JPH08160370A - Production of liquid crystal display device and apparatus for production used for the same - Google Patents

Abstract

PURPOSE: To decrease the amt. of an electrically negative gas to be used and to improve productivity and production yield by treating respective production stages as well as inspection, substrate transfer, transportation, etc., in a chamber in which a gaseous mixture composed of air and the electrical negative gas is sealed. CONSTITUTION: For example, a rubbing device is composed of a moving table 4 placed with a glass substrate 1 deposited with elements 2 and oriented films 3, a roller 6 wound with rubbing cloth 5 and the chamber 10 in which the air and the gaseous S6 (electrically negative gas) is sealed. The volumetric ratio of the gaseous SF6 is specified to 30% and the total gaseous pressure to 0.1MPa. Vacuum evacuation is also executed down to 30% lower than 0.1MPa at the time of evacuating the inside of the chamber 10 by a vacuum pump 11. As a result, the less gaseous SF6 is necessitated and the operation time to execute vacuum evacuation is shortened. The gaseous SF6 suppresses the discharge by electrification during the production stage and does not damage the elements on the liquid crystal display device any more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device and a manufacturing apparatus used therefor. More specifically, the present invention relates to a method for manufacturing a liquid crystal display device capable of improving productivity and a manufacturing device used for the same.

[0002]

2. Description of the Related Art A liquid crystal display device comprises, for example, a transparent insulating substrate and an element formed on the surface thereof. In each of the steps such as cleaning, drying, heating, resist coating, exposure, development, wet etching, substrate cutting, rubbing, thermocompression bonding, polarizing plate attachment, inspection, substrate transfer and transport in the method for manufacturing a liquid crystal display device, The transparent insulating substrate may be charged by peeling, rubbing, or the like, and discharge may occur depending on the amount of charge. For this reason, there is a risk that the element formed on the surface of the substrate is damaged by this discharge and becomes defective. Therefore, it is extremely useful to take measures so that discharge does not occur even if charging occurs, in order to improve the yield. As an example of taking such measures, as shown in FIG.
There is a rubbing device proposed in No. 720. In FIG. 8, 101 is a transparent insulating substrate, 102 and 103 are elements (electrodes) and alignment films deposited thereon, 104 is a stage for fixing the transparent insulating substrate 101, and 105.
Is a rubbing cloth for performing a rubbing treatment, 106 is a roller around which the rubbing cloth 105 is wound, and 107 is a generator for generating an atmosphere of the electrically negative gas 108. Has become. The electrically negative gas 108 filling the inside of the generator 107.
Is SF ₆ gas (sulfur hexafluoride).

In the rubbing device, the roller 10
The height of 6 is adjusted so that the rubbing cloth 105 contacts the alignment film 103 with an appropriate pressure. With the roller 106 rotated, the stage 104 having the transparent insulating substrate 101 fixed thereto is moved in the horizontal direction. At this time, the alignment film 1
03 is rubbed with the rubbing cloth 105 to perform a rubbing process. At this time, the rubbing cloth 105 and the alignment film 103
At the moment when they come into contact with each other and leave a minute distance, both surfaces are charged by frictional charging and an electric field is generated. However, since the dielectric strength of SF ₆ gas 108 is higher than this electric field strength, no discharge occurs. Therefore, the alignment film 103 due to the discharge
Also, the element 102 is not damaged.

[0004]

However, since the rubbing apparatus is configured so that the generator 107 of the closed container is filled with SF ₆ gas, the inside of the container is kept in a sufficiently vacuum state each time the treatment is performed. After that, it is necessary to fill SF ₆ gas. Therefore, there is a problem that a large amount of SF ₆ gas must be used every time the manufacturing process is performed. In addition, there is also a problem that it takes a lot of time for processing.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to reduce the amount of the electrically negative gas used and to reduce the amount of the electrically negative gas without requiring a great deal of time. Using a high dielectric strength, it is possible to suppress discharge even when the glass substrate is charged, and a method for manufacturing a liquid crystal display device that can be manufactured without damaging elements on the glass substrate, and The purpose is to obtain a manufacturing apparatus to be used.

