JP4482395B2 - Substrate bonding method and bonding apparatus - Google Patents

Description

  The present invention relates to a bonding method and a bonding apparatus in which two substrates are bonded together with a fluid interposed between these substrates via a sealing agent.

  In the manufacturing process of a flat display panel typified by a liquid crystal display panel, two substrates are opposed to each other at a predetermined interval, and a liquid crystal as a fluid is sealed between the substrates and bonded with a sealant. Done.

  In the bonding operation, the sealing agent is applied in a frame shape to one of the two substrates, and a predetermined amount of the liquid crystal is applied to a portion corresponding to the inside of the sealing agent frame of the substrate or the other substrate. It is granulated and supplied dropwise.

  Next, the two substrates are held on the upper holding table and the lower holding table, and are opposed to each other at a predetermined interval in the vertical direction. In this state, the horizontal directions of these substrates are the X, Y, and θ directions. Then, these substrates are bonded together.

  When the two substrates are aligned in the horizontal direction, the alignment accuracy is required to be as high as μm. Therefore, a high-magnification camera having a relatively shallow depth of focus is used as the alignment camera. .

  When aligning two substrates using a high-magnification camera, if the substrates are aligned with a large distance in the vertical direction, for example, with the two substrates separated by a relatively large distance, Two substrates cannot be positioned at the same time within the depth of focus of the camera with the magnification. Therefore, these substrates cannot be positioned with high accuracy, and the alignment accuracy may be lowered.

Therefore, conventionally, when aligning two substrates, these substrates are set at approximately the same interval as the bonded state, and in that state, the two substrates are imaged with a high-magnification camera, and one of them is based on the imaging result. The substrate is driven and aligned in the X, Y and θ directions. Such a prior art is shown in Patent Document 1.
JP 2001-51284 A

  By the way, when the two substrates are set to have approximately the same distance as the bonded state, the liquid crystal is crushed and spread between the two substrates, and the entire liquid crystal is almost completely filled between the substrates. At this time, one substrate may come into contact with the sealing material applied to the other substrate. Therefore, even if one substrate is moved in the horizontal direction based on the imaging result of the camera, the force required to move the substrate due to the resistance received from the sealant or the liquid crystal is increased. As a result, one substrate may not be moved accurately and smoothly in the horizontal direction.

  In addition, if the viscous resistance is greater than the holding force of the substrate, the substrate may be displaced on the holding table. Therefore, since the holding force of the substrate must be increased to prevent the substrate from shifting due to viscous resistance, the cost for increasing the holding force of the substrate may increase.

  It is an object of the present invention to provide a substrate alignment method and alignment apparatus in which one substrate is moved with a relatively light force so that two substrates can be aligned accurately.

The present invention, sealant is applied in a frame shape on either of the two substrates, have fluid in the portion corresponding to the frame of either the sealant of the two substrates are dropped, they two A laminating method for laminating a plurality of substrates through the sealing agent,
Holding one substrate on the upper surface of the lower holding table and holding the other substrate on the lower surface of the upper holding table provided facing the lower holding table;
Affixing the two substrates, which occurs when the one substrate and the other substrate are brought close to a position where the substrates are in contact with each other through the fluid but not in contact with the sealant in a reduced pressure atmosphere. A process of relatively horizontally driving and aligning in a state where a contact load smaller than a bonding load for alignment is applied;
After the alignment step, the step of releasing the holding state of the other substrate positioned above in a state where the contact load applied in the alignment step is maintained;
After releasing the holding state of the other substrate, the step of releasing the holding state of the other substrate in a state where the periphery of the two substrates are in contact via the sealant, the pressure of the reduced pressure atmosphere It is raised bonding of the substrate, characterized by comprising the steps of: adjust stuck through the sealing agent is pressurized by a load laminated above the two substrates by pressure difference between the inside and the outside of the two substrates Is in the way.

Just before the two substrates are in contact via the fluid, preferably further includes the step of aligning these two substrates.

The other substrate is positioned upward, and the peripheral portion and the central portion is being held separately, the step of releasing the holding state of the other substrate, releases the holding state of the peripheral portion of the substrate of the other side Then, it is preferable to release the holding state of the central portion.

In the step of match stick above, the atmosphere in which the two substrates are provided, it is preferable that the pressure is increased so as to gradually increase the pressure applied to the two substrates.

