JP2000039614A - Production of liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate stripe-like orientation defects and to improve display quality by executing plural times of rubbing treatments varying in rubbing angles with respect to alignment layers and making the rubbing angle of the later rubbing treatments larger than the angle of the previous rubbing treatments. SOLUTION: The first time rubbing direction A and the second time rubbing direction B are set at different directions and the rubbing treatment is first executed at the rubbing angle of 0 deg. to 10 deg. in an arrow A direction. Next, the rubbing treatment is so executed that the necessary twist angle may be obtd. in a range of 20 to 45 deg. in an arrow B direction. At the time of subjecting the color filter substrate 1 formed with columnar spacers 4 to the rubbing treatment in such a manner, the substrate is previously subjected to the rubbing treatment at the rubbing angle of 0 to 10 deg. and is then subjected to the rubbing treatment again at the angle larger than the same, by which the occurrence of the rubbing defects behind the columnar spacers 4 is obviated and the liquid crystal display panel having the good display grade may be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display panel using a substrate on which spacers are formed.

[0002]

2. Description of the Related Art FIGS. 6 to 12 show a conventional liquid crystal display panel. As shown in FIG. 6, in the liquid crystal display panel, the color filter substrate 1 and the opposing substrate 8 are opposed to each other, and are adhered to each other with a columnar spacer 4 so as to keep a constant interval, and the liquid crystal 6 is interposed between the substrates. It is constituted by.

On the color filter substrate 1, pixel portions 2 and black matrices 3 are alternately formed, and a surface thereof is provided with a flattening film 9 for smoothing the unevenness between the pixel portions 2 and the black matrix 3. To form ITO5,
An alignment film 7a for aligning the liquid crystal 6 is formed on the TO5.

Further, the liquid crystal 6 is also provided on the opposite substrate 8 in the same manner as described above.
An alignment film 7b for orienting is formed. Alignment film 7
It is necessary to perform a rubbing process on the substrates a and 7b in order to align the liquid crystal 6, and as shown in FIG. 7, a cloth is wound around the surface rotating in the direction of the arrow H while transporting the substrate in the direction of the arrow F. Rubbing is performed by rubbing with the rubbing roller 10.

The surface of the counter substrate 8 is flat, but the columnar spacers 4 are formed on the surface of the color filter substrate 1. Specifically, as shown in FIG. 8, a transparent resist used for forming red, blue, and green color filters is applied to the color filter substrate 1 to a predetermined thickness (3 to 6 μm) by a spin coater or printing. The pixel portion 2 is formed by pre-baking and evaporating the solvent.

A black matrix 3 extending in the X direction and the Y direction by the photolithography method is provided between adjacent pixel portions 2.
a and 3b are formed, and ultraviolet rays are irradiated through a photomask such that columnar spacers 4 are formed at regular intervals at the intersections of the black matrices 3a and 3b.

After development and washing, post-baking is performed to form columnar spacers 4 for keeping the distance from the opposing substrate 8 constant. An alignment film 7a is applied to the color filter substrate 1 by a spin coater or printing to a predetermined thickness (for example, 2 to 6 μm) and cured.

[0008] An orientation film 7b is also formed on the opposing substrate 8 in the same manner as described above. Incidentally, the twist angle of the liquid crystal 6 is determined by the rubbing direction of the alignment films 7a and 7b as shown in FIG. That is, the angle between the rubbing direction arrow C of the alignment film 7a of the color filter substrate 1 and the rubbing direction arrow D of the alignment film 7b of the counter substrate 8 is the twist angle α of the liquid crystal 6.

The rubbing direction and rubbing angle are as follows:
As shown in FIG. 10, the direction in which the rubbing roller 10 rubs the substrate (arrow G) is referred to as a rubbing direction, and the angle formed by the rubbing roller 10 with respect to a vertical line in the direction of travel of the substrate (arrow F) is referred to as a rubbing angle θ.

Generally, in a TFT panel, the twist angle α of the liquid crystal 6 is 90 ° counterclockwise, so that the rubbing angle θ4 of the color filter substrate 1 is 45 ° as shown in FIG.
Then, the rubbing angle of the counter substrate 8 is also 45 °.

The color filter substrate 1 and the opposing substrate 8 which have been subjected to such rubbing treatment are prepared by printing a seal resin on at least one of the substrates or applying the sealing resin to a predetermined position by a dispenser.
And the two substrates are bonded together and the sealing resin is cured. Then, the liquid crystal 6 is injected by a vacuum injection method, and the injection port is sealed with a sealing material to obtain a liquid crystal display panel.

[0012]

However, in the method of manufacturing a liquid crystal display panel as described above, since the columnar spacers 4 are formed on the color filter substrate 1 as shown in FIG. In doing so, a portion where the rubbing roller 10 does not reach the alignment film 7a around the columnar spacer 4 as a shadow of the columnar spacer 4 (arrow E).
Occurs. In addition, the rotation of the rubbing roller 10 is blocked by the columnar spacer 4, and an insufficient rubbing portion is generated from the columnar spacer 4 in the rubbing direction.

