JPH08271870A - Method for inspecting substrate for liquid crystal display device and its production - Google Patents

Abstract

PURPOSE: To remove foreign matter and obtain excellent display characteristics by forming a transparent resin layer for inspection immediately after forming a color filter layer, flattening the surface and detecting the reflection change of the foreign matter part. CONSTITUTION: The polyvinyl alcohol layer 21 higher in surface reflectance than that of the color filter layer 12 is formed by applying polyvinyl alcohol being the transparent resin for inspection on the color filter layer 12 by a spinner and drying them. Thus, since the surface is flattened and the reflection on the projecting foreign matter 20 part is more changed than that of the color filter layer 12 part, the projecting foreign matter 20 is detected by detecting the reflection changed part on the polyvinyl alcohol layer 21. Only the detected projecting foreign matter 20 part is eliminated from the polyvinyl alcohol layer 21 by a laser repair. Next, an over coat layer 13 is formed on the color filter layer where the projecting foreign matter removed part is remained as a recessed part 22 to flatten the surface of the color filter layer 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for a liquid crystal display device having a color filter, and more particularly to an inspection method and a manufacturing method for a substrate for a liquid crystal display device for detecting and removing foreign matter generated when forming a color filter layer.

[0002]

2. Description of the Related Art A color filter is formed on a glass substrate by a photolithography technique, and an overcoat layer of a transparent resin such as an acrylic resin for protecting and flattening the surface of the color filter is formed on the color filter. I
In an electrode substrate for a color liquid crystal display device, which is formed by patterning a transparent electrode made of a TO (Indium Tin Oxide) film, conventionally, a yield decrease due to mixing or adhesion of dust or foreign matter caused by the formation of a color filter layer, This is a major constraint on cost reduction.

Therefore, conventionally, in the electrode substrate forming process, after the color filter layer is formed and after the overcoat layer is formed, the detection and removal of dust and foreign matter mixed in or adhering to the color filter layer from above the overcoat layer. After that, the transparent electrode is patterned.

That is, when the electrode substrate 1 is formed, the surface of the color filter is rough, the reflectance is low, and light is diffusely reflected,
Since it is difficult to detect dust and foreign matter, the color filter layer 3 is formed on the glass substrate 2 as shown in FIG. 3A, and the overcoat layer 4 is further formed to flatten the surface.
As a result, the foreign matter 6 appears on the surface of the overcoat layer 4 as a protrusion [A] larger than it actually is, which makes it very easy to detect.

Therefore, as shown in FIG. 3B, the protrusion [A] portion on the glass substrate 2 is removed by laser repair, and then a transparent electrode is formed on the overcoat layer 4.

[0006]

Conventionally, foreign matter mixed in or attached to the color filter layer is detected from the overcoat layer after forming the overcoat layer on the color filter layer. Were removed together.

However, in such a method, the concave portion formed on the surface of the overcoat layer becomes deeper due to the removal of the foreign matter, and the protrusion [A] portion on the surface of the overcoat layer is larger than the actual foreign matter, so that the overcoat is not formed. When the protrusion [A] portion was removed so that only the flat portion of the layer surface was left, the area of the concave portion was increased.

Further, debris generated at the time of removing the foreign matter is scattered around, and the overcoat layer around the foreign matter is soiled, which hinders the flattening.

For this reason, the transparent electrode is not formed in the periphery where the foreign matter is removed, which causes a display defect or a new problem that the removed portion becomes a concave defect.

Therefore, the present invention is to eliminate the above-mentioned problems, and reliably detect dust and foreign matter generated during the formation of the color filter layer, and to form a transparent electrode without generating a new layer defect in the removed portion of the duster foreign matter. An object of the present invention is to provide a method for inspecting and manufacturing a substrate for a liquid crystal display device, which can be surely formed and can obtain good display characteristics.

[0011]

In order to solve the above-mentioned problems, the present invention provides a liquid crystal display device substrate in which a transparent electrode is formed on a color filter layer and an overcoat layer sequentially laminated on a transparent substrate, Performing a step of forming a color filter layer on a transparent substrate, a step of applying a polyvinyl alcohol resin layer on the color filter layer, and a step of detecting a foreign substance by detecting a change in reflection on the polyvinyl alcohol resin layer. It is a thing.

In order to solve the above problems, the present invention provides a liquid crystal display device substrate in which a transparent substrate is formed by sequentially laminating a color filter layer and an overcoat layer on the transparent substrate. A step of forming a filter layer, a step of applying an inspection transparent resin layer made of a material having a higher reflectance than the color filter layer on the color filter layer, and a reflection change on the inspection transparent resin layer. A step of detecting foreign matter by detecting, a step of removing the foreign matter, a step of removing the transparent resin layer for inspection after removing the foreign matter, and a step of removing the overcoat on the color filter layer after removing the transparent resin layer for inspection. The step of applying a coat layer and the step of forming the transparent electrode on the overcoat layer are carried out.

