JP2003295200A - Method of manufacturing liquid crystal display device and device for manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for manufacturing a liquid crystal display device wherein a combination deviation between substrates is reduced, a curvature and a recess of substrates which constitutes a liquid crystal cell is reduced and an accurate and uniform cell gap can be formed. <P>SOLUTION: The method for manufacturing the liquid crystal display device is provided with a stage for irradiating the sealant with light from the other substrate side and then a stage for irradiating the sealant with light from the one substrate side via the stage, when one substrate of a pair of substrates disposed via a photosetting sealant is placed on a stage having light transmissivity to be stuck to the other substrate. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a liquid crystal display device, and more particularly, to a method and a device for manufacturing a liquid crystal cell formed by bonding two substrates with a sealing material. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, there are various methods for manufacturing a liquid crystal display device, but the following method is generally adopted. First, a wiring layer and a pixel electrode are formed on the inner surfaces of two glass substrates, and an active element, a color filter and the like are also formed if necessary. Next, a sealing material is applied to one of the two glass substrates so as to surround the liquid crystal display area while leaving one opening.
The other glass substrate is attached via this sealing material.

The two glass substrates are bonded to each other under a predetermined pressure by a pressing device in a state where they are adhered to each other.
Light and heat are applied to the two pressure-bonded glass substrates to cure the sealing material, thereby forming a liquid crystal cell. Liquid crystal is injected into the liquid crystal cell from the opening of the sealing material under reduced pressure, and after the injection is completed, the opening is sealed.

The pressure bonding process of the glass substrate and the curing process of the sealing material are performed by various methods depending on the type of liquid crystal cell. For example, when a large number of spacers are dispersedly arranged between the glass substrates, the two glass substrates are pressed and temporarily pressure-bonded to each other, and the gap between the glass substrates is kept as it is or by transferring it to another jig. A liquid crystal cell having an accurate cell gap can be formed by curing the sealing material while holding it.

Although no spacer is arranged between the glass substrates, a spacer having a size similar to a desired cell gap is mixed in the sealing material and a pressure is applied to a portion where the sealing material exists. In addition, temporary pressure bonding may be performed, and then the sealing material may be cured.

[0006]

In the above-described conventional method for manufacturing a liquid crystal display device, the plane position between the substrates cannot always be set accurately when the two glass substrates are bonded together, and as a result, A misalignment between the two glass substrates occurs, which causes a problem of variation and deterioration of display characteristics due to the misalignment of the pixel structure formed on the inner surface of the glass substrate.

Further, in the method of manufacturing the one glass substrate as a small substrate corresponding to the liquid crystal display cell while leaving the other glass substrate in a large size, the plurality of small substrates are pressure-bonded and temporarily cured at once. In addition, the degree of deformation of the glass substrate changes greatly depending on the pressure at the time of pressure bonding and the degree of curing of the sealing material, so that the glass substrate after the completion of the liquid crystal cell is warped or dented, resulting in a liquid crystal with a uniform cell gap. There is also a problem that it is difficult to form cells. On the other hand, if pressure bonding and temporary curing are individually performed on the small substrates, it is expected that it will take a long processing time because the positioning work must be performed for each small substrate.

Therefore, the present invention solves the above-mentioned problems, and its object is to reduce the misalignment between the substrates and to reduce the warpage and dents of the substrates constituting the liquid crystal cell to achieve accurate and uniform. An object of the present invention is to provide a method and an apparatus for manufacturing a liquid crystal display device capable of forming a cell gap.

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems, the means taken by the present invention is a liquid crystal in which two substrates are adhered to each other via a sealing material and liquid crystal is injected between the substrates. In the method for manufacturing a display device, a temporary curing step of semi-curing the sealing material in a state where one of the substrates is pressure-bonded to the other substrate through the uncured sealing material at a predetermined pressure, And a main curing step of curing the sealing material in a state where the pressure is released to the two substrates that are pressure-bonded in the temporary curing step.

According to this means, in the temporary curing step, 2
The sealing material is semi-cured in a state where the substrates are pressure-bonded at a predetermined pressure, and then the sealing material is cured in the state where the pressure is released in the main curing step, so that the pressure is applied in the temporary curing step when the pressure is applied. At the time when the preliminary curing process is completed and the pressure is released, the substrate shape is appropriately restored by the proper binding force of the semi-cured sealing material and the restoring force of the substrate, and the deformation of the substrate is corrected. Therefore, by curing the sealing material without applying pressure in the subsequent main curing step, it is possible to secure the flatness of the substrate and the uniformity of the cell gap in the formed liquid crystal cell.

