JP2002350873A - Liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display element wherein an alignment state of any liquid crystal material is stabilized in the compatible relation to a sealing material and an inexpensive manufacturing method having a small number of stages can be realized. SOLUTION: The elution of the sealing material into a liquid crystal 3 is prevented by providing a seal barrier 10 forming a pattern parallel to a seal 6 inside the seal 6 to previously prevent the abnormality of the alignment state on the periphery of the seal 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art Originally, a liquid crystal cell is filled with liquid crystal in a method of manufacturing a liquid crystal display element by an injection method and a dropping method. The former injection method is generally handled in mass production, and a vacuum method is used. The liquid crystal is filled from the opening of the empty cell by utilizing the capillary phenomenon and the pressure difference. On the other hand, the dropping method is a method in which liquid crystal is dropped on a substrate in advance and then two substrates are bonded in a vacuum. In particular, the latter dropping method has an advantage that the lead time is very short.

[0003] A method of manufacturing a liquid crystal display element by a conventional dropping method will be described below. FIG. 7 shows a manufacturing process diagram of a liquid crystal display element by a conventional dropping method. FIG. 8 shows a cross-sectional configuration diagram of the liquid crystal display element completed in this manufacturing process.
Reference numerals 2a and 2b denote substrates provided with color filters, black matrices or active elements. Reference numeral 3 denotes a liquid crystal sandwiched between the substrates 2a and 2b and sealed by a seal 6. Reference numeral 4 denotes substrates 2a and 2
b is a spacer for maintaining the gap, 5a and 5b are deflecting plates, and 7 is an alignment film for aligning liquid crystal molecules.

[0004] This liquid crystal display device has a structure having a display electrode.
The liquid crystal 3 is interposed between the two substrates 2a and 2b, the spacers 4 are dispersed so as to form a predetermined gap, and the polarizing plates 5a and 5b and other optical members are provided outside the two substrates 2a and 2b. Install the film in the most suitable place. Polarizing plate 5a,
5b may be one, two, or not used depending on the principle mode.

In the case of a transmissive type, this liquid crystal display element is illuminated with a three-wavelength cold cathode tube or the like from the opposite side of the display surface to display an image. In the case of a reflective type, a reflective plate is provided on the opposite side of the display surface. It can be made brighter using outside light. In such a form, the liquid crystal display element can be driven as a display by voltage driving.

In FIG. 7, first, the substrates 2a and 2b are washed (S1a and S1b), and a liquid alignment film 7 is applied by offset printing or the like, and then tentatively baked and finally baked.
Is formed (S2a, S2b), and an alignment process such as rubbing is performed (S3a, S3b). Generally, after rubbing, water washing is performed to remove foreign substances and dirt on the surface.
The seal 6 is applied to the substrate 2a thus formed by drawing or printing (S4a), and the spacers 4 are uniformly spread on the substrate 2b (S4b). As shown in FIG. 9, the seal 6 is formed on the loop because there is no inlet. For the seal 6, a radical or cationic UV resin is used. The spacer 4 is formed by using a fixed type (S5b).
b requires a certain amount of adhesion strength. And
The conductive resin is spot-coated with a dispenser. next,
Although the liquid crystal 3 is dropped, it is more convenient to drop the liquid crystal 3 on the substrate 2a to which the seal 6 has been applied (S5a).
The liquid crystal 3 to be dropped can be calculated in advance from the display area of the liquid crystal display element and the gap thickness, and the liquid crystal 3 is dropped so that the liquid crystal 3 spreads uniformly.

Next, both substrates 2a, 2a are assembled using an assembling machine.
2b is attached (S6). The substrate 2a with the liquid crystal 3 dropped in the vacuum chamber is placed below, the substrate 2b is placed above, and the inside of the chamber is evacuated. 2b, and then the inside of the tank is returned to the atmosphere. Next, both substrates 2a, 2
The seal 6 between b is irradiated with ultraviolet rays to cure the seal 6 (S7). Next, the liquid crystal 3 is realigned in an annealing step (S8), and the substrates 2a and 2b are cut to complete a liquid crystal display element (S9).

According to the above-mentioned conventional method of manufacturing a liquid crystal display element by the dropping method, the process tact of the step of dropping the liquid crystal is about 1/100 of the process tact of the liquid crystal injection step of the vacuum injection method. Can be shortened. Therefore, it is possible to fabricate a liquid crystal display element in a shorter time, and it is considered to be the most suitable method for a field such as a monitor or a liquid crystal television which requires a large substrate size.

