JP2002323694A - Substrate bonding method and bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate laminating method and a laminating device by which two substrates can be accurately and reliably laminate together in a short time, even in a large substrate. SOLUTION: When two substrates are laminated together with mechanical pressurizing force in a vacuum chamber, pressurization mechanisms which pressurize the vicinities of four corner parts of the square substrates are respectively provided, the gap between the substrates is observed after pressurizing the vicinities with the predetermined pressurizing force, and the vicinities are pressurized after adjusting the pressurizing force of each pressurization mechanism based on the observation. Thus, the laminating device which can make the gap between the substrates after lamination almost uniform is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for bonding substrates such as liquid crystal display panels in a vacuum.

[0002]

2. Description of the Related Art In a manufacturing process of a liquid crystal panel, a distance between two glass substrates provided with a transparent electrode, a thin film transistor array and the like is set to 2 μm in order to form a space for sealing liquid crystal between the two substrates. There is a step of bonding with an adhesive (hereinafter, referred to as a sealing agent) to a degree.

For example, Japanese Patent Application Laid-Open No. 2001-512284 discloses that when a bonding position between a lower substrate and an upper substrate is adjusted, a pressure is applied to both substrates, and the lower surface of the upper substrate is applied to an adhesive on the upper surface of the lower substrate. The first pressure mechanism to be brought into contact with the upper substrate is bonded to the lower substrate with an adhesive, and the first substrate is pressed until a predetermined interval is reached.
A bonding apparatus including a second pressing mechanism for applying a pressing force different from the pressing mechanism, and having a configuration in which the first pressing mechanism and the second pressing mechanism operate at different timings to press each other is disclosed. Have been.

[0004]

However, when the substrate to be bonded is large, it is difficult to apply a uniform pressing force to the entire substrate by the above-mentioned conventional pressing mechanism, and it is necessary to observe the pressing state of each end of the substrate while observing the pressing state. In this case, it is necessary to adjust the respective pressures and perform the bonding.

[0005] The object of the present invention is to provide a large substrate.
An object of the present invention is to provide a substrate bonding method and a bonding apparatus for bonding two substrates accurately, reliably, and in a short time.

[0006]

In order to achieve the above object, the present invention provides a pressurizing mechanism for applying a pressurizing force in a vacuum chamber, a pressurizing mechanism for pressurizing near a central portion of a substrate,
A pressurizing mechanism is provided for pressurizing the vicinity of the four corners of the substantially square substrate, and a pressurizing mechanism for pressurizing the central part and / or a pressurizing mechanism for pressing the four corners is applied at a predetermined pressing force. After pressing, observe the distance between the substrates or the state of the adhesive being crushed, and individually control the pressing mechanisms that press each of the four corners according to the observation results, so that the substrate intervals become even. The lamination is performed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the substrate bonding apparatus according to the present invention will be described below in detail with reference to FIGS. FIG. 1 is a schematic side view showing the configuration of the substrate bonding apparatus of the present invention, and FIG. 2 is a top view of the substrate bonding apparatus shown in FIG.

<Structure of Substrate Bonding Apparatus of the Present Invention> As shown in FIG. 1, the substrate bonding apparatus of the present invention moves in the Z-axis direction having a stage S1, a substrate bonding section S2, and a pressing mechanism. And a stage section S3.
On the gantry 1, there are a frame 2 that supports the substrate bonding section S2 and a frame 3 that supports the Z-axis direction moving stage section S3. The stage section S1 is provided on the upper surface of the gantry 1. In addition, a control unit (not shown) for controlling the above-described units, the pressing mechanism, and the like is provided in the substrate bonding apparatus of the present embodiment.

The stage section S1 is provided with an X stage 4a having a drive motor 5, and the drive motor 5 causes the Y stage 4b provided on the X stage 4a to move in the X-axis direction in FIG. To be able to move to. Further, the Y stage 4b has a drive motor 6, and the drive motor 6 allows the .theta.
The stage 4c can be moved in the Y axis direction orthogonal to the X axis and the Z axis in FIG. Further, a support 10a for supporting the support column 10 is provided on the θ stage 4c provided with the drive motor 8, and the support 10a is moved by the drive motor 8 via the rotary bearing 7 to the Y stage 4b. It is configured to be rotatable with respect to.