The present invention, sealant is applied in a frame shape on either of the two substrates, have fluid in the portion corresponding to the frame of either the sealant of the two substrates are dropped, they two A laminating apparatus for laminating a plurality of substrates through the sealing agent,
A chamber;
Pressure adjusting means for adjusting the pressure in the chamber;
A lower holding table provided in the chamber and on which one substrate is placed on the upper surface;
An upper holding table provided opposite to the lower holding table and holding the other substrate on the lower surface;
Driving means for driving the said lower holding table and the upper holding table relatively toward or away from and horizontally,
A position in which the inside of the chamber is depressurized by controlling the pressure adjusting means, and the driving means is controlled in that state so that the two substrates are in contact through the fluid but not in contact with the sealant. The two substrates are aligned in the horizontal direction with a contact load smaller than the bonding load for bonding the two substrates, which occurs when the two substrates are brought close to each other. that after releasing the holding state of the while maintaining the contact load of the other held in the upper holding table board, the periphery of the two substrates by releasing the holding state of the other substrate is in contact through the sealant, the pressure regulating means controlled by the sealing agent of the above two substrates by the bonding load by increasing the pressure in the chamber In bonding apparatus of the substrate, characterized by comprising a through and match stick control means.

The upper holding table is provided with a first holding means for holding the peripheral portion of the other substrate by electrostatic force, and a second holding means for holding the central portion of the other substrate by electrostatic force. The release of the holding state of the other substrate held by the upper holding table by the control means is performed after the holding state of the peripheral portion of the other substrate by the first holding means is released . It is preferable to release the holding state of the central portion of the other substrate by the holding means.

  According to the present invention, when one substrate is moved in the horizontal direction and the two substrates are aligned, a large resistance does not act on the substrate to be moved. It becomes possible to carry out with high accuracy.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 5 show a first embodiment of the present invention. FIG. 1 is a schematic view showing an assembly apparatus 1 for a liquid crystal display panel according to the present invention. The assembling apparatus 1 includes a sealing agent application apparatus 2. The coating device 2 is supplied with a first substrate 3 which is one of first and second substrates 3 and 4 constituting a liquid crystal display panel.

  The coating apparatus 2 includes a table on which the first substrate 3 is supplied and placed, and a coating nozzle (both not shown) arranged above the table, and the coating nozzle is attached to the first substrate 3. By relatively driving in the X, Y, and Z directions, a sealing agent 5 (shown in FIG. 4) made of a viscoelastic material is applied to the inner surface of the first substrate 3 in a rectangular frame shape. .

  The first substrate 3 coated with the sealing agent 5 is supplied to the dropping device 7. The dropping device 7 has a table on which the first substrate 3 is placed and a dropping nozzle (both not shown) disposed above the table, and the dropping nozzle is disposed on the first substrate 3. Driven relatively in X, Y and Z directions. As a result, the liquid crystal 6 in the form of a liquid substance (fluid) is dropped and supplied in a predetermined arrangement pattern, for example, in a matrix, in a region surrounded by the sealant 5 on the inner surface of the first substrate 3.

  Here, the height h of the liquid crystal supplied to the first substrate 3 is set to be higher than the height H of the sealing agent 5 as shown in FIG. That is, if the total amount of the liquid crystal 6 supplied to the first substrate 3 is determined, the amount of the liquid crystal 6 per droplet is determined by the number of droplets, and the height per droplet of the liquid crystal 6 is also determined by the amount. Therefore, it is possible to set so that h> H by adjusting the number of droplets according to the total amount of the liquid crystal 6 supplied to the first substrate 3. Incidentally, the height h of the liquid crystal 6 is usually about 0.2 to 0.5 mm, and the height H of the sealing agent 5 is about 30 to 40 μm.

  The first substrate 3 onto which the liquid crystal has been dropped is supplied to the bonding apparatus 11. The bonding apparatus 11 is supplied with the second substrate 4 together with the first substrate 3. Then, the first substrate 3 and the second substrate 4 are positioned and bonded as will be described later. Thereby, a liquid crystal panel in which the liquid crystal 6 is filled between the pair of substrates 3 and 4 is assembled.

  The bonding apparatus 11 has a chamber 12 as shown in FIG. The inside of the chamber 12 is depressurized by a decompression pump 10 to a predetermined pressure, for example, about 1 Pa. A loading / unloading port 14 opened and closed by a shutter 13 is formed on one side of the chamber 12, and the first substrate 3 and the second substrate 4 are loaded / unloaded from the loading / unloading port 14.

