JP2002122871A - Method of manufacturing liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing liquid crystal display panel by which a bulge in the substrate in the periphery of the display region can be suppressed. SOLUTION: A main seal 3 to surround the display region 5 and double auxiliary seals 4 in the region outside the main seal except an opening 8 are formed on a first glass substrate 1, and the double auxiliary seals are connected to each other in the opening 8 to form a reduced pressure region 6 closed by the double auxiliary seals 4 and an atmospheric pressure region 7 surrounded by the main seal 3 and the auxiliary sub seal 4. A second glass substrate 10 is stucked together in a specified reduced pressure state to seal the reduced pressure region 6. Then, the stucked-together substrates are exposed to the atmospheric pressure state so that the substrates facing each other are pressed from the outside in the reduced pressure region 6 by the pressure difference between the atmospheric pressure and the reduced pressure. The region where the substrates around the reduced pressure region 6 bulge caused by the rebound of sinking in the substrates by the pressing force in the reduced pressure region 6 is restricted in the atmospheric pressure region 7 while the flatness of the substrates is kept in the display region 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal display panel, and more particularly to a method for manufacturing a liquid crystal display panel in which liquid crystal is injected and sealed between opposing substrates while maintaining flatness of a display area.

[0002]

2. Description of the Related Art As display devices for AV equipment and OA equipment,
Liquid crystal display devices are widely used because of their advantages such as thinness, light weight, and low power consumption. This liquid crystal display device displays an image by injecting liquid crystal into two opposing substrates, controlling the orientation direction of liquid crystal molecules by an electric field generated by electrodes provided on the substrates, and modulating light applied to the liquid crystal panel. Is what you do. In recent years, in such a liquid crystal display device, demands for higher definition and a larger screen have been increasing, and in order to improve the uniformity of display, the liquid crystal while maintaining the uniformity of the cell gap between opposing substrates has been increased. Various methods for injecting and bonding have been proposed.

As a typical liquid crystal injection method, an opposing glass substrate is bonded with a sealing material except for a region to be a liquid crystal injection hole, and then the bonded glass substrate is put in a vacuum vessel to reduce the pressure of the liquid crystal. A method of injecting liquid crystal using a pressure difference by returning the vacuum container to the atmospheric pressure with the injection hole immersed in the liquid crystal, and a sealing material except for the area where the opposite glass substrate is used as the liquid crystal injection hole and exhaust port After bonding with
A method of sucking the liquid crystal by immersing the liquid crystal injection hole in the liquid crystal and exhausting the liquid through an exhaust port (Japanese Patent Application Laid-Open No. 7-281200), or a method of sealing a glass substrate on a glass substrate in an atmosphere reduced in a vacuum vessel or the like. Is applied, a liquid crystal is dropped, and the other glass substrate is bonded. Then, the pressure is returned to the atmospheric pressure to cure the sealing material (Japanese Patent Application Laid-Open No. 4-285910, hereinafter, referred to as a liquid crystal dropping method). There is.

In the method of injecting liquid crystal by pressure difference or exhaust, it is necessary to seal the injection port with a resin or the like after injecting the liquid crystal. Although problems such as contamination occur, the liquid crystal dropping method can significantly reduce the liquid crystal injection time and the required amount of expensive liquid crystal as compared with other methods, thereby reducing the cost of the liquid crystal display device. This is a method that is expected especially for a large-sized liquid crystal panel.

A method of manufacturing a liquid crystal display panel by a liquid crystal dropping method described in Japanese Patent Application Laid-Open No. 4-285910 will be described with reference to FIGS. FIG.
FIG. 9 is a plan view showing a state of a liquid crystal panel after liquid crystal is injected by a conventional liquid crystal dropping method, and FIG. 9 is a process sectional view schematically showing a liquid crystal injection step by a conventional liquid crystal dropping method.

First, as shown in FIG. 9A, a screen printing method, a dispenser drawing method, or the like is formed on a first glass substrate 1 whose surface has been subjected to an orientation treatment in a vacuum container or the like that has been decompressed. By applying a sealing material made of an ultraviolet curable resin or the like, a main seal 3 surrounding the display area 5 of the liquid crystal panel and an auxiliary seal 4 surrounding the outside of the main seal 3 at a predetermined interval to form a decompression area 6 are formed. . At this time, the main seal 3 and the auxiliary seal 4 are applied so as to form a closed area without any break.