[0009]

In the manufacture of a liquid crystal display element using a dropping method, an ultraviolet-curable resin material is used for a seal, because the working time for curing the seal is shortened. This is because if the working time is long, the sealing material will be mixed in the liquid crystal near the seal,
This is because this causes poor alignment and threshold value deterioration. From such a viewpoint, it can be said that a UV-curable sealing material is most suitable for the dropping method.

[0010] However, even if an ultraviolet-curable sealing material that can be cured in a short time is used, some liquid crystal materials react sensitively with the sealing composition components, and further measures are taken against mixing of the liquid crystal and the sealing material. Is required.

Although various methods can be considered as the above countermeasures, the cost reduction of the liquid crystal panel is currently required most strongly. Therefore, it is necessary to reduce the number of steps as much as possible and to produce a panel with good performance. Is done.

As described above, in the manufacturing method having the liquid crystal filling step by the dropping method, impurities are mixed into the liquid crystal material when the sealing material in the wet state comes into contact with the liquid crystal material, thereby causing instability of the alignment state. This may cause the display quality of the liquid crystal panel to be poor.

In the present invention, in order to solve the above problem,
It is an object of the present invention to provide a liquid crystal display element which can stabilize an alignment state in a compatible relationship with a sealing material for any liquid crystal material, and can realize an inexpensive manufacturing method with a small number of steps. I do.

[0014]

According to a first aspect of the present invention, there is provided a liquid crystal display element provided between a pair of substrates facing each other and having a liquid crystal sealing seal having no opening.
The spacer includes a spacer that keeps a space between the pair of substrates and a seal barrier that is provided inside a position where the seal is provided and prevents elution of the sealant.

According to the first aspect of the present invention, since the seal barrier is provided inside the seal to prevent elution of the seal material, the seal material can be prevented from being dissolved in the liquid crystal. Therefore, the alignment state around the seal is also stabilized, and display defects of the liquid crystal display element can be prevented. Providing the seal barrier also contributes to making the gap uniform in the plane.

The liquid crystal display device according to the second aspect is the first aspect.
In the described invention, the spacer is a columnar projection.

According to the second aspect of the invention, the same effect as that of the first aspect of the invention is exhibited.

The liquid crystal display device according to the third aspect is the second aspect.
In the described invention, the seal barrier and the spacer are made of a photosensitive material.

According to the third aspect of the present invention, in the second aspect of the present invention, since the seal and the spacer of the columnar projection are made of the same photosensitive material, it is possible to manufacture them simultaneously. Therefore, an inexpensive manufacturing method that does not increase the number of steps can be realized.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid crystal display device and a method for manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1 is a cross-sectional configuration diagram of a liquid crystal display element according to an embodiment.
In FIG. 1, 1 to 7 are the same as those shown in FIG. The above substrate 2a, a color filter substrate in 2b, an array substrate active device is arranged, there is a substrate for a transparent electrode, etc. are formed, also made of resin and SiO ₂ such as Benzokuanamin the spacer 4 spherical In some cases, the spacer 4 is fixed to the substrates 2a and 2b in order to improve the uniformity of the gap. The sealing material 6 is desirably an ultraviolet curable type such as a radical type or a cationic type.

The difference from the conventional liquid crystal display device is that the seal 6
The point is that the seal barrier 10 is formed inside the inside. The height of the seal barrier 10 is desirably equal to or less than the height of the spacer 4, and should be equal to or less than the cell gap when the cell is completed. Further, as a method for forming the seal barrier 10, it is suitable to form a pattern by a photolithography method or a printing method.
The material of the seal barrier 10 is also determined by a forming method such as photosensitivity and thermosetting. Specifically, in the case of a photosensitive material, an ultraviolet curable composition based on an acrylic polymer, which is a main component of a color filter, is used and is hardened by ultraviolet light. In the case of a thermosetting material, a composition based on an acrylic polymer which is a main component of a color filter and including a thermosetting agent is employed as the material of the seal barrier 10. In addition,
Even when a composition containing a thermosetting agent based on an acrylic polymer which is a main component of a color filter is employed, it can be formed by a photolithography method by mixing an ultraviolet curing agent. Figure 2 shows the barrier pattern
Shown in

