WO2015014054A1

WO2015014054A1 - Preparation method for alignment film and preparation device therefor

Info

Publication number: WO2015014054A1
Application number: PCT/CN2013/088223
Authority: WO
Inventors: 李建; 宋省勋; 李鸿鹏
Original assignee: 北京京东方光电科技有限公司
Priority date: 2013-07-29
Filing date: 2013-11-29
Publication date: 2015-02-05
Also published as: CN103412440B; CN103412440A

Abstract

A preparation method for an alignment film, comprising: forming an alignment material layer on a substrate (1), the alignment material layer having a region (3) to be processed, and performing illumination processing on the region (3) to be processed, so as to reduce a pre-tilt angle of the region (3) to be processed. Further provided is a preparation device for an alignment film.

Description

Method for preparing oriented film and preparation device thereof

Embodiments of the present invention relate to a method of preparing an oriented film and a preparation apparatus therefor. Background technique

A liquid crystal display panel in a liquid crystal display (LCD) includes two substrates and a liquid crystal layer between the two substrates. The liquid crystal layer is obtained by injecting liquid crystal between the two substrates, and an electric signal is applied to the liquid crystal display panel to control the liquid crystal in the liquid crystal layer to realize image display.

In order to obtain uniform brightness and high contrast, liquid crystal molecules in the liquid crystal display panel must be aligned in a certain direction. Therefore, before the formation of the liquid crystal layer, it is necessary to form an alignment film on the two substrates separately, and then add liquid crystal molecules to the two substrates of the cassette, so that the liquid crystal molecules are aligned in a certain direction according to the alignment film. The alignment film is generally formed of an organic polymer film such as a polyimide resin.

In order to form an alignment film on a substrate, a rubbing method is generally employed. For example, a layer of an alignment material is coated on the substrate, and then the rubbing roller is brought into contact with the layer of the alignment material, and the rubbing roller is quickly moved in a certain direction. Since the rubbing roll is covered with a rubbing cloth having fine fluff, the surface condition of the layer of the alignment material is changed by the fine fluff on the rubbing cloth, and a uniform anchoring action is exerted on the liquid crystal molecules to form an oriented film. Thereby, the liquid crystal molecules are uniformly aligned in a certain area between the two substrates of the liquid crystal display at a certain pretilt angle.

However, since the surface of the substrate is not flat enough, the rubbing roller cannot sufficiently contact the directional material layer of all the regions, so that the anchoring ability of the alignment film prepared by the rubbing method to the liquid crystal molecules is inconsistent, and the contrast of the liquid crystal display panel is lowered. Summary of the invention

A first aspect of the present invention provides a method for preparing an alignment film, comprising: forming an alignment material layer on a substrate, the alignment material layer having a region to be processed, and performing illumination treatment on the region to be processed to reduce The pretilt angle of the area to be treated is small. For example, the method includes:

Coating the layer of the alignment material on the substrate, rubbing the layer of the alignment material with a rubbing roller; detecting a pretilt angle of each region of the rubbed layer of the alignment material, and the region having the pretilt angle greater than a preset value is a region to be processed ; as well as

The area to be processed is subjected to illumination processing to reduce the pretilt angle of the area to be processed. For example, the pre-tilt angle of each region of the rubbed alignment material layer is detected, and the region where the pre-tilt angle is greater than the preset value is the region to be processed further includes: obtaining a pre-tilt angle between the to-be-processed region and a preset value Difference.

For example, performing illumination processing on the to-be-processed area to reduce the pretilt angle of the to-be-processed area further includes: setting illumination time, illumination according to a difference between a pretilt angle of the to-be-processed area and a preset value The intensity is set according to the size of the substrate, and the illumination angle is set by using polarized light to make the pretilt angle of the to-be-processed area equal to a preset value.

For example, the polarized light is ultraviolet polarized light, visible polarized light, or infrared polarized light.

For example, the alignment material layer has photo-alignment properties.

For example, the alignment material layer is a polyimide material having photo-alignment properties or an alignment material having a light-oriented functional group.

For example, before the illuminating the area to be treated to reduce the pretilt angle of the area to be treated, the method further comprises: cleaning the rubbed layer of the aligning material.

A second aspect of an embodiment of the present invention provides an apparatus for producing an oriented film, comprising a rubbing roller for rubbing an alignment material layer. The device further includes: a mask plate having a light transmissive portion, wherein the light transmissive portion corresponds to the layer of the alignment material when the mask plate covers the layer of the alignment material a processing area; an illumination device, performing illumination processing on the to-be-processed area to reduce a pretilt angle of the to-be-processed area.