When a liquid crystal display panel is manufactured using the color filter substrate 1 having an insufficient rubbing portion as described above, in the halftone state, as shown in FIG. There was a problem that occurs.

According to the present invention, there is provided a method of manufacturing a liquid crystal display panel which eliminates an insufficient rubbing portion and eliminates a streak-like alignment defect when rubbing an alignment film after forming a spacer on a substrate. Is provided.

[0015]

A method of manufacturing a liquid crystal display panel according to the present invention is characterized in that a plurality of rubbing treatments are performed in different directions.

According to the present invention, even if a rubbing treatment is performed after forming a spacer on a substrate, an insufficient rubbing portion is eliminated, and a liquid crystal display panel having good display quality without streak-like alignment defects can be manufactured. .

[0017]

According to a first aspect of the present invention, there is provided a method of manufacturing a liquid crystal display panel, wherein a rubbing process of an alignment film formed on a first substrate is performed by removing a gap between the first substrate and a second substrate facing the first substrate. When a liquid crystal panel is manufactured by performing the rubbing process after forming the spacer holding the rubbing process, a plurality of rubbing processes with different rubbing angles are performed on the alignment film. Is set to be larger than the rubbing angle of the previous rubbing process.

According to this configuration, even if the first substrate is rubbed after the spacers are formed by performing the rubbing processes having different rubbing angles a plurality of times, an insufficient rubbing portion is eliminated. A liquid crystal display panel with good display quality without defective alignment can be manufactured.

According to a second aspect of the present invention, in the method for manufacturing a liquid crystal display panel according to the first aspect, the alignment film is treated at a rubbing angle of 0 to 10 ° and then reprocessed at a rubbing angle of 20 to 45 °. And

According to a third aspect of the present invention, in the method of manufacturing a liquid crystal display panel, the rubbing angle of the subsequent rubbing process is smaller than the rubbing angle of the previous rubbing process.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In addition, FIG.
12 that are the same as those shown in FIG.

(Embodiment) FIGS. 1 to 5 show (embodiment) of the present invention. Although the configuration of the liquid crystal display panel is almost the same as that of the above-described conventional example, in this (embodiment), a rubbing process having a different rubbing angle is performed a plurality of times, and a rubbing process performed later is performed. In that the rubbing angle is larger than the rubbing angle of the rubbing process performed first.

More specifically, as shown in FIG. 1, the first rubbing direction A and the second rubbing direction B are set to different directions, and the rubbing direction is first set in the direction of arrow A at a rubbing angle of 0 ° to 10 °. Perform processing.

In the rubbing process, the rubbing process in the above-mentioned conventional example is a portion where the rubbing roller 10 cannot reach the rubbing roller 10 due to the shadow of the columnar spacer 4 or is blocked by the columnar spacer 4 (arrow E). ) Is subjected to a rubbing treatment. That is, the portion that is not sufficiently rubbed in the second rubbing is rubbed first in the first rubbing.

When the rubbing angle at this time is 0 ° to 10 °, the rubbing roller 1
It has been confirmed that 0 has arrived and the insufficient rubbing portion as indicated by arrow E is eliminated.

The rubbing angle of the rubbing treatment is 10 °
When the value exceeds, a rubbing portion (arrow E) which is also insufficient for shading of the columnar spacer 4 is generated, and as shown in FIG. 12, when the liquid crystal display panel is formed, streak-like alignment disorder occurs.

Next, a rubbing process is performed in the direction of arrow B so as to obtain a required twist angle α in a range of 20 ° to 45 °. When the rubbing process is performed on the color filter substrate 1 on which the columnar spacers 4 are formed as described above, 0
By performing rubbing at a rubbing angle of 10 ° to 10 °, and then performing rubbing at a larger angle, a rubbing defect does not occur on the shadow of the columnar spacer 4 and a liquid crystal display panel having good display quality can be obtained. Can be Example 1 A TFT panel having a twist angle α of 90 ° in the counterclockwise direction was used, the substrate traveling speed was 40 mm / s, and the rubbing roller diameter was 20.
The rubbing treatment described below was performed under the conditions of cm, a rubbing roller rotation speed of 1200 rpm, and a pushing amount of 350 μm.

As shown in FIG. 2, the rubbing angle θ1 is set to 0.
The first rubbing treatment was performed in the direction of arrow A by setting it to 10 °. Next, as shown in FIG.
The rubbing treatment was performed in the direction of arrow B at 5 °.

The rubbing of the alignment film 7b of the counter substrate 8 was performed only once at a rubbing angle of 45 °. At least one of the color filter substrate 1 or the opposing substrate 8 that has been subjected to the rubbing process as described above is printed with a seal resin or applied to a predetermined position by a dispenser, so that the twist angle α of the liquid crystal 6 becomes 90 ° counterclockwise. The color filter substrate 1 and the opposing substrate 8 were aligned so that the two substrates were stuck together and the seal was cured.