Next, a manufacturing process of a method for manufacturing a liquid crystal display element by a dropping method using the substrate on which the above-mentioned seal barrier 10 is formed is shown in FIG. First, a substrate having the above-described seal barrier 10 formed on either the substrate 2a or 2b is prepared. Substrate 2 after cleaning (S1a, S1b)
A liquid alignment film 7 is offset-printed on a and 2b, and dried at a high temperature to form an alignment film 7 (S2a, S2b). Then, the surface 7 of the alignment film on the substrate is rubbed with a buff (S3a, S3b), and if there is a foreign substance on the surface, a cleaning step is performed. The seal 6 is applied to the substrate 2a thus formed by drawing or printing (S4a), and the liquid crystal 3 is dropped (S5a).
The spacers 4 are evenly spread on the substrate 2b (S4b) and fixed (S5b). The seal 6 is formed outside the seal barrier 10 as shown in FIG. Then, the conductive resin is applied in a spot manner with a dispenser. Then, both substrates 2a and 2b are bonded together using an assembling machine (S6). The substrate 2a on which the liquid crystal 3 is dropped is placed below in the vacuum chamber, the substrate 2b is installed above, and the inside of the chamber is evacuated. Then, the two substrates 2a and 2b are positioned so as to obtain the positioning accuracy of the upper and lower substrates 2a and 2b. 2b, and then the inside of the tank is returned to atmospheric pressure. Then, the sealing material 6 between the two substrates 2a, 2b
The seal 6 is cured by irradiating ultraviolet rays to the surface (S7). Next, the liquid crystal 4 is subjected to a re-orientation process in an annealing step (S
8), the substrates 2a and 2b are cut to complete the liquid crystal display device (S9).

As described above, in the present embodiment, since the seal barrier 10 is provided inside the seal 6 in parallel with the seal 6, it is possible to suppress the display defect phenomenon caused by the impurities being dissolved from the seal 6 beforehand. it can. Further, the provision of the seal barrier 10 contributes to maintaining the in-plane uniformity of the gap.

When the above-described dripping method is used, the manufacturing process of the cell is greatly changed, and the conventional off-line can be changed to in-line. In particular, an injection process that takes several tens of hours with a liquid crystal display element of several tens of inches can be processed in a few minutes, shortening the overall lead time, reducing equipment costs, and being effective against defects such as lot out. is there. Therefore, it is possible to provide a beautiful liquid crystal display device by improving the narrow gap accuracy required in a new mode in the future and the uniformity in the gap plane, and improve the alignment accuracy to increase the aperture ratio and achieve a bright liquid crystal display device. realizable. Especially LCD
Monitors are required to have a 20-inch liquid crystal display element, and such a demand will be sufficiently met in the future as the size of the substrate increases.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
1 is a cross-sectional configuration diagram of a liquid crystal display element according to an embodiment.
In FIG. 5, 1 to 7 are the same as those shown in FIG. The difference from the first embodiment is that a plurality of columnar projections 12 are formed at regular positions so as to form a predetermined gap. In the present embodiment, the projections 12 are formed on the substrate 2a, but there is no problem if they are formed on the substrate 2b. Generally, the projections 12 are formed by a photolithography method, and in the present embodiment, the seal barrier 10 is formed at the same time as the projections 12 are formed. The height of the seal barrier 10 may be the same as the height of the projection 12 forming the gap. However, the height of the seal barrier 10 is desirably equal to or less than the height of the protrusion 12, and it is necessary that the height of the seal barrier 10 be equal to or less than the cell gap in a completed state of the cell. In addition, it is suitable to form a pattern by a photolithography method as a method of forming the seal barrier 10 and the protrusions 12, and the material of the seal barrier 10 has the same photosensitivity as the protrusions 12. Specifically, as described in the first embodiment, an ultraviolet curable composition based on an acrylic polymer as a main component of a color filter, or an acrylic curable composition based on an acrylic polymer as a main component of a color filter is used. A material obtained by adding an ultraviolet curing agent to a composition containing a heat curing agent is used as the material of the seal barrier 10. The barrier pattern is the same as that shown in FIG.