At the upper end of the support column 10, a table 9 for mounting a lower substrate is provided. The lower end of the vacuum bellows 12 is fixed to the θ stage 4c via the arm 11. Further, in order to ensure good rotation and airtightness of the support column 10, the rotating bearing 13 and the seal 14 are fixed to the support column 10 by the arm 11, and when the support column 10 rotates, the arm 11 and the vacuum bellows 12 are configured so as not to rotate together with the support column 10.

The substrate bonding section S2 is provided in the chamber 1
5 and a table 9 arranged inside the chamber 15
And a pressure plate 16, a substrate holding claw 40 for holding the upper substrate 34 that has come off from the pressure plate 16 when the pressure in the chamber 15 is reduced as described later, and a gate valve 17 provided at the entrance and exit of the chamber 15. Have been. The table 9 is fixed on the stage S1 via the support pillar 10 as described above.

The pressure plate 16 is provided with a plurality of support columns 27.
Through the central guide plate 2 of the Z-axis direction moving stage section S3
9 is fixed. Further, the periphery of each support column 27 is surrounded by a chamber 15 at one end and a bellows 28 fixed at the other end to a central guide plate 29, so that a reduced pressure state in the chamber 15 at the time of bonding the substrates can be maintained. Is configured. In the present embodiment, the pressing plate 16
Are fixed to the central guide plate 29 via five support columns 27.

The lower part of the chamber 15 includes a chamber 15
Pipes 20a and 20b for evacuating the inside are provided. The pipes 20a and 20b are connected to a vacuum pump via a switching valve (not shown). The pressure in the chamber 15 when bonding the substrates is 5 × 1
0 is about ^-3 Torr.

Further, a plurality of windows 25 are provided in the upper part of the chamber 15 to shield the atmosphere for observing the alignment marks of the substrates to be bonded. These windows 25
, Through a mark recognition hole provided in the pressing plate 16 (not shown), the recognition camera 26 is configured to measure the displacement of the alignment marks on the upper and lower substrates.

The table 9 is provided with an electrostatic attraction mechanism comprising an electrostatic attraction electrode for attracting a substrate and a suction attraction mechanism comprising a plurality of suction attraction holes. Each suction hole is connected to a vacuum pump via a suction valve (not shown) installed outside the chamber 15 via a pipe 18. A bypass pipe is provided in the middle of the pipe 18 for opening to the atmosphere via a valve for vacuum breaking. By opening the vacuum breaking valve, the suction state can be forcibly released.

The table 9 receives the lower substrate 33 from a transfer machine (not shown) and places it on the table 9.
Alternatively, a plurality of lifting pins 35 for taking out the bonded substrate (hereinafter, the bonded substrate is referred to as a cell).
Is provided. The lifting pin 35 can move in the Z-axis direction through a hole provided in the table 9, and this movement is performed by a cylinder 36.

On the other hand, the pressing plate 16 is provided with an electrostatic attraction mechanism comprising an electrostatic attraction electrode, similarly to the table 9, and a suction attraction mechanism comprising a plurality of suction holes for reducing pressure. Each suction suction hole is connected to the vacuum chamber 1 via a pipe 19.
5 is connected to a vacuum pump via a suction valve (not shown) provided outside.

In this embodiment, the center guide plate 29
Are provided above the center guide plate 29 (above the support pillar 27), and four pressing mechanisms 41 to 44 are provided.
Is provided. Further, a linear guide that can move in the vertical direction with respect to the frame 3 is attached to the center guide plate 29. The driving units of the pressure mechanisms 41 to 45 are fixed supporting members 46 a and 46 provided on the frame 3.
b, 46c, 46d, 47.

The drive unit of this pressurizing mechanism is composed of motors 41a, 42a, 43a, 44a, 45a with encoders and ball screws 41b, 42b, 43b, 44b, 45b. Load cells 41c, 42c, 43
c, 44c and 45c are provided.

