JP2001154202A - Method of sticking glass substrate for liquid crystal panel together and device for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of sticking glass substrates for a liquid crystal panel together and a device for it which dispenses with temporary fixing of the two glass substrates after the positioning and the superposing, simultaneously removes air engagement into a sealant caused by warpage of the superposed glass substrates, furthermore, does not necessitate high rigidity and lowers flatness precision of the upper and lower surface plates. SOLUTION: In the method of sticking the glass substrates for the liquid crystal panel together and the device for it, the upper and lower glass substrates are suctionally held and brought close to each other so as to nearly contact with each other and are temporarily positioned through positioning mechanism. Subsequently the upper and lower glass substrates are brought into contact with each other and simultaneously they are finally positioned by decompressing inside the upper and lower glass substrates so as to press both of them together with the pressure difference with respect to the atmospheric pressure. A uniform gap is formed between the upper and lower glass substrates by keeping the final positioned state and heightening degree of the pressure reduction between them and subsequently the sealant is hardened with ultraviolet rays irradiation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for positioning two glass substrates on which transparent electrodes are printed, superposing them with a gap therebetween, and forming a uniform gap between the two glass substrates. The present invention relates to a method and apparatus for bonding a glass substrate for a liquid crystal panel for curing a sealant applied between two glass substrates.

[0002]

2. Description of the Related Art Conventionally, when bonding glass substrates for a liquid crystal panel as described above, two glass substrates on which transparent electrodes are printed are first positioned relative to each other and overlapped by providing a gap by pressing means. . Next, in order to maintain the superimposed state, the adhesive for temporary fixing applied at an appropriate interval between the two glass substrates was cured by ultraviolet irradiation or the like, and then the superimposed state was maintained. Shimashi
The sealing agent is transferred to a station where the sealing agent is cured, the gap between the glass substrates is uniformly formed by a pressing device, and then the sealing agent is applied between the two glass substrates by irradiation of ultraviolet rays or the like. Is cured to produce liquid crystal panels. In addition, there is a method in which the positioning of two glass substrates, the superposition, the uniform formation of the gap, and the hardening of the sealant are performed in one station. In this case, the uniform formation of the gap and the sealant are performed. It takes a long time to cure the resin, and during these operations, other operations cannot be performed, and the waiting time increases, resulting in extremely low production efficiency.

[0003]

However, in bonding the glass substrates for a liquid crystal panel as described above, first, an ultraviolet irradiation device for temporarily fixing the two glass substrates at the overlapping position is a sealing agent. This is required separately from the ultraviolet irradiation device for curing, and the structure of the device becomes complicated. Secondly, the glass substrate warps due to the restoring action of the spacer crushed when the two glass substrates in the superposed state are transferred to the sealing agent curing station. Separated from substrate
When air is trapped in the lubricant, bubbles are generated and the adhesive strength is reduced. Third, since a mechanical pressing force of about 6 to 8 N / cm ² is applied at the maximum when two glass substrates are superposed and the gap is uniformly formed, the apparatus has a strong rigidity that supports the pressing force. Structure is required.
Fourth, since the upper and lower platens for aligning and overlapping the two glass substrates and forming the gap uniformly need to press the entire surface of the glass substrate uniformly, the surface accuracy of the surface of the platen plate must be increased. There was a problem that the production of a ceramic surface plate was expensive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and can eliminate the need for temporary fixing after positioning and superposition of two glass substrates, and can provide a sealing agent due to warpage of the superposed glass substrates. It is an object of the present invention to provide a method and an apparatus for bonding a glass substrate for a liquid crystal panel, which can eliminate air entrapment in a liquid crystal panel, do not require high rigidity, and can lower the surface accuracy of the upper and lower platen surfaces. And

[0005]