Here, in the temporary curing step, the substrate is made substantially flat or slightly warped after the pressure is released after the temporary curing step is completed with respect to the pressure. It is preferable to semi-cure the sealing material by adjusting the curing degree of the sealing material.

According to this means, the flatness of the substrate and the uniformity of the cell gap in the liquid crystal cell after the temporary curing step are adjusted by adjusting the curing degree of the sealing material with respect to the pressure applied in the temporary curing step. Can be controlled.
When the degree of curing of the sealing material is low, the binding force of the sealing material is weakened, the restoring force of the substrate is increased, and it becomes difficult to control the flatness of the substrate. On the other hand, as the curing degree of the sealing material becomes higher, the binding force of the sealing material becomes stronger and strongly reflects the shape of the substrate in the pressure-bonded state, so if the substrate is deformed during pressure bonding, the deformation remains, and If the substrate is prevented from being deformed as much as possible at the time of pressure bonding, there is a high possibility that the original strain of the substrate is reflected or that the substrate has a defective seal.

In the temporary curing step, one of the substrates is pressure-bonded to the other substrate through the uncured sealing material at a predetermined pressure, and the one substrate is attached to the other substrate. It is preferable to have an alignment step of aligning with respect to each other and a semi-curing step of semi-curing the sealing material in a state of being pressurized with a pressure substantially similar to the predetermined pressure.

According to this means, the alignment is performed in a state where one substrate and the other substrate are pressure-bonded in the alignment step, and in the subsequent semi-curing step, the pressing force at the time of alignment is almost the same without changing. Since the sealant is hardened while being pressed by pressure, it is possible to suppress the occurrence of misalignment after alignment, thus preventing misalignment between the boards and accuracy and uniformity of the board spacing. Can also be improved.

In this case, further, before the alignment step, an alignment step of roughly aligning one of the substrates with the other substrate under a pressure lower than the predetermined pressure. It is desirable to have

[0016] According to this means, since the positioning is performed in a state where the pressure is applied at a low pressure in the positioning step, the sealing material is not largely deformed and the positioning is performed without applying a large stress. Therefore, it is possible to perform accurate alignment quickly and without impairing the sealing property of the seal portion.

On the other hand, it is assumed that the sealing material has a photo-curing property, and in the main curing step, the substrate is placed on a cooling stage having a light-transmitting property, and the cooling stage is allowed to pass through to the cooling stage side. Therefore, it is preferable to irradiate the sealing material with light.

According to this means, since the light is emitted from the side which is being cooled by the cooling stage, the cooling efficiency of the liquid crystal cell is increased, and the photo-curing treatment can be performed without overheating the liquid crystal cell. Become.

Further, the sealing material is photo-curable, and in the main curing step, the step of irradiating the sealing material with light from one substrate side and the sealing material from the other substrate side. And irradiating it with light.

According to this means, the liquid crystal cell is irradiated with light from both the front and back sides in different steps, so that the curing efficiency of the sealing material can be enhanced, and as a result, the liquid crystal cell can be rapidly and quickly. It is possible to carry out the photo-curing treatment without overheating the cell.

Further, it is preferable that the sealing material has a photo-curing property, and that in the main curing step, the sealing material is irradiated with light intermittently or increased / decreased at a predetermined frequency.

According to this means, the light intensity and the frequency are appropriately set to the liquid crystal cell by irradiating the light intermittently or increased / decreased at the predetermined frequency,
It is possible to prevent overheating of the liquid crystal cell.

Further, in order to solve the above-mentioned problems, the means taken by the present invention is that one of a pair of substrates arranged via a photo-curing sealing material is placed on a translucent stage. Then, a method of manufacturing a liquid crystal display device to be attached to the other substrate, the step of irradiating the sealing material with light from the other substrate side, and thereafter, from the one substrate side through the stage. Irradiating the sealing material with light. In this case, it is preferable that the irradiation of the light with which the one substrate is irradiated or the irradiation of the light with which the other substrate is irradiated is performed intermittently. Further, it is preferable that the stage includes a cooling mechanism, and the sealing member is irradiated with the light while the stage cools the stage. Further, it is preferable to irradiate the sealing material with light while blowing cooling air onto the other substrate. Further, it is preferable that the other substrate is smaller than the one substrate, and a plurality of the other substrates are attached to the one substrate.