  A first holding table 15 is provided in the chamber 12. The first holding table 15 is driven in the X, Y, and θ directions by the first driving source 16. The first substrate 3 to which the sealing agent 5 is applied and the liquid crystal 6 is dropped on the holding surface 15a (upper surface) of the first holding table 15 is supplied with the inner surface on which the liquid crystal 6 is dropped facing upward. Is done. The outer surface (lower surface) of the substrate 3 supplied to the holding surface 15a is held on the holding surface 15a with a predetermined holding force by, for example, electrostatic force.

  Above the first holding table 15, a second holding table 18 that is driven in the Z direction by the second driving source 17 to come in contact with and separate from the first holding table 15 is disposed. On the holding surface 18a on the lower surface of the second holding table 18, the second substrate 4 holds the outer surface by electrostatic force.

  Each holding table 15 and 18 is provided with a plurality of electrodes 15b and 18b, respectively. When power is supplied to these electrodes 15b and 18b, an electrostatic force for holding the substrates 3 and 4 can be generated on the holding surfaces 15a and 18a of the holding tables 15 and 18, respectively.

  The first substrate 3 and the second substrate 4 held on the holding surfaces 15a and 18a of the first holding table 15 and the second holding table 18 have four corners disposed below the chamber 12, respectively. Images are picked up by the four sets of imaging means 21 (only two sets are shown). Each imaging means 21 includes a first imaging camera 22 and a second imaging camera 23 having an imaging magnification higher than that of the first imaging camera 22.

  The first and second imaging cameras 22 and 23 of each imaging means 21 are driven in the X, Y, and Z directions by a positioning device 24 having X, Y, and Z tables. 24 is installed on a mounting plate 25 disposed below the chamber 12.

  At least a portion of the bottom wall of the chamber 12 facing the positioning devices 24 is formed in a transparent window 26. The portions corresponding to the transparent window 26 of the first holding table 15 disposed in the chamber 12 are the four corners of the first substrate 3 held on the holding surface 15a of the first holding table 15 and the first corner. Cavities that enable the first and second imaging cameras 22 and 23 to image the four corners of the second substrate 4 held on the holding surface 18a of the second holding table 18 via the first substrate 3. 27.

  Although not shown, coarse alignment marks and fine alignment marks are provided on the four corners of the first substrate 3 and the second substrate 4 outside the sealant 5, respectively. By aligning the coarse alignment marks of the substrates 3 and 4, the first substrate 3 and the second substrate 4 can be roughly aligned, and by aligning the fine alignment marks of the substrates. The pair of substrates 3 and 4 can be precisely aligned.

  In addition, in order to image the 1st, 2nd board | substrates 3 and 4, although the cavity part 27 was formed in the 1st holding table 15, the 1st holding table 15 whole was formed without forming the cavity part 27. You may form with a translucent material.

  As shown in FIG. 3, the imaging signals of the four sets of the first imaging camera 22 and the second imaging camera 23 (only one set is shown in FIG. 3) are input to the image processing unit 31 and converted into coordinate signals. The The coordinate signal converted by the image processing unit 31 is input to an arithmetic processing unit 33 provided in the control device 32. In this arithmetic processing unit 33, a pair of coarse alignment marks or fine alignments at the four corners of the first and second substrates 3 and 4 imaged by the four sets of the first imaging camera 22 or the second imaging camera 23. Based on the coordinate signal obtained from the miscellaneous signal of the mark, the relative positional deviation of the substrates 3 and 4 in the X, Y and θ directions is calculated.

  When the position shift of the pair of substrates 3 and 4 is calculated by the arithmetic processing unit 33, the position shift is stored in the storage unit 34 and also output to the drive unit 35. Accordingly, the drive unit 35 outputs a drive signal to the first drive source 16 that drives the first holding table 15, and drives the first holding table 15 in the X direction, the Y direction, and the θ direction. The first substrate 3 and the second substrate 4 are aligned.

  The alignment between the first substrate 3 and the second substrate 4 is a rough alignment based on the imaging signal from the first imaging camera 22 and a precise alignment based on the imaging signal from the second imaging camera 23. Is performed as described later.

  The drive unit 35 of the control device 32 also outputs a drive signal to the second drive source 17 and the positioning device 24. The second driving source 17 drives the second holding table 18 in the downward direction and holds the second substrate 4 held on the holding surface 18 a on the holding surface 15 a of the first holding table 15. Further, the liquid crystal 6 is brought into contact with the first substrate 3.

  At that time, the load with which the second substrate 4 applied to the first substrate 3 comes into contact with the liquid crystal 6, that is, the contact load is detected by a load detection mechanism (not shown) provided in the second drive source 17. It is like that. The contact load can be controlled by how much the weight of the second holding table 18 is applied to the first substrate 3 via the liquid crystal 6.

