JPH1138422A - Liquid crystal display device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device excellent in display quality and impact resistance by preventing the alignment control layer from being contaminated or damaged in a manufacturing process and improving the adhesive strength of a substrate. I do. SOLUTION: After a stripe-shaped electrode 2, an insulating layer 3 and an orientation control layer 4 are formed on a substrate 1, an orientation control layer 4 is formed.
An inorganic coating 5 made of an inorganic material is formed thereon, and the inorganic coating 5
The region between the electrodes 2 is exposed to ultraviolet light in a stripe shape. Next, a layer of an adhesive containing spacer beads is formed on the inorganic coating 5, and the adhesive is peeled off with a solvent such as water together with the unexposed portion of the inorganic coating 5 to form the spacing members 6 made of the adhesive. I do. Then, the electrode substrate 10 and the electrode substrate 20 are separated from each other by spacers 6 including spacer beads.
Glue by. As a result, the electrode substrates 10 and 20
It is held at regular intervals by the spacer beads and is firmly adhered.

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 used for a flat panel display and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art In general, a liquid crystal display device has a pair of substrates on which a transparent electrode is formed, a liquid crystal layer in which liquid crystal is sealed between the pair of substrates, and selectively applied to the transparent electrode. A device for optically detecting the optical axis of the liquid crystal displaced by the voltage, for example, a polarizer is provided. In the above-mentioned liquid crystal display element, the gap for enclosing the liquid crystal, that is, the cell gap is usually kept constant by spraying spacers made of glass fibers, glass beads, resin beads, etc. on the substrate. Is controlled.

However, in the method of controlling the cell gap using the spacer as described above, since both substrates are not adhered to the spacer, the cell gap is strictly controlled and the cell gap is maintained with respect to the external pressure applied to the substrate. Is difficult. On the other hand, strict control and maintenance of the cell gap are necessary to achieve the large size required for current liquid crystal display devices, and are expected to have superior characteristics over conventional nematic liquid crystals. This is an essential condition in a display device using a ferroelectric liquid crystal.

Accordingly, a method of spraying adhesive particles simultaneously with bead-shaped spacers so as to strictly control and maintain the cell gap (for example, see JP-A-62-17472).
No. 6) has been developed. However, in the above method, in order to obtain a practical adhesive strength, not only is it necessary to scatter the spacers at high density, but also the display quality deteriorates due to the spacers scattered in the pixels. Become.

On the other hand, in order to solve the above problem, a method has been found in which a spacer material made of a photosensitive resin is formed into an arbitrary shape by a method such as photolithography (see, for example, JP-A-1-257824). Gazette). According to this method, the two substrates are firmly bonded at regular intervals by the spacer provided between the pixels.

However, as described above, when a resin spacer material is formed on an alignment control layer in a liquid crystal display element, the following problems occur.

(I) The solvent used for applying the spacer material on the orientation control layer, the resin itself as the spacer material, the developer used for photolithography, etc., contaminate the orientation control layer. For this reason, the alignment control force for the liquid crystal provided to the alignment control layer by the rubbing treatment is reduced. Therefore, in order to prevent such a problem from occurring, a rubbing treatment may be performed after forming the spacer. However, in this case, the following problem occurs.

(Ii) Since the rubbing treatment is also applied to the resin spacer, an alignment regulating force is applied to the surface of the spacer. As a result, inconveniences such as abnormal alignment and poor switching of liquid crystal molecules, which cause alignment unevenness in the liquid crystal near the spacer, are caused.

To solve the above problems, for example, the following method can be applied.

Regarding the problem (i), JP-A-6-592 describes
As disclosed in Japanese Patent Publication No. 28 (Document A), first,
It is effective to form a protective film for protecting the alignment control layer from a developer or the like on the alignment control layer, and then form a columnar spacer made of an organic material on the protective film. Regarding the problem (ii), as disclosed in Japanese Patent Application Laid-Open No. 6-175133 (Document B), the arrangement of the spacers and the alignment control layer are set so that the alignment abnormality does not occur in the effective pixels. It is effective to devise a method for the alignment treatment.

[0011]

However, the method described in Document A has a problem that the manufacturing process is complicated. Specifically, a complicated process of forming an orientation control layer on a substrate, forming a protective film, subsequently forming a spacer by applying, exposing, and developing a spacer material and then removing an unnecessary protective film is performed. I need.

Further, the method described in Document A has a problem that deterioration of the orientation control layer cannot be completely prevented. That is, in this method, an unnecessary portion of the protective film formed on the orientation control layer is replaced with a hydrogen peroxide solution,
Since the alignment control layer is separated by an etching solution containing ammonia or the like, the alignment control layer is deteriorated by being exposed to the etching solution.

