JP2002296605A - Method of laminating liquid crystal substrates - Google Patents

Abstract

PROBLEM TO BE SOLVED: To laminate the upper substrate and lower substrate with high produc tivity, free from mixing bubbles into the gap between the lower substrate and the upper substrate. SOLUTION: Liquid crystal material 4 is dropped in the space surrounded by an annular seal-line 3 on the lower substrate 1 which is arranged in the vacuum chamber 5 where the upper substrate 2 is laid facing to the lower substrate 1 by means of vacuum-chucking. At least one of the substrates is moved toward the other substrate and pressurized to laminate keeping the inside of the vacuum chamber 5 in a vacuum-exhaust state. This method has the ability not only to prevent the introduction of air bubbles into the gap but also to vacuum chucking the upper substrate 2 reliably using a short- duration vacuum exhausting means by making the inside of the vacuum chamber 5 under pressure of 50-400 Pa.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bonding a liquid crystal substrate for bonding substrates constituting a liquid crystal panel in a liquid crystal display device.

[0002]

2. Description of the Related Art A liquid crystal panel in a liquid crystal display device is provided between a lower substrate made of a light-transmitting material such as a glass substrate and an upper substrate through an annular seal line made of an ultraviolet curing adhesive or the like. For example, they are arranged facing each other with a predetermined gap of about 5 μm, and a gap surrounded by the seal line is filled with a liquid crystal material.

As a method of bonding the lower substrate and the upper substrate with the liquid crystal material filled in the gap between the lower substrate and the upper substrate, one or more adhesives are applied to the lower substrate by applying an adhesive. An annular seal line is formed, a liquid crystal material is dropped into a space surrounded by the seal line, and then an upper substrate is disposed thereon to perform alignment (alignment) between the upper substrate and the lower substrate. A method of dropping a liquid crystal in which an upper substrate and a lower substrate are overlapped and pressed until the distance between the upper substrate and the lower substrate becomes a predetermined gap, and ultraviolet light is applied to cure the adhesive in the seal line is disclosed in, for example, 33
No. 3157, for example.

With respect to a specific example of such a method of bonding a liquid crystal substrate, a method disclosed in Japanese Patent Application Laid-Open No. 2000-137235 will be described with reference to FIG. First, FIG.
As shown in (a), a sealing material made of an ultraviolet curable adhesive is applied on the upper surface in an annular shape with a thickness of, for example, 30 μm to form an annular sealing line 23, and a liquid crystal material is filled in a space surrounded by the sealing line 23. The lower substrate 21 on which 24 has been dropped is
The upper substrate 22 is placed and fixed on a positioning table 26 in a vacuum chamber 25 via an elastic spacer 27, while the upper substrate 22 is vacuum-sucked by a suction disk 28 and spaced above the lower substrate 21 by, for example, about 0.5 mm. The lower substrate 21 and the upper substrate 22 are aligned by adjusting the position of the positioning table 26 in the horizontal direction in this state.

Next, the inside of the vacuum chamber 25 is evacuated to a vacuum of, for example, 100 to prevent air bubbles from entering the gap.
While maintaining the atmospheric pressure of Pa or less, the pressing means 29
The suction board 28 is moved downward to move the upper substrate 22 to the lower substrate 2.
1 and the gap g between the lower substrate 21 and the upper substrate 22 is 5 μm as shown in FIG.
And the lower substrate 21 and the upper substrate 22 are bonded together. After that, the sealing line 23 is cured by irradiating ultraviolet rays to complete the bonding.

The gap g between the lower substrate 21 and the upper substrate 22, which requires submicron precision, is
The lower substrate 2 is regulated by a bead interposed between the upper substrate 22 and a post spacer protruding from the lower substrate 21 or a fiber filled in the adhesive of the seal line 23.
1, regardless of the flatness of the upper substrate 22, the positioning table 26, and the suction disk 28, the predetermined gap g
The elastic spacer 27 contributes to ensuring the accuracy of the above.

[0007]

However, since the inside of the vacuum chamber 25 is kept at a pressure of 100 Pa or less as described above in order to prevent air bubbles from being mixed therein,
Even if the suction pressure in the above is about 20 to 30 Pa, the differential pressure is only about 80 Pa, and because the suction force of the upper substrate 22 is small, the upper substrate 22 drops unexpectedly during the work, and processing such as formation of a fine thin film is performed. There is a problem that the processing may cause damage to the very expensive upper and lower substrates 22 and 21.