[0006]

A method of manufacturing a liquid crystal display device according to the present invention is a method of manufacturing a liquid crystal display device comprising a transparent insulating substrate and an element formed thereon, which includes cleaning, drying, heating and resisting. Part or all of the manufacturing process, including coating, exposure, development, wet etching, substrate cutting, rubbing, thermocompression bonding, polarizing plate pasting, inspection, substrate transfer and transport, is performed with air and electrically negative gas. It is characterized in that it is processed in a chamber filled with the mixed gas of.

The volume ratio of the electrically negative gas in the mixed gas is preferably 3 to 90%.

It is preferable to stir the mixed gas regularly or continuously.

It is preferable that the entrance / exit of the transparent insulating substrate is provided at a position higher than the substrate processing section.

It is preferable to irradiate the transparent insulating substrate with ions in a mixed gas before exposing the transparent insulating substrate to an air atmosphere.

It is preferable to use SF ₆ gas or Freon gas as the electrically negative gas.

Further, in the manufacturing method used for the manufacturing method of the liquid crystal display device of the present invention, the chamber is a vacuum pump,
It is characterized by comprising an electrically negative gas cylinder and a valve for adjusting the volume ratio of the mixed gas.

A stirring device for stirring the mixed gas periodically or continuously is preferably provided in the chamber.

It is preferable that the chamber has an inlet / outlet port for the transparent insulating substrate at a position higher than that of the substrate processing section.

It is preferable that the chamber is provided with an ion generator for irradiating the transparent insulating substrate with ions in a mixed gas before the transparent insulating substrate is exposed to an air atmosphere.

[0016]

According to the method of manufacturing a liquid crystal display device of the present invention, the manufacturing process is carried out in a mixed gas of air and an electrically negative gas.
Therefore, the amount of electrically negative gas used is smaller than in the conventional case, the time for vacuuming the inside of the chamber is shortened, and the productivity is improved. Moreover, the high dielectric strength of the electrically negative gas suppresses the discharge even if the substrate is charged,
The yield can be improved without damaging the elements on the liquid crystal display device.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a liquid crystal display device according to the present invention and a manufacturing apparatus used therefor will be described below with reference to the accompanying drawings.

[Embodiment 1] FIG. 1 shows a rubbing apparatus to which an embodiment of a method for manufacturing a liquid crystal display device of the present invention is applied.
This rubbing apparatus has a moving table 4 on which a transparent insulating substrate 1 such as a glass substrate having an element (electrode) 2 and an alignment film 3 adhered on its surface is placed, and a rubbing cloth 5 for rubbing treatment. And a chamber 10 in which a mixed gas 9 of air and SF ₆ gas (electrically negative gas) is enclosed. And
The said chamber 10, one end of the vacuum pump 11 or other end thereof is connected the bifurcated inlet pipe 15 connected to the cylinder 12 of the SF ₆ gas. Immediately before the vacuum pump 11 and the cylinder 12, adjustment valves 13 and 14 are connected, respectively. The electrically negative gas is not limited to SF ₆ gas, and a gas capable of preventing discharge by trapping electrons, for example, Freon gas such as CHF ₂ Cl (F-22). It can also be used. In this embodiment, the volume ratio of SF ₆ gas in the mixed gas 9 is 30%, and the total gas pressure is 0.1 MPa.

Next, a method of manufacturing the liquid crystal display device of the present invention will be described with reference to a rubbing device.

When introducing the mixed gas 9 into the chamber 10, first, the valve 14 is closed, the valve 13 is opened, and the inside of the chamber 10 is evacuated by the vacuum pump 11. At this time, the volume ratio of SF ₆ gas in the mixed gas 9 is set to 3
Since it is adjusted to 0%, vacuuming is 3 MPa than 0.1 MPa.
It only needs to be reduced to 0%, and it can be done in a short time. After that, the valve 13 is closed and the valve 14 is opened to supply SF ₆ gas from the cylinder 12 into the chamber 10 so that the total pressure in the chamber is 0.
It is introduced until it reaches 1 MPa.