On the other hand, the method described in Document B has a problem that the shape and arrangement position of the spacer and the rubbing direction of the orientation control layer are considerably limited. For this reason, when the above method is adopted, the degree of freedom in designing a liquid crystal display element is greatly restricted. For example, when a wall spacer that can more firmly fix the substrate is used instead of the columnar spacer that fixes the substrate at the pinpoint, an abnormal alignment region occurs at both ends of the spacer. Therefore, in order to hide this, a considerable number of effective pixels cannot be used, and as a result, the aperture ratio of the pixels is significantly reduced.

The present invention has been made in view of the above circumstances, and a liquid crystal display element capable of strictly controlling and maintaining a cell gap and capable of performing high-quality display without alignment unevenness and switching failure. Another object of the present invention is to provide a method for manufacturing such a liquid crystal display element by a simple process.

[0015]

According to a first aspect of the present invention, there is provided a liquid crystal display device comprising: a liquid crystal layer made of a liquid crystal material; an electrode for applying a voltage to the liquid crystal layer; In a liquid crystal display device comprising a pair of substrates each having an alignment control layer for controlling the alignment of the liquid crystal layer on the electrode on the surface facing each other, and a spacer for maintaining a distance between the two substrates, It is characterized by taking.

That is, the liquid crystal display element includes an inorganic coating made of a photosensitive inorganic material formed on the alignment control layer in an inter-electrode region between the adjacent electrodes on one of the substrates; An adhesive spacing member that is formed on the coating, includes the spacer, and bonds the two substrates together.

In the above-mentioned liquid crystal display element, the spacing between the two substrates is kept constant by the spacer of the spacing member, and the two substrates are firmly bonded together over the entire surface by the adhesive spacing member. In the structure in which the spacing member is formed via the photosensitive inorganic film, the inorganic film can be patterned by light irradiation prior to the formation of the spacing member. The holder can be formed in a desired pattern.

When an adhesive is applied directly on the orientation control layer without using an inorganic coating to form a spacing member, it is necessary to apply the adhesive to the interelectrode region with high precision. However, it is difficult to apply the adhesive with sufficient accuracy. Further, even when the alignment control layer is subjected to a rubbing treatment after the formation of the gap holding member, unlike the above-mentioned resin spacer material, the gap holding body is not provided with the alignment regulating force by the rubbing treatment. The orientation of the liquid crystal molecules in the vicinity is not disturbed. Further, the inorganic coating also functions as a protective film for protecting the orientation control layer from the formation of an adhesive layer (application of an adhesive). In addition, unnecessary portions of the photosensitive inorganic material can be easily removed without using a solvent that attacks the alignment control layer, so that a decrease in the alignment function of the alignment control layer is suppressed as much as possible.

Further, in the liquid crystal display element in which the distance between the two substrates is kept constant and the two substrates are firmly bonded, as described above, the liquid crystal material is made strong. By using a dielectric liquid crystal material, the characteristics of the ferroelectric liquid crystal are not impaired. therefore,
A large-sized liquid crystal display device using a ferroelectric liquid crystal material can be easily realized.

In the liquid crystal display device according to the first aspect, a first step of forming the inorganic coating on the alignment control layer and a step of exposing the interelectrode region in the inorganic coating are provided. Two steps, a third step of forming an adhesive layer including the spacer on the inorganic coating, and a third step of forming the spacing member by removing an unexposed portion of the inorganic coating together with the adhesive layer thereon. It is manufactured by a manufacturing method including four steps and a fifth step of bonding the two substrates by the spacing member.

In the above manufacturing method, the inorganic film formed in the first step is exposed in the second step, so that the unnecessary portion of the adhesive layer formed on the inorganic film in the third step is removed in the fourth step. It is removed together with the unexposed portions of the inorganic coating. In this manner, the spacing member can be formed with high precision in the generally narrow inter-electrode region. Further, since the adhesive layer is removed together with the inorganic coating, the number of processing steps can be reduced. Furthermore, by exposing the photosensitive inorganic coating in advance, the inorganic coating can be removed with a solvent that does not deteriorate the orientation control layer.

According to the third aspect of the present invention, in the fourth aspect,
As described in above, it is preferable that a rubbing treatment is performed on the orientation control layer before the first step, and a thermosetting or thermoplastic adhesive material is used for forming the adhesive layer in the third step. In this case, the above-mentioned thermosetting or thermoplastic adhesive material exhibits adhesiveness by a subsequent step, for example, a heat treatment required for a step of bonding both substrates with a normal sealing agent. Can be performed simultaneously with the step of bonding both substrates with a sealant.