Further, in order to solve the above-mentioned problems, the means taken by the present invention is that one of a pair of substrates arranged via a photo-curable sealing material is placed on a stage and the other substrate is A manufacturing apparatus of a liquid crystal display device to be stuck, comprising: a plurality of light sources for irradiating light for curing the sealing material; a first stage on which the one substrate is mounted; And a side on which the one substrate is placed on the first stage and a side on which the one substrate is placed on the second stage. Is provided on the opposite side of the first stage, the pair of substrates is placed on the first stage, the sealing material is irradiated with the light, and then the pair of substrates is placed on the second stage. And irradiate the sealing material with the light through the stage. It is characterized in. In this case, at least one of the first and second stages preferably comprises a cooling mechanism. Further, it is preferable that the cooling mechanism allows cooling water to flow inside the stage to cool the stage. Further, it is preferable to further include a cooling nozzle for blowing cooling air to the pair of substrates.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a schematic structure of an embodiment of a liquid crystal display device manufacturing apparatus (substrate bonding apparatus) according to the present invention.

In this embodiment, the XY table 1
A cushioning material 11 is placed on the upper surface of 0, and a large-sized substrate 31 made of glass or the like is arranged on the surface of the cushioning material 11. On the surface of the large-sized substrate 31, a sealing material 32 made of an ultraviolet curable resin is applied in advance by a dispenser or the like so as to surround the liquid crystal enclosed area. A spacer (not shown) is mixed in this sealing material. A small substrate 33 made of glass or the like is pressure-bonded onto the sealing material 32 by a pressure bonding head 20 described later, and then the sealing material 32 is semi-cured.

The crimping head 20 can be moved up and down by an elevating mechanism (not shown) and a pressurizing mechanism utilizing hydraulic pressure, pneumatic pressure, etc., and a controlled pressure is applied between the large-sized substrate 31 and the small substrate 33. It is configured to be able to. Further, the pressure bonding head 20 is provided with a θ position adjusting mechanism for making itself rotatable about a vertical axis. The θ position adjusting mechanism and the XY table 1 are provided.
The alignment mechanism described below is configured to be performed by an X-direction adjusting mechanism and a Y-direction adjusting mechanism of 0.

The pressure bonding head 20 is composed of a pressure bonding base 21 made of a light transmitting material such as glass, and a light transmitting plate made of a light transmitting material such as glass laminated on the pressure bonding base 21 with a packing 23. 24, a plurality of alignment cameras 25 arranged above the translucent plate 24, and light emitted from an ultraviolet lamp for irradiating ultraviolet rays from above the translucent plate 24 is guided by an optical fiber 26a. And a light irradiation unit 26 configured to irradiate the light.

On the bottom surface of the pressure-bonding base 21, a pressing surface portion 21a having substantially the same area as the 1.3-inch rectangular small substrate 33 is formed. The small substrate 3 is attached to the pressing surface portion 21a.
A frame-shaped portion formed on the outer edge of the bottom surface of the pressure-bonding base 21 so as to abut the upper surface of the contact area for the sealing material of No. 3,
An intake recess formed inside is provided.
The intake recess is in communication with an intake hole 21b that is formed so as to extend vertically through substantially the center of the pressure-bonding base 21. The peripheral portion of the pressing surface portion 21a of the pressure-bonding base 21 is covered with the light shielding plate 22, and when the sealing material described later is semi-cured, another sealing material corresponding to the other small substrate 33 in the periphery is hardened. To prevent.

The upper opening of the air intake hole 21b is opened in a gap portion provided between the light transmission plate 24 and the air passage hole, and this air gap portion communicates with the air intake hole 24a provided in the light transmission plate 24. ing. The intake hole 24a is formed at a position outside the plane position of the pressing surface portion 21a, and is connected to an exhaust pipe 27 connected to an exhaust device (not shown). The air intake hole 21b, the gap and the air intake hole 24a are formed by the pressing surface portion 21a.
The intake passage is formed so as to deviate from the inside of the plane position to the outside.