On the other hand, it is conceivable to further lower the suction pressure of the suction disk 28. However, increasing the flatness of the suction surface of the suction disk 28 and the flatness of the upper substrate 22 to a level higher than the current level is necessary for commercialization. In practice, it is impossible to reduce the pressure. Therefore, there is a problem that the apparatus is increased in size to reduce the pressure, and it takes a long time to reach a predetermined pressure, and the productivity is significantly reduced. It is also conceivable to apply electrostatic attraction instead of vacuum attraction. However, electrostatic attraction may adversely affect elements on the substrate or may have an adverse effect of static electricity in a subsequent process. There is a problem that the versatility is limited.

The present invention has been made in consideration of the above-described conventional problems, and has no risk of air bubbles entering a gap between a lower substrate and an upper substrate.
It is an object of the present invention to provide a method for bonding a liquid crystal substrate which can bond an upper substrate and a lower substrate with high productivity.

[0010]

According to a method of bonding a liquid crystal substrate of the present invention, a liquid crystal material is dropped into a space surrounded by an annular seal line on a lower substrate, and the lower substrate is placed in a vacuum chamber. The upper substrate is vacuum-adsorbed in the vacuum chamber and placed on the lower substrate so as to face each other.
A pressure state of 00 Pa, at least one of the substrates is moved toward the other side and pressurized, and the two substrates are bonded to each other.
By limiting to Pa, air bubbles can be prevented from being mixed into the gap, and the suction pressure of the upper substrate can be achieved in a short time even if the flatness of the upper substrate and the suction disk remains unchanged. Even if it is set to about 30 Pa, the upper substrate can be sucked and held with high reliability, and a liquid crystal substrate having good image display quality can be manufactured with high productivity.

Further, a liquid crystal material is dropped into a space surrounded by an annular seal line on the lower substrate, the lower substrate is placed in a vacuum chamber, and the upper substrate is vacuum-adsorbed in the vacuum chamber so that the lower substrate is placed on the lower substrate. And the inside of the vacuum chamber is evacuated to a predetermined pressure state, and then, when one end of the upper substrate comes into contact with the seal line, the other end of the upper substrate is spaced from the seal line by a predetermined distance. When at least one of the substrates is moved toward the other side and pressurized so as to pass through an inclined state, and the two substrates are bonded together, the upper substrate comes into contact with the lower substrate in an inclined position, and then the inclination is reduced. Since pressure is applied while losing air bubbles, air bubbles that may enter the gap can be bonded together while being pushed from one end to the other end. Prevents mixing of air bubbles into the inner, a good liquid crystal substrate of the image display quality can be produced with good productivity.

Here, it is preferable that the substrate is moved and pressurized by setting the pressure state in the vacuum chamber to 50 to 400 Pa as described above, because the intrusion of bubbles can be further prevented. When one end of the upper substrate comes into contact with the seal line, 100-100
When a gap of 0 μm is generated, and thereafter, the movement speed is controlled so that both ends of the substrate do not exceed 30 to 300 μm / sec, and the movement and pressurization are performed, the above-described effect of preventing bubbles from being mixed can be surely obtained. .

Further, an annular seal line having a height in the range of t <T <4t is formed on the lower substrate, where t is the filling depth of the liquid crystal material and T is the height of the seal line. The lower substrate with the liquid crystal material dropped in the enclosed space is placed in a vacuum chamber, the upper substrate is vacuum-adsorbed in the vacuum chamber, placed opposite to the lower substrate, and the vacuum chamber is evacuated to a predetermined pressure. State, pressurize by moving at least one substrate toward the other side, pressurize and bond both substrates, by limiting the height dimension of the seal line low, in a state where the upper substrate is in contact with the seal line, The volume of space between the upper substrate and the liquid crystal material can be reduced, and the amount of air escaping from the seal line during pressurization can be reduced by that amount, so that air does not easily remain and air bubbles can be prevented from entering the gap. Display quality It can be produced with good productivity crystal substrate had.

Here, it is preferable that the substrate is moved and pressurized by setting the pressure state in the vacuum chamber to 50 to 400 Pa as described above, because the inclusion of bubbles can be further prevented. Also, at the time when one end of the upper substrate comes into contact with the seal line, at least one substrate is directed toward the other side so that the upper substrate passes through a state in which the upper substrate is inclined so that the other end of the upper substrate is at a predetermined interval with respect to the seal line. When the substrate is moved and pressurized, and the two substrates are bonded to each other, bubbles that may be mixed in the gap can be pushed out from one end to the other end, and furthermore, mixing of bubbles into the gap can be prevented, which is preferable. .

