JPH11101970A - Method for cleaning substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cleaning a substrate which can improve yield of orientation processed products by completely removing foreign matter on the substrate and further can reduce cleaning time and cleaning apparatus cost. SOLUTION: The method for cleaning the substrate before an oriented film transferring treatment transferring an oriented film to a translucent substrate in a manufacturing process of a liquid crystal panel composed of two sheets of transparent substrates stuck together via a sealant contains a process in which a foreign matter removing film 3 is applied to the translucent substrate 2, a process in which the foreign matter removing film 3 is dried and a process in which the foreign matter 1 stuck to the translucent substrate 2 is removed together with the foreign matter removing film 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for cleaning a substrate. More specifically, the present invention relates to a substrate cleaning method for removing foreign substances adhering to a light-transmitting substrate before an alignment film transfer process in a liquid crystal panel manufacturing process.

[0002]

2. Description of the Related Art A process for manufacturing a liquid crystal display element includes, for example, a glass substrate process for manufacturing and surface processing a glass substrate, and a pattern forming process for forming a thin film transistor (TFT) pattern on each glass pixel. And a color filter forming step of forming a color filter for realizing colorization on another glass substrate, and a liquid crystal panel in which both substrates are subjected to an orientation treatment, and then opposed to each other at a fixed interval and bonded with a sealing material. A panel (cell) assembling process by injecting liquid crystal into a liquid crystal panel, and a module assembling process to attach driving parts, a backlight and the like.

In the manufacturing process of the liquid crystal panel, it is necessary to uniformly apply (transfer) the alignment film on the glass substrate. Therefore, foreign matters on the glass substrate must be sufficiently removed before application (transfer). Conventionally, the removal of the foreign matter adhered on the glass substrate is performed by dry cleaning such as infrared (IR) cleaning and ultraviolet (UV) cleaning, scrub cleaning using a brush, ultrasonic (US) cleaning, and cavitation jet (CJ). Washing, megasonic (MS) washing, and washing with water such as detergents are performed in combination.

[0004]

However, in the conventional method for removing foreign matter before transferring the alignment film, the foreign matter cannot be completely removed, and the alignment film is uniformly coated (transferred) on the substrate.
There is a problem that an impossible part is formed and the yield of products is lowered. Further, since the substrate cleaning line combines the above-mentioned cleaning operations, there is a problem that the cleaning time and the cost of the cleaning equipment are excessively increased.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a method of cleaning a substrate which can completely remove foreign substances from the substrate, improve the yield of the alignment-treated product, reduce the cleaning time and reduce the cost of cleaning equipment. The aim is to provide a method.

[0006]

According to a substrate cleaning method of the present invention, an alignment film is transferred to the translucent substrate in a process of manufacturing a liquid crystal panel composed of two transparent substrates bonded together via a sealing material. A method of applying a foreign substance removing film to the light-transmitting substrate, a step of drying the foreign substance removing film, and a step of drying the foreign substance removing film together with the foreign substance removing film. The method is characterized by including a step of removing adhering foreign matter.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a substrate cleaning method according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory view showing one embodiment of the substrate cleaning method of the present invention.

In the liquid crystal panel according to the present invention, for example, an array substrate in which TFTs are formed on a light-transmitting glass substrate and a color filter substrate in which a color filter is formed on a light-transmitting glass substrate are opposed to each other. Are bonded together via a sealing material.

An array substrate and a color filter substrate (hereinafter simply referred to as a substrate) used in the liquid crystal panel.
After removing foreign substances attached during the production of the substrate,
An alignment film is formed.

In this embodiment, as shown in FIGS. 1A and 1B, a foreign substance removing film made of a water-soluble organic polymer film is formed on a substrate 2 to which foreign substances 1 adhere, as shown in FIGS. 3 is applied to a thickness of about several μm by a roll-type transfer device (not shown). Such a water-soluble organic polymer membrane,
A polymer which can remove the film by treating with water, for example, polyvinyl alcohol or polyvinyl butyral can be used. However, it is preferable to use polyvinyl alcohol which is inexpensive, can be dried at low temperature, and can be easily peeled off.

Then, the substrate 2 is placed on a drier (not shown), and the foreign matter removing film 3 is dried at a temperature of 50 ° C. for about 40 seconds, for example, to increase the adhesion to the foreign matter.

Next, when the foreign matter removing film 3 is made of polyvinyl alcohol, as shown in FIG. 1C, the film 3 is removed by washing with hot water. Thus, the foreign matter is removed from the substrate 2 together with the foreign matter removing film.

After the substrate 2 is thus cleaned, the substrate 2 is rotated and dried, and then the alignment film is transferred.

In this embodiment, the foreign matter removing film is formed of a water-soluble organic polymer film. However, the present invention is not limited to this, and has a property of being dissolved by an organic solvent. It can also be formed of a water-insoluble organic polymer film, for example, polyimide, novolak resin or epoxy resin. When polyimide is used as the foreign matter removing film, N-methylpyrrolidone or the like can be used as a solvent for the release agent.

Before the substrate is coated with the foreign substance removing film, the substrate is subjected to ordinary dry cleaning or pre-cleaning with water, so that large foreign substances can be removed in advance. It can be performed more efficiently.

[0017]

As described above, according to the present invention,
Since the foreign matter on the substrate can be cleaned only with the foreign matter removing film formed on the substrate and the release agent for the film, the substrate can be cleaned at very low cost. Therefore, the product yield in the alignment film transfer process can be improved.

Further, the cleaning time can be shortened as compared with the conventional cleaning, and the cost of the cleaning equipment can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a substrate cleaning method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foreign substance 2 Substrate (translucent board) 3 Foreign substance removal film

Claims (6)

[Claims] 1. A substrate cleaning method prior to an alignment film transfer process for transferring an alignment film to the translucent substrate in a process of manufacturing a liquid crystal panel including two transparent substrates bonded together via a sealing material. A substrate including a step of applying a foreign matter removing film to the light-transmitting substrate, a step of drying the foreign matter removing film, and a step of removing foreign matter adhering to the light-transmitting substrate together with the foreign matter removing film. Cleaning method. 2. The method for cleaning a substrate according to claim 1, wherein said foreign matter removing film comprises a water-soluble organic polymer film. 3. The method according to claim 2, wherein the water-soluble organic polymer film is polyvinyl alcohol. 4. The method for cleaning a substrate according to claim 1, wherein said foreign matter removing film comprises a water-insoluble organic polymer film. 5. The method according to claim 4, wherein the water-insoluble organic polymer film is polyimide. 6. The substrate cleaning method according to claim 1, further comprising a step of dry-cleaning or water-cleaning the light-transmitting substrate before applying the foreign matter removing film to the light-transmitting substrate. Method.