When an exhaust valve of an exhaust device (not shown) is opened, air is exhausted from the intake recess by the intake passage formed by the intake hole 21b, the gap and the intake hole 24a. Therefore, the small substrate 33 can be adsorbed to the pressing surface portion 21a of the pressure-bonding base 21.

Next, the operation of the apparatus having the above structure will be described. First, the small board 33 is provided at a material supply position not shown.
Is sucked and held by the pressing surface portion 21a, and then the pressure bonding head 20 is moved onto the large-sized substrate 31 and lowered in accordance with the position of the seal material 32 applied in advance. Next, the pressure bonding head 20 is lowered so that the outer edge portion of the small substrate 33 contacts the sealing material 32, and the small substrate 33 is pressure bonded to the large substrate 31.

When the position of the pressure bonding head 20 is stabilized, the position of the XY table is corrected by the alignment camera 25 so that the alignment marks (not shown) of the small substrate 33 and the large-sized substrate 31 are aligned, and the θ of the pressure bonding head 20 is adjusted. By correcting the rotation direction of the pressure bonding base 21 by the positioning mechanism, alignment is performed so that the small-sized substrate 33 is pressure-bonded to the large-sized substrate 31 at the regular position.

Next, the sealing material is semi-cured by irradiating it with ultraviolet rays from the light irradiating section 26. The degree of curing of the sealing material is set according to the degree of warpage or dent of the glass substrate, particularly the small substrate 33, in the liquid crystal cell to be formed, as described later. When the semi-curing of the sealing material is completed, the exhaust valve of the exhaust device (not shown) is closed and the pressure bonding head 20 is lifted to separate the pressing surface portion 21a from the small substrate 33. In this way, the above-mentioned device is used for the large-sized substrate 3
It is configured such that a plurality of small substrates 33 are sequentially crimped to a predetermined position on 1.

The pressurization state of the pressure bonding head 20 is shown in FIG. When the crimping head 20 descends and crimps the small substrate 33 to the large-sized substrate 31, the crimping head 20 first holds the pressurizing force at about 4 kg, during which the small substrate 3 is held.
Step 3 for position adjustment for roughly correcting the position of the large-sized board 31 is executed. For example, in this step, the small substrate 3 is used by using the alignment camera 25 described above, or by using another position sensor or the like.
3 is 5μ misalignment from the regular position on the large-sized board 31
Modify so that it is within m. The processing time of this step is about 1 second.

Next, the pressure of the pressure bonding head 20 is increased to about 8 kg, and thereafter, the pressure is kept constant. In this state, the steps for alignment are executed. In this step, the plane position of the small board 33 is determined by using the alignment camera 25 and the large board 3 is used.
Correct so that the error is within 1 μm with respect to 1.
The processing time of this step is about 6 seconds.

Subsequently, the pressure applied by the pressure bonding head 20 is maintained as it is, and a step for semi-curing the sealing material 32 is executed. In this step, the light irradiation unit 2
Ultraviolet rays are irradiated from 6 to cure the sealing material to a predetermined degree within the range where the sealing material is not completely cured. The processing time of this step is about 7 seconds.

In the present embodiment, rough position correction is performed in a state where the substrate is pressure-bonded with a small pressure force in the step, and then highly accurate position correction is performed in a state where the final pressure force is applied in the step, Then, in step, the sealing material is semi-cured by irradiating light without changing the pressure.

In the step, the position can be easily corrected because the applied pressure is low, and the large correction can be easily performed without causing a large deformation of the sealing material and without applying a large stress. In addition, in the step, since alignment is performed with a final pressing force or a pressing force close to the final pressing force, there is almost no change in the pressure bonding state between the substrates even after the alignment, and the liquid crystal cell assembly after the pressure bonding is finally completed. It is possible to prevent the occurrence of displacement (displacement in the plane direction between the two substrates).

Further, since the pressing force is hardly changed from step to step, the sealing material can be hardened while maintaining the alignment accuracy performed in the step. Where, for example,
As indicated by the broken line in FIG. 2, when the pressure in the step is large and the pressure is lowered in the step, the substrate floats in the seal portion, resulting in defective sealing, variations in cell thickness, misalignment of the substrate, and the like. On the contrary, as shown by the dotted line in FIG. 2, when the step pressing force is increased more than the step pressing force, even if the bending angle alignment is performed in the step, the pressing force is increased after that, and the misalignment occurs again in the step. There is a drawback that it does.

