JPH07318955A - Production of liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide a production method of a liquid crystal display element by which a liquid crystal material is not wasted or contaminated when the liquid crystal material is injected in the space between two insulating transparent substrates which constitute a cell and the production cost is decreased. CONSTITUTION:(a) A pattern for plural liquid crystal cells is formed on the one of a large-size insulating transparent substrate. (b) A sealing agent is applied around each cell pattern except for the injection port of a liquid crystal material. Further, at least two injection ports 3 for the liquid crystal material of the liquid crystal cell 10a are formed near to each other and a liquid crystal reservoir 7 is formed connecting to the injection ports 3. (c) One or more substrates 2a and 2b smaller than the substrate 1 are laminated in such a manner that the liquid crystal reservoir 7 is exposed. (d) Both of substrates 1, and 2a and 2b are adhered with the sealing agent 4. (e) The liquid crystal material is injected from the liquid crystal reservoir 7 to the space between the substrates 1, and 2a and 2b. Then the product is cut to divide into each liquid crystal cell 10a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device. More specifically, the present invention relates to a method for manufacturing a liquid crystal display device in which a method for injecting a liquid crystal material into a gap between two insulating transparent substrates which are adhered while maintaining a constant gap is improved.

[0002]

2. Description of the Related Art In general, a liquid crystal display device has two insulating transparent substrates each provided with an electrode pattern, an alignment film, etc., which are held in a fixed space and are adhered by a sealant around the electrode pattern. It is composed of a liquid crystal cell formed by enclosing a liquid crystal material in the gap, and a polarizing plate, a backlight, a circuit board and the like provided on both outer sides of the liquid crystal cell.

The manufacturing of this liquid crystal cell is generally performed as follows. First, form electrode patterns and alignment films for multiple liquid crystal cells on one insulating transparent substrate such as a large glass plate, and seal around the electrode patterns for each liquid crystal cell except for the liquid crystal material injection port. Apply the agent. Then, the other insulative transparent substrate provided with the opposing electrodes of each liquid crystal cell is overlaid so that the electrode patterns face each other, and is heated while being pressurized, whereby a large-sized insulative transparent substrate with the above-mentioned sealant is applied. Affix. After that, by cutting a large insulating transparent substrate further outside the sealant, it is separated for each liquid crystal cell, and the liquid crystal material is injected from the liquid crystal material injection port for each cell, and the injection port is sealed. A liquid crystal cell is manufactured by performing (a state in which two transparent substrates not filled with a liquid crystal material are attached to each other is simply called a cell, and a liquid crystal material is filled therein is called a liquid crystal cell. The same applies hereinafter). .

In order to improve the working efficiency in the step of injecting the liquid crystal material, a plurality of cells formed on a large transparent substrate should not be completely cut and separated into individual cells.
As shown in FIG. 5, the liquid crystal material injection port 3 is cut so that several cells are connected so that the liquid crystal material injection port 3 is aligned with the end in one direction, and the liquid crystal material injection port 3 of each cell is immersed in the liquid crystal reservoir. Alternatively, a method is used in which the liquid crystal material is dropped into the liquid crystal material injection port 3 by a dispenser or the like, and the liquid crystal material is injected collectively into several cells. FIG. 5 is a plan view showing a state where two large glass substrates 1 and 2 are pasted with a sealant 4.
An electrode pattern (not shown) of each cell is formed on the inner side surrounded by the sealing material 4. In this example, three cells 10 are provided, and after injection of the liquid crystal material, they are separated into individual cells 10 by a method such as scribing and breaking at the alternate long and short dash line P. The liquid crystal material is injected in a vacuum state by immersing the liquid crystal material injection port 3 in a liquid crystal reservoir or dropping the liquid crystal material into the liquid crystal material injection port 3 with a dispenser or the like, and then releasing the vacuum state to form a gap between the substrates. The liquid crystal material is injected by utilizing the pressure difference from the outside.