The center guide plate 29 or an auxiliary member 48 for applying a force to the center guide plate 29 includes Z
A linear guide 30 for moving in the axial direction is provided. The linear guide 30 is configured to be movable along a rail provided on the frame 3. By operating each pressing mechanism and moving the central guide plate 29 downward, the pressing plate 16 fixed to the support column 27 is moved.
Is pressed down, and the upper substrate 34 adsorbed on the pressure plate 16 is pressed against the lower substrate 33 to be pressed.

In this embodiment, five pressure mechanisms are provided. However, even if four force mechanisms are provided in the vicinity of four corners of a square substrate, force is applied evenly. Good. Further, in the present embodiment, the central guide plate 2
Although the pressure is applied to the pressure plate 16 via the pressure plate 9, the pressure mechanism may be configured to directly apply the force to the pressure plate 16.

Next, the operation of bonding the substrates for liquid crystal panels by the substrate bonding apparatus configured as described above will be described.

When bonding a liquid crystal panel substrate,
Upper substrate 34 or lower substrate 33 used for substrate bonding
The adhesive is applied in advance with a single stroke so as to form a frame on one side. FIG. 6 shows an example of forming the frame. Further, a predetermined amount of liquid crystal is dropped in a frame of the adhesive with the substrate coated with the adhesive as a lower substrate. Here, before the liquid crystal is dropped or before the substrates are bonded after the liquid crystal is dropped, spacers for defining a substrate interval are dispersedly arranged on the lower substrate or the upper substrate. This spacer may be mixed in the liquid crystal.
In the present embodiment, the application of the adhesive is performed on the lower substrate 33. However, the application of the adhesive may be performed on the upper substrate 34. In this case,
The liquid crystal dropping region on the lower substrate side needs to be in a region surrounded by the adhesive provided on the upper substrate.

After the adhesive is applied to one of the substrates as described above, a bonding operation is performed by a substrate bonding apparatus. Hereinafter, the bonding step will be described.

First, the upper substrate 34 is placed on a transfer machine (not shown) installed outside the chamber 15 so that the film surface of the upper substrate 34 faces downward. Adsorb by suction. Next, after opening the gate valve 17 at the entrance of the chamber 15 and inserting the hand of the transfer machine into the chamber, the pressure plate 16 is pressed against the upper substrate 34, and the suction and suction mechanism of the pressure plate 16 By using the holes to suck up the upper substrate 34 by vacuum suction, the pressure plate 1
6, the upper substrate 34 is sucked. After the substrate 34 is thus attracted to the pressure plate 16, the upper substrate 3
4 was stopped, and then the hand
5. Evacuate outside. In the present embodiment, the hand of the transfer machine has been described as having a suction suction function.
The transfer machine may be configured to simply hold the upper substrate by the claw mechanism and insert the upper substrate into the chamber.

Next, the tip of the elevating pin 35 provided on the table 9 in the chamber 15 is raised so as to protrude from the upper surface of the table 9, and the surface of the lower substrate 33 on which the liquid crystal is dropped is raised. After holding the lower substrate 33 with the hand of the transfer machine so as to face the lower substrate 33, the lower substrate 33 is inserted into the chamber 15, and the lower substrate 33 is transferred onto the lifting pins 35 which have been raised as described above. Put on. After the transfer, the transfer machine hand is retracted out of the chamber 15, the gate valve 17 is closed, and the elevating pins 35 are further lowered, whereby the lower substrate 33 is transferred onto the table 9. After transferring the lower substrate 33 to the table 9, the lower substrate 33 is vacuum-sucked to the table 9 by operating the suction holes of the table 9.

As described above, both substrates 33,
34 were fixed to the table 9 and the pressure plate 16, respectively.
First, open the valve on the exhaust pipe 20a side with the smaller diameter.
The gas in the chamber 15 is gradually exhausted. here
The pumping speed during pumping is such that the substrate does not run
The liquid crystal on the lower substrate 33 is not scattered.
The speed is set so that the minute does not freeze. Chamber 1
5 is gradually exhausted, and even if the exhaust speed increases,
Substrate does not run, liquid crystal does not scatter, and water freezes
Pressure (for example, if the vacuum
To a pressure at which the upper substrate 34 does not separate from the pressure plate 16.
Pressurized), close the valve of the pipe 20a,
Pressure for opening the valve b and bonding the upper and lower substrates
(5 × 10 ^-3Torr)
You.

