposure is performed from the back surface of the transparent insulating substrate using the color filter layer and the light-shielding layer as a mask. After applying this, an unexposed portion of the photosensitive resin is removed to form a black stripe in the gap between the transparent electrodes.

[Industrial application field]

The present invention relates to a method of manufacturing a color filter used in a display panel.

[Conventional technology]

As a method for manufacturing color filters used in liquid crystal display devices, etc., it has advantages such as a simple manufacturing process.
Electrodeposition method is attracting attention.

On the other hand, in order to improve the display quality of liquid crystal panels, especially the contrast, it is becoming necessary to use a black matrix that covers areas other than the display electrode portion with a light-shielding film.

In the conventional manufacturing method using the above electrodeposition method, a color filter layer is formed in a desired area by electrodeposition method, and then a photosensitive light-shielding resin is applied to the entire surface, and the color filter layer is used as an exposure mask on the back side. Exposure was performed to form a light shielding layer in areas other than the color filter layer.

The conventional manufacturing method described above is shown in FIGS. 3(a) to 3(d).

In the figure, l is a transparent insulating substrate such as a glass substrate,
2 is a transparent electrode made of a transparent conductive film such as indium oxide (ITO), 3 is a color filter layer formed by electrodeposition, and 4 is a light shielding layer made of photosensitive resin.

As shown in (a), a transparent electrode 2 and R, G, B color filter layers 3 are laminated on a transparent insulating substrate 1, and these are patterned as desired.

Next, as shown in (b), a photosensitive light shielding layer 4 is formed, and this is exposed to ultraviolet light from the back side of the transparent insulating substrate 1. In this step, since the color filter layer 3 blocks the ultraviolet rays necessary for exposure, only the portion of the light shielding layer 4 where the color filter layer 3 is not present is exposed.

Therefore, by performing a development process, as shown in (C),
, a light shielding layer 4 is formed around each pixel on which a color filter layer 3 is formed, and this interferes as a black stripe.

However, the black stripes formed by the above conventional method,
As seen in the plan view of FIG. 3(d), a complete black matrix is not formed. That is, since each color filter layer 3 is formed by electrodeposition, the pixels of the same color must be electrically connected. Therefore, in the illustrated example, it is necessary to electrically connect the vixels arranged in the vertical direction, but the light shielding layer 4 cannot be connected in the horizontal direction.

In order to solve this difficulty, it is possible to form the light shielding layer 4 using a photolithography process before or after the formation of the color filter layer 3, but in this case, accurate mask alignment is required, and the manufacturing The process becomes complicated and productivity decreases.

In addition, when making a liquid crystal panel using these color filters, the liquid crystal gap is generally maintained by dispersing fibers or plastic balls of a certain diameter in a volatile solvent such as Freon and spraying them on the substrate surface. are doing. However, especially in active matrices in which each pixel is driven by a thin film transistor (TPT), if each pixel has a complicated structure and there are significant height differences depending on the location, there may be a large amount of spacer The gap thickness is maintained by this, and the gap thickness is the height difference between the highest part and the display electrode surface plus the spacer diameter.However, especially in TPT, etc., the highest point is a narrow pass line. In many cases, because there are few spacers located on the pass line, these spacers cannot withstand the pressure and break, and the spacers located at a lower portion dominate the gap thickness.

Furthermore, since spacers are randomly distributed, spacers located on TFTs or pass line intersections may cause short circuits due to mechanical pressure.

Conventional spacers have such problems, and in order to solve this problem, it is desirable to form spacers at predetermined positions as part of the structure of the liquid crystal display panel.
Since this requires a complicated process, nothing that can be put to practical use has yet appeared.

[Problem that the invention seeks to solve]

As described above, conventionally it has been difficult to form a perfect black matrix, and there have been problems such as deviations in gap thickness and short circuits in pass lines caused by spacers.

An object of the present invention is to make it possible to form a complete black matrix that also serves as a spacer without complicating the manufacturing process.

[Means for solving problems]

The present invention takes advantage of the fact that when there is an insulating film on a transparent electrode, no electrodeposited film is formed on that part. A color filter layer is formed by two methods, and a light shielding layer is formed in other areas.

The present invention will be explained in detail below with reference to FIG.

First, a plurality of transparent electrodes 2 are formed on a transparent insulating substrate 1, and then an insulating film 5 is formed over the entire surface of the transparent insulating substrate 1, including the top of the transparent electrode 2 [see FIG. 4(a)].

Next, the insulating film 5 is selectively removed to expose the display electrode portion of the transparent electrode 2 (see FIG. 3B).

Next, a color filter layer is formed by electrodeposition, and after curing, the insulating film 5 is removed. As a result, the color filter layer 3 is formed on the display electrode section [see FIG. 10C].

A black or dark-colored light-shielding layer 6 is again formed on the area where the insulating film has been removed by electrodeposition (see FIG. 4(d)).

Here, if the height of this light-shielding layer 6 is made to match the gap of the liquid crystal, it will directly serve as a spacer for maintaining the gap.

Thereafter, the manufacturing process may be carried out according to the conventional manufacturing method. That is, by forming the light-shielding layer 6' in the gap between the transparent electrodes 2, a complete black matrix can be produced.

In the series of manufacturing steps described above, when patterning the insulating film 5, alignment only needs to be performed in the rotational direction;
It has a large margin in the horizontal (X, Y) direction.