Further, a liquid crystal material is dropped into a space surrounded by an annular seal line on the lower substrate, the lower substrate is placed in a vacuum chamber, and the upper substrate is vacuum-adsorbed in the vacuum chamber to remove the upper substrate. The vacuum chamber is evacuated to a first predetermined pressure state, and then at least one of the substrates is moved toward the other side, and at least a part of the upper substrate is close to or close to the seal line of the lower substrate. After contact
The inside of the vacuum chamber is further evacuated to a second predetermined pressure state lower than the first predetermined pressure, and both substrates are pressurized. When the two substrates are bonded to each other, the substrate is lifted at a relatively high first predetermined pressure state. After firmly holding the substrate and moving it until it comes into contact with the lower substrate, the substrate is pressurized at a second predetermined pressure lower than that to reliably prevent bubbles from being mixed into the gap. Thus, a liquid crystal substrate having good image display quality can be manufactured with high productivity.

Here, the first predetermined pressure is set to 50 to 400 P
When the second predetermined pressure is set to 10 to 50 Pa, the upper substrate can be surely sucked and held at the first predetermined pressure as low as possible, and the pressure is quickly reduced to the second predetermined pressure state to mix bubbles. This is preferable because it is possible to reliably prevent the occurrence of On the lower substrate, the filling depth of the liquid crystal material is t, and the height of the seal line is T.
When an annular seal line having a height in the range of t <T <4t is formed, the height dimension of the seal line is limited to a small value, so that it is possible to further prevent air bubbles from entering the gap as described above. preferable. Also, at the time when one end of the upper substrate comes into contact with the seal line, at least one substrate is directed toward the other side so that the upper substrate passes through a state in which the upper substrate is inclined so that the other end of the upper substrate is at a predetermined distance from the seal line. When it is moved and pressurized and the two substrates are bonded together, air bubbles that may be mixed into the gap can be pushed out from one end to the other end as described above. It is preferable because it can be prevented.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for bonding liquid crystal substrates according to the present invention will be described below with reference to FIGS.

FIG. 1 shows a process of manufacturing a liquid crystal substrate in which a space surrounded by a seal line 3 formed in a gap g between a lower substrate 1 and an upper substrate 2 is filled with a liquid crystal material 4.
First, as shown in FIG. 1A, a sealing material made of an ultraviolet curable adhesive is applied in a ring shape on the upper surface of the lower substrate 1 to form a ring-shaped sealing line 3, which is surrounded by the sealing line 3. A liquid crystal material 4 is dropped into the space, and the lower substrate 1 is placed on a positioning table 6 in a vacuum chamber 5 by an elastic spacer 7.
Place and fix via. Positioning table 6 is lower substrate 1
Is performed in the horizontal direction.

The lower substrate 1 and the upper substrate 2 are, for example, 550 mm ×
The lower substrate 1 and the upper substrate 2 each have a size of 670 mm, and one or a plurality of image display areas (hereinafter, referred to as display cells) according to the number of liquid crystal panels to be manufactured on the substrates 1 and 2.
Is formed, and the annular seal line 3 is formed by application so as to surround the periphery of each display cell.

The amount of liquid crystal material 4 to be dropped is precisely controlled so that the filling depth of each liquid crystal cell is equal to a predetermined gap g, for example, 5 μm. The liquid crystal material 4
In a state where is dropped, it has a mountain shape due to its viscosity as shown in FIG. When the lower substrate 1 and the upper substrate 2 are pressurized, the seal line 3 must be applied at an appropriate height so that the liquid crystal material 4 does not unexpectedly run over the lower substrate 1 and the upper substrate 2. 30 with plenty of time
In this embodiment, the height is set as low as possible within a range where the liquid crystal material 4 does not protrude. Specifically, as shown in FIG. 2, the filling depth of the liquid crystal material 4 is t, and the height of the seal line 3 is T, and t <T <4t, preferably 2t <T <3T. I have. That is, the filling depth of the liquid crystal material 4 is 5 μm, and the height of the seal line 3 is 5 to 20 μm, preferably 1 to 20 μm.
It is set to 0 to 15 μm.