Here, when the pressure in the chamber 15 is reduced as described above, the pressure in the vacuum chamber may be lower than the suction force of the upper substrate 33, and the upper substrate 34 may be separated from the pressure plate 16. Therefore, a substrate holding claw 40 is provided on the pressure plate 16 side in the chamber 15. When the pressure in the chamber 15 decreases and the upper substrate 34 separates from the pressure plate 16, the upper substrate 34 is supported by the substrate holding claws 40. The substrate holding claw 40 is moved (evacuated) so as not to be caught on the substrate end surface when the substrate is sucked and sucked or when the substrate is mechanically pressurized (when pressed by the pressing plate 16).

The process of bonding the two substrates 33 and 34 held on the table 9 and the pressure plate 16 as described above is shown in FIG.
This will be described in detail below with reference to FIG. FIG. 3 is a diagram showing a time chart of the depressurization state in the chamber, the action of the suction force, and the motor driving state positioning operation after the substrate is held, the substrate is pressed and bonded, and then the chamber is opened to the atmosphere. It is.

As shown in FIG. 3, first, at time t1, after the upper substrate 34 is attracted to the pressure plate 16 by suction / adsorption,
The lower substrate 33 is transferred onto the table 9 in the chamber 15 and is suction-adsorbed on the table 9. Next, at time t2, pressure reduction in the chamber is started. Here, at the time t3 in the middle of the depressurization process, the pressure in the chamber becomes smaller than the suction attraction force applied to the upper substrate 34 held by the pressure plate 16 by suction attraction, so that the upper substrate 34 cannot be suctioned and sucked, and There is a case where it falls on 40. In this case, at time t4 when a predetermined reduced pressure state is reached, electricity is supplied to the electrode for performing electrostatic attraction, and the upper substrate 34 is attracted to the pressure plate 16 again. Note that the predetermined reduced pressure state is a state in which no discharge occurs between the electrodes on the electrostatic attraction plate.

Here, the reason why the suction suction and the electrostatic suction are used together as described above in the present embodiment will be described below. In order to hold the upper substrate 34 on the pressure plate 16 only by vacuum suction, it is necessary to suction the upper substrate 34 with a suction force larger than the depressurizing force for depressurizing the inside of the chamber 15, and the vacuum pump also has a large capacity. I have to use things. Further, if the pressure is directly reduced after the electrostatic adsorption of the upper substrate 34 to the pressure plate 16 is performed in the air, the air remaining between the upper substrate 34 and the pressure plate 16 expands and escapes, so that the upper substrate 34 is partially removed. A gap is formed between the pressure plate 34 and the pressure plate 16, and a discharge phenomenon occurs between the positive and negative electrodes provided on the pressure plate 16, and the upper substrate 34 and the pressure plate 16 are damaged. Further, when the discharge is performed, the electrostatic attraction force is reduced, so that the upper substrate 34 falls, and further discharge may occur at a certain gap amount at this moment. This discharge in vacuum is generated according to the relationship between the amount of voltage, the pressure and the gap between the electrodes according to Paschen's law. Escapes, and this phenomenon always occurs.

As described above, in this embodiment, the electrostatic suction is performed after the vacuum is reduced to the extent that the discharge phenomenon does not occur. As a result, the size of the apparatus can be reduced, and both the substrates 33 and 34 can be reliably and completely mounted on the pressing plate 16 and the table 9.
Can be adsorbed. In the time chart shown in FIG. 3, the voltage is applied to the electrostatic attraction electrodes of the table 9 and the pressure plate 16 before the decompression is completed, and the electrostatic attraction is performed. It may be performed.

After the substrates 33 and 34 are fixed to the table 9 and the pressure plate 16 by suction and adsorption as described above, the pressure plate 1
6 is adjusted to be parallel to the table 9. afterwards,
In order to lower the central guide plate 29 of the Z-axis direction moving stage section S3, the motors of the pressing mechanisms are operated in cooperation to bring the upper substrate 34 closer to the lower substrate 33. First, the upper substrate 34
Before contacting with the adhesive provided on the lower substrate 34, the alignment marks provided on the upper and lower substrates are detected using the recognition camera 26, and the positional deviation between the substrates is measured. Next, using the measured values obtained, the table 9 on which the lower substrate 33 is placed is placed.
The operation of the stage S1 is controlled so that the lower substrate 33
Perform position adjustment.

