JP2001206734A - Glass substrate treating method and display device using the glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the handling of a glass substrate by suppressing the generation of the sticking phenomenon of a large scaled glass substrate to a stage. SOLUTION: The glass substrate 1 is cleaned with an acidic solution before a fine pattern is formed, then at least its one surface is roughened. It is preferable that a buffered hydrofluoric acid is used as the acidic solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a glass substrate and a display device using the glass substrate.

[0002]

2. Description of the Related Art A display device in which a fine pattern is formed on a glass substrate by using a photolithography process is used to cope with an increase in the size and cost of the display device, as represented by a thin film transistor type liquid crystal display device. The size of the glass substrate (mother glass) is becoming larger. A problem when handling such a large-sized glass substrate is sticking of the glass substrate during pattern printing.

In the photolithography process, a glass substrate is fixed to a stage of an exposure apparatus, and a pattern of a photomask is transferred to a resist by light from a light source.
By repeating the operation of adsorbing and peeling the hard glass substrate to and from the stage, the stage surface is flattened. As a result, when a certain number of sheets are processed, a phenomenon occurs in which the glass substrate sticks to the stage. This sticking phenomenon is more likely to occur as the size of the glass substrate increases. In order to prevent sticking between the stage and the glass substrate, it is necessary to periodically roughen the surface of the stage. However, in order to maintain the flatness of the stage and roughen its surface, advanced processing technology is required,
It is a heavy burden in terms of cost. In addition, stopping the production line to roughen the stage leads to a decrease in production efficiency.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to suppress the occurrence of sticking of a large-sized glass substrate and a stage and to facilitate the handling of the glass substrate. Another object is to improve the workability of the photolithography process and increase the manufacturing efficiency.

[0005]

According to a first aspect of the present invention, there is provided a method for treating a glass substrate, wherein the glass substrate is cleaned with an acidic solution before forming a fine pattern, and at least one of the glass substrates is cleaned. The surface is subjected to a surface roughening process.

According to a second aspect of the present invention, there is provided a method of processing a glass substrate, comprising the steps of:
The acidic solution is buffered hydrofluoric acid.

According to a third aspect of the present invention, there is provided a display device including, as a glass substrate, a glass substrate on which the processing method according to the first or second aspect is applied.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. First, a large size (for example, a size of 370 mm x 470 mm or more) that becomes a mother glass,
A glass substrate 1 having a thickness of about 1 mm is prepared. For this glass substrate, non-alkali glass or low-alkali glass before a coating and a fine pattern are formed is used. Next, a step of receiving and cleaning the glass substrate is performed. The receiving cleaning is usually performed by ultrasonic cleaning or brush cleaning. In addition to this, cleaning with an acidic solution is performed. As the acidic solution, a strong acid such as hydrochloric acid or sulfuric acid, hydrofluoric acid, or buffered hydrofluoric acid can be used. When a strong acid is used, the metal component in the glass melts out, and the silica forming the skeleton of the glass remains in a porous state. When hydrofluoric acid is used, silica is also eroded, so that the entire glass component is eroded. When buffered hydrofluoric acid is used, silica is eroded in the same manner as hydrofluoric acid, but a reactive component between buffered hydrofluoric acid and the eluted component precipitates to generate fine projections on the glass surface. These projections are much larger than projections formed on the glass surface when a strong acid or hydrofluoric acid is used. The surface of the glass is roughened by the presence of the protrusions, so that the surface of the glass becomes uneven including an air layer around the protrusions.

Therefore, in order to roughen the glass surface, it is preferable to form a plurality of fine projections 2 by washing with buffered hydrofluoric acid. For washing with buffered hydrofluoric acid, a method in which a glass substrate is immersed in a tank in which this solution is stored can be used, but a spray washing method is used to wash only one surface. That is, the glass substrate 1 was washed by spraying buffered hydrofluoric acid sprayed from a nozzle onto the back surface 1b of the glass substrate that was not used for film formation. The buffered hydrofluoric acid used for washing had a concentration of about 5%, and was sprayed for about several tens of seconds to roughen one surface 1b of the glass substrate.