In the present embodiment, the compact substrate 33 is pressed by the crimping base 21, so that the compact substrate 33 is pressed.
Deforms downward (concave), and the large substrate 31
Also, due to the deformation of the cushioning material 11, the cushioning material 11 is deformed in a downward convex shape. When the pressure applied by the pressure bonding head 20 is large to some extent, the deformation amount of the large substrate 31 becomes larger than the deformation amount of the small substrate 33. Therefore, as shown on the left side of FIG. When pressure is applied by 20, the cell gap becomes large in the central portion of the liquid crystal cell. When the pressing force is released in this state, the sealing material is incompletely hardened, so that there is a certain binding force against the deformation of the substrate, and the pressing force causes the substrate to be deformed. By virtue of the presence of the restoring force of the substrate, the warp of the substrate is reduced to a substantially flat state as shown on the right side of FIG. 3A, and the cell gap of the liquid crystal cell is made uniform. It

However, as shown on the left side of FIG. 3B, when the applied pressure is too large and the warp amount of the large substrate 31 becomes large, as shown on the right side of FIG. 3B, after the sealing material is cured. Even if the pressing force is released, the warp of the substrate may remain. In addition, such residual warpage of the substrate also occurs when the sealing material is excessively hardened, because the binding force of the sealing material makes it difficult to eliminate the deformation of the substrate under pressure. .

Unlike the present embodiment, when the small substrates are pressure-bonded to each other, or when the plurality of small substrates are pressed on the large substrate by a large and flat integral pressing surface portion, this embodiment is different from the present embodiment. Take a different look. That is, the upper substrate is deformed in a downward convex shape by the pressure applied during the crimping, while a force of deforming the lower substrate is hardly generated when the small substrates are crimped, and
When a plurality of small substrates are integrally pressed on a large substrate, since the force of deforming the lower substrate is weak, the amount of deformation of the lower substrate is small in any case, and the left side of FIG. As shown in, the cell gap at the center of the liquid crystal cell is smaller than that at the periphery. When the pressure is released in this state,
As shown on the right side of (c), the upper substrate is deformed from the recessed state to the warped state when released.

When the pressing force of the pressure bonding head 20 is small, the substrate is almost flat and the cell gap is uniform as shown on the left side of FIG. 3D, but when the pressing force is released, Due to the inherent distortion of the board,
As shown on the right side of FIG. 3D, the substrate may have a slightly warped shape or, on the contrary, may have a concave shape.

On the contrary, when the pressure applied by the pressure bonding head 20 becomes considerably large, the substrate becomes largely recessed as shown on the left side of FIG. 3 (e), and in this state, the sealing material 32 is excessively hardened. Even if the pressure is released,
It will remain recessed as shown on the right side of.

As described above, in this embodiment, the semi-curing of the sealing material causes a restoring action of the deformation of the substrate when the applied pressure is released. Therefore, even if the substrate is slightly warped during pressurization, The distortion of the liquid crystal cell can be reduced. Therefore, without worrying about the deformation of the liquid crystal cell,
At the time of pressure bonding, it is possible to apply a certain amount of pressure to surely obtain a desired cell gap, and it is possible to reduce the pressure bonding failure of the substrate.

The amount of restoration when the above-mentioned pressing force is released is
It changes depending on the degree of curing of the sealing material. FIG. 4 shows the relationship between the warp amount of the liquid crystal cell and the light irradiation time in this embodiment. In the present embodiment, if the light irradiation time to the sealing material is too short, the binding force of the substrate by the sealing material is too small and the warp amount (or the dent amount) of the substrate due to the original strain of the small substrate 33. There are many variations. On the other hand, if the light irradiation time to the sealing material is too long, the sealing material is excessively hardened and the binding force becomes large, and the warped state of the substrate at the time of pressurization is maintained, and the liquid crystal cell exhibits a large warp. Become.