FIG. 6 shows another example of a conventional method of injecting a liquid crystal material before cutting and separating into individual cells. This example is disclosed in JP-A-61-217018, and as shown in FIG. 6A, four cells 10 are formed on large glass substrates 1 and 2, and a sealing material 4 is used.
Is provided so as to surround an electrode pattern (not shown) or the like around each cell, and the sealant 4 of each cell 10 is continuous, and the liquid crystal material injection port 3 is provided on the large glass substrates 1 and 2. It is formed to gather in the center. As a result, the large glass substrates 1 and 2 form a sealed space by the series of sealant 4, and the glass substrate 2 at one of the central portions thereof is provided with the opening 7, and the liquid crystal material is provided from the opening 7 to each cell 10. Injecting. After injecting the liquid crystal material, the liquid crystal material injection port 3 is sealed with the sealant 8 and cut into individual liquid crystal cells 10a by a method such as scribing and breaking at the alternate long and short dash line A. 6B is a sectional view taken along the line D-D of FIG. 6A, and FIG. 6C is one liquid crystal cell 1 which is cut and separated.
0a shows a plan view of 0a.

[0006]

In the method of injecting the liquid crystal material after cutting and separating into the individual cells or exposing the liquid crystal material injection port aligned at one end, a sealing agent for each cell is used. Since the liquid crystal material enters the gap between the substrates on the outer side and the liquid crystal material spills from the liquid crystal reservoir, there is a problem that the amount of loss of the expensive liquid crystal material increases and the cost of the liquid crystal display element increases. Furthermore, since a large glass substrate, which is an insulative transparent substrate, is cut before injecting the liquid crystal material, dust generated at the time of cutting adheres to the transparent substrate, which easily mixes into the liquid crystal material and contaminates the liquid crystal material. There's a problem.

Further, in the above-mentioned method of injecting the liquid crystal material in a state where the large insulative transparent substrate is left as it is without cutting and separating into each cell or a set of several cells in advance, the opening 7 for injecting the liquid crystal material is formed. Must be provided at the center of a large insulating transparent substrate. It is relatively easy to provide an opening at the center of a large substrate with a film substrate made of polyethersulfone, polycarbonate, etc., but if a glass plate that is usually used as a substrate is used, cutting due to scribe and break will occur. The method cannot be used, and beam processing such as laser must be performed. Therefore, there is a problem that the production process becomes complicated and the equipment is expensive, which causes a cost increase.

The present invention has been made in order to solve such a problem, and a liquid crystal material can be simultaneously injected into a large number of cells in a simple manufacturing process without contaminating the liquid crystal material with dust or the like. An object is to provide a method for manufacturing a display element.

[0009]

According to the method of manufacturing a liquid crystal display device of the present invention, (a) a pattern for a plurality of liquid crystal cells is formed on one side of an insulating transparent substrate, and (b) the plurality of liquid crystal cells are formed. A sealant is provided around the pattern of each liquid crystal cell so that at least two liquid crystal material injection ports of the above liquid crystal material injection port are close to each other, and a liquid crystal reservoir communicating with the liquid crystal material injection ports of the at least two liquid crystal cells is formed. , (C) at least an electrode facing the liquid crystal cell pattern is formed, and one or two or more other insulating transparent substrates smaller than the one insulating transparent substrate are stacked so that the liquid crystal reservoir is exposed. , (D) the one insulative transparent substrate and the other insulative transparent substrate are attached by the sealant, and (e) a liquid crystal material is injected from the liquid crystal reservoir into the gap between the insulative transparent substrates. Then Wherein the cut and separated for each liquid crystal cell after the.

If the liquid crystal reservoir is made of the same material as the sealant provided around the pattern and is formed in a frame shape at the same time as the formation of the sealant, a special process for providing the liquid crystal reservoir is not required, and the manufacturing is performed. It is preferable because the number of steps does not increase.

If the liquid crystal reservoir is formed of a liquid crystal holder for adsorbing the liquid crystal material, the liquid crystal holder is simply placed on the liquid crystal material inlet of each cell without forming the liquid crystal reservoir. In addition, it is possible to easily inject liquid crystal material, and if a glass plate is used as a large insulating transparent substrate, a sealant is not attached to unnecessary parts, so it is possible to scribe the separation into individual liquid crystal cells. This is preferable because it can be performed by the break method.

[0012]

According to the present invention, at least two liquid crystal material injection ports of a plurality of cells formed on a large insulative transparent substrate are formed so as to be connected to a liquid crystal reservoir, and a large insulative transparent substrate is formed. Liquid crystal material is injected because the other insulating transparent substrate is formed smaller or pre-divided than one large insulating transparent substrate so as not to cover the liquid crystal reservoir when pasting and stacking It is not necessary to provide an opening for this in a large insulating transparent substrate.

