JP2000171768A - Manufacture of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the precision of a print pattern in the screen printing of a large-sized glass substrate, and to prevent a picture frame of a liquid crystal panel from becoming wider by shifting a form plate at each printing divided plural times, and printing the necessary number of sheets of the print patterns for multi-planes. SOLUTION: When the screen printing of a glass substrate 2 is carried out four times, a 1st printing is carried out (a) by shifting a form plate 3 onto a 1st area 11 of the glass substrate 2 and scratching squeegee 4 in the outward direction. Next, a 2nd printing is carried out (b) by shifting the form plate 3 onto a 2nd area 12 and scratching the squeegee 4 in the homeward direction. Similarly, a 3rd and 4th printing are carried out. Compared with a conventional single-time full space print by using a large form plate, it is possible to much improve positional accuracy in printing, and also suppress an increase in the width of picture frame of a liquid crystal panel. As a result, a highly accurate multi-plane printing can be realized even on a large-sized glass substrate 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal display device by manufacturing a liquid crystal display device by dividing a glass substrate having multiple faces.

[0002]

2. Description of the Related Art A liquid crystal display device has a structure in which liquid crystal is filled and sealed between glass substrates bonded at a predetermined gap. This liquid crystal display device has a printing step of printing an adhesive on a glass substrate, a bonding step of bonding a glass substrate on which the adhesive has been printed, a dividing step of forming a plurality of bonded glass substrates (liquid crystal cells), and a multi-face drawing. It is manufactured through a liquid crystal injection step of filling a liquid crystal cell with liquid crystal.

The adhesive for bonding the glass substrates in the above-mentioned printing process usually has a function of a sealant for sealing the liquid crystal, and is required to have high environmental resistance against temperature, humidity, etc. as well as adhesive strength. Is used. As a method of forming this adhesive (hereinafter, referred to as a sealant) on a glass substrate, there are a drawing method using a dispenser and a screen printing method using a printing plate.

The drawing method is a method in which a pattern is drawn by moving the dispenser over the substrate while extruding a sealant from the tip of the dispenser. Since the display area of the liquid crystal display device is in non-contact, there is no fear of glass substrate contamination. Clean without any. Further, the pattern can be changed only by changing the program, and there is no need to hold a plurality of printing plates unlike screen printing. However, when a complicated pattern or a large number of patterns are drawn, there is a drawback that the tact becomes long.

In the screen printing method, a sealing agent is placed on a printing plate placed on a glass substrate, and the printing plate is scratched with a squeegee. This is a method of forming a pattern on the top. The tact is constant irrespective of the pattern shape, but when changing the pattern, the printing plate needs to be replaced. Also, when the size of the printing plate is increased, the pattern accuracy is deteriorated, and the printing position may be shifted.

[0006]

In recent years, a liquid crystal display device has been required to have a larger size, and the size of a glass substrate has been increasing. When the drawing method is used, the pattern accuracy does not decrease even if the glass substrate is enlarged, but there is a problem that the tact is reduced when a large number of patterns are drawn. In the drawing method, if the glass substrate has four chamfers, 1
About 20 seconds and about 160 seconds for 8-chamfering are required, but with the screen printing method, a single printing can be performed for 60 seconds or less, regardless of the number of chamfers, and a tact of 120 seconds can be achieved even when printing four times. Therefore, from the viewpoint of productivity, screen printing is superior to the drawing method.

[0007] When the screen printing method is used, a large printing plate is required to cope with the above-mentioned increase in the size of the glass substrate. However, there is a problem that a large printing plate is difficult to handle and the printing pattern accuracy is deteriorated.

In general, when the size of the printing plate is increased, the accuracy of the printing plate is reduced. If the size of the plate is doubled, the accuracy is halved. Printing area 320 × 400mm, plate frame size 650
In the case of × 750 mm, the accuracy of the printing plate is about ± 100 μm. This is the case when the mask is a film dry plate. On the other hand, when the printing range is 550 × 650 mm, the printing plate accuracy is ± 170 μm. In addition, 600
In the case of × 800 mm, it is ± 200 μm.

[0009] If the printing plate precision is low, the printing position precision of the sealant will be low, and the production margin for seal printing will be reduced. Therefore, there is a problem that a design with a margin is required, and the frame of the liquid crystal panel is widened.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a liquid crystal display device in which the printing pattern accuracy of screen printing on a large glass substrate is improved and the frame of the liquid crystal panel is not widened.

[0011]

According to the method of manufacturing a liquid crystal display device of the present invention, when manufacturing a liquid crystal display device by dividing a multi-paneled glass substrate, screen printing on the glass substrate is divided into a plurality of times. Each time printing is performed, the printing plate is moved to print the required number of patterns of the multi-panel printing.

