JPS58145643A - Cleaning of indium-tin glass plate - Google Patents

Abstract

PURPOSE:To carry out the cleaning of a transparent glass plate coated with an In-Sn metallic film by using ultraviolet ray, thereby preventing the clarification of the above black metallic film by the cleaning process, and facilitating the patterning of the electrodes. CONSTITUTION:A glass plate 1 having a deposited In-Sn (IT) metallic film is irradiated by the ultraviolet radiation apparatus furnished with a high pressure mercury lamp 4 during the transportation with the conveyor 2. The surface of the plate 1 can be cleaned rapidly by the activity of ultraviolet ray to remove the dust and moisture from the surface of the plate 1. The temperature of the plate 1 can be suppressed to about 130 deg.C throughout the cleaning process, and the clarification of the IT metallic film by the overheating during the cleaning process can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning a glass plate formed of an oxide film of an In-5n metal film or a transparent electrode.

A liquid crystal display device is constructed by using two glass substrates and filling a gap between the glass substrates with a liquid crystal composition. Electrodes are formed on the surfaces of the glass substrates holding the liquid crystal composition in a shape corresponding to the display content in order to apply an electric field to the liquid crystal composition.

The electrode is formed of a transparent electrode at least on the side on which the display is viewed, and usually an In-5n metal oxide film (hereinafter referred to as an ITO film) is used.

The ITO film as described in item 1 is first coated with In-5n on the glass plate surface.
A metal film is deposited, and the deposited film is oxidized by firing to form a transparent conductive film.

However, when manufacturing a glass plate equipped with the above-mentioned ITO film, the glass plate surface must be kept clean, otherwise when a liquid crystal composition is sandwiched, the liquid crystal may be deteriorated or defects may appear in the display. There is a risk of causing inconvenience. Therefore, cleaning of the glass plate is performed at an appropriate stage of the manufacturing process. Conventionally, high-temperature heating has been widely used for cleaning glass substrates. Such high-temperature heating is effective in removing moisture and oil. However, as mentioned above, In-5n
When cleaning a glass plate on which metal has been deposited, the In-5n metal film is oxidized by exposing it to a high temperature heating atmosphere.
The film, which was black in its metallic state, changes to a transparent film through oxidation. Although the condition of the transparent film does not cause any problems on the glass plate of the finished liquid crystal display device, it requires more work than a black metal film when patterning the metal film into a shape that corresponds to the display content. It had the disadvantage of making it extremely difficult.

The present invention has been made in view of the drawbacks of the conventional method of manufacturing a glass plate equipped with an ITO film. A method for cleaning a glass plate is provided.

That is, the present invention cleans a glass plate on which an IT metal film is deposited by exposing it to ultraviolet light. Ultraviolet light has the effect of removing dust, moisture, etc. adhering to the surface of the glass plate. On the other hand, the temperature rise of the irradiated glass plate surface can be suppressed to about 130° C., and it is possible to prevent the IT metal film from becoming a transparent film due to baking during cleaning.

Also, the time required for cleaning is approximately 60 to 240 seconds under a mercury lamp.
Sufficient effects can be obtained with extremely short cleaning times such as EC.

FIG. 1 shows an apparatus for irradiating ultraviolet light onto a glass plate 1 on which an IT metal film is vapor-deposited. ing. A high-pressure mercury lamp 4 is installed as an ultraviolet light source in a space surrounded by the condensing reflector 3. The ultraviolet rays emitted from the mercury lamp 4 are directed toward the glass plate 1 either directly or reflected by the reflection plate 3, and quickly clean the glass plate 1 provided with the IT metal film. As shown in FIG. 3, the glass plate 1 carried by the conveyor 2 is cleaned by the ultraviolet rays 4 focused in a line from one end to the other.

During the above cleaning process, the lit mercury lamp 4 generates heat at the same time, so the space surrounded by the reflector plate 3 is removed from the outside to cool the mercury lamp 4 and to remove ozone, which is generated by the emitted ultraviolet rays. Exhaust hole 5 for communicating with
2 (a), (1)), which will be explained next.
As shown in the figure, an exhaust fan 6 is installed.

FIGS. 2(a) and (+) are a side view and a front view showing the overall appearance of the cleaning device equipped with the ultraviolet irradiation section, in which the ultraviolet irradiation section shown in FIG. 1 is inside the outer cover 7. It is stored.

Since the glass plate cleaned by ultraviolet irradiation is not exposed to high temperatures, the IT film remains as a metal film, and therefore has a black color. Next, it is patterned into a shape corresponding to the electrode pattern by a conventionally known process, and after pattern etching, it is fired at a high temperature to oxidize the metal and become IT.
A transparent conductive film of O is created. The glass plate provided with the above-mentioned ITO film can be used not only for liquid crystal display devices but also as an electrode substrate for ECDs and the like.

As described above, by cleaning the glass plate on which the IT film is formed using ultraviolet light, the glass plate on which the IT film is formed can be cleaned at a low temperature, the IT film can be maintained in the state of a metal film, and the metal film can be cleaned at a low temperature. Since it is black, it is easy to observe and the subsequent electrode patterning work is significantly facilitated.

[Brief explanation of drawings]

FIG. 1 is an enlarged view of the main parts of a cleaning device for carrying out the present invention, FIGS. 2(a) and (b) are a side view and a plan view of the same cleaning device, and FIG. 3 is a diagram showing the state of ultraviolet irradiation. It is. 1: IT film coated glass plate, 4: Mercury lamp.

Claims (1)

[Claims] 1 Create In-5rJ4: allantoic film on the surface of a transparent glass plate,
A method for cleaning an IT glass plate, characterized in that the glass plate surface coated with the In-5n metal film is cleaned by exposing it to ultraviolet light.