According to the third aspect of the present invention, there is provided the fifth aspect of the present invention.
As described in the above, while performing a rubbing treatment on the orientation control layer between the fourth step and the fifth step, and baking the inorganic coating under the spacing member before the rubbing treatment, In the third step, it is preferable to use a thermoplastic adhesive material for forming the adhesive layer.

In this case, the rubbing treatment for the orientation control layer is performed between the fourth step and the fifth step, so that the orientation control force of the orientation control layer is impaired by the treatment in the third step. Is completely gone. At this time, since the rubbing treatment is also applied to the spacing member formed on the orientation control layer, if the inorganic coating and the adhesive layer do not have sufficient hardness, they are peeled off by the rubbing treatment. When the inorganic coating and the adhesive layer are peeled, not only the formation of the spacing member becomes impossible, but also the peeled inorganic coating and the adhesive layer contaminate the substrate.

Therefore, in the present manufacturing method, the hardness of the inorganic coating is increased by firing the inorganic coating. In addition, if a thermosetting adhesive is used to form the adhesive layer, the adhesive loses its adhesive strength after being cured during the baking of the inorganic film, so the adhesive is re-adhered to join both substrates in the fifth step. It is necessary to apply an agent. Therefore, in the present manufacturing method, by using a thermoplastic adhesive instead of using a thermosetting adhesive, the inorganic coating is cured at the time of cooling after firing, and the fifth step is performed in the same manner as the manufacturing method of claim 4. At the same time, an adhesive layer which is softened by a heat treatment in a bonding step which can be performed and exhibits adhesiveness can be provided.

According to the third aspect of the present invention, there is provided the manufacturing method of the sixth aspect.
As described in above, it is preferable to form the adhesive layer by applying an adhesive material to which the spacer has been added in the third step. In this case, since the spacers are applied in a dispersed state in the adhesive material, the number of processing steps is reduced as compared with a method in which the spacers are dispersed separately from the application of the adhesive. In addition, spacers can be sprayed on desired portions of the applied adhesive material. Therefore, the spacers can be accurately distributed on the adhesive layer forming the spacing member.

[0027] In the above-mentioned production method according to claims 3 to 6, as described in claim 7, one kind selected from the group consisting of water, weak acid, weak alkali, lower alcohol and a mixture of lower alcohol and water. It is preferable to remove unexposed portions of the inorganic coating with a solvent. This can minimize the deterioration of the orientation control layer.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the liquid crystal cell (liquid crystal display element) according to the present embodiment has a pair of electrode substrates 10 and 20.
A liquid crystal layer 30 is formed between the pair of electrode substrates 10 and 20 by enclosing a ferroelectric liquid crystal material.

The above-mentioned electrode substrate 10 comprises a substrate 1, an electrode 2
.., An insulating layer 3 and an orientation control layer 4. The above-mentioned electrode substrate 20 has a substrate 11, electrodes 12, an insulating layer 13 and an orientation control layer 14.

The substrates 1 and 11 are made of a transparent insulating material such as glass and plastic. On the surface of the substrate 1, transparent and conductive electrodes 2 are formed in stripes parallel to each other. Electrodes 12 similar to the electrodes 2 are also formed on the surface of the substrate 11 in a stripe shape. The electrodes 2... And the electrodes 12 are arranged so as to be orthogonal to each other, and each intersecting region forms a pixel which is the minimum unit of display. Indium oxide, tin oxide, or indium tin oxide (ITO) is often used as a material for forming the electrodes 2 and the electrodes 12.

On the electrodes 2, a transparent insulating layer 3 and an alignment control layer 4 for controlling the alignment of the liquid crystal layer 30 are laminated in this order. Thereby, the electrode 2 adjacent to the electrode 2.
2) The surface of the substrate 1 appearing between 2 is covered with the insulating layer 3 and the orientation control layer 4. On the other hand, a transparent insulating layer 13 and an orientation control layer 14 for controlling the orientation of the liquid crystal layer 30 are laminated on the electrodes 12 in this order. As a result, the surface of the substrate 11 appearing between the electrodes 12 and the adjacent electrodes 12 is insulated from the insulating layer 13 and the orientation control layer 1.
4 covered.

The electrode substrates 10 and 20 need not include the insulating layers 3 and 13, respectively. However,
When the liquid crystal layer 30 has a thickness of 0.1
In a liquid crystal display element formed as thin as about 3 μm,
It is preferable that the electrode substrates 10 and 20 include the insulating layers 3 and 13 in order to ensure insulation between the electrode substrates 10 and 20.

