JP3023282B2 - Surface plate structure in glass substrate bonding equipment for liquid crystal display panels - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an upper and lower platen provided in a device for bonding glass substrates (upper and lower electrode plates) constituting a liquid crystal display panel.

[0002]

2. Description of the Related Art A liquid crystal display (LCD) is maintained at a predetermined distance between two glass substrates coated with a transparent conductive electrode by using a spacer having a thickness of several μm. The liquid crystal is sealed, and the two glass substrates are stuck together without misalignment by alignment marks.

[0003] By the way, 2 in the conventional bonding apparatus.
In order to bond two glass substrates, the alignment mark applied to the glass substrate in advance should be adjusted by moving the upper platen moving in the X direction and the lower platen moving in the Y and θ directions with a microscope and camera. It is driven by the detection data of the mark detecting means consisting of and performs coarse adjustment and fine adjustment by adjusting the movement. When the mark alignment is completed, the two glass substrates are pressed to crush the sealing material. This is to make the gap between the upper and lower glass substrates constant.

[0004] In the conventional bonding apparatus described above,
The lower platen is made of metal and the surface is finished flat, but the parallelism of the upper and lower platen surfaces is inclined in micron units or the thickness of the upper and lower glass substrates to be bonded. The upper and lower glass substrates a and b are added even if the gap between the glass substrates of the liquid crystal display panel formed by bonding is fixed at 5 to 7 μm. When the sealing material c is crushed by pressing, the crushing of the sealing material becomes uneven, and the gap between the upper and lower glass substrates becomes uneven. If the gap between the glass substrates is non-uniform, a completed liquid crystal display panel will have, for example, color unevenness and become a defective product.

In order to solve the above-mentioned problems, an airbag-like plate is used for both the upper and lower platens or the movable platen in place of the metal platen. Even so, a technique for ensuring a constant gap between substrates has been developed.

[0006]

However, in the case of the above-described airbag-like device, the glass substrate to be bonded cannot be suction-held on the platen side.
The mark aligning operation performed before the lower glass substrate is bonded cannot be performed by the bonding apparatus having the air bag surface plate. Therefore, mark alignment of the upper and lower glass substrates is performed by another device, and the two glass substrates for which the mark alignment has been completed are temporarily fixed using a resin-based adhesive or the like so that they do not shift. Lamination is performed by the above-mentioned laminating apparatus. Therefore, the above-mentioned apparatus has the inconvenience that the work of mark alignment and the work of bonding must be performed by separate apparatuses, and furthermore, the work of temporary fixing is required in order to move from the mark alignment process to the next bonding process. And the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to align marks on upper and lower glass substrates and to provide upper and lower glass substrates with marks. It is an object of the present invention to provide a surface plate of a bonding apparatus which can uniformly crush a sealing material between glass substrates and make a gap between upper and lower glass substrates uniform even if the substrate has an inclination or a taper.

[0008]

The technical means taken by the present invention to achieve the above object is to provide a fixed base plate having a lower surface plate and a movable base plate having an upper surface plate which can move up and down. In the apparatus for bonding a glass substrate for a liquid crystal display panel, a concave portion is formed on at least one of the upper and lower platens, leaving a peripheral edge on a surface of the metal platen body facing the glass substrate, and the lower surface opening of the concave portion is formed. Is closed with a thin plate, the periphery of the thin plate is adhered and fixed to the peripheral edge, suction holes are provided at appropriate positions on the thin plate, and each of the suction holes is connected to a vacuum means provided on the platen body. Further, the platen body is characterized in that it is provided with a means for supplying air to the recess.

As the thin plate for closing the concave portion of the metal platen body, a thin metal plate (for example, a stainless steel plate) having a thickness of 30 to 200 μm, preferably a thin stainless steel plate having a thickness of 100 μm, or a thin synthetic resin plate having a high Young's modulus (for example, polycarbonate) Thin plate). The suction hole provided in the thin plate is formed by making a hole in the thin plate, fitting and fixing a metal fitting flange in the hole, and connecting a miniature fitting to the fitting flange. The joint is connected to a connection port of a manifold arranged on the metal platen body so that a vacuum suction force is generated in the suction hole.

Further, air supply means is connected to the side surface of the peripheral edge of the metal plate body so as to communicate with the inside of the recess, and a thin plate for closing the opening surface of the recess by the air supplied from the air supply means. When the glass substrate is pressurized and swelled, a buffering action occurs.
The glass substrate is bonded by pressing, even if the movable base plate provided with the above-mentioned surface plate moves up and down mechanically, or the thin plate is expanded by the air pressure fed into the concave portion as described above. Either pressurization by varying the output amount, or a combination of the above-described two methods may be used. Each corner of the metal plate body is provided with a see-through portion for aligning the mark on the glass substrate.

