JPH05249467A - Apparatus for producing liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide stable liquid crystal orientation by controlling the humidity of a rubbing treatment device. CONSTITUTION:A substrate 13 formed with an oriented film 14 is installed on a table 12 installed within a device cover 11 and the outer periphery of a rotating rubbing roller 15 is brought into contact with the oriented film 14. The wet air from a humidifier 17 is introduced via an outdoor air introducing port 16 into this device cover 11. A discharge electrode 18 to be impressed and set with a high voltage from a high-voltage power source 19 is installed within the cover 11. The high-voltage power source is controlled by a control circuit 20 in accordance with the moisture detection signal from a moisture sensitive sensor 21. The high-voltage power source impressed to the discharge electrode 18 is subjected to on-off control in such a manner that the moisture is set within a prescribed range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing an active matrix type liquid crystal display device in which processing means for generating static electricity, for example, rubbing processing means for obtaining stable liquid crystal alignment is improved. Regarding

[0002]

2. Description of the Related Art In a manufacturing process of a liquid crystal display device, an alignment film is printed on a substrate and baked, and then the alignment film is rubbed. This rubbing treatment is performed by rubbing an alignment film formed of an insulating film with a rubbing cloth, and static electricity of, for example, several KV is generated.

Since such high-voltage static electricity causes destruction of the active element, it is necessary to keep the rubbing atmosphere in a high humidity state as disclosed in, for example, Japanese Patent Laid-Open No. 1-225918. It is considered to be. That is, by increasing the humidity of the processing atmosphere, the generation of static electricity is suppressed, and the effect of protecting the active element from destruction is exhibited.

However, the rubbing treatment atmosphere is, for example, 70
When it is in a high humidity state of not less than%, it is difficult to stably obtain the alignment state due to disordered fur of the rubbing cloth and swelling of the alignment film.

Further, since such a rubbing process is a dusting process, an apparatus for the rubbing process is constructed so as to be surrounded by a cover, and a heat generating part such as a rotating part of the rubbing roller is present in the cover. Is something
Therefore, the humidity control of the rubbing processing environment cannot be performed by air conditioning in a clean room.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points and effectively prevents destruction of an active element by treating high-voltage static electricity generated by a rubbing cloth, for example. It is an object of the present invention to provide an apparatus for manufacturing a liquid crystal display device, which enables the stable alignment state to be set, and particularly improves the rubbing process step in which static electricity is generated.

[0007]

A liquid crystal display manufacturing apparatus according to the present invention introduces moisture from a humidifying means into an apparatus cover having a mechanism for performing a process involving generation of static electricity inside, for example, a rubbing roller. In addition, a discharge electrode connected to a high voltage power source is provided in the cover. And
The high-voltage power supply for the discharge electrode is intermittently controlled according to the humidity in the cover.

[0008]

According to the liquid crystal display manufacturing apparatus configured as described above, since moisture is introduced into the apparatus cover, generation of high-voltage static electricity in the alignment film portion is effectively suppressed. The active element can be protected from high voltage breakdown. In addition, since a discharge electrode connected to a high-voltage power supply is provided inside the device cover, when the humidity in the atmosphere inside the device cover is ionized by the discharge from this electrode and the humidity inside the cover becomes higher than necessary. To lower this humidity. Therefore, by controlling ON / OFF of the high-voltage power supply based on the detection value from the humidity detecting means, the atmosphere in the apparatus cover can be stably set to the most effective humidity, and a highly reliable rubbing process can be performed. Done.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a rubbing process step part of an alignment film in a liquid crystal display device manufacturing apparatus, in which a device cover 11 for setting a rubbing processing atmosphere is set.
This device cover 11 is installed for preventing scattering of dust generated by the rubbing process to the surroundings and for controlling local humidity.

A table for processing is provided in the device cover 11.
12 is set, and the substrate 13 is set on the table 12. On the substrate 13, active elements composed of thin film transistors and thin film diodes are formed in a matrix arrangement. Then, on the surface of the substrate 13, an alignment film 14 is formed, which is formed by a spin coating method or the like and then appropriately baked.

The rubbing treatment is carried out by a rubbing roller 15 around which a rubbing cloth made of a non-woven fabric such as rayon or polyester is wound.
The rubbing roller 15 is rotated with its outer periphery in contact with the surface of the alignment film 14.

An outside air introduction port 16 is formed in the device cover 11 having the rubbing processing mechanism built-in.
The high-humidity air from the humidifier 17 is introduced into the outside air inlet 16, and the humidity from the humidifier 17 causes
The humidity inside the device cover 11 is increased.

A discharge electrode 18 is further set inside the apparatus cover 11 having a built-in rubbing mechanism as described above, and the discharge electrode 18 is supplied from a high-voltage power source 19, for example, 20K.
A high voltage of about V is applied and set. The high-voltage power supply 19 is turned on / off by a command from the control circuit 20, and the control circuit 20 is supplied with a detection signal from a humidity sensor 21 installed in the device cover 11 so that the device cover 11 When the internal humidity becomes higher than a predetermined value, a high voltage is applied and set to the discharge electrode 18. Then, when the humidity inside the cover 11 is lowered, the high voltage power source applied to the discharge electrode 18 is cut off.

Humidity control inside the apparatus cover 11 during the rubbing process is important for obtaining a stable alignment state in the alignment film 14. However, since such a rubbing process is a dusting process, this processing mechanism is not covered by the device cover.
Need to be covered by 11. Inside the cover 11, the roller 15
There is an influence of heat generation of the rotating mechanism part of the above, and it is impossible to control the humidity to the desired 60 ± 5% required, which is impossible with a normal air conditioner in a clean room. Sometimes needed.