As the material of the insulating layers 3 and 13, resins such as polyamide, polyimide, polyamide imide, polycarbonate, and acrylic resin, Si ₃ N ₄ , SiO ₂ ,
_{A1 2 0 3, Ta 2 0} 3 and the like of inorganic materials. On the other hand, examples of the material of the orientation control layers 4 and 14 include resins such as nylon, polyamide, polyimide, polyamideimide, and polyvinyl alcohol. In addition, the orientation control layer 4
14 is obtained by rubbing the surface of a coating made of the above-mentioned material with, for example, a cloth (uniaxial orientation treatment).

In the region of the substrate 10 between the adjacent electrodes 2 on the substrate 1, spacing members 6 are provided, for example, in a wall shape on the orientation control layer 4 via an inorganic coating 5. . The inorganic coating 5 is made of an inorganic material, and is formed in an arbitrary shape corresponding to the shape of the spacing member 6, for example, in a stripe shape. Further, the spacing member 6 is connected to the substrates 10 and 2.
It consists of a spacer for defining the interval between 0 and a thermoplastic or thermosetting adhesive. by this,
The distance (cell gap) between the substrates 10 and 20 is kept constant, and the substrates 10 and 20 are firmly adhered to each other.

As the spacer, for example, fibers or beads made of silica glass or beads made of resin are preferably used.

These substrates 10 and 20 are provided with an orientation control layer 4
The electrodes 2... And the electrodes 12... Are arranged so as to be orthogonal to each other, and are bonded together with a uniform spacing maintained by the spacing support 6. Also,
The periphery of the gap between the substrates 10 and 20 is bonded and fixed by a sealing agent (not shown). And
The gap between the substrates 10 and 20 is filled with a ferroelectric liquid crystal material so as to form the liquid crystal layer 30. A ferroelectric liquid crystal is suitable for large-capacity and high-definition display because it has excellent characteristics such as high-speed response and memory properties.

Further, the present liquid crystal cell is provided with polarizers (not shown) on the outer surfaces of the electrode substrates 10 and 20 for optically identifying changes in the optical axis of liquid crystal molecules in the liquid crystal layer 30.

In the liquid crystal cell constructed as described above, when a voltage is selectively applied to the electrodes 2 and 12 by a drive circuit (not shown), the alignment state of the liquid crystal molecules in the liquid crystal layer 30 is switched. The switching is identified by the above-mentioned polarizer, whereby a bright and dark display state is obtained.

Here, a method of manufacturing the present liquid crystal cell will be described with reference to FIGS. 2 (a) to 2 (c) and FIGS. 3 (a) and 3 (b).

First, as shown in FIG. 2A, after an electrode material (for example, IT0) is formed on the substrate 1, the electrodes 2 are formed by patterning in a stripe shape. An orientation control layer 4 is formed sequentially. The insulating layer 3 is formed by depositing or applying the above-described material on the substrate 1 on which the electrodes 2 are formed. The orientation control layer 4 is subjected to a rubbing treatment. Next, FIG.
As shown in (b), an inorganic material is applied to form an inorganic coating 5, and a photomask 40 is used to form an adjacent electrode 2.
The inorganic coating 5 between the two is exposed in the form of stripes with ultraviolet rays.

Further, after applying an adhesive 22 (thermosetting adhesive or thermoplastic adhesive) including spacer beads 21 (spacer) as shown in FIG. The unexposed portion of the inorganic coating 5 is peeled off together with the adhesive 22 using a weak acid, a weak alkali, a lower alcohol or a mixed solvent of a lower alcohol and water. As a result, as shown in FIG. 2C, inorganic coatings 5 and spacing members 6 are formed. Since the polymerization of the inorganic material is insufficient only by exposure to ultraviolet rays, the remaining stripe-shaped inorganic coatings 5 are baked so as to increase the hardness of the inorganic coatings 5.

Phosphoric acid, hydrochloric acid, acetic acid and the like are preferable as the weak acid, and sodium hydroxide is preferable as the weak alkali. Further, as the lower alcohol, ethanol, methanol, isopropyl alcohol and the like are preferable.

The thermosetting adhesive does not cure at the process temperature of the inorganic coating 5 (80 ° C. in the embodiment described later), withstands the patterning step of the inorganic coating 5, and forms the inorganic coating 5.
An adhesive that cures near the firing temperature (180 ° C. in the examples described later) and has heat resistance at that temperature is suitable. As such a thermosetting adhesive, specifically, a heat-resistant epoxy adhesive made of a polyfunctional resin is suitable. On the other hand, as the thermoplastic adhesive, an adhesive which does not cure at the process temperature of the inorganic coating 5, withstands the patterning step of the inorganic coating 5, and has adhesiveness and heat resistance near the firing temperature of the inorganic coating 5 is suitable. ing.