[0011]

According to the above-described means, at least one of the upper and lower platens in the bonding apparatus is provided with a concave portion leaving a peripheral edge in the metal platen main body, and the opening surface of the concave portion is closed with a thin plate. At the same time, the edge of the thin plate is adhered and fixed to the peripheral edge, and the thin plate is provided with a suction hole communicating with the vacuum suction means, so that the glass substrate is suction-held by the vacuum suction force generated in the suction hole. Therefore, the alignment work of the alignment mark provided on the glass substrate can be performed.

In addition, air is supplied into the recesses of the surface plate by the air supply means to expand the thin plate, so that the plate becomes like a drum skin. The surface plate becomes a surface plate having a buffer function. Therefore, the glass substrate is pressurized through the buffering action, whereby the taper or inclination of the glass substrate is absorbed by the buffering action of the thin plate closing the recess, the sealing material is uniformly crushed, and the gap between the upper and lower glass substrates is reduced. The gap is constant.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the surface plate according to the present invention is used as an upper surface plate on the movable base plate side will be described below with reference to the drawings. And a movable base plate 3 disposed above the fixed base plate 2. The lower glass substrate a is mounted and held on the fixed base plate 2. A lower surface plate 4 is provided, and an upper surface plate 5 for adsorbing and holding the upper glass substrate b is provided below the movable base plate 3.

Movable base plate 3 arranged above fixed base plate 2
Is mounted movably up and down via an engaging body 8 which slides in a vertical direction by engaging with a guide rail 7 fixed to four columns 6 constituting the machine frame 1. 2 on the top
The hanging rods 9 of the book are arranged and raised in a substantially rectangular shape in a plane,
The upper ends of the suspension rods 9 are connected by a connection plate 10 and
A spring 12 is resiliently mounted between the horizontal rod 11 and the connecting plate 10 on the hanging rod 9 penetrating the horizontal rod 11 passed therebetween, so that the movable base plate 3 does not descend to the bottom dead center by its own weight. It is supported by. An air cylinder 13 is used as a drive source for forcibly pressing down the movable base plate 3 to pressurize the movable base plate 3. The air cylinder 13 is fixed to the horizontal rod 11 by hanging, and the movable base plate 3 3 is pressed.

The lower stool 4 mounted on the fixed base plate 2 includes:
A lower member 14 that slides in the Y direction on the fixed base plate 2 and an upper member 15 that is mounted on the lower member 14 and that rotates horizontally, and the lower member 14 stands up and fixed on the fixed base plate 2 It is slidably supported via an engaging body 17 which engages with the two parallel guide rails 16 thus formed. The upper member 15 rotatably supported by the lower member 14 is supported via a bearing 18.

The upper surface plate 5 attached to the lower side of the movable base plate 3 so as to be movable and adjustable in the X direction has a peripheral edge formed on a surface of the metal surface plate main body 19 having a rectangular planar shape facing the glass substrate b.
A recess 21 having a predetermined depth is formed by extending the recess 20, and the lower surface opening of the recess 21 is closed by a thin plate 22. In addition, suction holes 23 are arranged on the surface of the thin plate 22 at equal intervals in the up, down, left and right directions, and each of the suction holes 23 is provided on a platen body.
Vacuum means is communicated via 24. Furthermore, the surface plate body 19
On the side surface of the peripheral edge 20 is formed a through-hole 25 communicating with the inside of the recess 21, the through-hole 25 is connected to the air supply means,
The thin plate 22 can be expanded by blowing air into the closed recess 21.

The thin plate 22 for closing the recess 21 has a thickness of 30 .mu.
Using a thin stainless steel plate of 00μ, preferably 100μ, it is formed in substantially the same shape as the metal platen body 19, and the peripheral edge of the thin plate 22 is fixed to the upper surface of the peripheral edge 20 of the platen body 19 with an adhesive. The formation of the suction holes 23 in the thin plate 22
The pipe joint flange 26 is fixed to the hole formed in the above, and a miniature pipe joint 27 is connected and fixed to the pipe joint flange 26. The miniature fitting 27 of each suction hole 23 is connected through a pressure-resistant hose or the like to a connection port 29 of a manifold 24 that is drilled in the thickness of the metal platen body 19 and communicates with a vacuum communication hole 28 and is mounted. Thereby, the suction hole 23 is configured to generate a vacuum suction force. Although the illustrated manifold 24 has four connection ports 29 and one manifold 24 corresponds to the four suction holes 23, the number of connection ports is not limited to that shown. 3 or 5
The number of the suction holes is arbitrary and is determined by the relationship with the number of suction holes formed in the thin plate 22. Of course, the arrangement of the suction holes 23 is
Is set so that the attraction force is evenly generated on the surface of.

