JPH08146406A - Production of substrate with color filter for liquid crystal display device - Google Patents

Abstract

PURPOSE: To assure the connection of electrodes of a first layer and electrodes of a second layer and to prevent the generation of non-lighted pixels by forming the sheet-like electrodes having a two-layered structure on the inner side of a substrate constituting a liquid crystal cell. CONSTITUTION: The glass substrate is provided with through-holes 2 at the time of forming the first layer of the sheet-like transparent electrodes 1a thereon. The substrate is provided with a resist 3 for forming contact holes so as to cross a part of these through-holes 2 and is formed with color filters 4 from above this resist. The resist 3 is removed and the contact holes 5 are formed. Further, the second layer of the sheet-like transparent electrodes 1b are formed from above the same. The first layer of the transparent electrodes 1a and the second layer of the transparent electrodes 1b are connected through the contact holes 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a substrate with a color filter for a liquid crystal display device, in which a two-layer sheet-like electrode having a color filter inside is formed on the inner surface of a substrate constituting a liquid crystal cell. It is about.

[0002]

2. Description of the Related Art In a simple matrix driving type liquid crystal color display device, it is necessary to provide a sheet-like transparent electrode for driving a liquid crystal on a color filter in order to improve display performance. Further, in order to increase the duty ratio of driving the liquid crystal, it is required to make the sheet resistance of the transparent electrode as small as possible.

In order to meet the above requirements, it has been proposed, for example, as shown in FIG. 8, to sandwich a color filter between sheet-like electrodes having a two-layer structure, and connect the color filters through contact holes.

That is, first, a sheet-shaped transparent electrode 1a of a first layer is formed on a glass substrate (not shown) ((a) of FIG. 8), and a resist 3 for forming a contact hole is provided thereon (FIG. 8). 8 (b)). Then, after the color filter 4 is formed thereon (FIG. 8C), the resist 3 is removed to form the contact hole 5 (FIG. 8D). Next, the sheet-like transparent electrode 1b of the second layer is formed from the above ((e) of FIG. 8).

In the liquid crystal cell having the above structure,
The transparent electrode 1b on the upper part of the color filter 4 is electrically connected to the lower transparent electrode 1a through the contact hole 5, and the two layers of transparent electrodes 1a and 1b are connected in parallel. Even if the sheet resistance of the upper transparent electrode 1b is not lowered, the apparent resistance value becomes low by using an ITO film or the like having a low resistance value for the lower transparent electrode 1a, so that it is about two layers. You can

[0006]

However, in the substrate with a color filter for a liquid crystal display device manufactured as described above, connection failure occurs in the contact hole 5 as in the portion A shown in FIG. 8 (f). Part may occur,
In this case, the two layers of transparent electrodes 1a and 1b have a poor connection, and an appropriate drive voltage is not transmitted to the upper transparent electrode 1b in that portion, and as a result, a non-lighted portion occurs in the display section. There is.

That is, in the above manufacturing method, since the contact hole 5 is formed by making a hole with the resist 3 when the color filter 4 is electrodeposited, the cross-sectional shape of the color filter 4 from which the resist 3 is removed is changed. As shown in FIG. 8, the color filter 4 has an inverse slope shape.
When the ITO film or the like to be the transparent electrode 1b is formed thereon by the sputtering method, the inside of the contact hole 5 is not sufficiently formed, resulting in the connection failure as described above.

The present invention has been made by paying attention to the above problems, and is for a liquid crystal display device in which a connection between two layers of sheet-like electrodes is ensured and non-lighted pixels are not generated. It is an object of the present invention to provide a method for manufacturing a substrate with a color filter.

[0009]

A method for manufacturing a substrate with a color filter for a liquid crystal display device according to the present invention is a two-layer sheet-shaped substrate in which a color filter is interposed inside the substrate forming a liquid crystal cell. In a method for manufacturing a substrate with a color filter for forming electrodes, a through hole is provided in a first sheet-like electrode formed on the substrate, and a resist for forming a contact hole is formed so as to cover a part of the through hole. Is formed, a color filter is formed thereon, the resist is removed to form a contact hole, and a second sheet-shaped electrode is further formed thereon to form the first electrode through the contact hole. The sheet-like electrode and the second sheet-like electrode are connected.

[0010]

In the method for manufacturing a substrate with a color filter for a liquid crystal display device according to the present invention, a resist for forming a contact hole is formed so as to cover a part of the through hole provided in the first sheet-shaped electrode on the substrate. Since the color filter is formed, the cross-sectional shape thereof becomes a slope when the color filter is formed, and the second sheet-shaped electrode formed on the upper side of the color filter is reliably connected to the first sheet-shaped electrode.

[0011]

1 is a perspective view showing an embodiment of the present invention, and the same reference numerals as those in FIG. 8 indicate the same constituent elements. 2 to 7 show various examples of the contact hole structure. In each drawing, (a) is a plan view, (b) is a longitudinal sectional view thereof, and (c) is a transverse sectional view thereof.

In this embodiment, when the contact hole 5 for connecting the two layers of transparent electrodes 1a and 1b sandwiching the color filter 4 is formed, the cross-sectional shape thereof is made into a slope shape to form a two-layer transparent electrode. The connection between 1a and 1b is ensured. Specifically, as shown in part B of FIG. 2C, when the color filter 4 is formed on the ITO stripe pattern (transparent electrode 1a) by the electrodeposition method, the color filter is oriented in the direction of the end face of the pattern. It is known that 4 protrudes, and the fact that the cross section of this portion has a slope shape is used.

It is an important point of this embodiment to create a slope-shaped color filter cross section inside the contact hole by forming a slit-shaped hole in the transparent electrode of the first layer using the above principle. There is. Below, Figure 1
A process of forming a new contact hole will be described.