In the above-described step of forming the inorganic coatings 5, an adhesive 22 including spacer beads 21 is used. Instead, as shown in FIG. No adhesive 23 (thermoplastic adhesive)
May be applied on the inorganic coating 5 and then the spacer beads 21. By doing so, the electrode substrates 10 and 2
Since the thermoplastic adhesive 23 is softened by heating when bonding the spacer beads 2 through a sealant, the spacer beads 2
1 enter the adhesive 23. Therefore, the adhesive 23 at this time is in a state similar to the state where the adhesive 22 already containing the spacer beads 21 is applied (see FIG. 3A).

On the other hand, I on the substrate 11 has the same shape as the electrodes 2.
The electrodes 12 are formed by patterning the TO, and the electrode substrate 20 is manufactured by forming the insulating layer 13 and the orientation control layer 14. The electrode substrates 10 and 12 are arranged such that the electrodes 2 and 12 are orthogonal to each other and the rubbing directions of the alignment control layers 4 and 14 are parallel to each other.
20 are adhered to each other with a sealant under heating.

At this time, the electrode substrates 10 and 20 are adhered to each other by the adhesive force exerted by the adhesive 22 or the adhesive 23 forming the spacing members 6 under heating.
After the adhesive 22 or the adhesive 23 is cured, the distance between the electrode substrates 10 and 20 is defined by the spacer beads 21 and the electrode substrates 10 and 20 are firmly bonded by the adhesive 22 or the adhesive 23. Finally, a ferroelectric liquid crystal material is injected into the space between the electrode substrates 10 and 20, and the injection port is sealed with a sealant to complete the liquid crystal cell.

The step of firing the inorganic coating 5 may be performed simultaneously with the step of bonding the electrode substrates 10 and 20. By doing so, the number of manufacturing steps of the liquid crystal cell can be reduced. Further, in the above-described manufacturing method, the rubbing treatment is performed on the orientation control layer 4 before the formation of the inorganic coating 5, but the rubbing treatment may be performed thereafter. This will be described in detail later in a second embodiment.

[0049]

EXAMPLES Next, a method for manufacturing a liquid crystal cell according to the present embodiment will be described in more detail with reference to examples and comparative examples.

The production conditions such as the film thickness, heating time and heating temperature in each material and each step described below are merely examples, and the present invention is not limited by these.

[Embodiment 1] In the method of manufacturing a liquid crystal cell of the present embodiment, first, an ITO film was formed to a thickness of 0.1 μm on a glass substrate 1 by a sputtering method, and then this was striped. Are formed by patterning the electrodes 2. Next, NHC A-2014 (product number), which is an insulating film material manufactured by Nissan Chemical Industries, is formed to a thickness of 0.1 μm on the substrate 1 and the electrode 2. Are formed so as to cover.

Further, the alignment control layer 4 is formed so as to cover the insulating layer 3 by forming an alignment film material AL-5417 (product number) made of Japan Synthetic Rubber to a thickness of 70 μm on the insulating layer 3. Then, a rubbing alignment process is performed on the alignment control layer 4.

Next, HM-5001 (product number), which is an inorganic coating agent manufactured by Nissan Chemical Industries, was coated on the orientation control layer 4 by 0.1 μm.
m, and dried at 80 ° C. for 5 minutes to form an inorganic coating 5 so as to cover the orientation control layer 4. The inorganic coating agent has a main component as a precursor of a plurality of inorganic oxides, and has solubility in water. In addition, the inorganic coating agent becomes insoluble in water as a result of oxidative polymerization of the above-described precursor by irradiation with ultraviolet light and calcination.

Thereafter, the inorganic coating 5 is irradiated with ultraviolet rays in a stripe form via the photomask 40,
The inorganic coating 5 between the adjacent electrodes 2 is exposed.

Then, a thermoplastic adhesive STAYST manufactured by Techno Alpha Co., which has good adhesion to the inorganic coating 5.
Silica beads (1.5 μm diameter) manufactured by Ube Nitto Kasei are added to IK383 (product number) as spacer beads 21 in advance, and the thermoplastic adhesive is applied on the inorganic coating 5 and dried at 80 ° C. for 10 minutes. I do. As a result, the silica beads are fixed on the inorganic coating 5 in a state where the silica beads are surrounded by the thermoplastic adhesive.