Next, the upper substrate 2 is vacuum-sucked by the suction disk 8 and inserted and arranged in the vacuum chamber 5, and the inside of the vacuum chamber 5 is filled with 50 to 400 Pa, preferably 150 P
evacuated to a pressure P ₁ of about a. The suction pressure of the suction disk 8 is a pressure range of 20 to 3 which can be achieved in a short time without particularly improving the flatness of the suction surface of the upper substrate 2 or the suction disk 8.
It is set to 0 Pa. As a result, the upper substrate 2 can be sucked and held with high productivity, and a sufficient pressure difference of about 100 Pa can be obtained between the pressure of 50 to 400 Pa in the evacuated vacuum chamber 5. It is possible to eliminate the risk of accidental drop and damage.

Next, the upper substrate 2 sucked and held by the suction disk 8 by the moving pressure means 9 for vertically moving the suction disk 8 and applying a pressing force is placed on the lower substrate 1 by, for example, 0.5 to 1 mm. The upper and lower substrates 1 and 2 which are opposed to each other with an interval D are image-recognized, and the positioning table 6 is positioned so that they match.
Adjust the position.

A height regulating member 10 is provided at each of the four corners of the suction cup 8, and a vertical linear actuator 11 is provided at a position facing the height regulating member 10 at each of the four corners of the positioning table 6. Then, as shown in FIG. 1B, the suction disk 8 is lowered until each height regulating member 10 comes into contact with the linear actuator 11. Each height regulating member 1
0, as shown in FIG. 3, one end of the upper substrate 2 is in contact with the seal line 3 and the other end of the upper substrate 2 is spaced from the lower substrate 1 by a predetermined distance d of, for example, about 100 μm or more. The length dimension of the substrate 2 is adjusted and set so as to abut on the linear actuator 11 in a state where the substrate 2 is inclined.

Next, the inside of the vacuum chamber 5 is evacuated,
The pressure state from P ₁ of 50~400Pa 10~50
Increase the degree of vacuum until the P ₂ of Pa. Further, all the linear actuators 11 are moved down at a predetermined speed V of about 30 to 300 μm / sec, and the lower substrate 1 is moved together with the suction plate 8 while the upper substrate 2 is removed from the above-mentioned inclined posture.
, And then, as shown in FIG.
Subsequently, pressure is applied by a predetermined pressure until the gap between the lower substrate 1 and the upper substrate 2 reaches a predetermined gap g. As a result, the lower substrate 1 and the upper substrate 2 are bonded together while extruding bubbles that may be mixed into the gap g between them from one end to the other end. afterwards,
The seal line 3 is cured by irradiating ultraviolet rays, and the upper substrate 2
And the lower substrate 1 are completed.

According to the configuration of the present embodiment described above, since the pressure state in the vacuum chamber 5 is limited to 50 to 400 Pa, the suction pressure of the upper substrate 2 can be achieved in a short time. Even if it is set to about 30 Pa, the upper substrate 2 can be suction-held with high reliability,
A liquid crystal substrate can be manufactured with high productivity.

When one end of the upper substrate 2 contacts the seal line 3, the other end of the upper substrate 2 is
After the upper substrate 2 contacts the lower substrate 1 in an inclined position by moving it through a state of being inclined so as to open by a predetermined interval d of 0 μm or more and pressing it toward the lower substrate 1, Pressurizing while eliminating the inclination,
As a result, air bubbles that may be mixed in the gap between the lower substrate 1 and the upper substrate 2 can be bonded while being pushed from one end to the other end. It is possible to prevent air bubbles from being mixed into g, and to manufacture a liquid crystal substrate having good image display quality.

The predetermined distance d is preferably about 100 to 1000 μm. When the pressure is 100 μm or less, the elastic spacer 7 interposed between the lower substrate 1 and the positioning table 6 is elastically deformed when a pressing force acts, and the amount of inclination is offset by the lifting of the other end of the lower substrate 1, and the above operation is sufficiently performed. On the other hand, when the thickness is 1000 μm or more, the effect is not improved despite the time required for the movement, and the productivity is merely reduced.

Further, the descent speed V of the linear actuator 11 from the inclined posture is set to 30 to 300 μm / sec.
By performing the movement and pressurization while controlling the speed to about the degree, the effect of preventing bubbles from being mixed can be reliably obtained. When the number of display cells on the substrates 1 and 2 is small, bubbles can easily escape from each space surrounded by the seal line 3, so that the descending speed V can be set high. On the other hand, when the number of display cells is large, since the two substrates 1 and 2 are almost parallel at the other end side of the substrates 1 and 2, bubbles in each space surrounded by the seal line 3 are hard to escape, and It is preferable to set the speed V low.