  A gas supply source 38 for supplying a pressurized gas such as nitrogen is connected to the chamber 12 via a flow rate adjusting valve 37. By adjusting the flow rate of the gas supplied into the chamber 12 by adjusting the opening of the flow rate adjusting valve 37, the pressure rising curve in the chamber 12 decompressed by the decompression pump 10 can be set to a predetermined profile. it can. The opening of the flow rate adjusting valve 38 is adjusted by the driving unit 35.

Next, a procedure for bonding the first substrate 3 and the second substrate 4 by the bonding apparatus 11 having the above configuration will be described with reference to FIGS.
First, as shown in FIG. 4A, the first substrate 3 is held on the first holding table 15 and the second substrate 4 is held on the second holding table 18. They are spaced apart from each other in the vertical direction at a predetermined interval. In this state, the decompression pump 10 is operated to depressurize the chamber 12 to a predetermined pressure, for example, 0.8 to 1 Pa, and then the four corners of the first substrate 3 and the second substrate 4 are subjected to the first imaging. Images are taken by the camera 22, and the substrates 3, 4 are roughly aligned in the X, Y, and θ directions.

  Next, the second driving means 17 is operated to drive the second holding table 18 downward in the Z direction at a moderate speed. As shown in FIG. 4B, when the second substrate 4 approaches the first substrate 3, the lower surface of the second substrate 4 is the sealing agent 5 and the liquid crystal 6 provided on the upper surface of the first substrate 3. Among them, the liquid crystal 6 is in contact with a number of liquid drops 6 dropped at a height h higher than the height H of the sealant 5. Each droplet-like liquid crystal 6 is deformed from the hemispherical state shown in FIG. 4A to the drum shape shown in FIG. 4B by capillary action.

  As a result, the drum-shaped liquid crystal 6 tries to return to the spherical shape due to the surface tension, so that the first substrate 3 is attracted to the second substrate 4 by the surface tension. At this time, the holding force of the first substrate 3 by the first holding table 15 and the downward force acting on the substrate 3 due to its own weight tries to hold the substrate 3 on the first holding table 15. However, if the upward force acting on the substrate 3 due to the surface tension of the liquid crystal 6 is weaker, the first substrate 3 is temporarily lifted from the first holding table 15 as shown in FIG.

If the second substrate 4 continues to be gently lowered even after its lower surface contacts the liquid crystal 6, the first substrate 3 contacts the upper surface of the first holding table 15 as shown in FIG. Thereafter, a large number of liquid crystals 6 in the form of droplets receive the weight of the second holding table 18 holding the second substrate 4. That is, a contact load is generated when the second substrate 4 contacts the first substrate 3 via the liquid crystal. The contact load at this time is set to be 0.063 kg / cm ² or less per unit area of the substrates 3 and 4, for example.

Bonding load when bonding by a sealing agent 5 pressurizes the two substrates 3 and 4, because it is usually 1 kg / cm ² or so, the contact load is sufficiently smaller than the load bonded . That is, in a state where the two substrates 3 and 4 are brought into contact with each other through the liquid crystal 6 by the contact load, the pressing force applied to each of the substrates 3 and 4 via the holding tables 15 and 18 is small.

  As a result, as shown in FIG. 4 (d), the distance between the first and second substrates 3 and 4 is such that the liquid crystal 6 does not fill up between the substrates 3 and 4, and the second substrate 4 It is maintained at an interval that does not contact the sealant 5. That is, each droplet-like liquid crystal 6 is deformed from the hemispherical state shown in FIG. 4A to the drum shape shown in FIG. 4D, but the adjacent droplet-like liquid crystals 6 are not integrated. That is, the liquid crystal 6 is not yet fully filled between the pair of substrates 3 and 4.

  In such a state, the adhesion force by the liquid crystal 6 does not occur over the entire opposing surface of the first substrate 3 and the second substrate 4, and the second substrate 4 contacts the sealing agent 5. Since the second substrate 4 is in contact with the liquid crystal 6, it is possible to prevent an increase in horizontal movement resistance acting between the substrates 3 and 4. In addition, since the second substrate 4 is in contact with the sealing agent 5, it is possible to prevent generation of movement resistance in the horizontal direction that acts between the substrates 3 and 4. Accordingly, when the first substrate 3 is aligned with the second substrate 3, the first substrate 3 can be moved smoothly and precisely with respect to the second substrate 4.