According to the present invention, it is possible to provide a method of manufacturing a liquid crystal display device in which the printing pattern accuracy of screen printing on a large glass substrate is improved and the frame of the liquid crystal panel is not widened.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, when manufacturing a liquid crystal display device by dividing a multi-panel glass substrate, screen printing on the glass substrate is divided into a plurality of times. Each time the printing plate is moved to print the required number of patterns of the multi-panel pattern, thereby improving the accuracy of screen printing on a large glass substrate. Can provide a method for manufacturing a liquid crystal display device in which the picture frame does not become wide.

According to a second aspect of the present invention, a single squeegee movable in the forward path and the backward path is moved by switching the moving direction each time the printing plate is moved, and the printing plate is scratched to scratch the glass substrate. 2. The method according to claim 1, wherein the squeegee can be reciprocally printed without returning the printing plate to a set position where the printing plate is scratched, thereby reducing tact as compared with one-way printing. Can be
Productivity can be improved.

According to a third aspect of the present invention, there is provided a first squeegee for scraping an adhesive for bonding a glass substrate on an outward path, and a second squeegee for scraping the adhesive on a return path,
The method for manufacturing a liquid crystal display device according to claim 2, wherein the first and second squeegees are switched and moved each time the printing plate is moved, and the printing plate is screen-printed by scratching the printing plate. Reciprocal printing can be performed, the tact can be reduced as compared with one-way printing, and productivity can be improved.

Hereinafter, a method for manufacturing a liquid crystal display device according to the present invention will be described based on specific embodiments. (Embodiment) A method of manufacturing a liquid crystal display device according to an embodiment of the present invention is as follows.
As shown in FIG. 1, when manufacturing a liquid crystal display device by dividing the glass substrate 2 obtained by taking multiple panels, screen printing on the glass substrate 2 is performed by moving the printing plate 3 each time printing is performed in a plurality of times. The required number of patterns for the multi-panel printing are printed.

As shown in FIG. 2, a screen printing apparatus for realizing screen printing on the glass substrate 2 includes a printing plate 3 having an opening pattern formed in a size that can accept accuracy, and a printing plate 3 having the opening pattern portion. A single squeegee 4 for filling the opening pattern portion with the sealant 6, a printing stage 8 on which the glass substrate 2 is placed, and the squeegee 4
A plate frame 5 for holding the glass substrate 2 and the printing plate 3 at a predetermined interval so that only a portion in contact with the glass substrate 2 is in contact with the glass substrate 2, and a control unit (not shown) for controlling these. It is configured. Also, this single squeegee 4 is shown in FIG.
As shown in FIG. 5, the printing plate 3 can be moved to the forward path A and the backward path B, and the moving direction is switched every time the printing plate 3 is moved, and the printing plate 3 is scratched to print the sealant 6 on the glass substrate 2 by screen printing. Is configured.

Here, a case where the sealant 6 is screen-printed on the entire surface of the glass substrate 2 having a size of, for example, 550 × 650 mm as a large substrate by the screen printing apparatus will be specifically described.

As in the prior art, when the 550 × 650 mm glass substrate 2 is screen-printed at one time, the printing position accuracy is as follows: the printing plate accuracy is 170 μm, the printing machine positioning accuracy is 20 μm, and the sum of squares thereof is Is 171 μm, which is almost the accuracy of the printing plate 3.

On the other hand, when printing is performed twice at 375 × 550 mm, the printing plate accuracy is 120 μm, the positioning accuracy of the printing press is 20 μm, and the square root of the sum of these squares is 122 μm. As described above, it is possible to improve the accuracy by 49 μm as compared with a single printing of a large plate. further,
When printing four times of 275 × 375 mm, the printing plate accuracy is 85 μm, the printing machine positioning accuracy is 20 μm,
The square root of the sum of these squares is 87 μm, which enables an improvement of 84 μm in accuracy compared to the conventional single-size printing.

When the screen printing on the glass substrate 2 is performed four times as described above, the printing plate 3 is moved to the first area 11 of the glass substrate 2 as shown in FIG. The squeegee 4 is scratched in the direction of the outward path A to execute the first printing. Next, as shown in FIG.
The printing plate 3 is moved to the second area 12, and the squeegee 4 is scratched in the direction of the return path B to execute the second printing. Next, as shown in FIG. 1C, a third region 13 of the glass substrate 2 is formed.
Then, the printing plate 3 is moved, and the squeegee 4 is scratched in the direction of the outward path A to execute the third printing. Finally, as shown in FIG. 1D, the printing plate 3 is moved to the fourth region 14 of the glass substrate 2 and the squeegee 4 is scratched in the direction of the return path B to perform the fourth printing.