The dielectric strength at 0.1 MPa is 30 kV / cm for air and 88 kV / cm for SF ₆ gas,
SF ₆ gas has a dielectric strength about three times that of air. These two
FIG. 2 shows the relationship between the mixing volume ratio of SF ₆ gas and the dielectric strength of the mixed gas when two gases are mixed. It can be seen from FIG. 2 that the dielectric strength is improved above the mixing ratio by mixing a small amount of SF ₆ gas with air. Volume ratio of 30% when SF ₆ gas of this embodiment, the dielectric strength is realized is approximately 90% of SF ₆ gas alone. Therefore, even if the rubbing process causes charging, the discharge can be suppressed.

As described above, in this embodiment, the chamber 1
The time required for introducing the mixed gas 9 into the chamber 0 is short, and even if charging occurs, discharge does not occur, so that the treatment can be performed without causing damage to the element 2. The amount of SF ₆ gas used is also smaller than filling the entire chamber 10 with SF ₆ gas, which is economically advantageous.

Although the volume ratio of SF ₆ gas is 30% in this embodiment, the dielectric strength is about 50% of SF ₆ gas alone and 150% of air alone even if the volume ratio is 3%. In addition, the discharge can be suppressed, and the work time for introducing the mixed gas can be extremely short. Also, set the volume ratio to 9
Even if it is 0%, air drawing in the introduction work may be performed from 0.1 MPa to 0.01 MPa, long time work is not required, there is no problem in terms of dielectric strength, and discharge is sufficiently suppressed. be able to.

[Second Embodiment] Next, a second embodiment of the present invention will be described. In the first embodiment, the chamber 10 is hermetically sealed, but in this embodiment, as shown in FIG. 3, the inlet 20a and the outlet 20b of the substrate 1 to the chamber 20 are located at a position higher than the substrate processing unit A. It is provided. The specific gravity of SF ₆ gas is 5.1, assuming that air is 1.
The specific gravity of the mixed gas 9 with ₆ gas is larger than that of air. Therefore, the region of the chamber 20 lower than the substrate inlet / outlet ports 20 a and 20 b is filled with the mixed gas 9, and the substrate inlet / outlet port 20 a
The substrate processing part A located at a position lower than a and 20b also becomes the atmosphere of the mixed gas 9, and the discharge due to charging can be suppressed. Further, in this embodiment, the work itself of introducing the mixed gas for each substrate processing is unnecessary, and the productivity can be further improved.

[Third Embodiment] Next, a third embodiment of the present invention will be described. Due to the specific gravity as shown in Example 2, even if the mixed gas is introduced, the SF ₆ gas stays at the bottom of the chamber with time, and the substrate processing section A becomes an air atmosphere instead of a mixed gas atmosphere. There is concern that the dielectric strength will decrease. Therefore, in this embodiment, as shown in FIG. 4, a device 16 for periodically or continuously stirring the mixed gas 9 such as a blower is provided at the bottom portion 30a of the chamber 30. Reference numeral 17 is a power source for the blower. As a result, the substrate processing unit A is always in the atmosphere of the mixed gas 9, so that it is possible to suppress discharge due to charging without lowering the dielectric strength.

In this embodiment, the stirring device 16 is applied to the first embodiment, but the same effect can be obtained by applying the second embodiment to the second embodiment.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described. In this embodiment, as shown in FIG. 5, an ion irradiation device 47 is attached to the chamber of the device shown in the second embodiment. In FIG. 5, reference numeral 48 is the power source, and 49 is the ions generated from the ion irradiation device 47. After the rubbing process is completed, the ion irradiation device 47 is provided with the substrate 1
From the mixed gas 9 of air and SF ₆ gas to the chamber 40
Before exiting to the air atmosphere at the substrate outlet 40b of the mixed gas 9
The substrate 1 is irradiated with ions 49 therein. As described above, according to this embodiment, the charge of the alignment film 3 can be removed before the alignment film 3 is exposed to the atmosphere having a dielectric strength lower than that of the mixed gas 9. Therefore, the alignment film 3 is exposed to the air atmosphere. No discharge is generated between the grounding portion (for example, the chamber 40) and damage to the element 2 and the alignment film 3 can be suppressed. Moreover, the work itself of introducing the mixed gas for each substrate processing is not required, and the productivity can be further improved.