Next, FIG. 6 shows a process chart of a method of manufacturing a liquid crystal display element by a dropping method using the above substrate. First, a substrate on which the protrusion 12 and the seal barrier 10 described above are formed on either the substrate 2a or 2b is prepared.
The liquid alignment film 7 is offset-printed on the cleaned substrates 2a and 2b (S1a and S1b), and dried at a high temperature to form the alignment film 7 (S2a and S2b). Then, the surface 7 of the alignment film on the substrate is rubbed with a buff (S3a, S3b),
If there is a foreign substance on the surface, it passes through a cleaning process. A seal 6 is applied to the substrate 2a thus formed by drawing or printing (S4
a), the seal 6 is formed outside the seal barrier 10 as shown in FIG. Then, the liquid crystal 3 is dropped (S5a), and the conductive resin is applied in a spot manner with a dispenser. Thereafter, the two substrates 2a and 2b are bonded together (S6). The substrate 2a on which the liquid crystal 3 is dropped is placed below, the substrate 2b is placed above, and the inside of the vacuum tank is evacuated. And 2b, and then the inside of the vacuum chamber is returned to atmospheric pressure. Then, the sealing material 6 between the two substrates 2a and 2b is cured so that the sealing material 6 is irradiated with ultraviolet rays (S7). Next, the liquid crystal 3 is subjected to a reorientation process in an annealing step (S8), and the substrates 2a and 2b are cut (S9) to complete a liquid crystal display element.

As described above, in the present embodiment, since the seal barrier 10 is provided inside the seal 6 in parallel with the seal 6, it is possible to prevent a display defect phenomenon caused by the impurity from escaping from the seal 6. it can. Further, since the seal barrier 10 and the projection 12 are formed at the same time, the number of manufacturing steps of the liquid crystal display element is not increased, and therefore, an increase in manufacturing cost can be prevented. In addition, the provision of the seal barrier 10 contributes to maintaining the in-plane uniformity of the gap.

When the above-described dripping method is used, the manufacturing process of the cell is greatly changed, and it is possible to perform in-line conversion from the conventional off-line. In particular, an injection process that takes several tens of hours with a liquid crystal display element of several tens of inches can be processed in a few minutes, shortening the overall lead time, reducing equipment costs, and being effective against defects such as lot out. is there. Therefore, it is possible to provide a beautiful liquid crystal display device by improving the narrow gap accuracy required in a new mode in the future and the uniformity in the gap plane, and improve the alignment accuracy to increase the aperture ratio and achieve a bright liquid crystal display device. realizable. Especially LCD
Monitors are required to have a 20-inch liquid crystal display element, and such a demand will be sufficiently met in the future as the size of the substrate increases.

[0030]

According to the first aspect of the present invention, since the seal barrier is provided inside the seal to prevent elution of the seal material, it is possible to prevent the seal material from being dissolved in the liquid crystal. it can. Therefore, the alignment state around the seal is also stabilized, and display defects of the liquid crystal display element can be prevented. Providing the seal barrier also contributes to making the gap uniform in the plane.

According to the second aspect of the present invention, the same effects as those of the first aspect of the invention are exhibited.

According to the third aspect of the present invention, in the second aspect of the present invention, since the seal and the spacer of the columnar projection are made of the same photosensitive material, it is possible to manufacture them simultaneously. Therefore, an inexpensive manufacturing method that does not increase the number of steps can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal display element according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a barrier pattern according to the embodiment of the present invention.

FIG. 3 is a manufacturing process diagram of a liquid crystal display element according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing a seal pattern according to the embodiment of the present invention.

FIG. 5 is a sectional view of a liquid crystal display device according to another embodiment of the present invention.

FIG. 6 is a manufacturing process diagram of a liquid crystal display element according to another embodiment of the present invention.

FIG. 7 is a manufacturing process diagram of a conventional liquid crystal display element.

FIG. 8 is a sectional view of a conventional liquid crystal display element.

FIG. 9 is a schematic view showing a conventional seal pattern.

[Explanation of symbols]

 2a, 2b Substrate 3 Liquid crystal 4 Spacer 6 Seal 10 Seal barrier 12 Projection

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiteru Yamada 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 2H089 LA09 LA42 MA07Y MA07Z NA22 QA01

Claims (3)

[Claims] 1. A liquid crystal sealing seal having no opening provided between a pair of opposed substrates, a spacer for maintaining a distance between the pair of substrates, and provided inside a position where the seal is provided. A liquid crystal display device comprising: a sealing barrier that prevents a sealing material from being eluted. 2. The liquid crystal display device according to claim 1, wherein the spacer is a columnar projection. 3. The liquid crystal display device according to claim 2, wherein the seal barrier and the spacer are made of a photosensitive material.