Thereafter, ultrasonic waves are applied to the substrate 1 in a state where the substrate 1 is immersed in pure water, so that the unexposed portions of the inorganic coating 5 are removed from the silica beads and the thermoplastic adhesive formed thereon. And peel off. Here, the application of ultrasonic waves is not an essential step, but since the polymerization of the inorganic coating 5 before firing is incomplete, it is desirable to peel off the inorganic coating 5 in a short time using ultrasonic waves. Thus, the inorganic coatings 5 and the spacing members 6 are formed. afterwards,
By heating at 180 ° C. for 1 hour, the inorganic coatings 5 are completely baked.

Then, the inorganic coating 5 and the spacing member 6
.. With the electrode substrate 10 and the electrode substrate 20 facing each other, a thermoplastic bond (sealant) is applied to the electrode substrates 10 and 2.
After applying to the peripheral portion of 0, 2 kg of the electrode substrates 10 and 20 are applied.
The electrode substrates 10 and 20 are bonded by heating to 180 ° C. while pressing with a force of / cm ² . further,
After injecting and filling SCE-8, which is a ferroelectric liquid crystal material manufactured by Merck, into the gaps between the electrode substrates 10 and 20, the liquid crystal cell is completed by sealing the injection port.

In the liquid crystal cell thus manufactured,
As a result, a cell gap of approximately 1.5 μm in height of the spacer beads 21 was secured, and the spacing members 6 did not peel off. Also, 5
Even when a pressure up to kg / cm ² is applied, the liquid crystal material (SCE-
8) No change in the orientation and no peeling of the spacing members 6 are observed. As described above, the adhesive strength of the electrode substrates 10 and 20 in the liquid crystal cell of the present embodiment is such that it can sufficiently withstand practical use.

[Embodiment 2] In the method of manufacturing a liquid crystal cell of the present embodiment, the rubbing treatment of the alignment control layer 4 is not performed before the application of the inorganic coating agent (HM-5001), and the inorganic coating 5
.. Are the same as in the manufacturing method of the first embodiment, except that they are performed after firing.

In the liquid crystal cell manufactured as described above, the orientation of the liquid crystal material (SCE-8) is controlled by the distance holding member 6.
... well maintained without any disturbance. Further, even if a pressure test similar to that of the liquid crystal cell of Example 1 was performed,
It was confirmed that the adhesive strength of the electrode substrates 10 and 20 was of a level that could be sufficiently used in practical use.

In this manufacturing method, if the inorganic coatings 5 and the spacing members 6 do not have sufficient hardness, they may be peeled off by a rubbing treatment. ing. For this reason,
When a thermosetting adhesive is used in place of the thermoplastic adhesive to form the spacing members 6 in the above-described manufacturing method, the thermosetting adhesive has an adhesive strength after heating by firing the inorganic coatings 5. Disappears. Therefore, in order to bond the electrode substrates 10 and 20, it is necessary to apply an adhesive again. Since such a process is difficult to put into practical use, it is not suitable to use a thermosetting adhesive in the above-mentioned production method.

[Comparative Example 1] In the manufacturing method of this comparative example, the electrode substrate 10 and the inorganic coatings 5 produced in Examples 1 and 2 were used.
An electrode substrate having the same structure as that of the electrode substrate except that the spacers 6 are not included is prepared. In addition, a rubbing treatment is performed on the orientation control layer of the electrode substrate, and silica beads (1.5 μm diameter, manufactured by Ube Nitto Kasei) are sprayed on the orientation control layer. After bonding such an electrode substrate and an electrode substrate having the same structure as the electrode substrate 20 by using a Konishi two-liquid mixed-type bond as a sealant, the SCE-8 is filled between the two electrode substrates. .

The orientation of the liquid crystal material (SCE-8) in the liquid crystal cell thus manufactured is very good, but when a pressure of 0.5 kg / cm ² is applied to the liquid crystal cell, the orientation of the liquid crystal material is broken. Was confirmed.

[Comparative Example 2] In the manufacturing method of this comparative example, an electrode substrate having the same structure as that of the electrode substrate 10 manufactured in Example 1 except that the inorganic coatings 5 and the spacers 6 were not used was used. The orientation control layer is subjected to a rubbing treatment,
Furthermore, on the orientation control layer, a photosensitive resin V-
259PA (product number) is applied to a thickness of 1.5 μm and further dried. Next, the photosensitive resin film is subjected to patterning and baking by mask exposure and development to form a striped spacer. And
After bonding the electrode substrate having the spacer and the electrode substrate having the same structure as the electrode substrate 20, SCE-8 is filled between the two electrode substrates.