Next, the main seal 3 is placed under a reduced pressure atmosphere.
A suitable amount of the liquid crystal 2 is dropped on the display area 5 surrounded by a circle using a liquid crystal dropping dispenser 9 or the like, and the second substrate 10 is positioned via a spacer such as a polymer bead or a silica bead. Are applied so that the cell gap becomes a predetermined value, and the main seal 3 and the auxiliary seal 4 are crushed and bonded (see FIGS. 9B and 9C).

After that, as shown in FIG. 9D, the vacuum vessel is returned to the atmospheric pressure state, and the pressure difference between the main seal 3 and the auxiliary seal 4 in the decompression region 6 is changed to the atmospheric pressure. The main seal 3 and the auxiliary seal 4 are drawn by attracting both substrates.
Is further crushed to form a desired gap, the main seal 3 and the auxiliary seal 4 are completely cured, liquid crystal is sealed, and a glass substrate is cut at a predetermined portion outside the main seal 3 to display a liquid crystal. Get a panel.

[0009]

However, in the above-described conventional method for manufacturing a liquid crystal panel, in the decompression region 6 surrounded by the main seal 3 and the auxiliary seal 4, both sides of the glass substrate are caused by a pressure difference from the atmospheric pressure. Since a strong pressing force is applied from the outside, as shown in FIG. 9D, in the outer peripheral portion of the display area 5 near the main seal 3, in the direction in which the glass substrate rises due to the recoil of the substrate in the decompression region 6 As a result, the cell gap is increased around the outer periphery of the display area 5, and the uniformity of the gap of the liquid crystal panel is impaired.

In order to solve this problem, it is only necessary to eliminate the reduced pressure region or reduce the degree of reduced pressure. However, if the reduced pressure region is eliminated, the final gap in the bonding step shown in FIG. It is necessary to pressurize with a considerable load, liquid crystal leaks at the time of pressurization, and the problem of unstable substrate holding from bonding to full curing of the seal material occurs. Further, if the degree of pressure reduction is weakened, there is a problem that bubbles easily enter the liquid crystal.

Japanese Patent Application Laid-Open No. 11-326922 discloses that the distance between the main seal 3 and the auxiliary seal 4 is 2 mm to 7 m.
A method is disclosed in which the sealing material is applied by a dispenser or the like, and the sealing material is placed in a pressurized state in order to increase the adhesive strength between the opposing substrates. Because it is greatly crushed by
It is difficult to accurately control the interval, and unevenness occurs on the substrate surface of the liquid crystal display panel due to a slight shift in the application position of the sealing material.

The present invention has been made in view of the above problems, and a main object of the present invention is to provide a method of manufacturing a liquid crystal display panel capable of suppressing the protrusion of a substrate around a display area. .

[0013]

In order to achieve the above object, the present invention has two substrates facing each other, a sealing material is provided on one of the substrates, and after a liquid crystal is dropped, a predetermined material is provided. In a method for manufacturing a liquid crystal display panel in which a liquid crystal is sealed by bonding a substrate on the other side in a reduced pressure state, when arranging the sealant, a second region is formed so as to surround a display region provided on the one side substrate. The seal material serving as the first seal is provided, and the seal material serving as the second seal is provided at predetermined intervals outside the first seal except for the region serving as the opening. Connecting the double second seals to each other at the opening, so that between the display area surrounded by the first seal and the first area surrounded by the second seal , The first seal and the inner second
A second region that is surrounded by the seal and is connected to the outside at the opening, and a liquid crystal is dropped into a region surrounded by the first seal, and the other substrate is adhered in the predetermined reduced pressure state. In addition, after the first region is sealed under reduced pressure, by exposing the bonded substrate to an atmospheric pressure state, in the first region separated from the display region by a predetermined distance,
The opposing substrate is pressed from both outer sides by a force corresponding to a pressure difference from the atmospheric pressure, and the deformation of the substrate caused by the pressing is reduced by the second region.