After the alignment, the central guide plate 29 is further lowered to crush the adhesive applied to the lower substrate 33, and the first bonding is performed in a state where the liquid crystal is sealed in a frame formed of the adhesive. . During the primary bonding operation, the upper substrate 3
Immediately after contact with the adhesive, the positioning operation is performed again using the camera. This positioning operation is repeated a plurality of times until the maximum pressure is completely applied. The reason for repeating the alignment several times in this way is that even if the pressing force is applied evenly, the adhesive is not evenly applied, so the method of crushing the adhesive is not uniform, and the force of the adhesive part is This is because a non-uniform portion of the action occurs, and as a result, a shear force acts between the upper and lower substrates to cause a displacement between the substrates.

After the first bonding, the voltage applied to the electrostatic attraction electrode of the pressure plate 16 is cut off, and then the attraction and attraction is stopped. Then, the pressure mechanism is operated to raise the pressure plate 16. Thereafter, gas is injected into the chamber 15 to return the pressure in the chamber 15 to the atmospheric pressure.

Here, it is difficult to make the pressing plate 16 strictly parallel to the upper surface of the table 9 at the time of bonding.
At the time of bonding, the adhesive is crushed unevenly, or the adhesive is crushed unevenly due to deformation of the substrate itself, and the distance between the substrates after bonding is not constant. Therefore, before the pressure plate 16 is lifted as described above, the amount of crushing of the adhesive on each side of the substrate is observed, and for the side having a small amount of crushing, a pressing mechanism disposed at the periphery (four corners). Among them, by adjusting the pressing force of the pressing mechanism on the side with the smaller crushing amount and lowering the pressing force of the pressing mechanism on the other side, the crushing amount of the adhesive is adjusted to be uniform. .

In this embodiment, the pressure in the chamber 1 is reduced.
Although the amount of crushing of the adhesive is observed in 5,
It may be performed after returning the inside of the chamber 15 to the atmospheric pressure. Further, several substrates may be bonded together, and the pressing force of each pressing mechanism may be set so that the amount of crushing of each part of the adhesive becomes uniform.

The operation for equalizing the amount of crushing of each part of the adhesive will be described below with reference to FIGS. FIG. 4 is a diagram showing an example of a state in which the adhesive 37 is crushed by an imbalance, and FIG. 5 is a diagram showing a method of adjusting a gap in the state of FIG.

As shown in FIG. 4, when the amount of crushing of the adhesive 37 on the left side in the figure is large and the amount on the right side is small, as shown in FIG.
The pressurizing mechanism is operated in the direction of the arrow by decreasing the pressurizing force of the pressurizing mechanisms 1 and 42 and increasing the pressurizing force of the pressurizing mechanisms 43 and 44. The central part is kept as it is. As described above, the non-uniformity of the gap between the substrates due to the deformation of the substrate and the non-uniform application amount of the adhesive 37 can be eliminated. In addition, in the present embodiment, in order to independently press the peripheral portion of the substrate, each pressing mechanism is configured to be independently driven. The method of observing the amount of crushing of the adhesive 37 may be visual, but may be a method of measuring using an optical system such as a camera or a method of detecting using a gap sensor or the like.

Here, when the size of the panel is small, a desired pressing force can be applied by the mechanical pressing mechanism as described above. However, when the size of the panel is large, the mechanical pressing force is increased. In order to set a predetermined distance between the substrates, it is necessary to increase the size of the pressing device itself and to apply a large pressing force. In order to maintain the size of the device at the current size, it is necessary to consider other pressing means.However, when the pressure is changed from a vacuum state to atmospheric pressure, the entire substrate is Large pressure can be applied to, for example, a substrate having a size of 1200 mm × 1000 m.
When atmospheric pressure is applied to the two substrates of m when the inside of the substrates is in a vacuum state, a force of 121.6 kN can be applied.

