JPH08286188A - Production of liquid crystal display element - Google Patents

Abstract

PURPOSE: To solve the nonuniformity of a rubbing treatment generated by the presence or absence of electrodes by specifying a rubbing treatment direction and an electrode taking-out angle to a specific range. CONSTITUTION: This process for producing the liquid crystal display element includes the treatment to form the plural electrodes 1, to form oriented films 2 on the substrates of the liquid crystal display element arranged with the terminals of these electrodes 1 at the edges of the substrates and to rub the surfaces of the oriented films 2 in one direction by rubbing rollers. The angle formed by the electrodes 1b of the taking-out parts with the direction of the patterns is set at >=15 deg. with the rubbing direction 3 and the surface of the oriented films 2 is rubbed by revolutions of 400 to 1000rpm by the rubbing roller.

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 liquid crystal display device which realizes uniformity of liquid crystal alignment by specifying a rubbing treatment direction and an extraction angle of an electrode.

[0002]

2. Description of the Related Art Conventionally, the arrangement state and organization of liquid crystal molecules are different depending on the surface state of a glass substrate constituting a liquid crystal cell, and when the liquid crystal is applied to a display or the like, the liquid crystal molecules are aligned in one direction. Needed to be present. This method of aligning liquid crystal molecules includes coating a glass substrate surface with a chemical substance to form an extremely thin alignment layer, or dissolving an aligning agent in liquid crystal to cause the aligning agent to be adsorbed on the substrate surface and aligning. For example, a layer is formed.

For example, a matrix type liquid crystal display device
In the part where the display electrodes of (LCD; Liquid Crystal Display) are taken out, the influence of friction etc. on the rubbing cloth used for the rubbing process is different depending on the presence or absence of the electrodes, so the alignment process of liquid crystal molecules is partially uneven. Therefore, a technique for obtaining uniform orientation is desired.

As a conventional technique for obtaining this uniform orientation, for example, JP-A-5-88180 or JP-A-5-88180 is used.
There is a technique disclosed in Japanese Patent No. 88181. That is, in the above-mentioned JP-A-5-88180, after rubbing the alignment film surface with the terminals of the electrodes also covered with the alignment film, the alignment film on the terminal array portion is removed, thereby covering the entire alignment film. A technique relating to an "orientation treatment method" is disclosed in which uniform rubbing is performed to obtain uniform orientation.

In the above-mentioned Japanese Patent Laid-Open No. 5-88181, the rubbing roller cloth is rubbed on the same material as the terminals to maintain the surface condition of the rubbing cloth. There is disclosed a technique relating to the "orientation treatment method", which is characterized in that a pseudo electrode made of the same material as the electrode terminal is provided in a non-existing portion.

[0006]

However, in the technique disclosed in the above-mentioned Japanese Patent Laid-Open No. 5-88180,
There was a problem that the number of steps was increased. Further, since the technique disclosed in the above-mentioned Japanese Patent Laid-Open No. 5-88181 is a method of adding a pseudo electrode between the electrode terminal group and the electrode terminal group, there is no electrode between the terminal and the terminal. The non-uniformity of the rubbing process due to the difference of No. is not dealt with, and it is not possible to obtain a completely uniform orientation, resulting in display unevenness.

The present invention has been made in view of the above problems. An object of the present invention is to determine the non-uniformity of the rubbing process caused by the presence or absence of an electrode by defining the angle between the rubbing process direction and the pattern direction of the lead-out electrode. The solution is to set it within a specific range.

[0008]

In order to achieve the above object, the present invention provides a liquid crystal display in which a plurality of electrodes including a terminal electrode and a lead-out electrode are formed, and the terminals of the electrodes are arranged at the edge of the substrate. In a method of manufacturing a liquid crystal display device, which comprises forming an alignment film on an element substrate and rubbing the surface of the alignment film in one direction with a rubbing roller, the direction of the pattern of the extraction electrode and the rubbing direction are formed. The angle is set to 15 ° or more, and the surface of the upper alignment film is rubbed by rotation by the rubbing roller.