According to the present invention, there are provided two substrates facing each other, a sealing material is provided on one of the substrates, and after the liquid crystal is dropped, the substrates on the other side are bonded together under a predetermined reduced pressure. In the method of manufacturing a liquid crystal display panel for sealing a liquid crystal, when disposing the sealing material, disposing the sealing material serving as a first seal so as to surround a display area provided on the one side substrate. In addition, the sealing material to be a second seal is provided twice at a predetermined interval outside the first seal except for a region to be an opening, and the double second seal is The first seal and the inner first seal are connected between the display area surrounded by the first seal and the first area surrounded by the second seal by being connected to each other at the opening. A second region surrounded by the second seal and having the opening formed therein Liquid crystal is dropped into a region surrounded by the first seal, and the other side of the substrate is bonded to the substrate under the predetermined reduced pressure, and the first region is sealed under the first reduced pressure. The bonded substrate is placed under a second reduced pressure state, and the opening is sealed to seal the second region under the second reduced pressure state. By exposing to the state, in each of the first region and the second region, the opposing substrate is pressed from both outer sides with a force corresponding to a pressure difference from the atmospheric pressure, and the pressing in the first region is performed. The deformation of the substrate caused by the above is alleviated by the second region.

In the present invention, the width of the second region is larger than the width of a raised region generated in the substrate around the first region due to the recoil of the substrate due to the pressing force in the first region. Preferably, it is set to be large.

In the present invention, the opening is preferably
It is preferable that the display area is formed in an area excluding a diagonal extension of the display area.

Further, the present invention has two substrates facing each other, a sealing material is provided on one substrate, and after the liquid crystal is dropped, the other substrate is adhered under a predetermined reduced pressure. In the method of manufacturing a liquid crystal display panel for sealing a liquid crystal, when disposing the sealing material, a first portion is formed so as to surround a display region provided on the one side substrate at a predetermined interval.
And the sealant serving as a second seal is provided outside the first seal, and liquid crystal is dropped on a region surrounded by the first seal. And bonding the substrate on the other side under the predetermined reduced pressure state to seal the area sandwiched between the first seal and the second seal under reduced pressure, and thereafter exposing the bonded substrate to an atmospheric pressure state. Thereby, in the decompression region, the opposing substrate is pressed from both outer sides with a force corresponding to a pressure difference from the atmospheric pressure, and deformation of the substrate caused by the pressing is caused by the first seal and the display region. This is alleviated by the area between them.

In the present invention, the distance between the display area and the first seal is determined by the width of the raised area generated on the substrate around the depressurized area due to the recoil of the substrate due to the pressing force in the depressurized area. Preferably, it is set to be larger.

As described above, according to the present invention, the two substrates facing each other in the decompression region surrounded by the double second seal are securely bonded together with the first seal and the second seal.
The flatness of the substrate in the display area can be ensured by absorbing the protrusion of the substrate in the area surrounded by the seal.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the method of manufacturing a liquid crystal display panel according to the present invention, a first glass substrate 1 includes a main seal 3 surrounding a display area 5;
A double auxiliary seal 4 is formed in an area other than the outer opening 8, and the double auxiliary seals are connected to each other at the opening 8, and the pressure reduction area 6 closed by the double auxiliary seal 4.
And an atmosphere region 7 surrounded by the main seal 3 and the auxiliary seal 4
After bonding the second glass substrate 10 in a predetermined reduced pressure state and sealing the reduced pressure area 6 under reduced pressure, the bonded substrate is exposed to the atmospheric pressure state, and the pressure difference from the atmospheric pressure in the reduced pressure area 6 is increased. Presses the opposing substrates from both outer sides, and the region in which the substrate around the decompression region 6 rises due to the recoil of the substrate by the pressing force in the decompression region 6 stops in the atmospheric region 7, and the substrate in the display region 5. Flatness is ensured.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

Embodiment 1 First, a method of manufacturing a liquid crystal display panel according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view showing a liquid crystal display panel according to a first embodiment of the present invention after injecting liquid crystal, and FIG. 2 is a process sectional view schematically showing a manufacturing method thereof. FIGS. 3 and 4 are plan views showing other structures of the first embodiment.

A liquid crystal display panel generally has a first glass substrate on which TFTs and the like are formed in a matrix, and a second glass substrate on which a color filter, a black matrix, and the like are formed. An alignment film subjected to an alignment process is formed on the opposite surface of the substrate. An insulating spacer such as a polymer bead or a silica bead having a predetermined shape is disposed between the two substrates to form a predetermined cell gap, and the alignment direction of the injected and sealed liquid crystal is set to at least one of the gaps. An image is displayed by controlling the electric field generated by the electrodes formed on the substrate. Therefore, in order to improve the display uniformity, it is necessary to make the cell gap uniform, and it is particularly important to ensure the flatness of the substrate in the display area. Here, a method of injecting liquid crystal into the liquid crystal display panel according to the present embodiment will be described with reference to FIG.