In the liquid crystal cell manufactured in this manner, deterioration of the orientation of the liquid crystal material (SCE-8) was observed as compared with Examples 1 and 2 and Comparative Example 1. It is considered that the cause is that the photosensitive resin was applied on the rubbed alignment control layer, and then peeled off, whereby the alignment control force of the alignment control layer was reduced.

Comparative Example 3 In the manufacturing method of this comparative example, the rubbing treatment was not performed before the application of the photosensitive resin, but instead the rubbing treatment was performed after patterning the photosensitive resin into stripes. The same processing as in Example 2 is performed. In the liquid crystal cell thus manufactured, as a result of the generation of a region that does not respond to an electric field in the liquid crystal layer around the spacer (photosensitive resin), remarkable deterioration in display characteristics was confirmed.
This is considered to be due to the effect of rubbing applied to the resin spacer affecting the liquid crystal layer.

[0067]

As described above, the liquid crystal display device according to the first aspect of the present invention comprises a liquid crystal layer made of a liquid crystal material, an electrode for applying a voltage to the liquid crystal layer, and an alignment of the liquid crystal layer on the electrode. A pair of substrates each having an alignment control layer for controlling the surface of the substrate, and a photosensitive inorganic material formed on the alignment control layer in an interelectrode region between the adjacent electrodes on one of the substrates. The structure includes an inorganic film and an adhesive spacing member formed on the inorganic film, including the spacer, and bonding the two substrates together.

As a result, the spacing between the two substrates is kept constant by the spacers of the spacing member, and the two substrates are firmly bonded over the entire surface by the adhesive spacing member. In addition, since the patterning of the inorganic coating can be freely performed by light irradiation prior to the formation of the spacing member,
The spacing member can be formed in a desired pattern together with the inorganic coating. Further, even when a rubbing treatment is performed on the alignment control layer after the formation of the spacing member, no alignment regulating force is applied to the spacing member, so that the alignment of the liquid crystal molecules near the spacing member is not disturbed. In addition, the inorganic coating also functions as a protective film for protecting the orientation control layer from the adhesive. Moreover, photosensitive inorganic materials
Unnecessary portions can be easily removed without using a solution that will attack the orientation control layer, so that the orientation function of the orientation control layer can be suppressed as much as possible. Therefore, there is an effect that the cell gap can be strictly controlled and maintained, and a high-quality display free from alignment unevenness and switching failure can be realized.

A liquid crystal display device according to a second aspect of the present invention comprises:
2. The liquid crystal display device according to claim 1, wherein the liquid crystal material is a ferroelectric liquid crystal material, so that a large display device particularly suitable for a ferroelectric liquid crystal having characteristics superior to a nematic liquid crystal can be easily put into practical use. This has the effect that it can be achieved.

According to a third aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, the method comprising the steps of: forming the inorganic coating on the alignment control layer;
A second step of exposing the interelectrode region in the inorganic coating, a third step of forming an adhesive layer including the spacer on the inorganic coating, and exposing an unexposed portion of the inorganic coating thereon. The method includes a fourth step of forming the spacing member by removing it together with the adhesive layer, and a fifth step of bonding the two substrates together by the spacing member.

As a result, the spacing member can be formed with high precision in the generally narrow electrode region. Also,
Since the adhesive layer is removed together with the inorganic coating, the number of processing steps can be reduced. Further, by exposing the photosensitive inorganic film to light, the inorganic film can be removed with a solvent that does not deteriorate the orientation control layer. Therefore, it is possible to easily produce a liquid crystal display element that can control and maintain the cell gap strictly and that can perform high-quality display without alignment unevenness and switching failure.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device according to the third aspect, wherein the alignment control layer is subjected to a rubbing treatment before the first step, while the rubbing treatment is performed in the third step. Since a thermosetting or thermoplastic adhesive material is used for the formation of the adhesive layer, the above-described thermosetting or thermoplastic adhesive is formed by a subsequent process, for example, a heat treatment required for a bonding process of both substrates with a sealant. Since the adhesive material exhibits an adhesive property, the process of the fifth step can be performed simultaneously with the step of bonding both substrates with a sealant. Therefore, there is an effect that the manufacturing process can be simplified by performing a process necessary for bonding together with other processes.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device according to the third aspect, further comprising performing a rubbing process on the alignment control layer between the fourth step and the fifth step. Before baking the inorganic coating under the spacing member before the rubbing treatment, while using a thermoplastic adhesive material to form the adhesive layer in the third step,
The orientation control force of the orientation control layer is not lost at all by the treatment in the third step. Further, since the hardness of the inorganic film is increased by firing the inorganic film, the inorganic film is not peeled off by the rubbing treatment. further,
By using a thermoplastic adhesive instead of a thermosetting adhesive, the inorganic coating cures during cooling after firing,
Similarly to the manufacturing method of the fourth aspect, it is possible to provide an adhesive layer that exhibits adhesiveness by being softened by heat treatment in a bonding step that can be performed simultaneously with the fifth step. Therefore, in addition to the effect of the manufacturing method of claim 4, there is an effect that the alignment control force of the alignment control layer can be almost completely maintained.