Also, assuming that the height of the seal line 3 on the lower substrate 1 is T and the filling depth of the liquid crystal material 4 is t, t <T <4t
And the height dimension of the seal line 3 is limited to a low value, so that the space volume between the upper substrate 2 and the liquid crystal material 4 can be reduced while the upper substrate 2 is in contact with the seal line 3, The amount of air escaping from the seal line 3 at the time of partial pressurization can be reduced, and the air is less likely to remain, and air bubbles can be more reliably prevented from entering the gap.

Further, as described above, the inside of the vacuum chamber 5 is brought into a pressure state of 50 to 400 Pa, and the upper substrate 2 sucked and held by the suction disk 8 is moved toward the lower substrate 1 so that at least one of the upper substrates 2 is moved. After the part approaches or comes into contact with the seal line 3 of the lower substrate 1, the inside of the vacuum chamber 5 is further evacuated to a pressure state of 10 to 50 Pa, and the substrates 1 and 2 are pressed and bonded. High 50-50
After firmly holding the upper substrate 2 under the pressure of 0 Pa and moving it until it comes into contact with the lower substrate 1, pressurization is performed at a pressure of 10 to 50 Pa to reliably prevent bubbles from being mixed into the gap. can do.

According to the present embodiment, as described above, a liquid crystal substrate having good image display quality can be manufactured with high productivity.

In the above embodiment, the upper substrate 2 is moved and pressed against the lower substrate 1. However, the lower substrate 1 may be moved and pressed against the upper substrate 2. Needless to say. Also, as a means for bonding the upper substrate 2 at a predetermined speed after the inclined position of the upper substrate 2, a height regulating member 10 is provided.
Although the linear actuator 11 has been used, the invention is not limited to this, and the moving pressurizing means 9 can be arbitrarily configured such as having such a function.

In the above embodiment, the vacuum chamber 5
After limiting the internal pressure to 50 to 400 Pa, the pressure was further evacuated to 10 to 50 Pa during the pressurizing step.
By limiting the pressure to 400 Pa, it is possible to prevent air bubbles from being mixed even when both substrates 1 and 2 are pressed and bonded with the same pressure. Conversely, 10 to 50 during the pressing step
If the chamber is evacuated to Pa, the pressure in the vacuum chamber 5 up to that time need not be limited to 50 to 400 Pa as described above, and may be higher. , 10 to 50 during the pressurizing step
Vacuum can be evacuated to a pressure state of Pa in a short time, and productivity is improved.

Also, the required effects can be obtained even when the above-mentioned oblique bonding of the upper substrate 2 and the limitation of the height of the seal line 3 are performed independently. However, by appropriately combining the above technical means, it is possible to more effectively prevent the air bubbles from being mixed with good productivity.

[0035]

According to the liquid crystal substrate bonding method of the present invention, the pressure state in the vacuum chamber is set to 50 to 400 Pa.
By setting the upper limit, it is possible to prevent air bubbles from being mixed in the gap, and to set the suction pressure of the upper substrate in a short time even if the flatness of the upper substrate and the suction plate remain unchanged. However, the upper substrate can be suction-held with high reliability.

Further, after the upper substrate is brought into contact with the lower substrate in an inclined posture, pressure is applied while eliminating the inclination, so that air bubbles which may be mixed in the gap are reduced from one end to the other end. It is possible to prevent air bubbles from entering the gap even if the pressure in the vacuum chamber is high to some extent.

The height of the seal line is defined as t, the filling depth of the liquid crystal material is defined as t, and the height of the seal line is defined as t.
By limiting the value to a low value in the range of <T <4t, the space volume between the upper substrate and the liquid crystal material can be reduced in a state where the upper substrate is in contact with the seal line, and escape from the seal line when pressurized. Since the amount of air is small, the air can be hardly left, and air bubbles can be prevented from entering the gap.

Further, after the upper substrate is reliably sucked and held at a relatively high first predetermined pressure state and moved until it contacts the lower substrate, pressure is applied at a lower second predetermined pressure state. As a result, it is possible to reliably prevent air bubbles from entering the gap.

As described above, according to the present invention, a liquid crystal substrate having good image display quality can be manufactured with high productivity by carrying out the above-mentioned methods singly or in an appropriate combination.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a liquid crystal substrate bonding step in one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a height dimension of a seal line in the embodiment.