In the area A shown in FIG. 4, the amount of warpage of the substrate is small, the variation in the amount of warpage is small, and a stable cross-sectional shape of the liquid crystal cell can be obtained. In this case, area A
In Fig. 3, there is a slight warp in the substrate, and the formed liquid crystal cell has a slightly large cell gap in the central portion. However, when forming a liquid crystal display, it is better that the substrate has a slight warp in an empty cell state.
It is more preferable than the case where the substrate is completely flat.
This is because in the subsequent liquid crystal injection process, the liquid crystal cell is depressurized and the liquid crystal is injected by the pressure difference between the inside and the outside. Therefore, a slight warpage of the substrate allows the liquid crystal to be injected smoothly. This is because a flat liquid crystal cell tends to be formed after the liquid crystal is injected.

FIG. 5 shows the amount of warpage of the liquid crystal cell and the sealing material when the small substrates are pressure-bonded to each other or when a plurality of small substrates are pressed on the large substrate by a large and flat integral pressing surface portion. The relationship with the light irradiation time is shown.
Here, if the area above the horizontal axis is warped on the substrate,
The region below the horizontal axis shows the case where the substrate has a depression.

In this case, the amount of warpage of the liquid crystal cell decreases almost linearly by increasing the light irradiation time to the sealing material, and eventually the formed liquid crystal cell has a cross section with a concave central portion. It takes on a shape. Also in this case,
As shown as a region B in FIG. 5, it is preferable to adjust the light irradiation time and set the curing degree of the sealing material so that the warp amount of the liquid crystal cell is small. The dotted line in FIG. 5 shows the amount of warpage when the pressure of the pressure bonding head is increased.

The liquid crystal cell temporarily hardened as described above is main hardened in a free state where no pressure is applied. This main curing step is performed by being divided into a first stage shown in FIG. 6 and a second stage shown in FIG. In this step, by completely curing the sealing material, the shape of the liquid crystal cell formed in the substantially ideal state in the above-mentioned temporary curing step is made difficult to deform so as to withstand external force. Further, as will be described later, it is possible to suppress overheating of the substrate and prevent positional deviation of the substrate that occurs when the sealing material is cured, by performing processing with an apparatus having a cooling mechanism in the process.

In the first stage, as shown in FIG.
A liquid crystal cell in which a plurality of small substrates 33 are adhered to a large-sized substrate 31 via a sealing material 32 is used as a cooling stage 40.
It is placed on the surface of and is irradiated with ultraviolet rays from above by the ultraviolet lamp 41. The cooling stage 40 is made of a surface material having high thermal conductivity, and cooling water circulates inside the cooling stage 40 to constantly cool the stage surface. From the obliquely upper side of the liquid crystal cell, cooling air is blown from the air nozzle 42 along the installation surface of the liquid crystal cell. The entire curing device is sealed by a hood and a casing of the device, and an exhaust duct (not shown) is attached.

The first stage is the large-sized substrate 31 of the liquid crystal cell.
In order to cure the photo-curable conductive resin (such as photo-curable resin mixed with conductive particles) applied on the upper electrode pad, a small substrate is used so that the conductive resin does not shade the electrode pad. It is provided mainly because it is necessary to irradiate light from the 33 side. However, in this first stage, the curing of the sealing material 32 also proceeds at the same time.

In the second stage, as shown in FIG.
A liquid crystal cell is placed on a cooling stage 50 having translucency, and an ultraviolet lamp 55 is arranged on the back surface side of the cooling stage 50 to irradiate light. Cooling stage 5
No. 0 secures the cooling performance by fixing the translucent plates 51 and 52 made of two pieces of glass or the like via the packing 53 and circulating the cooling water between the translucent plates 51 and 52. At the same time, it is said to have translucency. The air nozzle 54 blows cooling air onto the small substrate 33 as in the above, and, similarly to the above, this apparatus is also sealed from the surroundings and is provided with an exhaust duct.

In the second step, light is irradiated from the large-sized substrate 31 side of the liquid crystal cell and the light irradiation side is mainly cooled, so that the cooling efficiency is better than in the first step and the liquid crystal is The sealing material 32 can be cured without overheating the cells.

As described above, the curing process includes the first step and the second step.
By irradiating light from both the front and back sides of the liquid crystal cell, the efficiency of light irradiation to the sealing material 32 can be improved and the sealing material 32 can be uniformly cured in a short time. Further, in this way, the sealing material can be efficiently photocured, so that the liquid crystal cell can be prevented from being overheated.

