JPH0688964A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To accurately form a gap to a specified thickness between glass substrates by interposing spacer and spherical adhesive between two glass substrates and spreading the spacer and spherical adhesive in order of a smaller particle size. CONSTITUTION:When a liquid crystal display element is formed by spreading a spcer and spherical adhesive or by using spacers of different particle sizes, the material having a smaller particle size is frist spreaded on the glass substrate, or a spacers corresponding to the gap size between glass substrates are used. There is no any limit except the above, for example, any kind of spacer or any spreading method is used. Namely, by spreading the material successively in order of smaller particle size on the glass substrate, aggregation of the spacers during spreading can be prevented and the gap can be uniformly formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device capable of forming an accurate gap between glass substrates of a liquid crystal display device.

[0002]

2. Description of the Related Art Various characteristics such as response speed, contrast and viewing angle of a liquid crystal display element are closely related to the thickness of a liquid crystal layer. Further, if the liquid crystal layer has unevenness in thickness, unevenness in display occurs, and the visibility is significantly reduced. Therefore, when manufacturing the liquid crystal display element, it is necessary to set the gap between the glass substrates to a predetermined value (about several μm) and strictly regulate the variation. For example, STN type and SSFLC
The shape requires gap control with an accuracy of 0.05 to 0.1 μm.

Therefore, conventionally, when assembling a liquid crystal display element, not only is an adhesive agent applied on a glass substrate and heat and pressure are applied to bond the two glass substrates, but a spacer is interposed between the glass substrates. In general, silica glass-based or resin-based granular spacers are often used.

When the glass substrate is coated with an adhesive to bond the glass substrate, not only is the adhesive applied to the peripheral portion of the glass substrate, but the particle size adhesive is applied to almost the entire surface of the glass substrate. It is also sprayed in the same manner as spacers.

[0005]

However, if spacers or spherical adhesives are sprinkled on the glass substrate, the spacers tend to agglomerate and form a dumpling state, so that the thickness of the liquid crystal layer cannot be accurately formed to a predetermined value. There was a problem. In particular, when the spacers and the spherical adhesive have different sizes, such a problem becomes remarkable.

Further, even if the spacers can be dispersed relatively uniformly, in order to make the gap narrower, the spacers are formed on the glass substrate with the portions where the transparent electrodes are formed and the portions where the transparent electrodes are not formed. The difference in the size of the power gap cannot be ignored, and there is a problem that the predetermined gap cannot be accurately formed. For example, as shown in FIG. 1, the glass substrate 1a, 1b has a thickness of 500
In the case of forming a liquid crystal cell using the one having the angstrom transparent electrodes 2a and 2b formed thereon, the transparent electrode 2a,
When the gap size L ₁ of the portion where 2b is formed is set to 1.4 μm, the gap size of the glass substrate between the portion where the transparent electrode 2a is formed and the portion where the transparent electrode 2b is not formed L ₂ is (1.4 + 0.0
5) μm, and the size L ₃ of the gap between the glass substrates 1a and 1b where the transparent electrodes 2a and 2b are not formed.
Is (1.4 + 0.05 × 2) μm, but when only spacers with a particle size of 1.4 μm are used, the part where the transparent electrode is formed and the part where the transparent electrode is not formed on the glass substrate The difference in the gap with
It becomes impossible to form the gap size within the range of variation of about 1.4 ± 0.1 μm.

The present invention is intended to solve the problems of the prior art, and it is an object of the present invention to accurately form a gap between glass substrates of a liquid crystal display device to a desired value. .

[0008]

The inventors of the present invention have found that when a spacer and a spherical adhesive having different particle diameters are scattered between glass substrates to form a liquid crystal display element, if the particles having smaller particle diameters are scattered. When the spacers with different particle diameters are used, the gap control can be accurately performed according to the size of the gap between the glass substrates which is determined by the presence or absence of the transparent electrode formed on the glass substrate. The inventors have found out what can be done and have completed the present invention.