The gap between the substrates when the maximum pressure is mechanically applied by the pressing plate 16 in the current apparatus is about 15 μm.
m, and the bonding state is incomplete. That is, since the desired interval has not yet been achieved in the primary pressurization (preliminary pressurization) state, the amount of crushing of the adhesive is small, and the length of the contact portion between the adhesive and the upper and lower substrates is short. Furthermore, the liquid crystal sealed in the cell does not spread in the cell, and a large vacuum space is formed between the liquid crystals.
Further pressure is required to make the gap less than or equal to (preferably 4 μm or less).

When the substrate is subjected to secondary pressurization (pressurization by returning the inside of the chamber to atmospheric pressure: main pressurization), since the inside of the cell between the substrates is almost in a vacuum state, the surroundings are returned to atmospheric pressure, so that the substrate surface is restored. It is possible to apply pressure almost uniformly to the whole.
However, when the pressure is returned to the atmospheric pressure at a stretch, the adhesive 37 is not yet sufficiently crushed, so that the gas breaks the adhesive 37 and enters the vacuum space in the cell, resulting in a defective liquid crystal substrate. I will. Therefore, in this embodiment, after the pressurization by the pressurizing plate 16 is completed, the pressurizing plate 16 is separated from the substrate surface, the valve 22 of the thin pipe 21 is opened, and the gas pressurized by the pressure source is introduced into the chamber 15. To gradually return to atmospheric pressure. At the same time, by introducing the atmosphere (or nitrogen gas or the like) into the chamber 15 using the suction holes, the distribution of the gas in the chamber 15 can be made uniform. As described above, when the inside of the chamber 15 is gradually returned to the atmospheric pressure, pressure is gradually applied to the cell, and the adhesive 37 is gradually crushed. Since the difference between the pressure in the vacuum space in the cell and the pressure in the chamber 15 gradually increases,
The introduced gas does not break the adhesive and enter the cell, and the contact area between the adhesive and the upper and lower substrates gradually increases.

When the gap between the substrates becomes about 10 μm, the adhesive 37 is crushed and a flow occurs.
The viscosity decreases due to thixotropic properties. Adhesive 37
With the viscosity of the substrate lowered, a large pressing force is applied to the substrate by opening the air release valve 23 for rapidly returning the pressure to the atmospheric pressure.
At this time, the adhesive has already spread to the substrate, and the sealing property has been improved, so that gas does not break into the cell and enter the cell, and the adhesive has a reduced viscosity. Since the liquid crystal is quickly crushed and the liquid crystal is crushed and expanded by being pressed, the bonding time of the substrates is shortened. still,
The atmosphere release valve 23 is opened after detecting that a pressure gauge provided in the chamber 15 exceeds a predetermined pressure.

As described above, the bonding operation in this embodiment is performed. In the process of the present embodiment, the pressing mechanism for pressing the central portion of the pressing plate and the four pressing mechanisms for pressing the peripheral portion are simultaneously operated at the time of pressing, but the five pressing mechanisms are simultaneously operated. Instead, pressurize with the central pressurizing mechanism first, and remove the non-uniformity of the crushing of the adhesive due to the non-uniformity of the pressing force applied to the substrate or the non-uniformity of the amount of the adhesive. It is also possible to make the amount of crushing of the adhesive uniform by observing the state of crushing and operating each pressing mechanism individually based on the observation result.

In addition, without providing a pressing mechanism at the center, a pressing mechanism for pressing around each corner (square side) of the square substrate is arranged, and the four pressing mechanisms are controlled in a coordinated manner. The applied pressure is applied, and after the applied pressure is applied, the crushing amount of the adhesive is observed, and the four pressing mechanisms are independently driven according to the crushing amount, thereby equalizing the crushing amount of the adhesive. It is also possible to plan.

Hereinafter, another embodiment of the present invention will be described. FIG. 7 is a side view of another embodiment of the present invention, FIG. 7 (a) is a partial side view, and FIG. 7 (b) is a view when another embodiment has a collapse imbalance. .

The difference between this embodiment and the above-described embodiment is that the central guide plate 2
The point is that the four pressing mechanisms provided in the peripheral portion of the substrate move downward together with the central guide plate 29 when the substrate 9 is pushed down. That is, the four pressing mechanisms 41 to 44
The pressing mechanism guide member 55 is fixed so as to move together with the central guide plate 29. When a force is applied to the central guide member 29 from the four pressing mechanisms, the respective ball screws are driven to vary the distance between the pressing mechanism guide member 55 and the central guide member. Things. As described above, since the operations of the four pressing mechanisms can be performed separately from the operations of the central pressing mechanism, the control is simplified and the working time can be reduced.