After that, the liquid crystal 6 was injected by a vacuum injection method, and the injection port was sealed with a sealing material to produce a liquid crystal display panel. In the obtained liquid crystal display panel, the alignment film 7a around the columnar spacers 4 is sufficiently rubbed despite the rubbing treatment after forming the columnar spacers 4 on the color filter substrate 1, and the stripes from the columnar spacers 4 are formed. The liquid crystal display had good display quality without disorder of alignment in the shape.

In the above (embodiment), the TFT panel has been described, but the same effect can be obtained with the STN panel. As shown in FIG. 4, the STN panel generally has a twist angle β of the liquid crystal 6 of 220 to 270 ° clockwise.
For example, in the case of an STN panel having a twist angle of 250 ° clockwise, the color filter substrate 1 having the columnar spacers 4 is used as the first rubbing in FIG.
Rubbing angle θ1 of 0 to 10 ° as shown in
Next, as shown in FIG. 5, the rubbing angle θ3 is set to 35 ° and re-rubbing is performed.

The alignment film 7b of one counter substrate 8 is made of STN
The panel is rubbed once at a rubbing angle of 35 °. By performing such a rubbing process, the obtained S
In the TN panel, a liquid crystal display panel having good display quality without streak-like defective orientation can be obtained as described above.

In the above (embodiment), the rubbing angle of the rubbing process performed later is set larger than the rubbing angle of the rubbing process performed first, but the present invention is not limited to this, and the rubbing process performed later is not limited to this. The rubbing angle of the processing may be smaller than the rubbing angle of the rubbing processing performed before. Even with such a configuration, an insufficient rubbing portion is eliminated as in the above (embodiment), and a liquid crystal display panel having good display quality can be obtained.

[0034]

As described above, according to the method for manufacturing a liquid crystal display panel of the present invention, a plurality of rubbing treatments with different rubbing angles are performed on the alignment film, and the rubbing treatments are performed later. By making the rubbing angle of the rubbing process larger than the rubbing angle of the previous rubbing process, or making the rubbing angle of the subsequent rubbing process smaller than the rubbing angle of the previous rubbing process, the alignment film of the substrate on which the spacers are formed is formed. Even after rubbing,
The alignment film at the periphery of the spacer is also sufficiently rubbed, so that a liquid crystal display panel with good display quality without streak-like alignment defects can be manufactured.

[Brief description of the drawings]

FIG. 1 is a plan view of a color filter substrate according to an embodiment.

FIG. 2 is a diagram showing a first rubbing angle and a rubbing direction of a color filter substrate in the embodiment.

FIG. 3 is a diagram showing a second rubbing angle and a rubbing direction of a color filter substrate in the embodiment.

FIG. 4 is a diagram showing a twist angle of a liquid crystal of an STN panel in the embodiment.

FIG. 5 is a diagram showing a second rubbing angle and a rubbing direction of a color filter substrate of an STN panel in the embodiment.

FIG. 6 is a sectional view of a conventional liquid crystal display panel.

FIG. 7 is a diagram showing a rubbing step of a color filter substrate.

FIG. 8 is a plan view of a color filter substrate.

FIG. 9 is a diagram showing a twist angle of a liquid crystal of a TFT panel.

FIG. 10 is a schematic diagram showing a rubbing angle and a rubbing direction in a rubbing process.

FIG. 11 is a schematic diagram showing a rubbing angle and a rubbing direction in a rubbing process.

FIG. 12 is a view showing streak unevenness of a conventional liquid crystal display panel.

[Explanation of symbols]

 Reference Signs List 1 color filter substrate 2 pixel portion 3a black matrix extending in X direction 3b black matrix extending in Y direction 4 columnar spacer 5 ITO 6 liquid crystal 7a, 7b alignment film 8 counter substrate 9 flattening film 10 rubbing roller 11 streak-like alignment failure

Claims (4)

[Claims] 1. A rubbing process for an alignment film formed on a first substrate is performed after a spacer for maintaining a distance between the first substrate and a second substrate facing the first substrate is formed on the first substrate. When manufacturing a liquid crystal panel, a plurality of rubbing treatments having different rubbing angles are performed on the alignment film, and the rubbing treatments of the plurality of times are changed to the rubbing angle of the previous rubbing treatment. A method of manufacturing a liquid crystal display panel that is larger than an angle. 2. The method for manufacturing a liquid crystal display panel according to claim 1, wherein the alignment film is processed at a rubbing angle of 0 ° to 10 ° and then reprocessed at a rubbing angle of 20 ° to 45 °. 3. A rubbing process for an alignment film formed on a first substrate is performed after a spacer for maintaining a distance between the first substrate and a second substrate facing the first substrate is formed on the first substrate. When manufacturing a liquid crystal panel, a plurality of rubbing treatments having different rubbing angles are performed on the alignment film, and the rubbing treatments of the plurality of times are changed to the rubbing angle of the previous rubbing treatment. A method of manufacturing a liquid crystal display panel smaller than an angle. 4. The method for manufacturing a liquid crystal display panel according to claim 3, wherein the alignment film is treated at a rubbing angle of 20 ° to 45 ° and then retreated at a rubbing angle of 0 ° to 10 °.