In the above-mentioned main curing step, cooling is performed as described above, and the ultraviolet lamps 41, 5 are further added.
By intermittently irradiating light from 5, the liquid crystal cell is prevented from overheating. In this embodiment, as shown by the dotted line in FIG. 8, the light irradiation is intermittently performed at a cycle of 100 seconds.
As a result, the temperature of the liquid crystal cell periodically rises and falls as shown by the solid line in FIG. 8, and even if irradiation is continued for a long time, the temperature does not rise unnecessarily unlike the conventional case. Therefore, overheating of the liquid crystal cell can be prevented even if the light irradiation amount is increased.

The intermittent period of light irradiation is appropriately set according to the heat dissipation of the liquid crystal cell. By optimizing the intermittent cycle and the light irradiation intensity, curing can be completed quickly without overheating the liquid crystal cell. This light irradiation does not necessarily have to be intermittent, and the same effect can be obtained by increasing or decreasing the light irradiation intensity.

In the manufacturing method of the above-mentioned embodiment, the present invention is applied to a manufacturing process set so that a plurality of small-sized substrates are pressure-bonded to a large-sized substrate, but the present invention is applied to such a manufacturing process. The present invention is not limited to the above, but can be applied to a manufacturing process in which large-sized substrates including a plurality of liquid crystal display bodies are pressure-bonded to each other, or a small-sized substrate for forming a single liquid crystal display body is pressure-bonded to each other. Further, not only when the small substrates are pressure-bonded one by one, but as shown in FIG.
As described with reference to (e) and FIG. 5, for a manufacturing process configured to crimp a plurality of small substrates at one time or crimp with a crimp head having a flat pressing surface portion. Can also be applied.

The method adopted in the present embodiment is such that the sealing material is allowed a certain degree of restoration of the substrate, while having a certain degree of restraining force that prevents the restoration of the substrate. The substrate deformed by the pressurization is restored to a certain extent when the pressure is released, and a cell shape that is as flat as possible is formed in the restored state, and a more ideal cell shape is reproduced by such a method. You can get good quality.

[0061]

As described above, the present invention has the following effects.

In the temporary curing step, the sealing material is semi-cured in a state where the two substrates are pressure-bonded at a predetermined pressure, and thereafter,
By curing the sealing material with the pressure released in the main curing step, the substrate deformed by the pressure during pressure bonding in the temporary curing step is semi-cured at the time when the temporary curing step is completed and the pressure is released. Since the substrate shape is appropriately restored by the proper binding force of the sealing material and the restoring force of the substrate, and the deformation of the substrate is corrected, by curing the sealing material without applying pressure in the subsequent main curing step, The flatness of the substrate and the uniformity of the cell gap in the formed liquid crystal cell can be ensured.

By adjusting the degree of curing of the sealing material with respect to the pressure applied in the temporary curing step, the flatness of the substrate and the uniformity of the cell gap in the liquid crystal cell after the temporary curing step can be controlled. When the degree of curing of the sealing material is low, the binding force of the sealing material is weakened, the restoring force of the substrate is increased, and it becomes difficult to control the flatness of the substrate. On the other hand, as the curing degree of the sealing material becomes higher, the binding force of the sealing material becomes stronger and strongly reflects the shape of the substrate in the pressure-bonded state, so if the substrate is deformed during pressure bonding, the deformation remains, and If the substrate is prevented from being deformed as much as possible at the time of pressure bonding, there is a high possibility that the original strain of the substrate is reflected or that the substrate has a defective seal.

In the alignment step, alignment was performed in a state where one substrate and the other substrate were pressure-bonded, and in the subsequent semi-curing step, pressure was applied at almost the same pressure with almost no change in pressure during alignment. Since the sealing material is cured in this state, it is possible to suppress the occurrence of positional deviation after alignment, so that it is possible to prevent misalignment between the boards and improve the accuracy and uniformity of the board spacing. .

In the positioning step, since the positioning is performed in a state of being pressed with a low pressure, it is possible to perform the positioning without significantly deforming the sealing material and without applying a large stress. It is possible to perform accurate alignment quickly and without impairing the sealing property of the seal portion.