In order to achieve the above-mentioned object, a method of bonding a glass substrate for a liquid crystal panel according to the present invention is to disperse a large number of spacers on the upper surface of the glass substrate and to seal the outer periphery of the spacers. A lower glass substrate on which a sealing agent is applied in a ring shape and alignment marks are provided on the left and right outer positions of the sealant, and an alignment mark corresponding to the alignment mark on the lower surface thereof; Holding the upper glass substrate by suction while facing the upper glass substrate, and bringing the upper glass substrate closer to just before contacting the sealant, and detecting the positional relationship of the respective alignment marks while detecting the lower glass. Correcting the right and left and front and back and the horizontal rotation position of the substrate to temporarily align the upper and lower glass substrates; and after contacting the upper glass substrate with the sealant while maintaining the positional relationship between the upper and lower glass substrates. Up and down Depressurizing the upper and lower glass substrates by detecting the both alignment marks while pressing the upper and lower glass substrates by the pressure difference between the substrate and the atmosphere, and adsorbing the upper and lower glass substrates. After releasing the holding, the pressing force due to the reduced pressure between the upper and lower glass substrates is increased to crush the spacers uniformly to form a uniform gap between the upper and lower glass substrates, and the upper and lower glass substrates are separated through the upper glass substrate. Transporting to the ultraviolet irradiation position in a state of being sucked and held; and irradiating ultraviolet rays from below the transported upper and lower glass substrates to cure the sealant. is there.

Further, the apparatus for bonding a glass substrate for a liquid crystal panel according to the present invention has a horizontal X,
The suction and suction surface is constituted by a plurality of blocks provided on the Y-axis and the horizontal rotation direction θ-axis so as to be finely movable and provided on the upper surface thereof to prevent warping of the lower glass substrate, and a plurality of watermarks are provided on a peripheral portion. A lower platen penetrating the hole up and down, and a length that is fitted to the outer periphery of the lower platen with a gap therebetween, is fixedly detachable, and has an inner upper surface covering the upper surface of the through hole. An auxiliary frame provided with a transparent flexible sheet, and an image of a position of an alignment mark arranged below the lower surface plate corresponding to the through hole and attached to the upper and lower glass substrates. An imaging determination mechanism for determining an amount of displacement and transmitting an operation signal of the movable unit; and a suction penetrating vertically above and below the lower surface plate so as to be detachably supported by a lifting device and corresponding to the auxiliary frame. Absorb the edge of the upper glass substrate into the hole and its inner position. A block body provided to prevent warping of the upper glass substrate is formed inside the suction suction hole while a suction hole to be made and a communication hole which penetrates vertically in the center thereof and communicates with the atmosphere are provided. An upper surface plate provided with a flexible sheet stretched over, and a pressure curing station provided with a plurality of ultraviolet light irradiation devices inside the lower surface plate at a plurality of outside portions of the lower surface plate. Features.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. In FIG. 1, reference numeral A denotes a set station for performing positioning and superposition of two glass substrates, and reference numeral B denotes a plurality of pressure hardening members arranged at appropriate intervals on the outer periphery of the set station A. It is a station. Between the set station A and each of the pressure stations B, B, a not-shown conveying means for conveying an upper platen holding and holding an glass substrate and an auxiliary frame (described later) is arranged.

Next, the set station A is shown in FIGS.
4 will be described. A lower platen 3 is fixed via a support frame 2 to a movable means 1 which is finely movable in the X and Y axes in the horizontal direction and in the horizontal rotation direction θ axis direction. An annular packing 4 is attached to the, and through holes 5, 5 penetrating vertically are formed in the left and right positions slightly inside the annular packing 4.

Further, inside the through holes 5, 5 on the upper surface of the lower platen 3, a plurality of blocks 6, 6 for preventing warpage of the glass substrate are formed at the same height at appropriate intervals. A concave portion defined by the plurality of block bodies 6 and the upper surface of the lower platen 3 communicates with a suction hole 7 communicating with a suction means (not shown). The suction surface of the lower platen 3 is smaller than the outer dimension of the glass substrate by about 15 to 20 mm.

On the outer periphery of the lower platen 3, an auxiliary frame 8 fixed and detachable by a clamp arm (not shown) so as not to move in the horizontal and vertical directions with a gap of about 5 mm from the lower platen 3. Provided and fitted and arranged,
Inside the upper part of the auxiliary frame 8, a transparent flexible sheet 9 having a length to close the upper part of the annular packing 4 and the through holes 5, 5 of the lower surface plate 3 holds a frame-shaped sheet retainer 10. Has been fixed through. Further, below the through holes 5, 5 in the lower platen 3, alignment marks M1, M2 of a glass substrate, which will be described later, are formed.
The position of the alignment marks M1 and M2 is determined by image processing, and a signal is transmitted to the movable means 1 in accordance with the amount of the deviation to move the lower platen 3 horizontally. Imaging determination mechanisms 11 and 11 for fine movement in the X and Y axes and the horizontal rotation direction θ axis are provided.