According to a sixth aspect of the present invention, in the method of manufacturing a liquid crystal display element, the adhesive layer is formed by applying the adhesive material to which the spacer is added in the third step of the manufacturing method of the third aspect. Therefore, the number of processing steps is reduced as compared with the method in which the spacer is sprayed separately from the application of the adhesive. Further, the spacers can be accurately distributed on the adhesive layer forming the spacing member. Therefore, in addition to the effect of the manufacturing method of the third aspect, the liquid crystal display element can be manufactured in a more simplified process, and the function of maintaining the distance between the two substrates by the distance maintaining member can be further ensured. It has the effect of being able to.

The method for producing a liquid crystal display element according to claim 7 of the present invention is the method for producing a liquid crystal display element according to any one of claims 3 to 6, wherein water, a weak acid, a weak alkali, a lower alcohol and a mixture of a lower alcohol and water are used. Since the unexposed portion of the inorganic coating is removed by one kind of solvent selected from the group consisting of, the deterioration of the orientation control layer can be minimized. Therefore, there is an effect that a decrease in the alignment regulating force applied to the alignment control layer by the rubbing treatment performed before or after the removal of the inorganic coating can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a liquid crystal cell according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing each step of manufacturing one electrode substrate constituting the liquid crystal cell.

FIG. 3 is a sectional view showing a state of an adhesive applied on an inorganic film in the liquid crystal cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1.1 Substrate 2.12 Electrode 4.14 Alignment control layer 5 Inorganic coating 6 Spacer 21 Spacer beads (spacer) 22.23 Adhesive 30 Liquid crystal layer

Continuation of the front page (71) Applicant 390040604 United Kingdom THE SECRETARY OF STATE FOR DEFENSE IN HER BRITANNIC MAJES TY'S GOVERNMENT OF THE THE UNERED KINGDOM OF GREEN BRIGHTNOR BRIGHTNOR BIRTH Road (No address) Defence Evaluation and Research Agency (72) Inventor Masami Kido 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka

Claims (7)

[Claims] 1. A pair of substrates each having a liquid crystal layer made of a liquid crystal material, an electrode for applying a voltage to the liquid crystal layer, and an alignment control layer for controlling the alignment of the liquid crystal layer on the electrodes on opposite surfaces. A liquid crystal display element having a spacer for maintaining a distance between the two substrates, wherein a photosensitive inorganic material formed on the alignment control layer in an interelectrode region between the adjacent electrodes on one of the substrates. A liquid crystal display device comprising: an inorganic film formed on the inorganic film; and an adhesive spacing member that includes the spacer and bonds the two substrates together. 2. The liquid crystal display device according to claim 1, wherein said liquid crystal material is a ferroelectric liquid crystal material. 3. A first step of forming the inorganic coating on the orientation control layer, a second step of exposing the interelectrode region in the inorganic coating, and forming an adhesive layer containing the spacer on the inorganic coating. A third step of forming, and a fourth step of forming the spacing member by removing an unexposed portion of the inorganic coating together with the adhesive layer thereon.
And a fifth step of bonding the two substrates by the spacing member.
2. The method according to claim 1, further comprising the steps of: 4. A rubbing treatment is applied to the orientation control layer before the first step, and a thermosetting or thermoplastic adhesive material is used for forming the adhesive layer in the third step. The method according to claim 3. 5. A rubbing treatment for the orientation control layer between the fourth step and the fifth step, and baking the inorganic coating under the spacing member before the rubbing treatment. The method according to claim 3, wherein a thermoplastic adhesive material is used for forming the adhesive layer in the third step. 6. The method according to claim 3, wherein the adhesive layer is formed by applying an adhesive material to which the spacer is added in the third step. 7. The unexposed portion of the inorganic coating is removed by one kind of solvent selected from the group consisting of water, weak acids, weak alkalis, lower alcohols and mixtures of lower alcohols and water. 7. The production method according to any one of items 1 to 6.