JPH0933927A - Substrate for liquid crystal and method for washing after rubbing treatment of substrate for color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the occurrence of unequal washing at the time of washing work after the rubbing treatment of a display substrate for liquid crystals. SOLUTION: Isopropyl alcohol (CH3 CH(OH)CH3 ) or an aq. soln. 15 of isopropyl alcohol is made to flow on the surface of the substrate 1 for liquid crystals or color filters so as to cover the entire part of the substrate surface prior to the execution of washing by injecting ultrasonic waves or pure water of a high pressure in the method for washing the surface of the substrate after the surface of the high-polymer film formed on the surface of the substrate is subjected to a rubbing treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method for rubbing a liquid crystal substrate and a color filter substrate, and more specifically, a process for forming an alignment film on a display substrate side and a color filter side substrate in a manufacturing process of a liquid crystal display substrate. In the above, the present invention relates to a method of coating a polymer film such as polyimide on the surface of these substrates, rubbing the film surface, and then cleaning the surface of the substrate.

[0002]

2. Description of the Related Art As a cleaning method after rubbing a liquid crystal display substrate, pure water is fluidized into a layer on the entire surface of the substrate before the cleaning is started as in JP-A-7-64091 so as to cover the entire surface. There is a method of controlling the uneven cleaning by performing the treatment by the above method.

[0003]

However, even if the surface of the substrate is uniformly covered with pure water before the start of cleaning, the unevenness during cleaning remains as it is, and as a result, the alignment performance of the alignment film changes. However, the display quality of the manufactured LCD may be adversely affected, and the LCD often becomes defective depending on the degree. This is likely to occur when an alignment film having a wide viewing angle or an alignment film having good light transmittance is used, which is considered to be caused by hydrolysis of water on the surface of the alignment film. The present invention has been made to solve the above problems, and after rubbing a liquid crystal substrate or a color filter substrate, the substrate after the rubbing treatment using a treatment liquid such as water or pure water An object of the present invention is to provide a cleaning method capable of preventing uneven cleaning on the surface of a substrate when cleaning the surface.

[0004]

[Means for Solving the Problems] When the surface of a polymer film formed on the surface of a liquid crystal or color filter substrate is rubbed and then the surface of the substrate is washed,
Before cleaning by jetting ultrasonic waves or high-pressure pure water, clean the substrate surface with isopropyl alcohol (CH ₃ CH (OH) CH
₃ ) Alternatively, an aqueous solution of isopropyl alcohol is caused to flow over the surface of the substrate so as to cover the entire surface of the substrate so that uneven cleaning is not generated during subsequent cleaning with water or pure water.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view of an example of a cleaning apparatus for carrying out the cleaning method according to the present invention, and FIG. 2 is a perspective view of the main part thereof.

This cleaning apparatus is composed of a pretreatment chamber 4, an ultrasonic cleaning chamber 9 and a draining chamber 14 which are successively connected.
Further, transfer rollers 3 for transferring the substrate 1 are arranged in a line between these chambers, and a group of these transfer rollers 3 constitutes a substrate transfer path. A spray pipe 2 is arranged above the transfer roller 3 in the pretreatment chamber 4. As shown in FIG. 2, the spray pipe 2 is a cylindrical pipe having a large number of nozzles 17, and the isopropyl alcohol (C
H ₃ CH (OH) CH ₃ ) or an aqueous solution 15 of this isopropyl alcohol is sprayed in a shower shape. In the figure, 5 is a tank for storing isopropyl alcohol or its aqueous solution, and 7 is a pump for pumping the liquid. If the solution is isopropyl alcohol, add 1
It is desirable to contain 0 vol% or more.

When the isopropyl alcohol or its aqueous solution 15 is sprayed onto the substrate 1 in this manner, the surface of the substrate 1 is covered with these liquids as shown in FIG. Sonic cleaning room 9
And is ultrasonically cleaned. In the figure, 10 is a pure water tank for storing pure water 16 used in ultrasonic cleaning, and 11 is a pump for pumping and pressurizing the pure water 16.
The pump 6 is positioned above the transport roller 3 by the pump 11 and supplied to the ultrasonic transducer 8.

The substrate 1 that has been ultrasonically cleaned in the ultrasonic cleaning chamber 9 is transferred to the draining chamber 14 and drained by air knives 12 and 13 provided above and below the transfer roller 3. It is transported to the next process.

In the present invention, the substrate 1 after the rubbing treatment is coated with isopropyl alcohol or its aqueous solution on the entire surface before the surface is wet with water or pure water. It is possible to prevent a hydrolysis reaction caused by being wet with pure water. Therefore, it is possible to remove only stains attached by the rubbing process without causing unevenness due to cleaning. FIG. 3 shows the experimental results of this example and comparative example.

[0010]

As described above, the present invention provides a method for cleaning liquid crystal substrates and color filter substrates after rubbing treatment.
It has an extremely practical effect of preventing uneven cleaning due to water or pure water, improving quality, and preventing defective products.

[0011]

[Brief description of drawings]

FIG. 1 is an explanatory view of a cleaning device for carrying out a cleaning method according to the present invention.

FIG. 2 is a perspective view of a main part thereof.

FIG. 3 is an explanatory diagram tabulating the results of implementation of the method according to the present invention and a comparative example.

[Explanation of symbols]

1 Substrate 2 Spray Pipe 3 Transport Roller 4 Pretreatment Chamber 5 Tank 7 Pump 8 Ultrasonic Transducer 9 Ultrasonic Cleaning Chamber 10 Pure Water Tank 11 Pump 12 Air Knife 13 Air Knife 14 Draining Chamber 15 Isopropyl Alcohol or Its Aqueous Solution 16 pure water 17 nozzles

Claims (1)

[Claims] 1. In a cleaning method of rubbing a film surface of a polymer film formed on a surface of a substrate for liquid crystal or a color filter and then cleaning the surface of the substrate, ultrasonic waves or high-pressure pure water is jetted. Before cleaning the substrate surface with isopropyl alcohol (CH ₃ CH (OH) CH
₃ ) A cleaning method after rubbing a liquid crystal substrate and a color filter substrate, wherein an aqueous solution of isopropyl alcohol is caused to flow over the substrate surface so as to cover the entire substrate surface.