An upper surface plate 12 is provided above the lower surface plate 3 and the auxiliary frame 8 so as to be fixed and detachable by a clamp arm attached to a lifting device (not shown). An outer annular packing 13 to be pressed against the upper surface of the auxiliary frame 8 and an inner annular packing 14 to be pressed against the peripheral edge of the glass substrate are provided at the lower peripheral edge of the 12 and at a position corresponding to the annular packing 4. At the position between the outer annular packing 13 and the inner annular packing 14 on the upper stool 12, a plurality of suction holes 15, 15 penetrating vertically and communicating with suction means (not shown) are formed. A plurality of suction suction holes 16, 16 communicating with suction means (not shown) are also formed at positions corresponding to the through holes 5, 5 in the board 3.

At the center of the lower surface of the upper platen 12, a plurality of blocks 17 for preventing warpage of the glass substrate are attached at appropriate intervals. A communication hole 18 that penetrates vertically and communicates with the atmosphere is formed at the intermediate position. In addition, the inside of the lower surface of the suction suction holes 16, 16 in the upper platen 12 is
A flexible sheet 19 is stretched, and its periphery is a frame-shaped sheet.
It is fixed by the presser foot 20. Next, press-fit curing
The operation B will be described with reference to FIG. Each pressure hardening station B has a loading / unloading door 2 which is moved up and down by a cylinder (not shown) on the side corresponding to the set station A.
1 and an ultraviolet irradiation device L for irradiating ultraviolet light upward at the bottom of an irradiation chamber 23 to which a cooling fan 22 for cooling the inside is mounted. A plurality is arranged on the outer periphery of A. The same number of auxiliary frames 8 and upper stools 12 are prepared in accordance with the number of the pressure hardening stations B.

[0013] With this structure, as shown in FIG. 2, a large number of spacers U are sprayed on the upper surface while the upper platen 12 is raised, and a sealing agent R surrounding the whole is scattered. A lower glass substrate P2 on which an alignment mark M2 is attached at a position corresponding to the through holes 5, 5 in the lower platen 3, and suction suction holes 16, 16 in the upper platen 12. Positioning mark on the bottom surface corresponding to
The upper glass substrate P1 on which the upper plate M1 is mounted is carried into the upper portion of the lower platen 3 and the lower portion of the upper platen 12, respectively, by a transfer device (not shown).

Then, as shown in FIG. 3, the upper glass substrate P1
The closed space Q is formed by the inner ring packing 14, the flexible sheet 19, and the upper surface of the upper glass substrate P1 by bringing the closed space Q into close contact with the lower surface of the inner ring packing 14. The upper glass substrate P1 is sucked and held on the lower surface of the upper stool 12 by generating a predetermined suction force by a suction means (not shown) communicated by 16. On the other hand, after the lower glass substrate P2 is placed on the suction surface of the lower surface plate 3, a predetermined suction force is generated by suction means (not shown) connected by the suction holes 7, so that the lower glass substrate P2 is Adsorbed and held on the upper surface. When the upper and lower glass substrates P1 and P2 are adsorbed,
A force acts so as to generate a warp due to the suction force, but a plurality of warp-preventing block bodies 6 provided at intervals.
6, 17, 17 prevent warpage.

Next, an elevating device (not shown) for raising and lowering the upper platen 12 is moved down to stop the descent just before the lower surface of the upper glass substrate P1 comes into contact with the sealant R on the lower glass substrate P2. At this time, the outer annular packing 13 of the upper stool 12 is in close contact with the upper surface of the auxiliary frame 8. At this time, the image pickup judging mechanisms 11, 11 are operated to pick up images of the alignment marks M1, M2 of the upper and lower glass substrates P1, P2 through the see-through holes 5, 5 and the transparent flexible sheet 9. The shift amount is determined by image processing, and a signal corresponding to the shift amount is transmitted to the movable means 1 to move the lower platen 3 finely in the horizontal X and Y axes and the horizontal rotation direction θ axis. The glass substrate P2 is moved to perform alignment with the upper glass substrate P1. At this time, there is a gap of about several hundreds μm between the upper and lower alignment marks M1 and M2, and the resolution of the imaging determination mechanism 11 is reduced.