As described above, the surface of the glass substrate 1 before the formation of the coating film can be roughened by adding a cleaning step using an acid, particularly buffered hydrofluoric acid, during the receiving cleaning step. Then, the glass substrate 1 that has been subjected to the cleaning and the surface roughening treatment is subjected to a plurality of photolithography processes for forming various coatings necessary for forming a display device and a fine processing thereof in a subsequent process. The formation of a fine pattern by the fine processing is performed on the surface 1a opposite to the surface 1b roughened in the cleaning step.

Due to the existence of the roughened surface 1b,
The sticking of the stage 3 and the glass substrate 1 in the photolithography process after the receiving cleaning step is prevented. That is, the large glass substrate 1 vacuum-adsorbed to the stage 3
When the substrate is released from the vacuum suction state and removed, the presence of the roughened surface 1b secures an air passage between the glass substrate 1 and the stage 3, so that the release of the vacuum state can be expedited. The prevention of sticking also acts to reduce the amount of static electricity generated when the glass substrate is removed from the stage. By reducing the amount of generated static electricity, the possibility that the fine wiring formed on the surface of the glass substrate is broken by static electricity can be reduced. The effect of the roughening is increased as the size of the glass substrate increases, and the present invention is applied to a large glass substrate having a short side length exceeding 300 mm, particularly a large glass substrate having a short side length exceeding 500 mm. It turned out to be effective. By subjecting one surface of the glass substrate 1 to the surface roughening treatment as described above, the surface roughening treatment for the surface of the stage 3 which had conventionally been required to be performed about once a month, We were able to reduce it about once a year.

The glass substrate 1 can be used for producing a display device. For example, a glass substrate having a desired fine pattern formed on one surface is bonded to each other with a sealing material interposed therebetween, and liquid crystal is injected between the substrates, whereby a liquid crystal display device is manufactured. The roughness of the roughened surface of the glass substrate is so small that the roughened surface is indistinguishable to the observer, and when the optical film such as a polarizing plate is attached with an adhesive. Since it is filled with the adhesive, it hardly affects the optical characteristics of the display device.

[0013]

As described above, according to the present invention, the adhesion between the glass substrate and the stage in the photolithography process can be achieved by simply adding an acid cleaning step, particularly a cleaning step using buffered hydrofluoric acid, to the initial cleaning step of the glass substrate. Can be suppressed. As a result, a reduction in the breakage rate of the glass substrate,
The throughput of the processing apparatus can be improved and the damage due to electrostatic breakdown can be reduced, which greatly contributes to the improvement in productivity.

[Brief description of the drawings]

FIGS. 1A and 1B are cross-sectional views of a main part of a glass substrate for explaining an embodiment of the present invention, in which FIG. 1A shows a state before cleaning and FIG.

FIG. 2 is a cross-sectional view schematically showing a mounted state of a glass substrate and a stage.

[Explanation of symbols]

 1 glass substrate 2 protrusion 3 stage

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takao Yamauchi 3-201 Minamiyoshikata, Tottori-shi, Tottori Sanyo Electric Co., Ltd. (72) Inventor Makoto Murakami 3-201 Minamiyoshikata, Tottori-shi, Tottori Sanyo Tottori F term in the company (reference) 2H025 AB20 DA19 EA01 2H090 JA04 JB02 JC03 JC06 JC19 2H096 AA30 CA01 CA03 4G059 AA01 AC01 BB04 BB14

Claims (3)

[Claims] 1. A method for treating a glass substrate, wherein the glass substrate before forming a fine pattern is cleaned with an acidic solution to perform a roughening treatment on at least one surface of the glass substrate. 2. The method according to claim 1, wherein the acidic solution is buffered hydrofluoric acid. 3. A display device comprising a glass substrate on which the processing method according to claim 1 has been applied.