  Alignment marks (not shown) provided at the four corners of the first substrate 3 and the second substrate 4 by the second imaging camera 23 with a contact load applied to the first and second substrates 3 and 4. Image. The imaging signal of the second imaging camera 23 is converted into a coordinate signal by the image processing unit 31 and input to the control device 32. Accordingly, the control device 32 operates the first drive source 16 to drive the first holding table 15, and aligns the first substrate 3 with the second substrate 4 with high accuracy.

  In positioning, the load applied to the first and second substrates 3 and 4 is maintained at a contact load sufficiently smaller than the bonding load as described above. As a result, the second substrate 4 is not in contact with the sealant 5 applied to the first substrate 3, and the liquid crystal 6 is not fully filled between the opposing surfaces of the second substrate 4 and the first substrate 3. The

  Therefore, it is possible to prevent the adhesive force of the sealant 5 from acting on the first substrate 3 or the adhesion force of the liquid crystal 6 to occur over the entire surface of the first substrate 3 and the second substrate 4 facing each other. it can. As a result, the first substrate 3 can be smoothly moved in the X, Y, and θ directions with a relatively light force with respect to the second substrate 4, and the alignment of these substrates can be performed with high accuracy.

  That is, when adjacent liquid crystals 6 in the form of droplets are integrated and filled between the pair of substrates 3 and 4, the adhesion force due to the liquid crystal 6 acts on the entire opposing surface of the substrates 3 and 4, so the adhesion force is large. Thus, the first substrate 3 cannot be accurately moved in the horizontal direction with respect to the second substrate 4.

  However, if the load applied to the substrates 3 and 4 at the time of alignment is a contact load, the load is sufficiently smaller than the bonding load. Therefore, adjacent liquid crystals 6 are integrated between the substrates 3 and 4. It is possible to prevent the entire substrate from being filled, and also to prevent the second substrate 4 from coming into contact with the sealing agent 5. For this reason, the first substrate 3 can be smoothly moved with a relatively light force, so that the alignment accuracy of the substrates 3 and 4 can be improved.

  In this way, as shown in FIG. 4D, the alignment between the first substrate 3 and the second substrate 4 is finished, and the energization to the electrode 18b of the second holding table 18 is stopped, The holding state of the second substrate 4 held on the holding surface 18 is released. As a result, the second substrate 4 is separated from the second holding table 18, so that the second substrate 4 is superimposed on the first substrate 3 via the liquid crystal 6 and the sealant 5.

  That is, in the state where the second substrate 4 is held by the second holding table 18, the second substrate 4 is in a state of being separated from the sealant 5 as shown in FIG. When the holding state of the second substrate 4 by the holding table 18 is released, particularly the peripheral portion of the second substrate 4 bends downward due to its own weight and comes into contact with the sealant 5.

  When the holding state of the second substrate 4 is released, the flow rate adjusting valve 37 is opened, gas is supplied from the gas supply source 38 into the chamber 12, and the pressure in the chamber 12 is increased. Thereby, the pressure difference between the inside and outside of the first and second substrates 3 and 4 in which the gas enters between the second substrate 4 released from the holding state and the holding surface 18a of the second holding table 18 and overlaps. Since the first and second substrates 3 and 4 are pressurized by this, the liquid crystal 6 is crushed and filled between the two substrates 3 and 4 as shown in FIG. , 4 are bonded by the sealant 5. At this time, the second substrate 4 is lowered by the amount by which the liquid crystal 6 is crushed.

  If the gas is introduced into the chamber 12 after the second holding table 18 is lifted in the state shown in FIG. 4D, the holding surface 18a of the second holding table 18 and the second substrate 4 Since a gap is formed between the upper surface and the upper surface, it is possible to efficiently and reliably pressurize the first and second substrates 3 and 4 with the gas introduced into the chamber 12.

  When the gas is supplied into the chamber 12 to pressurize the two substrates 3 and 4, the opening degree of the flow rate adjusting valve 37 is controlled, and the pressure in the chamber 12 is represented by a straight line X or a curve Y in FIG. Raise along. That is, the pressure in the chamber 12 is not increased rapidly but is gradually increased to atmospheric pressure.

  When the pressure in the chamber 12 is gradually increased, when the two substrates 3 and 4 are bonded together, it is possible to prevent the substrate 3 and 4 from being subjected to an impact due to sudden pressurization. Therefore, it can prevent that the board | substrates 3 and 4 receive a damage, and the shift | offset | difference arises in the positioned board | substrates 3 and 4.