Next, the upper platen 12, the outer ring packing 13 and the inner ring packing 14 attached to the lower surface of the upper platen 12, the auxiliary frame 8, the transparent flexible sheet 9, the upper and lower glass substrates P1, P2.
A predetermined suction force is generated by the suction means (not shown) connected to the closed space S defined by the step (a), and the space between the upper and lower glass substrates P1 and P2 is reduced in pressure. A pressing force is applied to the upper glass substrate P1 via the sheet 19. This pressing force is initially at least 0.5 N / cm ² (more preferably 1 N / cm ² ).
/ Cm ² ), and gradually increase to a maximum of 4 N / cm ² (more preferably, 3 N / cm ² ). During this time, the imaging and image processing of the alignment marks M 1 and M 2 and the amount of displacement are performed in the same manner as described above. Is determined, and the movable means 1 is operated to align the upper and lower glass substrates P1, P2. At this time, since the distance between the upper and lower alignment marks M1 and M2 is reduced to about 10 μm, high-precision imaging becomes possible, and the amount of positional deviation is reduced by ± 1 μm.
It can be adjusted to about m. The lower glass substrate P1 moves during alignment, but the lower glass substrate P2 moves.
The sealed space S is maintained by the bending of the transparent flexible sheet 9 which is in close contact with the lower surface of the substrate.

Next, when the positioning is completed, the upper surface plate 1
2 through the suction holes 16 and 16 and the suction holes 7 of the lower platen 3.
Stops the suction action of, and fixes upper platen 12 and auxiliary frame 8
Release the clamp arm (not shown)
Upper platen 12, auxiliary frame 8 and
Aligned top and bottom that are held together by suction
Glass substrates P1 and P2 are pressed and hardened at station B
It is carried into the irradiation chamber 23. At this time, the suction holes 15, 15
Up and down by suction means (not shown)
3N / cm on substrate P1, P2^TwoAppropriate pressing force acts
7N / cm during transport^TwoPressing force up
(Minimum 2N / cm^TwoUp to 8 N / cm ^TwoIf it is good)
The spacer U is evenly crushed and the upper and lower glass substrates P1, P2
To form a uniform gap between them.

Thereafter, in the set station A, another upper surface plate 12 and an auxiliary frame 8 are carried in, and the above operation is repeated to align the upper and lower glass substrates P1, P2 with the upper surface plate 12 and the auxiliary frame. The operation of carrying the press-hardening station B together with the body 8 is sequentially performed. On the other hand, the lower part of the upper and lower glass substrates P1 and P2, which is carried into the irradiation chamber 23 of the pressure hardening station B by the ultraviolet irradiation apparatus L disposed below, is partially passed through the transparent flexible sheet 9. Irradiation of uniform ultraviolet light is performed, and the sealant R is cured with uniform strength in a state where uniform gaps are formed by the spacer U, whereby a liquid crystal panel bonded with high precision is completed. At the time of this press bonding and hardening, the cooling fan 22 is operated and the upper platen 12
Further, cooling is performed so that the auxiliary frame 8 is not heated to a high temperature.

Next, a take-out device (not shown) is positioned below the liquid crystal panel, the suction operation from the suction holes 15 and 15 is stopped, and the liquid crystal panel is transferred onto the take-out device. After the 12 and the auxiliary frame 8 are carried out and the completed liquid crystal panel is taken out by the take-out device, the upper and lower glass substrates P1, P2 after the next alignment are carried in together with the upper surface plate 12 and the auxiliary frame 8, The above operation is repeated. It is preferable to provide 5 to 6 pressure curing stations B with respect to the set station A.

[0020]

According to the present invention, as is apparent from the above description, the upper and lower glass substrates are suction-held and brought close to the point of contact, and are temporarily aligned through the alignment mechanism. The final position is adjusted while depressurizing the inside of the glass substrate and pressing both by the pressure difference from the atmospheric pressure, and while maintaining this final alignment state, increasing the degree of decompression between the upper and lower glass substrates and between the upper and lower glass substrates After the uniform gap is formed, the sealant is cured by irradiating ultraviolet rays, so that an ultraviolet irradiation device for temporarily fixing the upper and lower glass substrates becomes unnecessary, and the structure of the device can be simplified.
Further, since the warpage of the glass substrate is eliminated, air does not bite into the sealant, and the adhesive strength of the sealant is not reduced. Furthermore, since the upper and lower glass substrates are superposed and a uniform gap is formed by using the pressing force due to the pressure difference from the atmospheric pressure due to the reduced pressure, it is not necessary to make the device a strong structure, and the surface accuracy of the upper and lower platens is improved. There are various effects such as the need for high precision and reduction in the cost of platen production.