[0013]

The present invention is constructed as described above, and a foreign substance can be easily detected by applying a transparent resin layer for inspection immediately after forming a color filter layer, flattening the surface, and detecting a change in reflection of a foreign substance portion. After that, the foreign matter removal area can be made smaller than before by removing only the foreign matter portion from the transparent resin layer for inspection, and the foreign matter can be removed by applying the overcoat layer after removing the transparent resin layer for inspection. It is possible to fill the recesses formed in the portions with the overcoat layer and planarize it, and it is possible to form a good transparent electrode.

Further, when the foreign matter is removed, the fragments of the foreign matter scattered around are removed together by removing the transparent resin layer for inspection, and the overcoat layer and the transparent electrode layer are not adversely affected. The flatness can be surely achieved, and a good display without display defects can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a partial cross-sectional view of the liquid crystal display device 10. A color filter layer 12 is formed on a first glass substrate 11a which is a transparent substrate of the first electrode substrate 10a, and the color filter layer 12 is formed thereon. A first transparent electrode 14a made of ITO is patterned through an overcoat layer 13 made of an acrylic resin which is a transparent resin for protecting and flattening the first alignment film 16a.

On the second glass substrate 11b of the second electrode substrate 11b, a second transparent electrode 14b made of ITO,
The second alignment film 16b is formed.

A liquid crystal composition 18 is sandwiched between the two electrode substrates 10a and 10b facing each other with a spacer 17 interposed therebetween.

Next, the manufacturing process of the first electrode substrate 10b having the color filter layer 12 will be described with reference to FIG. First, as shown in FIG. 2A, the first glass substrate 11a
The color filter layer 12 is formed on the top by photolithography technology.
To form. Reference numeral 20 is a convex foreign substance having a diameter of 20 μm and a height of 4 μm mixed in the color filter layer 20.

Next, polyvinyl alcohol 21 which is a transparent resin for inspection is applied on the color filter layer 12 by a spinner and further dried, and as shown in FIG. 2B, it is a transparent resin layer for inspection and has a surface reflectance. Is the color filter layer 12
A higher polyvinyl alcohol layer 21 is formed. As a result, the surface is flattened and the reflection of the convex foreign matter 20 portion is changed compared to the color filter layer 12 portion. Therefore, in the subsequent surface inspection, the reflection change portion on the polyvinyl alcohol layer 21 is changed. The convex foreign matter 20 by detecting the
Will be detected.

Here, the size of the convex foreign matter 20 is the diameter 20.
If the thickness is 4 μm, the polyvinyl alcohol layer 2
The size of the reflection changed portion on 1 is enlarged to 200 μm in diameter and 6 μm in height for easy detection.
When removing 0, use a microscope or the like to remove the convex foreign matter 20.
While watching, only the portion of the convex foreign matter 20 is removed.

That is, only the portion of the convex foreign matter 20 detected as shown in FIG.
It is erased by laser repair from above. At this time, the fragments 20a of the convex foreign matter 20 scatter around, but since these adhere to the polyvinyl alcohol layer 21, after that, the polyvinyl alcohol layer 21 is melted in water, and as shown in FIG.
As shown in (d), if the polyvinyl alcohol layer 21 is removed, the debris 20a attached around the convex foreign matter removed portion will also be removed.

Next, an overcoat layer is applied on the color filter layer 12 which is left as the concave portion 22 where the convex foreign matter is removed, dried and baked to form the overcoat layer 13 as shown in FIG. 2 (e). Are formed to flatten the surface of the color filter layer 12.

Further, as shown in FIG. 2F, after patterning a first transparent electrode 14a on the overcoat layer 13, a first alignment film 16a is formed to form a first electrode substrate. Complete.

With this structure, the color filter layer 1
2 has a polyvinyl alcohol layer 21 having a large surface reflectance.
By forming the above, the convex foreign matter 2 can be easily detected by detecting the portion where the reflection on the polyvinyl alcohol layer 21 is changed.
0 can be detected.

When detecting the convex foreign matter 20, the convex foreign matter 20 is detected.
Even if the polyvinyl alcohol layer 21 rises up to the surroundings, the polyvinyl alcohol layer 21 is removed after the convex foreign matter 20 is removed.
Since it is only necessary to remove the convex foreign matter 20 from above 1, it is possible to minimize the removed portion, and there is no fear of obstructing the planarization by the overcoat layer 13 thereafter.