For example, the apparatus further includes: a pretilt angle detecting device that detects a pretilt angle of each region of the layer of the alignment material rubbed by the rubbing roller, and the region where the pretilt angle is greater than a preset value is the region to be processed. The difference between the two.

For example, the illumination device sets the illumination time and the illumination intensity according to the difference between the pretilt angle of the to-be-processed area and the preset value, sets the illumination angle according to the substrate size, and utilizes the polarization. The light is subjected to illumination processing on the area to be processed such that the pretilt angle of the area to be processed is equal to a preset value.

For example, the light transmissive portion of the mask includes a hollowed out region and/or a transparent region.

For example, the alignment material layer has photo-alignment properties.

For example, the alignment material layer is a polyimide material having photo-alignment properties or an alignment material having a light-oriented functional group. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments will be briefly described below. Obviously, the drawings in the following description are merely the present invention. Some of the embodiments can be obtained by those skilled in the art from the drawings without any creative work.

1 is a schematic flow chart 1 of a method for preparing an oriented film according to an embodiment of the present invention;

2 is a schematic flow chart 2 of a method for preparing an oriented film according to an embodiment of the present invention;

3 is a schematic plan view of a substrate in an embodiment of the present invention;

4 is a schematic plan view of a mask covering a substrate according to an embodiment of the present invention; and FIG. 5 is a schematic flow chart 3 of a method for preparing an alignment film according to an embodiment of the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without making creative labor are within the scope of the present invention.

Embodiments of the present invention provide a method for preparing an oriented film. As shown in FIG. 1, the method for preparing the alignment film includes:

Step S101, forming an alignment material layer on the substrate, the alignment material layer having a region to be processed, and performing illumination processing on the region to be processed to reduce a pretilt angle of the region to be processed.

In the technical solution of the present embodiment, a method for preparing an alignment film is provided, the method comprising: forming an alignment material layer on a substrate, the alignment material layer having a region to be processed, and the to-be-processed The area is subjected to illumination processing to reduce the pretilt angle of the area to be treated. Thereby, the pretilt angle of the area to be treated can be made to meet the preset value, and the anchoring ability of the liquid crystal molecules to be treated is improved, so that the arrangement of the liquid crystal molecules on the alignment film is uniform, and the contrast of the liquid crystal display panel is improved. Improve the user experience.

It should be noted that any desired structure and components may be provided on the substrate before the formation of the alignment material layer. For example, a thin film transistor, a pixel electrode, a common electrode, a color film, a black matrix or a spacer, or the like, or a combination of two or more of them may be disposed on the substrate as needed, and is not limited herein.

For example, as shown in FIG. 2, the step S101 further includes:

Step S201, coating an alignment material layer on the substrate, and rubbing the alignment material layer with a rubbing roller.

After the rubbing roller is rubbed, the anchoring ability of the liquid crystal molecules is generated everywhere in the layer of the alignment material, so that the liquid crystal molecules can be aligned in a certain direction on the layer of the alignment material.

The non-planar structure such as protrusions or depressions on the substrate may affect the friction effect of the rubbing roller on the layer of the alignment material, so that the protrusions or depressions or their surrounding regions cannot be sufficiently rubbed, resulting in protrusions or depressions or their surrounding regions against the liquid crystal molecules. The anchoring effect is weaker than the anchoring action of the flat portion on the substrate, affecting the alignment of the liquid crystal molecules, and reducing the contrast of the liquid crystal display panel.

Step S202: Detect a pretilt angle of each region of the rubbed alignment material layer, and the region where the pretilt angle is greater than a preset value is a region to be processed.

For example, the pretilt angle detecting device is used to detect various regions of the rubbed alignment material layer. It is possible to focus on the area of the substrate having protrusions or depressions, and the pretilt angle of the surrounding area of the protrusions or depressions.

Usually, after the rubbing by the rubbing roller, the pretilt angle of the region where the rubbing material is sufficiently rubbed is equal to the preset value; the pretilt angle of the region where the rubbing is not sufficiently rubbed is larger than the preset value.

In general, the preset value of the pretilt angle is small, usually no more than 5°.

Step S203: Perform illumination processing on the to-be-processed area to reduce a pretilt angle of the to-be-processed area.