Note that the liquid crystal substrate used in the present embodiment is a large-sized substrate which is used for multi-paneling. For this reason, as shown in FIG. 6, the substrate used in the present embodiment is provided with a dummy seal 39 so as to surround the entirety of the seal 37 constituting a plurality of liquid crystal substrates. Due to the action of the vacuum state with the dummy seal portion, the entire surface of the substrate formed by the dummy seal has a uniform pressure distribution, and by using this apparatus, it is possible to form a liquid crystal panel with more accurate substrate spacing. Become.

[0049]

As described above, by using the bonding apparatus and the bonding method of the present invention, two substrates (particularly, a liquid crystal substrate) can be bonded with high accuracy, in a short time, and safely. .

[Brief description of the drawings]

FIG. 1 is a front view of a substrate bonding apparatus according to the present invention.

FIG. 2 is a top view when FIG. 1 is viewed from above.

FIG. 3 is a diagram showing a time chart of the operation of each unit when bonding is performed in a vacuum.

FIG. 4 is a diagram when there is an imbalance in collapse of a seal between substrates when mechanical pressure is applied in a vacuum.

5 is a diagram illustrating an adjustment method when the imbalance in FIG. 4 occurs.

FIG. 6 is a view showing an example of an application shape of a seal member when the bonding apparatus of the present invention is used.

FIG. 7 is a side view of another embodiment of the present invention, and FIG.
FIG. 7A is a partial side view, and FIG. 7B is a view when there is an imbalance of collapse in another embodiment.

[Explanation of symbols]

9 table, 15 chamber, 16 pressure plate, 20a
... Piping, 20b ... Piping, 22 ... Valve that gradually returns to atmospheric pressure
23 ... air release valve, 33 ... lower substrate, 34 ... upper substrate, 37
... adhesive, 40 ... substrate holding claws, 41-45 ... pressure mechanism.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masayuki Saito 5-2-2 Koyodai, Ryugasaki-shi, Ibaraki Pref. Hitachi Techno Engineering Co., Ltd. Ryugasaki Plant (72) Inventor Yukinori Nakayama 5-2-2 Koyodai, Ryugasaki-shi, Ibaraki Hitachi (72) Inventor Takao Murayama 5-2-2 Koyodai, Ryugasaki-shi, Ibaraki Hitachi Techno Engineering Co., Ltd. Ryugasaki Plant F-term (reference) 2H088 FA01 FA09 FA16 FA30 MA20 2H089 LA41 NA22 NA24 NA37 NA38 NA48 NA49 NA60 2H090 JB02 JC11 JC18 5G435 AA01 AA17 BB12 KK03 KK05 KK09 KK10

Claims (8)