Since the cooling stage irradiates light from the side where the liquid crystal is cooled, the cooling efficiency of the liquid crystal cell is increased, and the photo-curing process can be performed without overheating the liquid crystal cell.

Since the liquid crystal cell is irradiated with light from both the front and back sides in different steps, the curing efficiency of the sealing material can be improved, and as a result, the liquid crystal cell can be rapidly heated without overheating. It becomes possible to perform photo-curing treatment.

By irradiating light which is intermittently or increased / decreased at a predetermined frequency, the light intensity and the frequency are appropriately set for the liquid crystal cell, whereby it becomes possible to prevent the liquid crystal cell from overheating.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an apparatus for manufacturing a liquid crystal display device according to the present invention.

FIG. 2 is a time chart showing a pressing force in a temporary curing step in the embodiment of the method for manufacturing the liquid crystal display device according to the present invention.

FIG. 3 is a conceptual explanatory diagram (a) for explaining the cross-sectional shape of the liquid crystal cell at the time of pressurization in the temporary curing step and after releasing the applied pressure.
(E).

FIG. 4 is a graph showing the relationship between the amount of warpage of the liquid crystal cell and the light irradiation time in the temporary curing step in the above embodiment.

FIG. 5 is a graph showing a relationship between a warp amount of a liquid crystal cell and a light irradiation time in a temporary curing step in a method different from the above embodiment.

FIG. 6 is an apparatus configuration diagram showing a processing state in a first stage of a main curing step in the above embodiment.

FIG. 7 is an apparatus configuration diagram showing a processing state in the second stage of the main curing step in the above embodiment.

FIG. 8 is a graph showing a light irradiation cycle and a temperature change of a liquid crystal cell in a main curing step in the above embodiment.

[Explanation of symbols]

10 XY table 11 cushioning material 20 crimping head 21 Crimp base 21a Pressing surface part 21b intake hole 24 Translucent plate 24a intake hole 25 Alignment camera 26 Light irradiation unit 27 Exhaust pipe

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshinori Sumita             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation F-term (reference) 2H089 NA24 NA39 NA42 NA44 NA45                       NA48 NA50 NA51 NA53 NA60                       QA03 QA04 QA11 QA13 QA14

Claims (9)

[Claims] 1. A liquid crystal display device in which one substrate of a pair of substrates arranged via a photo-curable sealant is placed on a translucent stage and attached to the other substrate. A method of irradiating the sealing material with light from the other substrate side, and thereafter irradiating the sealing material with light from the one substrate side through the stage. A method for manufacturing a liquid crystal display device, comprising: 2. The irradiation of the light with which the one substrate is irradiated, or the irradiation of the light with which the other substrate is irradiated,
The method for manufacturing a liquid crystal device according to claim 1, wherein the method is performed intermittently. 3. The liquid crystal display device according to claim 1, wherein the stage has a cooling mechanism, and the sealing member is irradiated with the light while the stage cools the stage. Method. 4. The method for manufacturing a liquid crystal display device according to claim 1, wherein the sealing material is irradiated with light while blowing cooling air onto the other substrate. 5. The substrate according to claim 1, wherein the other substrate is smaller than the one substrate, and a plurality of the other substrates are attached to the one substrate. A method for manufacturing the liquid crystal device described. 6. An apparatus for manufacturing a liquid crystal display device, wherein one of a pair of substrates arranged via a photo-curable sealing material is placed on a stage and is attached to the other substrate. A plurality of light sources that irradiate light for curing the sealing material; a first stage that mounts the one substrate and a second stage that has a light-transmitting property; A first substrate is mounted on the first stage, and a second substrate is mounted on the opposite side of the second stage. After placing the pair of substrates on one stage and irradiating the sealing material with the light, the pair of substrates is placed on the second stage, and the sealing material is exposed to the light through the stage. A device for manufacturing a liquid crystal display device, which is characterized by irradiating a liquid crystal display device. 7. The liquid crystal display device manufacturing apparatus according to claim 6, wherein at least one of the first and second stages includes a cooling mechanism. 8. The liquid crystal display device manufacturing apparatus according to claim 7, wherein the cooling mechanism circulates cooling water inside the stage to cool the stage. 9. The apparatus for manufacturing a liquid crystal display device according to claim 6, further comprising a cooling nozzle for blowing cooling air to the pair of substrates.