[Brief description of the drawings]

FIG. 1 is a configuration sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where upper and lower glass substrates are carried into a set station.

FIG. 3 is a cross-sectional view showing a state in which upper and lower glass substrates are suction-adsorbed to upper and lower stools.

FIG. 4 is a sectional view of a set station showing an alignment state of upper and lower glass substrates.

FIG. 5: Sealant curing of upper and lower glass substrates (UV irradiation)
It is sectional drawing which shows a state.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 movable means 3 lower surface plate 5 see-through hole 6 17 block body 7 suction hole 8 auxiliary frame 9 transparent flexible sheet 11 imaging determination mechanism 12 upper surface plate 15 suction hole 16 suction suction hole 18 communication hole 19 flexibility Sheet 23 Irradiation room A Set station B Pressure curing station L Ultraviolet irradiation device M1 M2 Alignment mark P1 Upper glass substrate P2 Lower glass substrate QS Sealed space R Sealant U Spacer UV UV light

Claims (3)

[Claims] 1. A large number of spacers are sprayed on the upper surface of the sealer, and a sealant is annularly applied to the outer periphery of the spacer, and positioning marks are provided at left and right outer positions of the sealant. Making the lower glass substrate opposed to an upper glass substrate provided with an alignment mark corresponding to the alignment mark on the lower surface thereof, and sucking and holding the upper glass substrate by suction. A step of correcting the horizontal position of the lower glass substrate from side to side and horizontally while detecting the positional relationship of the respective alignment marks, and performing temporary alignment of the upper and lower glass substrates while detecting the positional relationship of each alignment mark; After the upper glass substrate is brought into contact with the sealant while maintaining the positional relationship between the glass substrates, the pressure between the upper and lower glass substrates is reduced, and the upper and lower glass substrates are pressed by the pressure difference between the upper and lower glass substrates. Positioning mark The step of final positioning of the upper and lower glass substrates by the detection of, and pressing the spacer by uniformly reducing the pressure between the upper and lower glass substrates after releasing the suction holding of the upper and lower glass substrates by uniformly crushing the spacer. A step of transporting the upper and lower glass substrates to the ultraviolet irradiation position while holding the upper and lower glass substrates by suction while forming a uniform gap between the upper and lower glass substrates, and irradiating ultraviolet rays from below the transported upper and lower glass substrates. Curing the sealant by using a liquid crystal panel. 2. The pressing force on the upper and lower glass substrates in the final alignment step is at least 0.5 N / cm ^2.
Characterized in that with Yuku by gradually increasing up to 4N / cm ² Yuku increase the pressing force by decompression after releasing the suction and holding of the lower glass substrate from the lowest 2N / cm ² up to 8N / cm ² from A method for bonding a glass substrate for a liquid crystal panel according to claim 1. 3. A plurality of X- and Y-axes in the horizontal direction and a θ-axis in the horizontal rotation direction which are supported by the movable means 1 so as to be finely movable and provided on the upper surface thereof to prevent the lower glass substrate P2 from warping. A lower platen 3 which constitutes a suction suction surface with the block bodies 6 and is formed by penetrating a plurality of through holes 5, 5 in the peripheral portion up and down, and is fitted with a gap on the outer periphery of the lower platen 3. An auxiliary frame 8 provided with a transparent flexible sheet 9 having a length on the inner upper surface thereof for closing the upper surface of the see-through holes 5, 5; The upper and lower glass substrates P are arranged below the
1, an imaging determination mechanism 11 for imaging the positions of the alignment marks M1 and M2 attached to P2, determining an amount of displacement thereof, and transmitting an operation signal of the movable means 1, and the lower surface plate 3.
A suction hole 15 that is detachably supported by the lifting device above and that vertically penetrates a position corresponding to the auxiliary frame 8;
15 and suction suction holes 16, 16 for sucking the peripheral portion of the upper glass substrate P1 at an inner position thereof, and a communication hole 18 which penetrates vertically and communicates with the atmosphere at the center thereof. , 16 provided inside the upper glass substrate P1 to prevent warpage of the upper glass substrate P1,
An upper surface plate 12 provided with a flexible sheet 19 stretched over the lower surface plate 17, and a plurality of pressure hardening stations B arranged outside the lower surface plate 3 and provided with an ultraviolet irradiation device L therein. And a bonding apparatus for a glass substrate for a liquid crystal panel.