Since the alignment material layer of the region to be treated is not sufficiently rubbed, the orientation material layer of the region to be treated is not sufficiently oriented. By the illumination treatment, the layer of the alignment material of the area to be treated can be further oriented to achieve the purpose of sufficient orientation, and the pretilt angle of the area to be treated is reduced to meet the pre-treatment. Set the value. After having a region, the mask is covered on the rubbed and detected layer of the alignment material, and the mask has a light-transmissive region, and the size and shape of the light-transmitting region correspond to respective regions in which the pretilt angle is greater than a preset value. An area in which each pretilt angle is larger than a preset value is exposed as a to-be-processed area; an area in which other pretilt angles are equal to a preset value is covered to prevent the surface of the sufficiently rubbed area from being damaged.

Alternatively, the regions of the alignment material layer that are not sufficiently rubbed may be analyzed in advance, for which the shape of the mask is designed such that the mask has a plurality of light-transmissive regions which are hollow regions and/or transparent regions. Alternatively, a temporary mask may be formed using a material such as photoresist after detecting a region that is not sufficiently rubbed, and a region that is not sufficiently rubbed may be exposed as a region to be treated.

For example, when it is detected that the pretilt angle of a certain area is greater than a preset value, for example, the pretilt angle of the area is 6°, it is necessary to obtain a difference between the pretilt angle of the area and a preset value, which is convenient for the areas. When the illumination processing is performed, the appropriate illumination time and illumination intensity can be set according to the difference, so that the pretilt angle of the to-be-processed area can meet the preset value after the illumination processing. Generally, the greater the difference, the longer the illumination time or the greater the illumination intensity. Based on this situation, multiple batches of the area to be processed can be illuminated in batches based on the difference. That is, some of the areas to be treated having one of the differences may be illuminated by designing a mask, and then other areas to be processed having the other difference may be illuminated.

Generally, the area to be treated is distributed on the substrate and in various places of the layer of the oriented material after the rubbing. Therefore, it is necessary to set the illumination angle according to the size of the substrate, so that each of the areas to be treated can obtain sufficient illumination to ensure each The pretilt angle of the area to be treated can approach or even be equal to the preset value, so that the liquid crystal molecules can also exhibit a uniform and consistent arrangement in the pre-tilt angles corresponding to the preset values in the areas to be treated, so as to improve the contrast of the display device and improve the contrast. Display the display effect of the device.

In addition, the light used for the illumination treatment is usually polarized light, and the light source is generally a high-pressure mercury lamp, a xenon lamp, a lamp, or the like, and then a monochromatic polarized light is obtained by a filter device and a polarizer. The polarized light is ultraviolet polarized light, visible polarized light or infrared polarized light.

For example, before the illumination treatment of the area to be treated, the rubbed layer of the alignment material should be cleaned to prevent the presence of foreign matter on the layer of the alignment material from affecting the effect of the illumination treatment.

Since the alignment material layer needs to be subjected to light treatment, the alignment material layer is preferably a photo-alignment polyimide material such as RN-2241V2467 (product model), or the like. An oriented material having a photo-alignment functional group. However, since any polyimide has a slight photo-alignment ability, other polyimides can also be used.

Next, the method shown in Fig. 2 will be exemplified by taking the preparation process of the alignment film on the color filter substrate 1 as an example. It is to be understood that the following description is only illustrative, and is not intended to limit the scope of the invention.

First, an alignment material layer is deposited on the color filter substrate 1, and the alignment material layer is subjected to a rubbing treatment using a rubbing roller.

As shown in FIG. 3, the color filter substrate 1 is preliminarily provided with a protruding spacer 2, and after the alignment material layer is deposited on the color filter substrate 1, when the alignment material layer is rubbed by the rubbing roller, the protruding spacer 2 hindering the movement of the friction roller, causing the friction roller to be insufficiently received in a certain area around the bottom of the spacer 2, thereby reducing the anchoring ability of the liquid crystal molecules around the spacer 2, resulting in liquid crystal molecules being separated The pretilt angle around the pad 2 does not coincide with the pretilt angle elsewhere, affecting the contrast of the display device.

After the detection by the pretilt angle detecting device, the periphery of the spacer 2 which is not sufficiently rubbed becomes the area to be treated 3. As shown in Fig. 4, after the upper mask 4 is covered, the area to be treated 3 will be exposed, and the area which has been sufficiently rubbed is covered by the mask 4.

For example, before the mask 4 is covered, the color filter substrate 1 needs to be cleaned to prevent the environment or foreign matter from interfering with the light treatment.