As shown in FIG. 1A, a glass substrate (not shown) on which an ITO film having a sheet resistance of about 10 Ω / cm ² is formed as a first sheet-shaped transparent electrode 1a of the first layer is formed into a stripe shape by a photolithography method. Pattern. At that time, the photomask is designed so that a through hole (slit-shaped hole) 2 having a width of about 20 μm is formed in a portion corresponding to the space portion of the opposing side pattern.

In FIG. 1B, a resist 3 for forming a contact hole is formed by photolithography so as to cover a part of the through hole 2 while straddling it. Here, it is formed so as to straddle one side of the through hole 2.

In FIG. 1 (c), the color filter 4 is formed by the electrodeposition method while the resist 3 for forming the contact hole is attached. At this time, the cross section on the opposite side of the through hole 2 without the resist 3 has a gentle slope shape as shown in the figure, with the color filter 4 protruding.

(D) In FIG. 1D, after the color filter 4 is main-baked at 250 ° C. for 2 hours, the resist 3 is removed with a caustic soda to form the contact hole 5. As a result, a portion where the transparent electrode 1a of the first layer is exposed from below the color filter 4 is formed.

(E) In FIG. 1E, an ITO film to be the second sheet-shaped second transparent electrode 1b is formed on the color filter 4 by a sputtering method. At this time, the transparent electrode 1a of the first layer and the transparent electrode 1b of the second layer, which are exposed from the bottom of the color filter 4, are connected through the upper surface of the color filter 4 having a slope-shaped cross section.

After that, the second layer transparent electrode 1b is patterned by stripes by photolithography so as to be in parallel with the first layer transparent electrode 1a, whereby the formation of the contact hole 5 of this embodiment is completed.

In this way, by connecting the transparent electrode 1a of the first layer and the transparent electrode 1b of the second layer through the contact hole 5, the connection between the transparent electrodes 1a and 1b of the two layers is ensured. Become. Therefore, it is possible to stably manufacture a simple matrix type liquid crystal display device in which no non-lighted pixels are generated.

Although the structure of the contact hole 5 is shown in FIGS. 2 to 7, the color filter 4 is actually used.
Is about 1 μm, and the lateral width of the sloped portion of the color filter 4 is about 5 μm. That is,
This part has a gentle slope with an aspect ratio of 1: 5.

In the method shown in the conventional example, since the connection between the two layers of electrodes 1a and 1b is made using the back side of this sloped portion (reverse sloped portion), the non-lighted pixel The occurrence cannot be completely prevented. Further, in the method of the conventional example, when the thickness of the color filter 4 exceeds the height of the resist 3 for forming the contact hole, the resist 3 is insufficiently removed. An opening will be provided. However, this method has a problem that it is very weak in side etching when patterning the second-layer transparent electrode 1b.

In the present invention, by adopting the structure shown in FIGS. 2, 3, 5, and 7, for example, the opening is necessarily on the inner side of the upper part of the pattern, and a structure resistant to side etching can be obtained. . Further, by adopting the structure shown in FIGS. 2 to 5 and 7, even if a connection failure occurs in a part of the contact holes 5, the drive voltage is transmitted through the adjacent contact holes 5 in the vicinity. Therefore, it is possible to more completely prevent the generation of non-lighted pixels.

FIG. 2 shows an example in which the resist 3 is provided so as to straddle one side of the slit-shaped through hole 2 to form the contact hole 5, and FIG. 3 shows the resist 3 as two semicircular through holes. FIG. 4 shows an example in which the contact hole 5 is formed by covering both sides of the hole 2, and FIG. 4 shows an example in which the resist 3 is provided outside the two semicircular through holes 2 to form the contact hole 5. There is.

Further, FIG. 5 shows an example in which the contact hole 5 is formed by providing the resist 3 so as to cover both sides at the central portion of the slit-shaped through hole 2, and FIG. 6 shows the same from both ends of the slit-shaped through hole 2. An example in which two resists 3 are provided on the outer side to form the contact holes 5, and FIG. 7 shows an example in which the resist 3 is provided so as to straddle one side of the central portion of the U-shaped through hole 2 to form the contact holes 5, respectively. Shows.

[0026]

As described above, according to the present invention, the contact hole is formed by providing the resist so as to straddle a part of the through hole formed in the sheet-shaped electrode of the first layer, and thus the color filter. When it is formed, its cross-sectional shape becomes a slope shape, the connection between the two layers of sheet-like electrodes is made reliable, and it is possible to stably manufacture a liquid crystal display device in which unlighted pixels do not occur. There is an effect that.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing another structure example of a contact hole.

FIG. 3 is an explanatory view showing another structure example of a contact hole.

FIG. 4 is an explanatory view showing another structure example of a contact hole.

FIG. 5 is an explanatory diagram showing another example of the structure of the contact hole.

FIG. 6 is an explanatory view showing another structure example of the contact hole.

FIG. 7 is an explanatory view showing another structure example of the contact hole.

FIG. 8 is a perspective view showing a conventional example.

[Explanation of symbols]

 1a Transparent electrode 1b Transparent electrode 2 Through hole 3 Resist 4 Color filter 5 Contact hole

Claims (1)

[Claims] 1. A method of manufacturing a substrate with a color filter, wherein a two-layer sheet-shaped electrode having a color filter inside is formed on the inner surface of a substrate constituting a liquid crystal cell. A through hole is provided in the sheet-shaped electrode of, a resist for forming a contact hole is formed so as to cover a part of the through hole, a color filter is formed on the resist, and then the resist is removed to make contact. A hole is formed, a second sheet-shaped electrode is formed on the hole, and the first sheet-shaped electrode and the second sheet-shaped electrode are connected through the contact hole. A method for manufacturing a substrate with a color filter for a liquid crystal display device.