  Further, when the two substrates 3 and 4 in contact are pressed and bonded together with an internal and external pressure difference, the entire substrates 3 and 4 are compared with the case where the second holding table 18 is lowered and pressed and bonded. Can be pressurized at a uniform pressure. In other words, it is extremely difficult to eliminate the variation in flatness between the first holding table 15 and the second holding table 18. When pressure is applied by lowering the second holding table 18 in such a state of variation, uniform pressure cannot be applied to the entire surfaces of the two substrates 3 and 4.

  Accordingly, there arises a problem that the collapsed state of the sealant 5 becomes non-uniform and the liquid crystal distribution becomes non-uniform between the two substrates 3 and 4. And even if the two board | substrates 3 and 4 once received and bonded by the non-uniform | pressure pressurization gave the pressurization by the pressure difference inside and outside after that, the non-uniform crushing state of the sealing agent 5 mentioned above It is difficult to correct the uneven distribution of liquid crystal and liquid crystal.

  On the other hand, after the two substrates 3 and 4 are aligned with the contact load, the pressure applied by the internal and external differential pressures is applied to the two substrates 3 and 4 without applying pressure by the second holding table 18. When bonded together, uniform pressurization can be performed without being affected by the above-described variation in flatness. As a result, the collapsed state of the sealant 5 can be prevented from becoming uneven. That is, the two substrates 3 and 4 can be bonded with a uniform thickness.

  In the first embodiment, the precise alignment of the substrates 3 and 4 is performed with the second substrate 4 in contact with the first substrate 3 via the liquid crystal 6 as shown in FIG. However, after the rough alignment is performed in the state shown in FIG. 4A, the first fine alignment is performed immediately before the second substrate 4 is lowered and brought into contact with the liquid crystal 6. The second precise alignment may be performed in the state of 4 (d).

  As described above, if the fine alignment is performed twice, the alignment accuracy can be improved as compared with the case of the single alignment. In addition, the first alignment can be easily performed because the two substrates 3 and 4 are in a non-contact state.

The second precise alignment in a state where the two substrates 3 and 4 are in contact with each other through the liquid crystal 6 is because the substrates 3 and 4 are aligned with considerable accuracy in the first alignment. The distance by which the second substrate 4 is moved in the horizontal direction can be reduced. That is, since the distance moved in the horizontal direction while the two substrates 3 and 4 are in contact with each other via the liquid crystal 6 can be reduced or almost eliminated, alignment can be performed easily and reliably.
Note that only the first precision alignment may be performed, and the second precision alignment may be omitted.

  6 and 7 show a second embodiment of the present invention. In this embodiment, as shown in FIG. 6, the electrodes provided on the second holding table 18 that holds the second substrate 4 are arranged in the first group G <b> 1 located in the periphery of the second holding table 18. Electrode 18b-1 and a second group G2 electrode 18b-2 located in the center. The first group G1 is composed of eight electrodes 18b-1, and the second group G2 is composed of four electrodes 18b-2.

  When two substrates are bonded together using the second holding table 18 having the above-described configuration, the procedure shown in FIGS. 7A to 7E is performed. First, in the decompressed chamber 12, as shown in FIG. 7A, the first substrate 3 and the second substrate 4 which are held by the holding tables 15 and 18 and are opposed to each other at a predetermined distance are roughened. Align.

  Next, as shown in FIG. 7B, the second holding table 18 is lowered to a position just before the second substrate 4 comes into contact with the liquid crystal 6 provided on the first substrate 3, and in this state, the first holding table 18 is lowered. The substrate 3 and the second substrate 4 are precisely aligned.

  When the precise alignment is completed, the energization to the electrode 18b-1 of the first group G1 among the electrodes provided on the second holding table 18 is stopped. Thereby, the second substrate 4 is released from the holding state of the peripheral portion due to electrostatic force. As a result, the peripheral portion of the second substrate 4 bends downward as shown in FIG. 7C, so that the peripheral portion of the second substrate 4 is applied to the peripheral portion of the first substrate 3. 5 is contacted. That is, the entire periphery of the second substrate 4 comes into contact with the sealing agent 5, so that the space S between the first and second substrates 3 and 4 is sealed.

  Next, the energization to the electrode 18b-2 of the second group G2 of the second holding table 18 is stopped. Thereby, as shown in FIG. 7D, the second substrate 4 is separated from the second holding table 18 and comes into contact with the liquid crystal 6 supplied to the first substrate 3.

  When the holding state of the second substrate 4 is released, a gas is supplied into the chamber 12 and the pressure in the chamber 12 is gradually increased until it reaches atmospheric pressure. At this time, the pressure in the chamber 12 is gradually increased along a profile indicated by a straight line X or a curve Y in FIG.

