KR20120129925A - Method for manufacturing display device - Google Patents

Abstract

Provided is a method of manufacturing a display device in which a conductive film is provided on a glass substrate without using a sputtering method. The conductive polymer is applied to the surface of the glass after the chemical polishing step and the chemical polishing step of bringing the etching solution into contact with the surface of the glass substrate for display device to set the arithmetic mean roughness Ra of the glass surface to 0.7 nm to 70 nm. A film forming step of forming a conductive film of 1200 mW / sq is provided, and the total light transmittance of the glass substrate after the film forming step is 87% or more with respect to the glass substrate having a plate thickness of 0.5 mm.

Description

Manufacturing method of display device {METHOD FOR MANUFACTURING DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a display device in which a light transmissive conductive film is provided on a surface of a glass substrate.

The liquid crystal display device is constructed by enclosing a liquid crystal between abutted glass substrates constituted by a pair of glass substrates. And when static electricity charges a glass substrate, since it adversely affects the display operation of a liquid crystal, the structure which prevents electrification by providing a conductive film on the surface of a glass substrate is known (for example, patent document 1).

In general, indium tin oxide (ITO) is used as the conductive film, and the transparent electrode is formed of a film by sputtering.

[Prior Art Literature]

[Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 8-241626

However, as long as the indium constituting ITO is not only a rare metal, but also a sputtering method is adopted, there is a problem that a considerable amount of waste is produced as the target material (ITO).

Here, in the antistatic film on the surface of the exposed glass substrate exposed to the user, a low resistivity similar to that of the transparent electrode is not required, and it is interpreted as sufficient if the electrical conductivity is exhibited to the extent that the charging can be prevented.

The present invention has been made in view of the above problems, and an object thereof is to provide a method of manufacturing a display device in which a conductive film is provided on a glass substrate without using a sputtering method.

In order to achieve the above object, in the method of manufacturing a display device according to the present invention, an etching solution is brought into contact with a surface of a glass substrate for a display device, and chemical polishing is performed to set the arithmetic mean roughness Ra of the glass surface to 0.7 nm to 70 nm. And a film forming step of applying a conductive polymer to the glass surface after the chemical polishing step to form a conductive film of 400 to 1200 kW / sq, and measuring the total light transmittance of the glass substrate after the film forming step. It is characterized by setting it as 87% or more with respect to a 0.5 mm glass substrate.

In the present invention, since the arithmetic mean roughness Ra of the glass surface is set to 0.7 nm to 70 nm in the chemical polishing step, reliable adhesion with the conductive polymer can be achieved. On the other hand, if Ra <0.7nm, the glass surface is too flat, the adhesiveness of the electrically conductive film by a conductive polymer will deteriorate, and the fault which peels off easily with ethanol etc. in an adhesion test arises. On the other hand, when Ra> 70 nm and the glass surface is too rough, clear display characteristics cannot be maintained as a display device.

Moreover, in the film formation process of this invention, a conductive polymer is apply | coated to the glass surface, and the electrically conductive film of 400-1200 GPa / sq is formed. Here, the resistivity is not a volume resistivity (Volume cm) but a surface resistivity (cm / sq) = volume resistivity / film thickness per unit area (cm ² ). In the case of a transparent electrode such as a liquid crystal display device, a surface resistance value of about 5 to 40 kW / sq is required, but 400 to 1200 kW / sq is sufficient for antistatic applications. However, preferably, the glass substrate after a film formation process is set to the surface resistivity of 1000 Pa / sq or less.

In this invention, it is preferable that the HAZE rate of a glass substrate after a film formation process is set to less than 1.5% evaluated by the glass substrate of 0.5 mm of plate | board thickness. Here, HAZE rate means diffusion transmittance / total light transmittance x 100, and is a value specified based on JISK 7136.

In general, the thicker the film thickness of the conductive film, the lower the surface resistivity and the higher the conductivity. On the other hand, the HAZE rate is increased and the transparency is lowered. Therefore, in consideration of this point, the film thickness of the conductive polymer is preferably set to 100 nm to 250 nm.

Although it is preferable that the glass substrate of this invention is comprised with the alkali free glass, More preferably, it is necessary to comprise the alumino silicate glass. Moreover, although polyacetylene, polythiophene, etc. are used suitably as a conductive polymer, More preferably, a polythiophene type conductive polymer should be used.

The etching solution of the present invention is not particularly limited as long as the glass surface is appropriately roughened, but preferably contains 0.5 to 3% by weight of hydrofluoric acid, 0 to 10% by weight of hydrochloric acid, and 0 to 5% by weight of sulfuric acid. It is composed.