In this embodiment, the ion irradiation device 47 is
Although an example in which it is exposed to the mixed gas 9 is shown, it is installed in the chamber 40 in an air atmosphere so that the ions 49 enter the mixed gas 9 from the air atmosphere and then the alignment film 3 is irradiated with the ions 49. You may

Further, in the present embodiment, an example in which the ion irradiation device is attached to the device shown in the second embodiment has been shown, but the same effect can be obtained even if it is attached to the device for stirring by the blower shown in the third embodiment. There is.

Further, in the method shown in the first embodiment, since the chamber 10 is sealed, it is necessary to close the chamber 10 in order to take out the substrate 1 after the processing is completed. Exposed to air atmosphere.
Therefore, the ions may be irradiated before the sealing of the chamber 10 is broken.

[Fifth Embodiment] In the first to fourth embodiments, an example in which the method for manufacturing a liquid crystal display device of the present invention is applied to a rubbing device is shown. However, in the manufacturing process of the liquid crystal display device, other than the rubbing process, such as cleaning, drying, heating, resist coating, exposure, development, wet etching, substrate cutting, thermocompression bonding, polarizing plate pasting, inspection, substrate transfer and transportation. Even in the process, the substrate is electrically charged due to peeling or friction, and discharge is likely to occur between the substrate and the ground. Therefore, the present invention can be applied to these steps as well. An example in which the present invention is applied to the drying step is shown in FIG. In FIG. 6, reference numeral 51 is a hot plate for heating and drying the substrate 1, 52 is a pin for lifting the substrate 1 from the hot plate 51 after the completion of the drying process, which is usually housed in the hot plate 51. Reference numeral 53 is a sensor for detecting the position of the substrate 1 attached to the chamber 50. During the drying process, the pins 52 are stored in the hot plate 51,
Is in close contact with the hot plate 51. Pin 52 after processing
As a result, when the substrate 1 is separated from the hot plate 51, peeling charging occurs and the substrate 1 is charged. As a result, the electric field between the substrate 1 and the ground, for example, the position sensor 53 is increased, but the dielectric strength of the mixed gas 9 is high, so that no discharge occurs and the same effect as in the first embodiment is obtained.

[Embodiment 6] In the above-mentioned Embodiments 1 to 5, the present invention is applied to each step by making each step independent, but the present invention is applied to some or all steps. You may apply. As an example, FIG. 7 shows an example in which the cleaning process and the drying process are connected by a transport system. In FIG. 7, reference numeral 64 is pure water for cleaning the substrate 1, and 65 is a nozzle for spraying the pure water 64. Reference numeral 66 is a roller for carrying the substrate 1 that has been cleaned to the drying step.

Between the steps, the substrate 1 is not exposed to the air atmosphere, discharge can be suppressed, and
Since it is not necessary to open the chamber 60 between steps, it is sufficient to introduce the mixed gas 9 only once, which is economical and improves productivity.

[0034]

As described in the foregoing, according to the manufacturing method of the liquid crystal display device of the present invention, a mixed gas of electrically negative gas such as air and SF6 gas, for example, the volume ratio of SF ₆ gas 3 to 90 The manufacturing process is carried out under a mixed gas of 100%. Therefore, the amount of electrically negative gas used in the manufacturing process can be reduced, and the working time for evacuating the inside of the chamber is shorter than that required in the conventional case where a sufficient vacuum state was required. As a result, the productivity of the liquid crystal display device can be improved.

Further, the high dielectric strength of the electrically negative gas is
Suppresses discharge due to electrification caused by peeling and friction in the manufacturing process. Therefore, the elements on the liquid crystal display device are not damaged. As a result, the manufacturing yield can be improved. In addition, since the substrate processing section is constantly kept in the mixed gas atmosphere by periodically or continuously stirring the mixed gas, it is possible to suppress discharge and improve the yield.