Therefore, there is no contamination or waste of the liquid crystal material,
Moreover, the liquid crystal material can be simultaneously injected into a plurality of cells by a simple process.

[0014]

The method for producing the liquid crystal display device of the present invention will be described below with reference to the drawings.

[Embodiment 1] FIGS. 1 and 2 are explanatory views of a manufacturing process for explaining a manufacturing method of a liquid crystal display element of the present invention.

FIG. 1 shows one large insulative transparent substrate 1 made of a glass plate, soda glass, borosilicate glass or the like.
FIG. 3 is a plan view showing a state in which a sealant 4 is provided around electrode patterns and the like (not shown) formed for each cell. The size of the large insulative transparent substrate 1 varies depending on the type of the target liquid crystal cell, but is usually 200 to 5
Those having a size of about 00 mm × 200 to 500 mm are used. An electrode pattern for each liquid crystal cell, a thin film transistor, an alignment film, a protective film, etc. (not shown) are provided on the transparent substrate 1, and a sealing agent 4 made of epoxy resin or the like is provided around the pattern with a width of 100 to 500 μm. The thickness is set to about 20 to 50 μm by screen printing or coating with a dispenser.

In this embodiment, four liquid crystal cell patterns are formed on a glass plate of about 300 mm × 400 mm. The sealant 4 of each cell is formed so as to surround the pattern of each cell, but a liquid crystal material injection port 3 is provided in a part thereof. In this embodiment, the liquid crystal material injection ports 3 of the two cells 10 are provided so as to be close to each other, and the liquid crystal reservoir 7 has the above-mentioned sealant so as to communicate with the liquid crystal material injection ports 3 of the two cells 10. 4 are simultaneously formed in a frame shape. Therefore, in the present embodiment, the pattern of two cells is surrounded by a series of sealant 4, and two sets each having a liquid crystal reservoir 7 formed at the center thereof, one large insulative transparent substrate 1 Is formed in.

Next, as shown in FIG.
The other insulative transparent substrates 2a and 2b on which electrode patterns for individual cells are formed are superposed on the insulative transparent substrate 1 with a spacer (not shown) interposed, and thermocompression-bonded. As a result, the above-mentioned sealant 4 is compressed,
The thickness is about 4 to 6 μm, which is the same as the diameter of the spacer.
In this embodiment, the other insulative transparent substrate is divided into two substrates 2a and 2b, which are smaller than the transparent substrate 1 so that the liquid crystal reservoir 7 is not covered. That is, the present invention is characterized in that the liquid crystal reservoir 7 is exposed even when the upper and lower insulating transparent substrates are laminated and attached. Therefore, it is not necessary to provide an opening in the transparent substrate by laser processing or the like, and the liquid crystal material can be easily injected. As a result, since the liquid crystal material can be injected by the dispenser, it is not necessary to collect a large number of cells for injecting the liquid crystal material and inject the liquid crystal material by batch processing, and the liquid crystal material can be injected for each transparent substrate. Therefore, continuous processing before and after the injection of the liquid crystal material is possible.

As described above, the other transparent substrate 2a, 2b
The sealing agent 4 is compressed to a thickness of about 4 to 6 μm by overlapping and thermocompression bonding, but since the sealing agent in the liquid crystal reservoir 7 part is not pressed by the transparent substrate, its thickness is almost unchanged. The thickness of 20 to 50 μm is maintained as it is. Also, if necessary, apply a thick sealant in advance to a portion that is not pressurized by using a dispenser or the like.
A sealing wall with a thickness of ~ 500 μm can be formed. Therefore, the liquid crystal reservoir 7 becomes a recess surrounded by a thick wall in a frame shape (see FIG. 2B, which is a cross-sectional view taken along the line AA of FIG. 2A), and the liquid crystal material is dripped to remove the liquid crystal material. Is retained.