[For production]

The insulating film 5 has a pattern that partially covers the transparent electrode 2, and is formed by an exposure method using a mask. Thereafter, by performing electrodeposition using the insulating film 5 as a mask, a color filter layer 3 is formed on the exposed display electrode portion of the transparent electrode 2, and then a transparent The surface of the electrode 2 is exposed, and since the color filter layer 3 has a light-shielding property, if the electrodeposition method is applied again, a light-shielding layer 6 will be formed on the removal trace, and finally a photosensitive light-shielding resin is applied. When back exposure is performed, only the gaps between the transparent electrodes 2 are translucent, so only this portion of the light-shielding resin film is exposed and remains, and the other portions are removed. Therefore, a light shielding layer 6.6'' is formed in areas other than the display electrode portion, and these form a black matrix.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1(a) to 2(d) and FIG. Note that FIGS. 1(a) to 1(d) are cross-sectional views taken along the line ■-■ in FIG. 2.

[See Figures 2(a) and 3] 1 is a transparent insulating substrate such as a glass substrate, and 2 is a striped transparent electrode made of an ITO film with a sheet resistance of about 15 Ω/hole on the glass substrate 1. . After forming a plurality of striped transparent electrodes 2 in parallel in this way, about 1,000 ml of insulating material such as polyvinyl alcohol (PVA) is applied.
It is spin-coded to the thickness of a human body and hardened by heat treatment at a temperature of about 160° C. for about 1 hour.

[Axes in Figure 2), see Figure 3] Next, a resist film is formed to cover a plurality of striped regions perpendicular to the transparent electrode 2, which is indicated by the hatched line downward to the left in Figure 3, and this is used as a mask to apply oxygen. (0□) Plasma etching is performed to remove the exposed portion of the insulating film 5, and the resist film used as the mask is removed.

Through this process, as shown in the figure, a plurality of striped insulating films 5 are formed perpendicular to the transparent electrode 2. Transparent electrode 2
The surface is covered with the insulating film 5 at regular intervals.

[See Figures 2(C) and 3] Next, electrodeposition is performed using a suspension of an anionic electrodeposition material (polyester type) to form a color filter layer 3 on the exposed surface of the transparent electrode 2. Form.

Next, the insulating film 5 is removed by treatment with Ox plasma (applied power: 300 W, time: about 1 minute).

At this time, the thickness of the color filter layer decreased by about 1000 Å or less, and no change was observed in the characteristics.

[See Figures 2(d) and 3] Next, electrodeposition is performed by applying a voltage to the transparent electrode 2 in a black electrodeposition bath. No adhesion occurs, and the black light-shielding layer 6 is formed only in the area where the insulating film 5 has been removed (the part where the surface of the transparent electrode 2 is exposed).

In this step, the thickness of the light shielding layer 6 is set to a thickness d (for example, 4 to 5 μm) corresponding to the required gap thickness by controlling the applied voltage and application time, and this is used as the above-mentioned spacer.

Furthermore, by spin-coding a black photosensitive resin over the entire surface and exposing it to light from the back side of the transparent insulating substrate 1, back exposure is performed using the color filter layer and the electrodeposited layer as a mask. A light shielding layer 6' is formed in a portion where the light shielding layer 6 is not present.

As is clear from the above explanation, these two light shielding N6, 6° form a grid shape with each color filter layer 3 as an outlet,
Form a complete black matrix. Therefore, the contrast of the color liquid crystal display device is improved and a good display can be obtained.

Note that the present invention is not limited to the above-mentioned embodiment, and can be implemented with various modifications.

For example, a resist film is formed on the striped transparent electrode 2 to open the hatched portion downward to the left in FIG. The resist film is removed by plasma etching to expose the surface of the display area of the transparent electrode 2, the color filter layer 3 is formed on this exposed part by electrodeposition, and finally the back surface is formed in the same manner as in the above embodiment. The materials used in the zero-line modification in which the light shielding layer 6' can also be formed by an exposure method may be the same as in the above embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, a liquid crystal display device having good display quality can be obtained without complicating the manufacturing process.

[Brief explanation of the drawing]

Figures 1 (a) to (d) are cross-sectional views of essential parts showing one embodiment of the present invention in the order of manufacturing steps; Figure 2 is a plan view of essential parts showing the above embodiment; and Figure 3 (a).
-(B) are explanatory diagrams of conventional problems. In the figure, 1 is a transparent insulating substrate, 2 is a transparent electrode, 3 is a color filter layer, and 4, 6, and 6 degrees are light-shielding surfaces of the present invention - Example 1) Sweat surface m. Light■ Figure 3

Claims (2)

[Claims] (1) A plurality of striped transparent electrodes (2) are formed on a transparent insulating substrate (1), and an insulating film (5) covers the other parts of the transparent electrodes (2) except for the display electrode part. Next, a color filter layer (3) is formed on the exposed display electrode part of the transparent electrode by electrodeposition, and then the insulating film (5) is removed to expose the surface of the underlying transparent electrode (2). A light-shielding layer (6) is formed by electrodeposition on the exposed surface of the transparent electrode (2), and then a photosensitive light-shielding resin is applied on the transparent insulating substrate, and the transparent electrode (2) is coated with a light-shielding resin. After performing back exposure from the back surface of the insulating substrate (1) using the color filter layer (3) and the light shielding layer (6) as a mask, the unexposed portion of the photosensitive resin layer is removed and the transparent electrode ( 2) A light shielding layer (6') is formed in the gap, and a black matrix is formed by the light shielding layer (6) on the transparent electrode (2) and the light shielding layer (6') formed in the gap between the transparent electrodes (2). A method for forming a color filter, characterized by forming a color filter. (2) The method for forming a color filter according to claim 1, characterized in that the light-shielding layer (6) is formed to a predetermined thickness, and the light-shielding layer (6) also serves as a spacer.