[Claims] 1. An adhesive is applied to at least one of two substrates to be bonded, and the position of the other substrate is adjusted in a reduced pressure chamber. A first to fourth pressing mechanisms, each of which is independently pressurizable in the vicinity of a position corresponding to four corners of the substrate, and a main processing unit. A fifth pressure mechanism for performing pressure, and after operating the first to fourth pressure mechanisms in addition to the fifth pressure mechanism, the fifth pressure mechanism is operated in accordance with the bonding state of the substrates. A substrate bonding apparatus, comprising: a control unit that variably controls pressures of first to fourth pressing mechanisms. 2. A pressure plate having a holding table for holding one of two substrates to be bonded in a chamber in a reduced pressure state, a pressure plate provided with a suction mechanism for sucking the other substrate, and A pressing mechanism for pressing the other substrate against the one substrate, and a positioning mechanism for positioning the two substrates, wherein the pressing mechanism comprises four corners of the substrate. The first to fourth pressing mechanisms are arranged in the vicinity of the unit and can be independently pressurized. The first to fourth pressing mechanisms are operated to a predetermined pressure, and after observing the bonding state, A substrate bonding apparatus, comprising: a control unit that variably controls pressurizing forces of the four pressing mechanisms according to a bonding state. 3. The substrate bonding apparatus according to claim 1, wherein the suction mechanism provided on the pressure plate includes a suction suction mechanism that performs suction suction and an electrostatic suction mechanism that performs suction by electrostatic force. It is equipped with two suction mechanisms, and operates from the atmosphere to a vacuum state until the bonding by mechanical pressure is completed. A substrate bonding apparatus configured to operate a suction mechanism. 4. The substrate bonding apparatus according to claim 1, wherein after the mechanical pressurization is completed in the reduced pressure chamber, atmospheric pressure is applied to the substrate. A substrate bonding apparatus, wherein pressure is applied to set a substrate interval to a predetermined interval. 5. A pressure-reduced chamber, wherein at least one of the two substrates is surrounded by an adhesive, and a liquid crystal is dropped on a portion corresponding to a sealing surface surrounded by the adhesive, and the liquid crystal is dropped. After fixing the substrate to the table with the suction suction mechanism provided on the table with the liquid crystal dropping surface of one of the substrates facing up, and fixing the other substrate by suction and suction to the pressure plate, the inside of the chamber was depressurized, When the predetermined decompression state is reached,
Activate the electrostatic attraction mechanism to securely adsorb the other substrate to the pressure plate, perform alignment with the lower substrate in that state, and after positioning is completed, apply pressure to the center of the pressure plate and the four corners. The pressure bonding is performed by operating the five pressing mechanisms for pressing, and thereafter, the intervals between the substrates are observed, and the respective pressing mechanisms provided in the vicinity of the four corners according to the intervals between the substrates are observed. A substrate bonding method in which the distance between substrates is made substantially uniform by changing the pressure and applying pressure. 6. An annular adhesive is applied to one of the two substrates in a vacuum chamber, and liquid crystal is dropped on the annular surface, and then fixed on a table with the liquid crystal surface facing upward. Then, the other substrate is adsorbed to the pressure plate, and after positioning with the lower substrate, the upper substrate and the lower substrate are pressure-bonded by the pressure mechanism provided at the center of the pressure plate, and bonded with a predetermined pressure. After the alignment is completed, the distance between the bonded substrates is measured, and according to the measurement result, the four pressing mechanisms for pressing the vicinity of the four corners of the pressing plate are independently operated, and the distance between the substrates is determined. A substrate bonding method, wherein the substrates are bonded so as to be substantially uniform. 7. A pressure-reduced chamber, wherein at least one of the two substrates is surrounded by an adhesive, and a liquid crystal is dropped on a portion corresponding to a sealing surface surrounded by the adhesive, and the liquid crystal is dropped. After fixing the substrate to the table with the suction suction mechanism provided on the table with the liquid crystal dropping surface of one of the substrates facing up, and fixing the other substrate by suction and suction to the pressure plate, the inside of the chamber was depressurized, When the predetermined decompression state is reached,
Activate the electrostatic attraction mechanism to securely adsorb the other substrate to the pressure plate, perform alignment with the lower substrate in that state, and after positioning is completed, apply pressure to the center of the pressure plate and the four corners. The pressure is bonded by operating the five pressing mechanisms for pressing, and then the inside of the chamber is returned to the atmospheric pressure, the state of the seal between the substrates is crushed, and the four corners are determined according to the crushed state of the seal. A substrate bonding method in which the pressing force of each of the pressing mechanisms provided in the vicinity is changed and pressurized so that the amount of crushing of the seal between the substrates is made substantially uniform. 8. An annular adhesive is applied to one of the two substrates in a vacuum chamber, and liquid crystal is dropped on the annular surface, and then fixed on a table with the liquid crystal surface facing upward. Then, the other substrate is adsorbed to the pressure plate, and after positioning with the lower substrate, the upper substrate and the lower substrate are pressure-bonded by the pressure mechanism provided at the center of the pressure plate, and bonded with a predetermined pressure. After the alignment is completed, the pressure is once returned to the atmospheric pressure, the collapse state of the seal of the bonded substrates is observed, and according to the observation result, four pressing mechanisms for pressing the vicinity of the four corners of the pressing plate are independently provided. And bonding the substrates so that the amount of crushing of the seal between the substrates is substantially uniform.