The method of actually injecting the liquid crystal material into the substrate gap of each cell can be performed in the same manner as in the conventional method, but, for example, the entire transparent substrates 1 and 2 attached with a constant gap are placed in a vacuum chamber. After putting it under a reduced pressure of about 10 ⁻² to 10 ⁻³ Torr, a vacuum state is created between both substrates, and then an appropriate amount of liquid crystal material is dropped into a liquid crystal reservoir 7 to fill it. After that, by releasing the vacuum state of the vacuum chamber and making the surroundings atmospheric pressure, the vacuum state between both transparent substrates and the atmospheric pressure state of the surrounding face each other via the liquid crystal material,
When left for 0.5 to 1 hour, the liquid crystal material is injected into the narrow gap due to the pressure difference.

After that, the liquid crystal material injection port 3 is sealed with a sealant (not shown), and the liquid crystal cell 10a is completed by cutting and separating along the one-dot chain line P in FIG. after that,
A liquid crystal display element is completed by providing a polarizing plate, a backlight, a circuit board, etc. as in the conventional case.

[Embodiment 2] FIG. 3 is a view for explaining another embodiment of the method for manufacturing a liquid crystal display element of the present invention, and is a plan view (a) of the process corresponding to FIG. 2 of Embodiment 1 and FIG. That C-
It is C sectional drawing (b).

In this embodiment, four cells 10 are formed on a large insulative transparent substrate, and the liquid crystal material injection ports 3 of the two cells 10 are provided close to each other and communicate with a common liquid crystal reservoir 7. However, in this embodiment, the liquid crystal reservoir 7 is not formed in a concave shape by the sealant wall, but is composed of a liquid crystal holder for adsorbing and holding a liquid crystal material. The other configuration is the same as that of the first embodiment except for the difference.

As the liquid crystal holder, a sheet-like member made of glass wool which is usually used for adsorbing the liquid crystal material is used, and one or two sheets are stacked so as to cover the liquid crystal material injection port 3. . As a method of injecting liquid crystal material,
As in Example 1, the entire transparent substrate adhered with a constant gap was put in a vacuum chamber and put under a reduced pressure of about 10 ⁻² to 10 ⁻³ Torr to make the gap between both substrates a vacuum state. Then, an appropriate amount of liquid crystal material is dropped onto a liquid crystal holder, which is the liquid crystal reservoir 7, by a dispenser or the like to be adsorbed. After that, as in Example 1, the vacuum state of the vacuum chamber is released and left for 0.5 to 1 hour to inject the liquid crystal material into the cell.

According to the present embodiment, the gap between both transparent substrates is evacuated or the liquid crystal material is injected through the liquid crystal holder made of glass wool or the like, but it is left alone and no direct man-hours are required. Since there is no extra sealing agent when cutting and separating into cells of, if a glass plate is used as the substrate,
It is possible to easily cut and separate by scribing and breaking, and it is possible to reduce the number of work steps.

[Embodiment 3] FIG. 4 is a view for explaining still another embodiment of the method for manufacturing a liquid crystal display device of the present invention, and is a plan view of a process corresponding to FIG. 2 of Embodiment 1.

In this embodiment, four cells 10 are formed on a large insulative transparent substrate, and the liquid crystal material injection ports 3 of the two cells 10 are provided close to each other and communicate with a common liquid crystal reservoir 7. The liquid crystal material injection port 3 is not provided in the central portion of the transparent substrate 1 but is provided on the edge side in the present embodiment, except that the liquid crystal material injection port 3 is different from the first and second embodiments. The other structure is the same as that of the first embodiment. For the liquid crystal reservoir 7, either structure of the first embodiment or the second embodiment can be applied.

According to the present embodiment, even if the other transparent substrate 2 on the upper side is not divided into two, it is made smaller than the one transparent substrate 1 and is attached so that the liquid crystal reservoir 7 at the edge is exposed. It is possible to form the liquid crystal cell 10a in the same manner as in the first and second embodiments described above, and there is an advantage that the work of attaching the two transparent substrates becomes easy. The central portion of the large insulative transparent substrate is advantageous in forming the electrode pattern because the processing such as film formation and etching can be performed uniformly. In this embodiment, the liquid crystal cell is disposed in the central portion of the large insulative transparent substrate. Since the liquid crystal cells are arranged close to each other, there is an advantage that the product yield is improved.