Obviously, the spacer 2 is spread over the color filter substrate 1, and the alignment material layer covers the entire color filter substrate 1. When the mask 4 is covered with the upper layer of the alignment material, it is first subjected to a rough alignment, i.e., it is ensured that the mask 4 can cover substantially the entire layer of the alignment material. Then, by fine alignment, the relative position of the light-transmitting region 5 on the mask 4 and the area to be treated 3 is adjusted, and the light-transmitting region 5 should be just exposed to each of the regions 3 to be treated as optimal, so In the process of the bit, it is also necessary to perform the alignment detection and feedback, that is, whether the transparent region 5 has been able to expose only the respective to-be-processed regions 3, and if this has been achieved, the fine alignment is stopped, and the illumination processing is prepared. If this is not achieved, the fine alignment will be performed again until the light-transmitting region 5 has been able to expose only the respective regions 3 to be treated.

The pretilt angle detecting device needs to obtain the difference between the pretilt angle of the to-be-processed area 3 and the preset value while detecting, and when the light processing is to be performed on the processing area 3, the illumination time and the illumination may be set according to the difference. strength. In addition, since the size of the color filter substrate 1 is generally large, the light emitted by the illumination device needs to be irradiated to all the regions 3 to be treated of the layer of the alignment material covered on the color filter substrate 1. Therefore, it is also necessary to set the illumination angle, such as the swing angle of the illumination device, according to the size of the color filter substrate 1.

Thereafter, the illumination device emits ultraviolet polarized light, visible polarized light or infrared polarized light, the area to be treated 3 receives the light emitted by the illumination device, and the layer of the alignment material of the area to be treated 3 generates surface anisotropy, so that the pre-processed area 3 is pre-processed. The inclination angle meets the preset value, and the anchoring ability of the liquid crystal molecules to be treated is improved.

In addition, it is possible for an experienced technician to know in advance where the layer of oriented material is an insufficiently rubbed area, i.e., the area to be treated that needs to be illuminated, after the rubbing roll is processed. Therefore, these expected areas to be treated can be pretreated by illumination treatment before rubbing. Based on this, the method for preparing the alignment film shown in FIG. 1 can also be as shown in FIG. 5, comprising: Step S301, depositing an alignment material layer on the substrate.

Step S302, covering a mask layer on the layer of alignment material, the mask panel having a light transmissive region, and the light transmissive region corresponding to the region to be processed.

Step S303: Perform illumination processing on the to-be-processed area to reduce a pretilt angle of the to-be-processed area.

Step S304, rubbing the layer of the alignment material subjected to the illumination treatment with a rubbing roller.

In the method corresponding to Fig. 5, the area to be treated may be pre-divided, and the area to be processed is usually located on a substrate having a recessed or raised area or a recess or protrusion (e.g., a spacer of a color filter substrate). The mask has light-transmissive areas, and the size and shape of the light-transmissive areas match the area to be treated. After covering the upper mask, only the area to be treated on the substrate is exposed. In the light treatment, only the area to be treated is subjected to illumination treatment, and the layer of orientation material of the area to be treated generates surface anisotropy to reduce the The pretilt angle of the area to be treated increases the anchoring ability of the area to be treated to the liquid crystal molecules.

After that, the frictional roller is used to rub the layer of the alignment material, and the flat region can obtain sufficient friction. The pretilt angle of the portion of the alignment material layer meets the preset value; and the sufficient frictional depression or protrusion or their surroundings cannot be obtained. In the processing area, since the pre-illumination treatment is performed before the rubbing, the crystal molecules can be arranged in a pretilt angle conforming to a preset value in each region of the alignment material layer, thereby improving the contrast of the display device.

After rubbing the layer of the alignment material with the rubbing roller, the rubbed layer of the alignment material should also be cleaned, Preventing foreign matter on the layer of the alignment material, such as scraps of materials such as nylon, fiber or lint covering the friction roller, affecting the processing and processing after the substrate.

Further, in the embodiment of the present invention, there is further provided an apparatus for preparing an oriented film, comprising a rubbing roller for rubbing an alignment material layer. The apparatus further includes a mask having a light transmissive portion, the light transmissive portion corresponding to the area to be treated of the layer of oriented material when the mask is overlying the layer of oriented material.

Additionally, the apparatus further includes an illumination device that performs illumination processing on the area to be treated to reduce the pretilt angle of the area to be treated.