[0009]

That is, according to this method, the change in the surface condition of the rubbing cloth on the outer peripheral surface of the rubbing roller is substantially uniform over the entire rubbing region of the alignment film, and the entire surface is rubbed in substantially the same condition.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 shows a conceptual diagram of a method for manufacturing a liquid crystal display element of the present invention, and description will be given. In FIG. 1, reference numeral 1
Is an electrode, in particular, reference numeral 1a is a terminal electrode, and reference numeral 1b is a lead-out electrode. Reference numeral 2 indicates an alignment film, reference numeral 3 indicates a rubbing processing direction, and θ indicates an intersection angle between the rubbing processing direction and the extraction portion electrode 1b.

As a material for the electrode 1, ITO (Indiu
m Thin Oxide) can be adopted. Polyimide or the like can be used as the material of the alignment film 2. This polyimide is formed by a method in which a polyacic acid solution is transferred and printed on a glass substrate by offset printing and then baked at 200 to 300 ° C., or a polyimide solution is formed by the same printing and then 150 to 20.
It can be performed by a method such as firing at 0 ° C.
The thickness of the alignment film made of this polyimide is 200 to 10
00 [angstrom]. Rubbing direction 3
Is a direction in which the surface of the alignment film is rubbed by a rubbing cloth 12 wound around a rubbing roller (corresponding to reference numeral 11 in FIG. 2 described later). As a material for this rubbing cloth, rayon, cotton, nylon or the like can be adopted.

Here, the actual rubbing process will be described with reference to FIGS. The electrode 1 and the alignment film 2 are formed on the glass substrate 13 as shown in FIG. In the rubbing process, the rubbing roller 11 in which a rubbing cloth 12 made of a flocked cloth is wound around the outer peripheral surface is attached to the rubbing roller 1 in FIG.
The rotation is performed in the direction 6 and the table 14 having the glass substrate 13 mounted thereon is passed in the direction 15 in FIG. In this case, the rubbing direction is the direction indicated by reference numeral 3 in the figure. The rubbing roller 11
Are arranged such that their axial directions are orthogonal to the rubbing direction of the alignment film 2. At the time of such rubbing, the glass end face, the terminal electrode 1a, the extraction electrode 1
The rubbing cloth 12 comes into contact in the order of b and the alignment film 2.

This rubbing process is performed by the rubbing roller 11
Is performed while rotating at a high speed of 400 to 1000 rpm, for example, so that friction and heat due to friction are generated. Friction differs between the material ITO of the electrode 1 and the material polyimide of the alignment film 2, and therefore the friction heat also differs, and the effect on the rubbing cloth 12 also differs between the electrode portion 1 and the alignment film 2. In the prior art, this phenomenon causes non-uniformity of the orientation, and the non-uniformity of the orientation causes non-uniformity of display, which is a fatal defect for display on a display.

For example, FIG. 5 is a diagram showing a non-uniform orientation phenomenon, in which the orientation on the orientation film 2 is different from the surroundings in a portion where the angle θ formed between the extraction electrode 1b and the rubbing direction 3 is small. Is clear from the figure.

In order to prevent the rubbing of the alignment film 2 from being non-uniform, the rubbing cloth 12 is affected by friction or the like at least while the rubbing cloth 12 reaches the end face of the alignment film 2. It is necessary to contact the electrode within a predetermined range, and it is necessary that there is no contact area.

In the present invention, θ was experimentally changed, and a range was investigated in which the difference in the influence of friction or the like on the rubbing cloth 12 depending on the presence or absence of an electrode did not cause nonuniformity of liquid crystal alignment.
As a result, the nonuniform orientation was not generated in all regions, but was related by the angle θ formed by the rubbing direction 3 and the direction of the extraction electrode 1b.