Further, by providing the entrance and exit of the substrate at a position higher than the substrate processing section, the work of introducing the mixed gas for each substrate processing becomes unnecessary, and the productivity can be further improved.

Also, after the substrate is manufactured, it is irradiated with ions before it is exposed to the air atmosphere.
Since the charge on the substrate can be removed, the yield can be further improved.

Furthermore, the manufacturing apparatus of the present invention has a simple structure and requires only a vacuum pump, an electrically negative gas cylinder, and a valve for adjusting the volume ratio of the mixed gas in the chamber. The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment in which a method for manufacturing a liquid crystal display device of the present invention is applied to a rubbing process.

FIG. 2 is a characteristic diagram showing dielectric strength of a mixed gas of air and SF ₆ gas with respect to a mixed volume ratio of SF ₆ gas.

FIG. 3 is a cross-sectional view showing a second embodiment in which the method for manufacturing a liquid crystal display device of the present invention is applied to a rubbing process.

FIG. 4 is a cross-sectional view showing a third embodiment in which the method for manufacturing a liquid crystal display device of the present invention is applied to a rubbing process.

FIG. 5 is a cross-sectional view showing a fourth embodiment in which the method for manufacturing a liquid crystal display device of the present invention is applied to a rubbing process.

FIG. 6 is a cross-sectional view showing a fifth embodiment in which the method for manufacturing a liquid crystal display device of the present invention is applied to a drying step.

FIG. 7 is a cross-sectional view showing a sixth embodiment in which the method for manufacturing a liquid crystal display device of the present invention is applied to a cleaning step and a drying step connected by a transport system.

FIG. 8 is a sectional view showing a conventional rubbing device.

[Explanation of symbols]

1 transparent insulating substrate, 2 elements, 3 alignment film, 9 mixed gas, 10, 20, 30, 40, 50, 60 chamber,
11 vacuum pump, 12 cylinders, 13, 14 adjusting valve, 16 stirrer, 47 ion irradiation device, 49 ion.

Claims (10)

[Claims] 1. A method of manufacturing a liquid crystal display device comprising a transparent insulating substrate and an element formed thereon, cleaning,
Part or all of the manufacturing process, including drying, heating, resist coating, exposure, development, wet etching, substrate cutting, rubbing, thermocompression bonding, polarizing plate attachment, inspection, substrate transfer, and transportation, is performed with air and electricity. A method for manufacturing a liquid crystal display device, which comprises processing in a chamber in which a mixed gas with a negative gas is sealed. 2. The manufacturing method according to claim 1, wherein the volume ratio of the electrically negative gas in the mixed gas is 3 to 90%. 3. The manufacturing method according to claim 1, wherein the mixed gas is agitated periodically or continuously. 4. The entrance / exit of the transparent insulating substrate is provided at a position higher than the substrate processing section.
The manufacturing method described. 5. The method according to claim 1, wherein the transparent insulating substrate is irradiated with ions in a mixed gas before the transparent insulating substrate is exposed to an air atmosphere. 6. The manufacturing method according to claim 1, wherein SF ₆ gas or Freon gas is used as the electrically negative gas. 7. The manufacturing apparatus used in the manufacturing method according to claim 1, wherein the chamber comprises a vacuum pump, an electrically negative gas cylinder, and a valve for adjusting the volume ratio of the mixed gas. A manufacturing apparatus characterized by: 8. The manufacturing apparatus according to claim 7, wherein a stirring device for stirring the mixed gas periodically or continuously is provided in the chamber. 9. The manufacturing apparatus according to claim 7, wherein an entrance of the transparent insulating substrate is provided in the chamber at a position higher than that of the substrate processing section. 10. The ion generator for irradiating the transparent insulating substrate with ions in a mixed gas before the transparent insulating substrate is exposed to an air atmosphere is provided in the chamber. Or the manufacturing apparatus according to 9.