  Since the second substrate 4 is pressurized by supplying gas into the chamber 12, the two substrates 3 and 4 can be bonded together as shown in FIG. At the time of bonding, the peripheral portions of the two substrates 3 and 4 are in contact with the sealant 5 before the gas is supplied into the chamber 12. It is possible to reliably prevent gas from entering and remaining between the substrates 3 and 4.

  First, among the electrodes provided on the second holding table 18, the energization to the electrode 18b-1 of the first group G1 is stopped, and the holding state of the peripheral portion of the second substrate 4 is released. After the peripheral portion of the second substrate 4 was brought into contact with the sealant 5, the energization to the electrode 18b-2 of the second group G2 was stopped.

  Therefore, the second substrate 4 can be brought into contact with the first substrate 3 via the sealant 5 before the second substrate 4 is completely released from the holding state by the second holding table 18. As a result, it is possible to prevent as much as possible the occurrence of displacement between the two substrates 3 and 4 after precise alignment.

  In this embodiment, the electrodes provided on the second holding table 18 are divided into two groups, and the holding state of the peripheral portion of the second substrate 4 is released and then the holding state of the central portion is released. However, the holding state of the entire second substrate 4 may be simultaneously released so that the second substrate 4 is brought into contact with the first substrate 3 via the liquid crystal 6.

  That is, after the two substrates 3 and 4 are precisely aligned in the state shown in FIG. 7B, the holding state of the second substrate 4 is released. As a result, the second substrate 4 moves away from the second holding table 18 and comes into contact with the first substrate 3 via the sealant 5 and the liquid crystal 6 as shown in FIG. 7D or 4D. Will do.

  In addition, among the electrodes provided on the second holding table 18, the holding state of the peripheral portion of the second substrate 4 is released and then the holding state of the central portion is released. The holding state of the peripheral part may be released after the central part of the second substrate 4 is released and the central part of the second substrate 4 is bent and brought into contact with the liquid crystal 6.

  Further, from the state shown in FIG. 7B, the second holding table 18 is lowered to bring the second substrate 4 into contact with the first substrate 3 through the liquid crystal 6 and held in this state. The energization of the electrodes 18a-1 and 18b-1 of the table 18 may be canceled.

  In these examples as well, the two substrates 3 and 4 can be aligned with a relatively light force with high accuracy, and the flatness between the first holding table 15 and the second holding table 18 is also possible. Even when there is a variation in thickness, since uniform pressing can be performed without being affected by the variation in flatness, the two substrates 3 and 4 can be bonded to each other with a uniform thickness.

  The present invention is not limited to the above embodiments. For example, the first substrate is held on the lower holding table by electrostatic force, but an elastic sheet such as rubber is attached to the upper surface of the lower holding table. The first substrate may be held immovably on the lower holding table by the frictional force of the elastic sheet. The elastic sheet may be approximately the same size as the lower holding sheet, or may be divided into a plurality of blocks.

  The surface of the elastic sheet (holding surface) is made of a non-adhesive material or processed to reduce the adhesive force so that the first substrate 3 and the elastic sheet can be easily separated. It is preferable to use what has been applied.

  In the second embodiment, a case where one liquid crystal display panel is formed from a pair of substrates 3 and 4, that is, a so-called single-sided case has been described, but a plurality of liquid crystal display panels are formed from a pair of substrates 3 and 4. May be chamfered. In the case of multi-chamfering, as shown in FIG. 8, the sealing agent 5 is applied to the first substrate 3 in the form of a plurality of rectangular frames, and the dummy sealing agent 5 a is formed around the first substrate 3. It may be applied in a rectangular frame shape.

In such a case, in the step of FIG. 7C, the peripheral portion of the second substrate 4 comes into contact with the dummy sealant 5a. It is effective to perform the embodiment.
In the present invention, the sealant may be applied to the second substrate or both substrates, and the liquid crystal may also be dropped onto the second substrate or both substrates.

  Although the upper holding table is driven in the vertical direction, the lower holding table 15 may be driven in the vertical direction, and both the holding tables may be driven in the vertical direction.

  In the above embodiment, the example in which the first substrate and the second substrate are bonded to each other with the sealant has been described. However, in order to bond the first substrate and the second substrate separately from the sealant, an adhesive is used. And two substrates may be bonded together with this adhesive, and a sealant having a function of sealing at least liquid crystal may be used.