First, as shown in FIG. 2 (a), the first glass substrate 1 whose surface has been subjected to an orientation treatment is placed in a vacuum vessel or the like, and the inside of the vacuum vessel is evacuated to, for example, several Pa to several tens Pa. After the reduced-pressure atmosphere, a sealing material made of an ultraviolet-curable resin or the like is placed on the first glass substrate 1 using a dispenser or the like, for example, with a width of 0.3 to 0.4 mm and a height of 30 to 40.
Apply with a thickness of about μm. At this time, the main seal 3 is applied so as to surround the display area 5 having a size of about 200 mm × 300 mm formed on the first glass substrate 1, and in the present embodiment, a predetermined distance is provided outside the main seal 3. In this case, the auxiliary seal 4 is applied twice. The double auxiliary seal 4 is connected to each other at an opening 8 having a width of about 5 mm shown in FIG.
A closed region is formed by itself.

Here, the area surrounded by the auxiliary seal 4 is
Since this is a region provided for pressing the first glass substrate 1 and the second glass substrate 10 so that the cell gap in the display region 5 has a desired value, the area of the region is:
The optimal size is set according to the size of the display area, the layout of the electrode terminals, the degree of pressure reduction, and the like. For example, the distance between the outer auxiliary seal 4 and the inner auxiliary seal 4 is set to 20 to
When the thickness is about 30 mm, the substrate can be satisfactorily pressed.

As will be described later, the area between the main seal 3 and the auxiliary seal 4 is pressed by a pressure difference from the atmospheric pressure to the decompression area 6 surrounded by the auxiliary seal 4, so that a depression is formed in the glass substrate. The distance between the first glass substrate 1 and the second glass substrate 10 in the decompression region 6 is set so as to avoid the problem that the glass substrate in the vicinity is raised due to the generated reaction. For example, if the glass substrate is set to about 10 to 20 mm, the bulge of the glass substrate will be
And the flatness of the substrate in the display area 5 can be ensured.

Next, as shown in FIG. 2 (b), a liquid crystal is applied between the substrates in a state where the main seal 3 is crushed by using a liquid crystal dispenser or the like in a region inside the main seal 3 under a reduced pressure atmosphere. An appropriate amount of liquid crystal 2 is dropped so as to be filled. Next, as shown in FIG. 2C, the second glass substrate 10 having an alignment film formed on the opposite surface is aligned with the first glass substrate to form the first glass substrate.
To the glass substrate 1. Thereafter, for example, 0.
By applying a load of about 1 N / mm ^2, the main seal 3 and the auxiliary seal 4 are crushed by an appropriate amount, the inner surface of the main seal 3 is filled with the liquid crystal 2, and the area surrounded by the auxiliary seal 4 is sealed to reduce the pressure reduction area 6. Form. Note that the degree of vacuum and the degree of pressurization of the reduced-pressure atmosphere in the above steps can be appropriately changed according to the degree of crushing of the sealing material, the area of the display region 5, and the like.

Thereafter, the inside of the vacuum vessel is returned to the atmospheric pressure. Then, as shown in FIG. 2D, the inside of the region surrounded by the auxiliary seal 4 is maintained in a reduced pressure state, and the first glass substrate 1 and the second glass substrate 10 are separated from the atmospheric pressure. A force acts in the direction of pressing from both outer sides, and the main seal 3 and the auxiliary seal 4 are further crushed, so that the gap between both substrates becomes a desired value, for example, about 4 to 5 μm. At this time, since both substrates are pressed only in the decompression region 6, a depression of about 0.1 to 0.2 μm occurs in the substrate in the decompression region 6. The recoil of the substrate in the decompression region 6 causes the substrate to rise in the air region 7 surrounded by the main seal 3 and the auxiliary seal 4 inside the substrate. As a result, the shape of the substrate is waved as shown in the figure. It becomes a struck shape.