Therefore, in the apparatus shown in the embodiment, in order to increase the humidity in the apparatus cover 11 which is the rubbing processing section, the humidity generated in the humidifier 17 is introduced into the apparatus cover 11 from the outside air inlet 16. Introduce.

By introducing moisture into the apparatus cover 11 as described above, the humidity of the atmosphere of the rubbing process is increased, and the effect of preventing static electricity is increased. However, when the humidity of the rubbing treatment atmosphere in the device cover 11 becomes high humidity of 70% or more, a stable alignment state of the liquid crystal cannot be obtained.

In this way, when the humidity of the rubbing atmosphere exceeds the upper limit of the set range, it is detected by at least one humidity sensor 21 installed in the cover 11, and the humidity detected by this humidity sensor 21. When it exceeds 70%, the control circuit 20 detects this and gives a command to the high-voltage power supply 19 to set a high voltage to the discharge electrode 18.

[0018] When a high voltage is applied to the discharge electrode 18, the moisture in contact with the electrode 18 ionized by high voltage discharge ^- and ^{_{[2H 2 O → 4H + +}} 2O 2 (2H 2 + O 2)],
The humidity inside the device cover 11 is reduced.

Due to such continuous high-voltage discharge, the humidity of the rubbing treatment atmosphere in the apparatus cover 11 is lowered. Before the ambient humidity becomes lower than the lower limit of the set range, the humidity sensor 21 detects The control circuit 20 controls the high-voltage power supply 19 based on the detection signal of, and cuts off the high-voltage power supply applied to the discharge electrode 18.

Here, although the introduction of moisture from the outside air introduction port 16 may be carried out at all times, in a situation where the humidity is lowered, the humidifier 17 is controlled or a valve mechanism (not shown) is used to remove the moisture. The introduction may be controlled to be stopped.

As described above, the high-voltage power supply 19 is controlled based on the humidity sensor 21 and the detection signal thereof, and the high-voltage power supply applied to the discharge electrode 18 is controlled to be turned on / off to thereby cover the device cover.
Humidity of the rubbing treatment atmosphere in 11 can be controlled, and this atmosphere can be maintained in a preferable humidity range. Therefore, a stable liquid crystal alignment state can be reliably obtained.

FIG. 2 shows the humidity during rubbing treatment as "60 ± 5".
% ", The amount of static electricity charged on the substrate 13 by the rubbing process decreases as the humidity increases. And, at 70% humidity, it is 0 KV (measurement limit of the measuring device is 0.05 KV). It was

Considering the breakdown voltage of the active element, the charging voltage must be 0.6 KV or less, and for this purpose, a humidity of at least 50% or more is required. But 7
At a high humidity of 0% or more, although the effect against static electricity is exhibited, it enters a region where an LCD with a poor alignment state is generated. Therefore, the humidity atmosphere during rubbing is 50-
It is 70%, and it is effective to control to “60 ± 5%”.

In the above embodiment, the example of the rubbing process for controlling the alignment of the liquid crystal has been described, but this can be applied to the sticker printing process as it is. The sticker printing is performed by a screen printing method, and static electricity is generated during printing. This static electricity causes harmful effects such as scattering of the seal material.

In this case, if the atmospheric humidity is increased during sticker printing, the effect of removing the harmful effects of static electricity is exerted, but on the other hand, the adverse effect of high humidity on the seal material occurs, and it is the same as during rubbing. It is necessary to control the humidity range of the processing atmosphere. Therefore, even in such sticker printing, by installing the discharge electrode and controlling the ON / OFF of the high-voltage power source in accordance with the atmospheric humidity, it becomes possible to perform good sticker printing.

Further, this embodiment can be applied to the spacer spraying step for forming the portion for storing the liquid crystal. That is, when the spacers are sprayed onto the substrate 13 by spraying from the nozzles, there is a problem that the spacers aggregate due to static electricity. In order to solve such a problem, humidity control at the time of spraying is important, and such local humidity control can be performed by the humidifying means and the high voltage discharging means.

An apparatus for performing such a seal printing step and a spacer spraying step, instead of the rubbing roller 15 of the apparatus shown in FIG. 1, has a squeegee and a seal printing section such as a screen printing plate in the apparatus cover 11 or a spacer. A spray nozzle should be installed.

[0028]

As described above, the rubbing treatment can surely prevent the active element from being broken by the static electricity generated during the rubbing treatment for manufacturing the liquid crystal display device according to the present invention, thereby realizing a stable liquid crystal alignment state. The atmosphere of can be set to a preferable humidity range,
A highly reliable liquid crystal display device can be manufactured easily and reliably.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating particularly a rubbing processing unit of a liquid crystal display device manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between humidity in a rubbing processing atmosphere and electrostatic substrate charging voltage.

[Explanation of symbols]

11 ... Device cover, 12 ... Table, 13 ... Substrate, 14 ... Alignment film, 15 ... Rubbing roller, 16 ... Outside air inlet, 17 ... Humidifier, 18 ... Discharge electrode, 19 ... High voltage power supply, 20 ... Control circuit, 21
… Humidity sensor.

Claims (1)

[Claims] 1. A device cover in which a mechanism for performing a process involving generation of static electricity of a liquid crystal display device is installed inside, a humidifying means for introducing moisture into the device cover, and installed in the cover. A discharge electrode connected to a high voltage power source for ionizing atmospheric humidity, and a humidity detecting unit installed in the cover for detecting the humidity in the cover, and the humidity in the cover detected by the humidity detecting unit. The high voltage power supply of the discharge electrode is controlled in accordance with the above item, and a manufacturing apparatus of a liquid crystal display device.