As described above, the screen printing on the glass substrate 2 is performed by moving the printing plate 3 every time printing is performed in a plurality of times to print the required number of patterns for the multi-panel printing. Print pattern 1 is printed.

In the second and subsequent printings, the printing plate 3 is prevented from coming into contact with the printed sealant 6 again. This can be avoided by providing a space 7 between the print pattern 1 and the print pattern 1 based on the relationship between the actual print area and the plate frame size, the height of the sealant 6 after printing, and the like. Space 7 is set.

With such a configuration, if the same printing pattern 1 is repeated, the printing plate 3 formed to have a size relatively small as compared with the glass substrate 2 and tolerable in accuracy is used, and divided into plural times. Each time printing is performed, the printing plate is moved to print the required number of patterns for multi-panel printing. It is possible to greatly improve the size of the liquid crystal panel, prevent the frame of the liquid crystal panel from being widened, and realize a highly accurate multi-paneling even with the large glass substrate 2. Specifically, the mechanical positioning accuracy of the screen printing machine is ± 20 μm or less, which is higher than that of the printing plate 3. Even if the printing stage 8 is moved, a large printing plate is used as before. The printing position accuracy can be made very high as compared with the case where printing is performed all at once.

As shown in FIG. 3, since the squeegee can move to the forward path A and the backward path B and can perform reciprocal printing, the tact time can be reduced more than in one-way printing, and the productivity can be improved. .

In this embodiment, a single squeegee 4 that can move to the forward path A and the backward path B scrapes the sealant 6 as an adhesive for the printing plate 3 and performs screen printing on the glass substrate 2. A is provided with a forward squeegee as a first squeegee that scrapes the sealant 6 of the printing plate 3 in A, and a return squeegee as a second squeegee that scrapes the sealant 6 of the printing plate 3 in the return pass B. Each time is moved,
Even when the second squeegee is switched and moved to scratch the printing plate 3 and perform screen printing on the glass substrate 2,
When one squeegee is scratching the printing plate 3, the other squeegee is returned to the set position where the printing plate 3 is scratched.

[0027]

As described above, according to the method of manufacturing a liquid crystal display device of the present invention, when manufacturing a liquid crystal display device by dividing a multi-panel glass substrate, screen printing on the glass substrate is performed a plurality of times. By moving the printing plate each time the printing is performed separately and printing the required number of patterns of the multiple printing, the printing position is compared with the conventional printing using a large printing plate and printing all at once. It is possible to provide a method for manufacturing a liquid crystal display device, which can have extremely high accuracy, can improve the printing pattern accuracy of screen printing on a large glass substrate, and does not widen the frame of a liquid crystal panel. Even with a large-sized glass substrate, it is possible to realize high-precision multi-panning.

In the case where a single squeegee that can be moved in the forward path and the backward path is moved by switching the moving direction each time the printing plate is moved, and the printing plate is scratched and screen-printed on a glass substrate, the squeegee is used. Reciprocal printing can be performed without returning the printing plate to the set position where the printing plate is scratched. Tact can be reduced as compared with one-way printing, and productivity can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a screen printing process according to an embodiment of the present invention.

FIG. 2 is a schematic side view showing a printing operation of the screen printing apparatus according to the embodiment.

FIG. 3 is a schematic side view showing a reciprocating printing operation of the screen printing apparatus according to the embodiment.

[Explanation of symbols]

 Reference Signs List 1 printing pattern 2 glass substrate 3 printing plate 4 squeegee 5 plate frame 6 sealing agent 7 space 8 printing stage 11 first region 12 second region 13 third region 14 fourth region

Claims (3)

[Claims] 1. A method of manufacturing a liquid crystal display device by dividing a glass substrate having a plurality of screens, the screen printing on the glass substrate is performed by moving a printing plate each time printing is performed in a plurality of times. A method for manufacturing a liquid crystal display device that prints a number of patterns. 2. The liquid crystal according to claim 1, wherein a single squeegee movable in the forward path and the return path is moved by switching the moving direction each time the printing plate is moved, and the printing plate is scratched to perform screen printing on a glass substrate. A method for manufacturing a display device. 3. A first squeegee for scraping the adhesive for bonding the glass substrates on the outward path and a second squeegee for scraping the adhesive on the return path, and the first and second squeegees are moved each time the printing plate is moved. 3. The method for manufacturing a liquid crystal display device according to claim 2, wherein the squeegee is switched and moved to scratch the printing plate and screen-print the glass plate.