However, the range in which the substrate rises due to the recoil of the substrate in the decompression region 6 is at most about 10 mm from the end of the decompression region 6, while the width of the atmosphere region 7 is 10 to 20 mm as described above. Since it is set, the ridge of the substrate can be completely absorbed in the atmosphere region 7, and the flatness of the substrate is secured in the display region 5 surrounded by the main seal 3. Thereafter, the main seal 3 and the auxiliary seal 4 are cured, and the glass substrate is cut at a predetermined portion outside the main seal 3 to form a liquid crystal display panel.

As described above, according to the liquid crystal display panel manufacturing method of the present embodiment, the display area 5 surrounded by the main seal 3 is provided.
Since an atmosphere region 7 maintained at the same pressure as the external pressure is formed between the pressure reduction region 6 and the pressure reduction region 6 surrounded by the auxiliary seals 4 for pressing the two opposing substrates from both outer sides, the pressure reduction region Since the uplift of the substrate due to the recoil of the depression of the substrate at 6 is alleviated in the atmospheric region 7 and does not proceed to the display region 5, the flatness of the substrate can be ensured in the display region 5.

In this embodiment, it is sufficient that the decompression region 6 is formed outside the display region 5 with the air region 7 interposed therebetween, and the shape of the decompression region 6 surrounded by the auxiliary seal 4 is pressurized. It can be formed arbitrarily according to the shape, area, and the like of the display area 5 that is the target. For example, as shown in FIG. 3, a plurality of openings 8 are provided near the center of each side of the display area 5 to maintain an area surrounded by the main seal 3 and the auxiliary seal 4 at atmospheric pressure. Alternatively, in consideration of the layout of the electrode terminals formed around the display area 5, a structure in which a plurality of small decompression areas 6 are provided as shown in FIG. According to the experiment by the inventor of the present application, when the opening 8 is provided near the corner of the display area 5, the cell gap tends to be wide at the corner of the display area 5 where the pressing force is not easily applied. Is preferably provided in a region excluding the vicinity on the diagonal extension of the display region 5.

Embodiment 2 Next, a method of manufacturing a liquid crystal display panel according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a plan view showing a liquid crystal display panel according to a second embodiment of the present invention after injecting liquid crystal, and FIG. 6 is a process sectional view schematically showing a manufacturing method thereof. In the present embodiment, the uplift of the substrate is further suppressed by reducing the atmospheric area formed between the main seal and the auxiliary seal shown in the first embodiment to a predetermined degree of vacuum. .

Referring to FIG. 6, a method of injecting liquid crystal into the liquid crystal display panel according to the present embodiment will be described. First, similarly to the first embodiment described above, the first glass substrate 1 on which an alignment film having been subjected to an alignment treatment is formed is placed in a vacuum container or the like, and the inside of the vacuum container is, for example, several Pa to several Pascals. After the first reduced pressure atmosphere of about 10 Pa, a sealing material made of an ultraviolet curable resin or the like is applied on the first glass substrate 1 using a dispenser or the like. At this time, the main seal 3 surrounding the display area 5 and the double auxiliary seal 4 are formed outside the main seal 3 at a predetermined interval, and the double auxiliary seals 4 are connected to each other at the opening 8. The closed region is formed by the double auxiliary seal 4 itself.

Here, the distance between the main seal 3 and the auxiliary seal 4 and the distance between the auxiliary seals 4 are determined by the size of the display area 5,
The optimal value is set in consideration of the degree of decompression, the layout of the electrode terminals on the outer periphery of the display area, and the like. However, the distance between the main seal 3 and the auxiliary seal 4 is 10
About 20 mm, the interval between the auxiliary seals 4 is 20 to 30
mm is preferable.

Next, as shown in FIG. 6B, under the first reduced pressure state, an appropriate amount of the liquid crystal 2 is dropped into the area inside the main seal 3 using a liquid crystal drop dispenser 9 or the like. As shown in (c), similarly, the second glass substrate 10 having the alignment film formed on the opposing surface is aligned and bonded. Thereafter, for example, a load of about 0.1 N / mm ² is applied to crush the main seal 3 and the auxiliary seal 4 by an appropriate amount, so that the liquid crystal 2 is filled in the internal area of the main seal 3 and the area surrounded by the auxiliary seal 4 is The first pressure reduction region 6a is formed by sealing.