FIG. 3 is an explanatory diagram of an inclined state of an upper substrate in the embodiment.

FIG. 4 is a sectional view showing a conventional liquid crystal substrate bonding step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower substrate 2 Upper substrate 3 Seal line 4 Liquid crystal material 5 Vacuum chamber 8 Suction board 9 Moving pressure means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takanori Funabashi 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Norihiko Egami 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.F-term (reference)

Claims (11)

[Claims] 1. A liquid crystal material is dropped into a space surrounded by an annular seal line on a lower substrate, the lower substrate is placed in a vacuum chamber, and the upper substrate is vacuum-adsorbed in the vacuum chamber to form a liquid crystal material on the lower substrate. And the inside of the vacuum chamber is 50 to 4
A method for bonding liquid crystal substrates, wherein at least one of the substrates is moved toward a counterpart under a pressure of 00 Pa and pressed to bond both substrates. 2. A liquid crystal material is dropped into a space surrounded by an annular seal line on the lower substrate, and the lower substrate is placed in a vacuum chamber, and the upper substrate is vacuum-adsorbed in the vacuum chamber and And the inside of the vacuum chamber is evacuated to a predetermined pressure state, and then, when one end of the upper substrate comes into contact with the seal line, the other end of the upper substrate is spaced from the seal line by a predetermined distance. A liquid crystal substrate bonding method, wherein at least one of the substrates is moved toward a mating side and pressed so as to pass through an inclined state, and the two substrates are bonded to each other. 3. The method for bonding liquid crystal substrates according to claim 2, wherein the substrate is moved and pressurized by setting the pressure in the vacuum chamber to 50 to 400 Pa. 4. When one end of the upper substrate comes into contact with the seal line, a distance between the other end of the upper substrate and the seal line is reduced.
An interval of 0 to 1000 μm is generated, and then the moving speed of both ends of the substrate is 30 to 300 μm / sec.
4. The method for bonding liquid crystal substrates according to claim 2, wherein the movement and pressurization are performed so as not to exceed the range. 5. The method according to claim 1, wherein the filling depth of the liquid crystal material is t,
When the height of the seal line is T, an annular seal line having a height in the range of t <T <4t is formed, and a lower substrate in which a liquid crystal material is dropped in a space surrounded by the seal line is placed in a vacuum chamber. In a vacuum chamber, the upper substrate is vacuum-adsorbed and placed opposite to the lower substrate, the inside of the vacuum chamber is evacuated to a predetermined pressure state, and at least one substrate is moved toward the other side and pressurized, A method for bonding liquid crystal substrates, comprising bonding both substrates. 6. The method for bonding liquid crystal substrates according to claim 5, wherein the substrate is moved and pressurized by setting the inside of the vacuum chamber to a pressure of 50 to 400 Pa. 7. When at least one of the substrates is in contact with the other end of the upper substrate, the upper substrate is inclined so that the other end of the upper substrate is at a predetermined distance from the seal line when one end of the upper substrate comes into contact with the seal line. 7. The method for bonding liquid crystal substrates according to claim 5, wherein the substrates are moved toward each other and pressurized to bond both substrates. 8. A liquid crystal material is dropped into a space surrounded by an annular seal line on the lower substrate, and the lower substrate is placed in a vacuum chamber. The vacuum chamber is evacuated to a first predetermined pressure state, and then at least one of the substrates is moved toward the other side, and at least a part of the upper substrate is close to or close to the seal line of the lower substrate. After the contact, the inside of the vacuum chamber is further evacuated to a second predetermined pressure state lower than the first predetermined pressure, and both substrates are pressurized to bond the two substrates together. Matching method. 9. The method for bonding liquid crystal substrates according to claim 8, wherein the first predetermined pressure is 50 to 400 Pa and the second predetermined pressure is 10 to 50 Pa. 10. An annular seal line having a height in the range of t <T <4t, where t is the filling depth of the liquid crystal material and T is the height of the seal line, on the lower substrate. The method for bonding a liquid crystal substrate according to claim 8 or 9, wherein: 11. When one end of the upper substrate comes into contact with the seal line, at least one of the substrates is moved to the other side so that the upper substrate passes through a state in which the upper substrate is inclined such that the other end of the upper substrate is at a predetermined distance from the seal line. And pressurize,
11. The two substrates are bonded together.
The method for bonding a liquid crystal substrate according to any one of the above.