In each of the above embodiments, a pair of transparent substrates 1, 2
Although the example of forming four liquid crystal cells has been described above, the number of liquid crystal cells taken from a pair of transparent substrates is not limited to four and may be any number of two or more. In this case, the other transparent substrate is not limited to two minutes, but may be divided into a large number, and the liquid crystal reservoir may be exposed. Further, the number of cells provided with the liquid crystal material injection ports in the vicinity is not limited to two, and may be four, for example.
An injection port for the liquid crystal material of each cell may be provided close to the center of each cell, and a liquid crystal reservoir may be formed in the center. In short, two or more cells are provided, and at least a part of two or more cells of the two or more cells are provided close to each other, and a liquid crystal reservoir communicating with them is provided, and the other transparent substrate is one transparent. It may be formed to be smaller than the substrate so that the liquid crystal reservoir is exposed when the substrates are stacked.

According to the present invention, when the upper and lower insulative transparent substrates are laminated and attached, the sizes of the two substrates are different,
At least the side edges of the upper and lower substrates have aligned portions, so that the alignment can be performed with reference to the side edges or the alignment formed on the upper and lower substrates. As a result, the alignment can be performed in the same manner as the conventional one, and the sticking can be easily performed.

[0031]

According to the present invention, since the liquid crystal material is quantitatively supplied to the liquid crystal material injection port by the dispenser, the exudation of the liquid crystal material to the outer peripheral portion of the sealant of each cell which is a problem in the conventional method. And there is no waste of liquid crystal material. Further, since there is no step of cutting the transparent substrate before injecting the liquid crystal material, there is no risk of liquid crystal contamination by fine powder such as glass powder.

Further, the liquid crystal cell can be manufactured efficiently in a short time without requiring a special process such as providing an opening for injecting the liquid crystal material in the transparent substrate.

As a result, the cost of the liquid crystal display element can be reduced and an inexpensive liquid crystal display element can be obtained.

[Brief description of drawings]

FIG. 1 is a process explanatory view of an example of a method for producing a liquid crystal display element of the present invention.

FIG. 2 is a process explanatory view of an example of a method for producing a liquid crystal display element of the present invention.

FIG. 3 is a process explanatory view of another embodiment of the method for producing a liquid crystal display element of the present invention.

FIG. 4 is a process explanatory view of still another embodiment of the method for manufacturing a liquid crystal display element of the present invention.

FIG. 5 is a process explanatory view of an example of a conventional method for manufacturing a liquid crystal display element.

FIG. 6 is a process explanatory view of another example of a conventional method for manufacturing a liquid crystal display element.

[Explanation of symbols]

1 insulating transparent substrate, 2a substrate, 2b substrate, 3 liquid crystal injection port, 4 sealing agent, 7 liquid crystal reservoir, 10 cells,
10a Liquid crystal cell.

Front page continuation (72) Inventor Yuichiro Sato, 997 Miyoshi, Nishigoshi-cho, Kikuchi-gun, Kumamoto, in Advanced Display Co., Ltd. (72) Hirofumi Shirakura, 997 Miyoshi, Nishigoshi-cho, Kikuchi-gun, Kumamoto

Claims (3)

[Claims] 1. A pattern for a plurality of liquid crystal cells is formed on one side of (a) an insulating transparent substrate, and (b) at least two liquid crystal material injection ports of the plurality of liquid crystal cells are close to each other. A sealant is provided around the pattern of each liquid crystal cell, and a liquid crystal reservoir communicating with the liquid crystal material injection ports of the at least two liquid crystal cells is formed, and (c) an electrode facing the liquid crystal cell pattern is formed. At least formed
One or two or more other insulative transparent substrates smaller than the one insulative transparent substrate are stacked so that the liquid crystal reservoir is exposed, and (d) the one insulative transparent substrate and the other insulative transparent substrate. Attach the substrate with the sealing agent,
(E) Next, a method for producing a liquid crystal display device, characterized in that a liquid crystal material is injected from the liquid crystal reservoir into the gap between the insulating transparent substrates, and then cut and separated for each liquid crystal cell. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal reservoir is made of the same material as a sealant provided around the pattern and is formed in a frame shape at the same time when the sealant is formed. Manufacturing method. 3. The method of manufacturing a liquid crystal display element according to claim 1, wherein the liquid crystal reservoir is formed by a liquid crystal holder that adsorbs a liquid crystal material.