Thereafter, in the first embodiment described above, the inside of the vacuum vessel was returned to the atmospheric pressure.
As shown in (d), the inside of the vacuum container is set to a predetermined degree of vacuum between the first reduced pressure state and the atmospheric pressure, and the area surrounded by the main seal 3 and the auxiliary seal 4 is set to the second reduced pressure. State.
Thereafter, the opening 8 provided in the auxiliary seal 4 is sealed with a resin or the like to seal a region surrounded by the main seal 3 and the auxiliary seal 4, thereby forming a region between the main seal 3 and the auxiliary seal 4. And a region surrounded by the auxiliary seals 4 are set in a reduced pressure state with different degrees of vacuum.

Thereafter, when the inside of the vacuum vessel is returned to the atmospheric pressure,
In the region 6a surrounded by the auxiliary seal 4, the first reduced pressure state is maintained, and a force acts in a direction of pressing the first glass substrate 1 and the second glass substrate 10 from both outer sides due to a difference from the atmospheric pressure, The main seal 3 and the auxiliary seal 4 are further crushed, and the gap between the two substrates becomes a desired value of about 4 to 5 μm. At this time, in the first decompression region 6a, the substrate has a thickness of 0.1 to 0.2 μm.
The substrate is about to bulge in a region 6b surrounded by the main seal 3 and the auxiliary seal 4 due to the reaction, and the region 6b surrounded by the main seal 3 and the auxiliary seal 4 also Is maintained in the decompressed state, the elevation of the substrate is suppressed by the pressure difference from the external pressure. As a result, the flatness of the substrate in the display region 5 is further maintained as compared with the first embodiment. become.

As described above, according to the liquid crystal display panel manufacturing method of the present embodiment, the display area 5 surrounded by the main seal 3 is provided.
And an auxiliary seal 4 for pressing two opposing substrates.
A second decompression region 6b set to an arbitrary degree of vacuum between the internal pressure of the first decompression region 6a and the atmospheric pressure is formed between the first decompression region 6a and the first decompression region 6a surrounded by. Second decompression region 6b due to the recoil of the depression of the substrate in first decompression region 6a
Is suppressed, and the flatness of the substrate can be ensured in the display area.

In this embodiment, the pressure in the second decompression region 6 b is equal to the atmospheric pressure and the pressure in the first pressure region surrounded by the auxiliary seal 4.
The pressure is set to an arbitrary value between the first pressure reducing region 6a and the pressure in the first pressure reducing region 6a, the interval between the auxiliary seals 4, the interval between the main seal 3 and the auxiliary seal 4, and the like. It can be set to an optimal value according to it.

Embodiment 3 Next, a method of manufacturing a liquid crystal display panel according to a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a diagram showing a state after liquid crystal injection of a liquid crystal display panel according to a third embodiment of the present invention,
(A) is a plan view and (b) is a cross-sectional view. This embodiment is different from the first and second embodiments described above in that the auxiliary seal is made a single layer and a margin is provided between the main seal and the display area to suppress the unevenness of the substrate in the display area. is there.

The method for injecting liquid crystal in the liquid crystal display panel according to this embodiment will be described. First, as in the first and second embodiments, a first liquid crystal panel having an alignment film formed on the opposing surface is formed.
Glass substrate 1 is placed in a vacuum container or the like, and the inside of the vacuum container is
For example, after a reduced pressure atmosphere of several Pa to several tens Pa is applied, a sealing material made of an ultraviolet curable resin or the like is applied on the first glass substrate 1 using a dispenser or the like. At this time, the main seal 3 is formed with a predetermined margin in the display area 5 composed of the pixel array formed on the first glass substrate 1 and an auxiliary seal is provided outside the main seal 3 at a predetermined interval. 4 is formed as a single layer.

Next, under a reduced pressure state, an appropriate amount of liquid crystal 2 is dropped into the area inside the main seal 3 using a liquid crystal dropping dispenser 9 or the like.
The glass substrate 10 is aligned and bonded. Thereafter, a load of about 0.1 N / mm ² is applied to the main seal 3.
The auxiliary seal 4 is crushed by an appropriate amount to fill the interior of the main seal 3 with liquid crystal, and a region surrounded by the main seal 3 and the auxiliary seal 4 is sealed.

Thereafter, by returning the inside of the vacuum container to the atmospheric pressure, the area surrounded by the main seal 3 and the auxiliary seal 4 is maintained in a reduced pressure state, and the first glass substrate 1 and the first glass substrate 1 A force acts in the direction of pressing the second glass substrate 10 from both outer sides, and a depression is generated in the substrate in the decompression region 6, and the substrate rises around the inside of the main seal 3 due to the reaction. However, in this embodiment, since a predetermined margin is provided between the display area 5 and the main seal 3,
Since the protrusion of the substrate is limited only to the vicinity of the main seal 3 and does not reach the display region 5, the flatness of the substrate in the display region 5 is maintained.