That is, as shown in FIG. 6, inhomogeneity of orientation occurs in the portion where θ = 0 °, and the inhomogeneity of orientation is alleviated as θ becomes larger, and when θ = 15 °, it is completely inconsistent. There was no uniform orientation and no non-uniformity had occurred up to θ = 70 °. From this experimental result, it was found that uniform orientation can be realized by setting the pattern of the lead-out electrode 1b such that θ ≧ 15 °.

Here, FIG. 4 shows a sectional view of an LCD manufactured by the method for manufacturing a liquid crystal display element of the present invention, and will be described. In the figure, the glass substrate 13 coated with the alignment film 2 subjected to the rubbing treatment according to the present invention and another glass substrate are adhered by a sealant 21. This sealing agent 21
As the material, an epoxy-based material or the like can be applied. On the other hand, the connection member 22 for inputting a signal required for display is connected to the electrode 1. The connecting member 22 is formed of a heat seal material or TAB (Tape Automated Bonding). The sealing agent 21 and the glass substrate 13
A liquid crystal 23 is placed in the space formed by, and a spacer material 24 is provided to secure the thickness of the liquid crystal layer. Reference numeral 1a is a terminal electrode, which corresponds to a connection region with the connection member 22. Further, reference numeral 1b is an extraction portion electrode corresponding to between the alignment films 2 and 1a. The rubbing direction of the LCD having such a configuration needs to be set so as to match the position where the display is viewed, that is, in consideration of visual characteristics. Therefore, it is practically difficult to arbitrarily set the rubbing direction according to the pattern. Therefore, the present invention in which the pattern direction of the extraction portion electrode 1b is changed is very effective.

As described above, according to the method of manufacturing a liquid crystal display element of the present invention, a uniform liquid crystal alignment is obtained by forming an electrode pattern in which the crossing angle θ between the rubbing direction and the extraction portion electrode 1b is 15 ° or more. Is obtained, and a uniform display without display unevenness can be obtained. Therefore, according to the present invention, it is possible to manufacture a liquid crystal display element capable of uniform display.

[0020]

According to the present invention, the unevenness of the orientation of the rubbing treatment caused by the presence or absence of the electrode is solved by setting the rubbing treatment direction and the electrode take-out angle within a specific range.
It is possible to provide a method for manufacturing a liquid crystal display device having uniform optical characteristics and preventing the occurrence of stripe-shaped display unevenness.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a method for manufacturing a liquid crystal display element according to an example.

FIG. 2 is a diagram for explaining an actual rubbing process.

FIG. 3 is a diagram showing a state in which an electrode 1 and an alignment film 2 are formed on a glass substrate 13.

FIG. 4 is a diagram showing electrodes 1a and 1b as a cross-sectional view in an LCD state.

FIG. 5 is a diagram showing an example of a non-uniform orientation phenomenon.

FIG. 6 is a diagram showing a relationship between a rubbing processing direction and a crossing angle of the extraction electrode 1b, and a non-uniform orientation occurrence rate.

[Explanation of symbols]

1 ... Electrode, 1a ... Terminal part electrode, 1b ... Extraction part electrode,
2 ... Alignment film, 3 ... Rubbing direction, 11 ... Rubbing roller, 12 ... Rubbing cloth, 13 ... Glass substrate, 14 ... Table, 15 ... Table moving direction, 16 ... Rubbing roller rotating direction, 21 ... Sealing agent, 22 ... Connecting member, 23
... liquid crystal, 24 ... spacer agent.

Claims (1)

[Claims] 1. An alignment film is formed on a liquid crystal display element substrate in which a plurality of electrodes including a terminal electrode and a lead-out electrode are formed, and terminals of the electrodes are arranged at a substrate edge, and a surface of the alignment film. In the method for manufacturing a liquid crystal display device, which comprises rubbing in one direction with a rubbing roller, the angle formed between the direction of the pattern of the extraction electrode and the rubbing direction is set to 15 ° or more, and the rubbing roller rotates for upward alignment. A method of manufacturing a liquid crystal display device, which comprises rubbing the surface of a film.