On the other hand, the display device of the present invention is preferably a liquid crystal display device, and the conductive polymer is formed of a film on the exposed side surface of the butted glass substrate.

According to the present invention described above, the conductive film can be formed on the glass substrate without using the sputtering method, and the antistatic film can be formed at low cost.

Hereinafter, although an Example is described, it does not specifically limit this invention.

<Notice glass>

Several glass substrates of aluminosilicate glass of 100 mm x 100 mm x 0.6 mm are prepared.

<Work order>

(1) Each glass plate was washed with water and chemically polished with an etching solution. Here, as the etching solution, various compositions were prepared, and the polishing time was also changed appropriately.

(2) After each glass plate was washed with water, it was immersed in IPA (isopropyl alcohol), substituted, and dried with the dryer.

(3) A seplegyda (Shin-Etsu polymer) which is a polythiophene-based conductive polymer was applied to the surface of the glass plate. Using a bar coater of core wires No6, No8, and No10, three groups coated with a film thickness of about 120 nm, 160 nm, and 200 nm were produced.

(4) Drying after electroconductive polymer application was performed at 150 degreeC for 10 minutes in the drying furnace.

<Evaluation of results>

(1) adhesion test

About the dried glass plate, the peeling test was performed using the cellophane tape, and the relationship with the arithmetic mean roughness Ra after the chemical polishing of each glass plate was verified.

As a result, it was confirmed that the adhesion between the glass and the conductive film was maintained when the arithmetic mean roughness Ra was about 0.7 nm to 70 nm.

On the other hand, when the composition of the etching solution and the polishing time change, the arithmetic mean roughness Ra of the glass plate after chemical polishing changes, and in general, the longer the polishing time and the higher the hydrofluoric acid concentration, the arithmetic mean roughness Ra becomes Increases.

Therefore, in view of the above tendency and workability, the etching solution consisting of 0.5 to 3% by weight of hydrofluoric acid, 0 to 10% by weight of hydrochloric acid, 0 to 5% by weight of sulfuric acid, and the remaining water is used for several minutes (1 to 1%). In the chemical polishing process of 2 minutes), it was found that etching of the glass surface by 5 mu m (single side 2.5 mu m) is appropriate.

(2) optical properties

Therefore, the total light transmittance, surface resistivity, and HAZE rate of the three groups of glass plates subjected to the chemical polishing process set under the above conditions were as follows. Here, the transmittance | permeability was measured based on JISK 7361-1 using the spectral colorimeter SD-5000 (Japan Color Industry Co., Ltd.). In addition, HAZE rate was measured based on JISK 7136 using turbidimeter NDH 5000 (Japan Color Industry). Surface resistance was measured based on JISK 7194 using Lorestar MCP-T250 (Mitsubishi Chemical).

Group 1 (No 6) 2nd group (No 8) 3rd group (No 10) Transmittance (average value) 88.5% 88.2% 87.0% Resistivity 800-1100 600-800 400 to 600 HAZE rate 0.86-1.08 0.96-1.02 1.1 to 1.5

Claims (7)

A chemical polishing step of bringing the etching solution into contact with the surface of the glass substrate for display device to set the arithmetic mean roughness Ra of the glass surface to 0.7 nm to 70 nm;
And a film forming step of applying a conductive polymer to the glass surface after the chemical polishing step to form a conductive film of 400 to 1200 Pa / sq.
The total light transmittance of a glass substrate after a film formation process was made into 87% or more with respect to the glass substrate of 0.5 mm of plate | board thickness, The manufacturing method of the display apparatus characterized by the above-mentioned. The method of claim 1,
The HAZE rate of a glass substrate after a film formation process is less than 1.5% in the glass substrate of 0.5 mm of plate | board thickness. The method according to claim 1 or 2,
The film thickness of the conductive polymer is 100nm to 250nm manufacturing method of the display device. 4. The method according to any one of claims 1 to 3,
The glass substrate is made of aluminosilicate glass. 5. The method according to any one of claims 1 to 4,
A method for manufacturing a display device, wherein a polythiophene-based conductive polymer is used. The method according to any one of claims 1 to 5,
The etching solution comprises 0.5 to 3% by weight of hydrofluoric acid, 0 to 10% by weight of hydrochloric acid, and 0 to 5% by weight of sulfuric acid. 7. The method according to any one of claims 1 to 6,
The display device is a liquid crystal display device, wherein the conductive polymer is formed on a exposed surface of a glass substrate bonded to each other by a film.