  Further, although the example of the liquid crystal display panel assembling apparatus has been described, the present invention can also be applied to other display panels, such as an organic electroluminescence display panel assembling apparatus.

1 is a schematic diagram of an apparatus for assembling a liquid crystal display panel according to a first embodiment of the present invention. The longitudinal cross-sectional view which shows schematic structure of the bonding apparatus which bonds a pair of board | substrate. The block diagram which shows the control system of a bonding apparatus. Explanatory drawing which showed the procedure which bonds together two board | substrates. Explanatory drawing when introducing gas in a chamber and raising a pressure. The top view of the 2nd holding table which shows 2nd Embodiment of this invention. Explanatory drawing which showed the procedure when bonding two board | substrates together using the holding table shown in FIG. Explanatory drawing which shows the sealing agent apply | coated to the 1st board | substrate of multiple chamfering.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Pressure reduction pump (pressure adjustment means), 12 ... Chamber, 15 ... 1st holding table, 16 ... 1st drive source, 17 ... 2nd drive source, 22 ... 1st imaging camera, 23 ... 2nd , 32 ... control device, 37 ... flow rate adjusting valve (pressure adjusting means), 38 ... gas supply source (pressure adjusting means).

Claims (6)

Sealing agent is applied in a frame shape on either of the two substrates, a portion corresponding to the frame of either the sealant of the two substrates fluid is being dropped, these two substrates A laminating method for laminating via the sealing agent,
Holding one substrate on the upper surface of the lower holding table and holding the other substrate on the lower surface of the upper holding table provided facing the lower holding table;
Affixing the two substrates, which occurs when the one substrate and the other substrate are brought close to a position where the substrates are in contact with each other through the fluid but not in contact with the sealant in a reduced pressure atmosphere. A process of relatively horizontally driving and aligning in a state where a contact load smaller than a bonding load for alignment is applied;
After the alignment step, the step of releasing the holding state of the other substrate positioned above in a state where the contact load applied in the alignment step is maintained;
After releasing the holding state of the other substrate, the step of releasing the holding state of the other substrate in a state where the periphery of the two substrates are in contact via the sealant, the pressure of the reduced pressure atmosphere It is raised bonding of the substrate, characterized by comprising the steps of: adjust stuck through the sealing agent is pressurized by a load laminated above the two substrates by pressure difference between the inside and the outside of the two substrates Method. 2. The method for bonding substrates according to claim 1, further comprising the step of aligning the two substrates immediately before the two substrates contact each other through a fluid. The other substrate is positioned upward, and the peripheral portion and the central portion is being held separately, the step of releasing the holding state of the other substrate, releases the holding state of the peripheral portion of the substrate of the other side The substrate bonding method according to claim 1, wherein the holding state of the central portion is then released. In the step of match stick above, the atmosphere in which the two substrates are provided, one of the claims 1 to 3, characterized in that the pressure is increased to increase gradually the pressure applied to the two substrates A method for bonding substrates according to any one of the above. Sealing agent is applied in a frame shape on either of the two substrates, a portion corresponding to the frame of either the sealant of the two substrates fluid is being dropped, these two substrates A laminating apparatus for laminating via the sealing agent,
A chamber;
Pressure adjusting means for adjusting the pressure in the chamber;
A lower holding table provided in the chamber and on which one substrate is placed on the upper surface;
An upper holding table provided opposite to the lower holding table and holding the other substrate on the lower surface;
Driving means for driving the said lower holding table and the upper holding table relatively toward or away from and horizontally,
A position in which the inside of the chamber is depressurized by controlling the pressure adjusting means, and the driving means is controlled in that state so that the two substrates are in contact through the fluid but not in contact with the sealant. The two substrates are aligned in the horizontal direction with a contact load smaller than the bonding load for bonding the two substrates that occurs when the two substrates are brought close to each other. that after releasing the holding state of the while maintaining the contact load of the other held in the upper holding table board, the periphery of the two substrates by releasing the holding state of the other substrate is in contact through the sealant, the pressure regulating means controlled by the sealing agent of the above two substrates by the bonding load by increasing the pressure in the chamber Bonding apparatus of the substrate, characterized by comprising a through and match stick control means. The upper holding table is provided with a first holding means for holding the peripheral portion of the other substrate by electrostatic force, and a second holding means for holding the central portion of the other substrate by electrostatic force. The release of the holding state of the other substrate held by the upper holding table by the control means is performed after the holding state of the peripheral portion of the other substrate by the first holding means is released. 6. The substrate bonding apparatus according to claim 5, wherein the holding state of the central portion of the other substrate by the holding means is released.

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