As described above, according to the method of manufacturing the liquid crystal display panel of this embodiment, the main seal 3 and the auxiliary seal 4 are formed by forming the main seal 3 large outside the display area 5 with a predetermined margin. The protrusion of the substrate due to the recoil of the depression of the substrate in the decompression region 6 surrounded by {circumflex over ()} can be reduced at the margin, and the flatness of the substrate can be ensured in the display region 5.

In the present embodiment, the distance between the display area 5 and the main seal 3 depends on the degree of vacuum of the decompression area 6 surrounded by the main seal 3 and the auxiliary seal 4, the layout of electrode terminals around the display area 5, and the like. It can be changed to any value depending on conditions. Further, in this embodiment, the auxiliary seal 4 is formed as a single layer. However, the present invention is not limited to the above-described embodiment. Auxiliary seal 4 as in the second embodiment.
Can also be formed doubly.

Each of the embodiments described above can be applied to any liquid crystal display device having a structure in which liquid crystal is sandwiched between two opposing substrates. Such as a TN type liquid crystal display device that drives liquid crystal by a vertical electric field, and an IPS type liquid crystal display device in which a comb-shaped electrode is provided on one substrate and the liquid crystal is driven by an electric field between the comb-shaped electrodes. It is apparent that the present invention can be applied to such a type of liquid crystal display device.

[0047]

As described above, according to the method of manufacturing a liquid crystal display panel of the present invention, in the liquid crystal injection by the dropping method, the cell gap is adjusted to a desired value while ensuring the flatness of the substrate in the display area. It has the effect that it can be done.

The reason is that an auxiliary seal is provided double outside the main seal surrounding the display area, the inside of the area surrounded by the double auxiliary seal is depressurized, and the main seal and the auxiliary seal are combined. By setting the enclosed area to atmospheric pressure or reduced pressure, the substrate is reliably pressed in the area enclosed by the auxiliary seal, and the bulge of the substrate generated by the recoil of the substrate in the auxiliary seal area is defined as the main seal. This is because relaxation can be achieved in a region surrounded by the auxiliary seal.

Further, a main seal is formed in consideration of a margin in the display area, and a single or double auxiliary seal is provided outside the main seal, and the pressure between the main seal and the auxiliary seal or between the auxiliary seals is reduced. This is because the flatness of the substrate in the display area can be ensured by pressing the substrate and reducing the protrusion of the substrate caused by the reaction at the margin provided between the display area and the main seal.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state of a liquid crystal display panel according to a first embodiment of the present invention after injecting liquid crystal.

FIG. 2 is a cross-sectional view schematically showing a liquid crystal injection step of the liquid crystal display panel according to the first embodiment of the present invention.

FIG. 3 is a plan view showing another embodiment of the liquid crystal display panel according to the first embodiment of the present invention.

FIG. 4 is a plan view showing another embodiment of the liquid crystal display panel according to the first embodiment of the present invention.

FIG. 5 is a plan view showing a state after injecting liquid crystal in a liquid crystal display panel according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view schematically showing a liquid crystal injection step of a liquid crystal display panel according to a second embodiment of the present invention.

FIGS. 7A and 7B are diagrams showing a liquid crystal display panel according to a third embodiment of the present invention after injecting liquid crystal, wherein FIG. 7A is a plan view and FIG.

FIG. 8 is a plan view showing a state after liquid crystal injection of a conventional liquid crystal display panel.