That is, according to the present invention, in a method of manufacturing a liquid crystal display device in which a spacer and a spherical adhesive are interposed between two glass substrates, the spacer and the spherical adhesive are ordered from a glass substrate having a smaller particle diameter. Disclosed is a method for manufacturing a liquid crystal display element, which is characterized in that it is sprayed on.

Further, the present invention provides a liquid crystal display device characterized in that a spacer having a particle diameter corresponding to the size of the gap between the glass substrates is interposed between the two glass substrates.

Further, as a method of manufacturing a liquid crystal display element in which spacers having different particle diameters are interposed, spacers having different particle diameters are scattered on a glass substrate from the smaller particle diameter. A manufacturing method is provided.

As described above, according to the present invention, when a spacer and a spherical adhesive are dispersed to form a liquid crystal display element, or when spacers having different particle diameters are used to form a liquid crystal display element, the particle diameter is small. It is characterized in that it is sprayed on the glass substrate from one side or that a spacer having a particle diameter corresponding to the size of the gap between the glass substrates is used as the spacer. The manufacturing method can be the same. For example, regarding the spraying of spacers, there is no particular limitation on the type of spacers used, the spraying method, and the like. However, in order to perform the gap control more accurately, it is preferable to set the dispersion density of the spacers within a suitable range according to the type of the spacers used and the like.

For example, when spacers having a particle size of about 1.40 μm are used, it is preferable that the dispersion density is 30 to 500 pieces / mm ² , and more preferably 50 to 200 pieces / mm ² . In fact, when manufacturing a liquid crystal display device using a ferroelectric liquid crystal with the cell gap of the liquid crystal display device being 2 μm or less, if spacers having a particle size of 1.4 μm are dispersed at a dispersion density of 80 to 120 cells / mm ² , the cells are The gap can be set to 1.4 ± 0.1 μm, and even when a good liquid crystal alignment state can be obtained, the spacers are dispersed at a density of 10,000.
Number / mm ² in and spraying the gap of the cell 2.7 ± 1.
It becomes 3 μm, and the alignment state of the liquid crystal becomes poor.

Further, in order to perform the gap control more accurately, it is preferable that the spacers are not present at the end portions of the glass substrates when the glass substrates are adhered after the spacers are dispersed. That is, when the spacers are scattered on the glass substrate, the spacers generally have a large tendency to aggregate at the end portions with respect to the central portion of the glass substrate,
If the glass substrates are adhered to each other as they are, the resulting cell of the liquid crystal display element has a bulged end portion with respect to the central portion. Therefore, it becomes difficult to accurately control the gap in the peripheral portion adjacent to the bonded portion of the glass substrate. For example, when a spacer having a particle diameter of 1.4 μm is used to set the gap between the glass substrates of the liquid crystal display device to 1.4 μm, the spacer is scattered over the entire surface of the glass substrate and then the spacer at the end of the glass substrate is removed. If the glass substrates are adhered to each other without doing so, a gap of about 1.4 ± 0.1 μm can be formed in the central portion of the glass substrates, but a gap of about 5 μm can be formed in the adhering portion of the glass substrates. It is not possible to form the gap in the peripheral portion of the glass substrate to be formed similarly to the central portion. On the other hand, for example, when a 2.5-inch panel is used as the glass substrate, its edge is wiped with a width of 2 mm, and the floating spacer is removed, the gap in the peripheral portion of the glass substrate becomes 1. It is possible to form the film with a thickness of about 4 ± 0.1 μm.

As a method of removing the spacers at the end portions of the glass substrate as described above, the spacers on the peripheral portion of the glass substrate are physically removed by spraying the spacers or the like, or when the spacers are dispersed. The peripheral portion of the glass substrate may be masked so that spacers are not scattered on that portion. The width of the end of the glass substrate from which the spacer is removed is appropriately determined according to the size of the cell of the liquid crystal display element, the set value of the gap, the type of the spacer used, and the like. For example, in the above example, a spacer having a particle size of 1.4 μm is used, and the end portion of the 2.5-inch panel is wiped off with a width of 2 mm, but the end portion of the 5.5-inch panel is wiped off with a width of 3 mm. Similar results are obtained.

[0016]

According to the method of the present invention, when a liquid crystal display element is formed by interposing a spacer and a spherical adhesive between glass substrates, or when a liquid crystal display element is formed by using spacers having different particle diameters. Since the particles having smaller particle diameters are scattered on the glass substrate, the spacers can be prevented from agglomerating at the time of scattering. Therefore, the gap between the glass substrates can be formed uniformly.

According to the liquid crystal display element of the present invention,
Since a spacer having a grain size according to the size of the gap between the glass substrates is interposed between the glass substrates, the desired gap setting value is small and the thickness of the transparent electrode formed on the glass substrate. It is possible to accurately control the gap even when the value cannot be ignored.

Therefore, according to the present invention, it is possible to reduce the thickness unevenness of the liquid crystal layer of the liquid crystal display element and prevent the occurrence of display unevenness.

[0019]

EXAMPLES The present invention will be described in detail below based on examples.

Example 1 First, two glass substrates (5.5 inch panel) having an ITO film (thickness 500 angstrom) as a transparent electrode and an alignment film formed by the SiO oblique deposition method were prepared.

Next, on one of the glass substrates, the grain size 1.
A 40 μm spacer (trade name, Shin sphere, manufactured by Catalysts & Chemicals Industries Co., Ltd.) is dispersed in alcohol and evenly dispersed by a conventional method, and then a spherical adhesive having a particle size of 5 μm (trade name, Trepal, Toray) Made) and the width of the edge of the glass substrate is 3
Wipe off with mm. Then, an adhesive (trade name, struct bond, manufactured by Mitsui Toatsu Kagaku Co., Ltd.) is applied to the peripheral portion of the other glass substrate, superposed on the glass substrate on which the spacers have been scattered, heated and pressed to form a cell, A liquid crystal display element was produced using a ferroelectric liquid crystal (trade name, CS-1014, manufactured by Chisso Corporation).

In this case, the density of the scattered spacers is 80
It was set to 120 pieces / mm ² .

As a result, the aggregate number of the spacer and the spherical adhesive was 3 or less per 1 mm ² , and the gap of this cell was 1.4 ± 0.2 μm. The contrast was 50 on average.

Comparative Example 1 A liquid crystal display device was produced in the same manner as in Example 1 except that the spherical adhesive was sprayed before the spacer.

As a result, the number of aggregated spacers and spherical adhesives was 40 per 1 mm ² .

Example 2 Two glass substrates similar to those used in Example 1 were prepared, and a spacer having a particle size of 1.40 μm (trade name, sphere, Catalyst Kasei Kogyo Co., Ltd.) was provided on the transparent electrode of one of the glass substrates. Particle size of 1.
50 μm spacers (trade name, sphere, manufactured by Catalysts & Chemicals Industry Co., Ltd.) are sprinkled, and spherical adhesive (trade name, Trepearl, manufactured by Toray Industries, Inc.) having a particle size of 5 μm is sprinkled, and the same as Example 1. Then, a liquid crystal display element was produced.

As a result, the cell gap of this liquid crystal display device was 1.4 ± 0.1 μm, and the gap control was performed better than in Example 1.

[0028]

According to the present invention, the gap between the glass substrates of the liquid crystal display element can be accurately formed to a desired value.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a cell of a liquid crystal display element.

[Explanation of symbols]

 1a, 1b Glass substrate 2a, 2b Transparent electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidehiko Takanashi 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Mayumi Miyashita 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Nobue Kataoka 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (3)

[Claims] 1. A method of manufacturing a liquid crystal display device, wherein a spacer and a spherical adhesive are interposed between two glass substrates, and the spacer and the spherical adhesive are scattered on the glass substrate from the one having a smaller particle size. A method for manufacturing a liquid crystal display device, which is characterized by the above. 2. A liquid crystal display device, characterized in that a spacer having a particle diameter corresponding to the size of the gap between the glass substrates is interposed between the two glass substrates. 3. A method of manufacturing a liquid crystal display device, wherein a spacer is interposed between two glass substrates, wherein spacers having different particle diameters depending on the size of the gap between the glass substrates are used. A method for manufacturing a liquid crystal display element, which comprises spraying from a glass substrate onto a glass substrate.