Moreover, since the polyvinyl alcohol layer 21 is easily soluble in water, no special device or solvent is required for its removal.

Further, the debris generated when the convex foreign matter 20 is removed is also removed together with the polyvinyl alcohol layer 21, and there is no fear of hindering the flattening of the surface as in the conventional case.

Further, since the overcoat layer 13 is formed after the convex foreign matter 20 is removed, even if the concave portion is formed in the portion where the convex foreign matter 20 is removed, it is easily filled with the overcoat layer 13, so that the surface is easily flattened. The transparent electrode is not formed unlike the conventional case, and a display defect does not occur, so that an extremely good image can be obtained, which in turn improves the yield at the time of manufacturing the electrode substrate and reduces the production cost. There are also things.

The present invention is not limited to the above-mentioned embodiment, but may be changed within the scope of the invention. For example, the material of the transparent resin layer for inspection has a high reflectance and a foreign substance. It is not limited as long as it can be removed after removing, but if it is polyvinyl alcohol, it does not require a special device or solvent when removing, and can be removed very easily with water, and further on the color filter layer. It is more suitable as a transparent resin layer for inspection because it has less residue.

Further, the method of forming the color filter layer, the method of removing foreign matters, the material of the overcoat layer and the like are arbitrary.

[0031]

As described above, according to the present invention, by applying the transparent resin layer for inspection having a high reflectance on the color filter layer, it is easy to remove dust or foreign matter mixed in or attached to the color filter layer. Can be detected.

Moreover, since the transparent resin for inspection is removed after removing dust and foreign matter, only the foreign matter needs to be removed, the foreign matter removal area can be made smaller than before, and the foreign matter removal portion can be removed when the overcoat layer is applied thereafter. It is possible to fill it surely.

Further, although the fragments of the foreign matter scattered at the time of removing the foreign matter also adhere to the transparent resin for inspection, they are removed together with the transparent resin for inspection, so that there is no fear of affecting the color filter layer and the overcoat layer.

By applying the overcoat layer after removing the transparent resin for inspection, the concave portions formed in the foreign substance removed portion can be easily filled, and the overcoat layer can be surely flattened. The upper transparent electrode can be reliably formed over the entire surface, a liquid crystal display device having extremely good display characteristics can be obtained without causing a missing or a concave defect of the transparent electrode, thereby improving the manufacturing yield. Also, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a liquid crystal display element of an embodiment of the present invention.

FIG. 2 shows a manufacturing process of a first electrode substrate according to an embodiment of the present invention, (a) is an explanatory view showing a state where a color filter layer is formed, and (b) shows a state where a polyvinyl alcohol layer is formed. Explanatory drawing shown, (c) is an explanatory view showing a state in which convex foreign matter has been removed, (d) is an explanatory view showing a state in which the polyvinyl alcohol layer has been removed, and (e) is an explanation showing a state in which an overcoat layer has been formed. FIG. 6F is an explanatory diagram showing a state in which the first transparent electrode and the first alignment film are formed.

3A and 3B show a conventional foreign matter detection and removal step, and FIG. 3A is an explanatory view showing a state in which an overcoat layer is applied;
FIG. 4 is an explanatory diagram showing a state in which the protrusion [A] on the surface of the overcoat layer is removed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device 10a ... 1st electrode substrate 11a ... 1st glass substrate 12 ... Color filter 13 ... Overcoat layer 14a ... 1st transparent electrode 20 ... Convex foreign material 21 ... Polyvinyl alcohol layer

Claims (2)

[Claims] 1. A substrate for a liquid crystal display in which a transparent electrode is formed on a transparent substrate on which a color filter layer and an overcoat layer are sequentially laminated, a step of forming a color filter layer on the transparent substrate, and A method for inspecting a substrate for a liquid crystal display device, comprising: a step of applying a polyvinyl alcohol resin layer on the filter layer; and a step of detecting a change in reflection on the polyvinyl alcohol resin layer to detect foreign matter. 2. In a substrate for a liquid crystal display device in which a transparent substrate is formed by sequentially laminating a color filter layer and an overcoat layer on the transparent substrate, a step of forming a color filter layer on the transparent substrate, A step of applying an inspection transparent resin layer made of a material having a higher reflectance than the color filter layer on the filter layer, a step of detecting a foreign substance by detecting a change in reflection on the inspection transparent resin layer, A step of removing foreign matter, a step of removing the transparent resin layer for inspection after removing the foreign matter, a step of applying the overcoat layer on the color filter layer after removing the transparent resin layer for inspection, A method of manufacturing a substrate for a liquid crystal display device, comprising the step of forming the transparent electrode on a coat layer.