The upper surface plate 5 is provided with a see-through portion 30 at each corner for marking the upper and lower glass substrates a and b. The see-through portion 30 has a bellows on a bellows supporter 31 which is screwed and fixed to the metal platen body 19 side so as to follow the vertical movement of the thin plate 22 stretched on the lower surface of the metal platen body 19. The connection fitting 32 is fitted and assembled, while the thin plate 22 is provided with a hole of a predetermined diameter,
A bellows connection fitting 33 is adhered and fixed to the inner surface of the hole 22 so as to coincide with the center of the hole, and a bellows 34 is spanned between the bellows connection fitting 33 and the bellows connection fitting 32. Incidentally, the above-mentioned four see-through portions 30 are paired with each other being located on a diagonal line, and one set is used for a rough alignment mark and the other set is used for a fine alignment mark.

Next, a bonding apparatus A having the above-mentioned surface plate
The lower glass substrate a is placed on the lower platen, and the upper glass substrate b is placed on the lower surface of the upper platen 5 in the suction hole provided in the thin plate 22. The movable base plate 3 on which the upper surface plate 5 is attached is pressed down by the action of the air cylinder 13 to hold the upper glass substrate b on the lower glass substrate a on the lower surface plate 4.
The upper surface plate 5 is brought into contact with the surface in the X-direction in accordance with the detection data of the mark detecting means comprising a microscope and a camera in that state.
The lower platen 4 is moved and adjusted in the Y and θ directions to roughly and finely align the upper and lower glass substrates. The above-described mark alignment is performed by a see-through portion 30 provided at a corner of the upper surface plate 5.

At the time when the mark alignment is completed as described above, the movable base plate 3 is further pushed down to press the upper and lower glass substrates to crush the sealing material c, and the two are bonded together. As described above, since the upper platen 5 has a buffer structure in which the opening surface of the recess is closed by the thin plate 22 and air is sent into the recess and sealed therein, the upper glass substrate b is pressed by an air bag. Therefore, even if the upper and lower glass substrates have irregular thicknesses (taper), the unevenness is absorbed by the buffer structure of the upper platen 5, and a uniform distributed load acts on the upper glass substrate b. Then, the sealing material c is uniformly crushed, and as a result, the gap between the upper and lower glass substrates is kept constant, and high-precision bonding is achieved.
(See Fig. 5)

[0021]

The platen structure used in the apparatus for bonding glass substrates for a liquid crystal display panel of the present invention is constructed as described above, so that the upper and lower glass substrates are pressurized via a buffer structure.
As a result, unevenness (taper) of the thickness of the glass substrate can be absorbed, and the sealing material can be uniformly crushed. Therefore, it is possible to provide a surface plate of a bonding apparatus capable of realizing high-precision bonding in which the gap between the upper and lower glass substrates is uniform.

Further, in the case where the transparent portions are provided at each corner of the surface plate as in claim 2, marks can be aligned on the upper and lower glass substrates before bonding by the surface plate. After completion, bonding can be performed with uniform load distribution by pressing as it is. Therefore, it is possible to provide a surface plate capable of continuously performing the mark alignment and the lamination while absorbing the unevenness of the plate thickness.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a bonding apparatus equipped with a surface plate according to the present invention.

FIG. 2 is a partially cutaway plan view showing a surface plate provided in the bonding apparatus.

FIG. 3 is a longitudinal sectional view taken along line (3)-(3) in FIG. 2;

FIG. 4 is a longitudinal sectional view taken along line (4)-(4) in FIG. 2;

FIG. 5 is an explanatory view showing an operation of bonding the glass substrates by the above-mentioned surface plate.

[Explanation of symbols]

 A: Laminating device 2: Fixed base plate 3: Movable base plate 4: Lower platen 5: Upper platen 19: Metal platen body 20 ... Peripheral edge 21 ... Depression 22 ... Thin plate 23 ... Suction hole 30 ... Transparent part

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiyoo Katagiri 2-9-9 Kandanishikicho, Chiyoda-ku, Tokyo Shin-Etsu Engineering Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) G02F 1/1339 505 G02F 1/13 101

Claims (2)

(57) [Claims] An apparatus for bonding a glass substrate for a liquid crystal display panel comprising a fixed base plate having a lower surface plate and a movable base plate having an upper surface plate and moving up and down, wherein at least one of the upper and lower surface plates is bonded. A recess is formed by leaving a peripheral edge on a surface of the metal platen body facing the glass substrate, and a lower surface opening of the recess is closed with a thin plate, and the periphery of the thin plate is adhesively fixed to the peripheral edge, and Adsorption holes are provided at appropriate positions on the thin plate, each suction hole is connected to a vacuum means disposed on the platen body, and the platen body is provided with air supply means to the recess. Surface plate structure characterized by the following. 2. A glass substrate for a liquid crystal display panel according to claim 1, wherein a transparent portion for aligning a mark on the glass substrate is provided at each corner of said rectangular platen body. Surface plate structure in bonding machine.