Further, the apparatus for preparing an oriented film in the embodiment of the present invention further includes a pretilt angle detecting device that detects a pretilt angle of each region of the layer of the alignment material rubbed by the rubbing roller, and the region where the pretilt angle is greater than a preset value is Describe the processing area.

When detecting the pretilt angle of each region of the alignment material layer rubbed by the rubbing roller, when the pretilt angle of a certain region is found to be larger than a preset value, this region is the region to be treated. The pretilt angle detecting device further obtains a difference between the pretilt angle of the to-be-processed area and a preset value, so that the illumination device sets the illumination time and the illumination intensity according to the difference. In addition, the illumination device sets the illumination angle according to the size of the substrate. The light emitted by the illumination device is typically polarized light. In the illumination device, the light source is generally a high-pressure mercury lamp, a xenon lamp, a lamp, or the like, and then a monochromatic polarized light is obtained by a filter device and a polarizer. The polarized light is ultraviolet polarized light, visible polarized light or infrared polarized light.

The light transmissive portion of the reticle includes a hollowed out region and/or a transparent region.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

claims

1. A method for preparing an alignment film, including:

An orientation material layer is formed on the substrate, the orientation material layer has an area to be processed, and the area to be processed is subjected to light treatment to reduce the pretilt angle of the area to be processed.

2. The preparation method of the alignment film according to claim 1, wherein the method includes: coating the alignment material layer on the substrate, rubbing the alignment material layer using a friction roller; detecting the rubbed alignment material layer The pretilt angle of each area, the area where the pretilt angle is greater than the preset value is the area to be processed; and

The area to be treated is subjected to illumination treatment to reduce the pretilt angle of the area to be treated.

3. The preparation method of the alignment film according to claim 2, wherein the pretilt angle of each area of the rubbed alignment material layer is detected, and the area where the pretilt angle is greater than the preset value is the area to be processed. It also includes:

The difference between the pretilt angle of the area to be treated and the preset value is obtained.

4. The method for preparing an alignment film according to claim 3, wherein subjecting the area to be treated to light treatment to reduce the pretilt angle of the area to be treated further includes:

Set the illumination time and illumination intensity according to the difference between the pretilt angle of the area to be processed and the preset value, and set the illumination angle according to the substrate size;

The area to be treated is illuminated using polarized light so that the pretilt angle of the area to be treated is equal to a preset value.

5. The preparation method of the alignment film according to claim 4, wherein

The polarized light is ultraviolet polarized light, visible polarized light or infrared polarized light.

6. The preparation method of the alignment film according to any one of claims 1 to 5, wherein

The orientation material layer has photo-alignment properties.

7. The method for preparing an alignment film according to claim 6, wherein the alignment material layer is a polyimide material with photo-alignment, or an alignment material with photo-alignment functional groups.

8. The method for preparing an alignment film according to claim 2, before performing light treatment on the area to be treated to reduce the pretilt angle of the area to be treated, the method further includes: cleaning and rubbing. The orientation material layer.

9. An orientation film preparation device, including a rubbing roller for rubbing the orientation material layer, The device also includes:

Mask plate, the mask plate has a light-transmitting part, and when the mask plate covers the orientation material layer, the light-transmitting part corresponds to the area to be processed of the orientation material layer;

Illumination equipment performs lighting treatment on the area to be treated to reduce the pretilt angle of the area to be treated.

10. The alignment film preparation device according to claim 9, further comprising:

Pretilt angle detection equipment detects the pretilt angle of each area of the orientation material layer rubbed by the friction roller, and the area where the pretilt angle is greater than the preset value is the area to be processed.

11. The alignment film preparation device according to claim 10, wherein the value.

12. The alignment film preparation device according to claim 11, wherein

The illumination equipment sets the illumination time and illumination intensity according to the difference between the pretilt angle of the area to be treated and the preset value, sets the illumination angle according to the size of the substrate, and uses polarized light to illuminate the area to be treated. Illumination processing is performed so that the pretilt angle of the area to be treated is equal to a preset value.

13. The alignment film preparation device according to claim 12, wherein the polarized light is ultraviolet polarized light, visible polarized light or infrared polarized light.

14. The alignment film preparation device according to claim 9, wherein:

The light-transmitting part of the mask plate includes a hollow area and/or a transparent area.

15. The apparatus for preparing an alignment film according to claim 14, wherein the alignment material layer has photo-alignment.

16. The alignment film preparation device according to claim 15, wherein the alignment material layer is a polyimide material with photo-alignment, or an alignment material with photo-alignment functional groups.