FIG. 9 is a cross-sectional view schematically showing a liquid crystal injection step of a conventional liquid crystal display panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st glass substrate 2 liquid crystal 3 seals 4 auxiliary seals 5 display area 6 decompression area 6a 1st decompression area 6b 2nd decompression area 7 atmosphere area 8 opening 9 dispenser for liquid crystal dropping 10 second glass substrate 11 Sealing material

Claims (8)

[Claims] 1. A substrate having two opposing substrates, a sealing material provided on one substrate, a liquid crystal being dropped, and a liquid crystal being sealed by bonding the other substrate under a predetermined reduced pressure. In the method of manufacturing a liquid crystal display panel, when disposing the seal material, the seal material serving as a first seal is disposed so as to surround a display area provided on the one side substrate, and an opening is provided. The sealing material to be the second seal is provided twice at a predetermined interval outside the first seal except for the area to be the part, and the double second seals are mutually placed in the opening. By connecting, the first seal and the inner second seal are located between the display area surrounded by the first seal and the first area surrounded by the second seal. Providing a second region connected to the outside at the opening, The liquid crystal is dropped on the area surrounded by the seal of No. 1 and the other side of the substrate is bonded under the predetermined reduced pressure state to seal the first area under reduced pressure. In the first area separated from the display area by a predetermined distance, the opposing substrates are pressed from both outer sides by a force corresponding to a pressure difference from the atmospheric pressure, and the substrate generated by the pressing is pressed. A method for manufacturing a liquid crystal display panel, wherein the deformation of the liquid crystal panel is reduced by the second region. 2. A liquid crystal device comprising two substrates facing each other, a sealing material provided on one substrate, a liquid crystal being dropped, and a liquid crystal being sealed by bonding the other substrate under a predetermined reduced pressure. In the method of manufacturing a liquid crystal display panel, when disposing the seal material, the seal material serving as a first seal is disposed so as to surround a display area provided on the one side substrate, and an opening is provided. The sealing material to be the second seal is provided twice at a predetermined interval outside the first seal except for the area to be the part, and the double second seals are mutually placed in the opening. By connecting, the first seal and the inner second seal are located between the display area surrounded by the first seal and the first area surrounded by the second seal. Providing a second region in which the opening is formed, the second region being surrounded by The liquid crystal is dropped into a region surrounded by the seal, and the other side substrate is bonded in the predetermined reduced pressure state, and the first region is sealed in the first reduced pressure state. Is placed under a second reduced pressure state, and the opening is sealed to seal the second region in a second reduced pressure state,
Then, by exposing the bonded substrate to an atmospheric pressure state, in each of the first region and the second region, the opposing substrate is pressed from both outer sides with a force corresponding to a pressure difference from the atmospheric pressure. A method for manufacturing a liquid crystal display panel, wherein the substrate is pressed and deformation of the substrate caused by pressing in the first region is reduced by the second region. 3. The liquid crystal display panel according to claim 2, wherein the pressure inside the second area is set to a predetermined pressure lower than the atmospheric pressure and higher than the pressure inside the first area. Manufacturing method. 4. The predetermined pressure is set to a pressure that can suppress a bulge generated on the substrate around the first region due to a recoil of the substrate by the pressing force in the first region. The method for manufacturing a liquid crystal display panel according to claim 3, wherein: 5. The method according to claim 1, wherein the width of the second region is reduced by the reaction of the substrate to be depressed by the pressing force in the first region.
5. The method of manufacturing a liquid crystal display panel according to claim 1, wherein the width is set to be larger than the width of the raised area generated on the substrate around the area. 6. The method for manufacturing a liquid crystal display panel according to claim 1, wherein said opening is formed in a region excluding the vicinity of a diagonal extension of said display region. 7. A liquid crystal device comprising two substrates facing each other, a sealing material provided on one substrate, a liquid crystal dropped, and a liquid crystal sealed by bonding the other substrate under a predetermined reduced pressure. In the method of manufacturing a liquid crystal display panel, when the sealing material is provided, the seal serving as a first seal is formed so as to surround a display area provided on the one side substrate at a predetermined interval. A material is provided, the seal material serving as a second seal is provided outside the first seal, and liquid crystal is dropped in a region surrounded by the first seal, and the predetermined pressure-reduced state is obtained. After bonding the substrate on the other side and decompressing and sealing a region sandwiched between the first seal and the second seal, exposing the bonded substrate to an atmospheric pressure state, In the above, the opposing bases are applied with a force corresponding to a pressure difference from the atmospheric pressure. A method for manufacturing a liquid crystal display panel, wherein a plate is pressed from both outer sides, and deformation of the substrate caused by the pressing is reduced by an area between the first seal and the display area. 8. A distance between the display area and the first seal is set to be larger than a width of a raised area generated on the substrate around the depressurized area due to a recoil of the substrate due to a pressing force in the depressurized area. The method for manufacturing a liquid crystal display panel according to claim 7, wherein: