JPH0963478A - Manufacture of panel for cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a cathode-ray tube which has superior electromagnetic wave shielding performance and eliminates any need of providing an undercoat on the bottom layer of a transparent conductive film. SOLUTION: In this panel 1 for a cathode-ray tube, at first, a panel glass 10 is preheated at approximately 450 deg.C. Vapor of zinc acetylacetonate is sprayed on its outer surface and ZnO film 11 is formed by a CVD method under atmospheric pressure so that a panel for a cathode-ray tube is manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a cathode ray tube panel having excellent electromagnetic wave shielding properties.

[0002]

2. Description of the Related Art A cathode ray tube is composed of a panel on which an image is displayed, and a funnel and a neck tube which are formed behind the panel.

In a cathode ray tube, an electron beam emitted from an electron gun mounted in a neck tube is deflected by a deflection coil attached around a funnel. Particularly, an unnecessary electromagnetic wave generated from this deflection coil leaks to cause a cathode ray tube. There is a risk that other electronic devices around the device may malfunction or may adversely affect the human body.

Therefore, in the conventional cathode ray tube, a transparent conductive film made of SnO ₂ or the like is formed on the outer surface of the panel in order to impart the performance of shielding electromagnetic waves.

[0005]

However, SnO ₂
Since the transparent conductive film made of, for example, has a high sheet resistance (resistance value per square) of 1 × 10 ⁶ Ω / □ or more, it has a drawback of low conductivity.

For example, as a transparent conductive film made of SnO _2, a film having a film thickness of 200 to 400 Å is generally used, but since the surface resistance of this is 1 × 10 ⁶ Ω / □, it is conductive. Is low, which is insufficient to completely shield unwanted electromagnetic waves.

There are various methods for forming such an SnO ₂ film, but since it is inexpensive and suitable for mass production, CVD (Chemical Vapor) is used.
The Por Deposition) method is widely used.

However, when the SnO ₂ film is formed directly on the outer surface of the panel by the CVD method, the heat treatment of the panel causes the alkali component in the glass to react with chlorine contained in the Sn raw material which is the chemical source, resulting in conductivity. Is damaged. In order to prevent such a reaction between the alkaline component and chlorine, an undercoat made of a SiO ₂ film may be provided as a lower layer of the SnO ₂ film, but forming such a SiO ₂ film increases the cost. It is not preferable because it becomes a factor.

The present invention has been made in view of the above circumstances, and provides a method for producing a panel for a cathode ray tube which has an excellent electromagnetic wave shielding property and which does not require an undercoat under the transparent conductive film. That is the purpose.

[0010]

The method for manufacturing a panel for a cathode ray tube according to the present invention is characterized in that a halogen-free Zn organic compound is used as a chemical source and a ZnO film is formed on the outer surface by a CVD method. To do.

Further, the present invention is preferably characterized in that the halogen-free Zn organic compound is zinc acetylacetonate, and the ZnO film has a thickness of 100 to 90.
It is characterized by having a film thickness of 0Å.

[0012]

In the present invention, a halogen-free Zn organic compound is used as a chemical source. Since this compound does not contain chlorine, it is used to form a ZnO film on the outer surface of the panel glass by the CVD method. Even if it is formed directly, the reaction with the alkaline component in the glass is suppressed, so that the undercoat made of the SiO ₂ film is not necessary.

ZnO thus formed on the panel
Film has a refractive index of substantially the same 2.0 to 2.1 and SnO ₂ film (nd), also inexpensive compared to the In ₂ O ₃ film used as a SnO ₂ film in the same manner as the transparent conductive film The performance is stable, and it is possible to obtain a sheet resistance of 1 × 10 ³ Ω / □ or less.

In the present invention, Z containing no halogen is used.
It is preferable to use zinc acetylacetonate as the n-organic compound because the reason is that if zinc acetylacetonate is used, ZnO is produced by a CVD method under normal pressure.
This is because a film can be formed. As a Zn organic compound containing no halogen, for example, dimethyl zinc, diethyl zinc, and the like exist, but when these are used as a chemical source, it is necessary to use a reduced pressure CVD method, which makes handling and equipment complicated. Become.

In the present invention, the ZnO film has a thickness of 10
It is preferable to have a film thickness of 0 to 900 Å because the reason is that when the film thickness is less than 100 Å, it is 1 × 10
This is because it becomes difficult to obtain a sheet resistance of ³ Ω / □ or less, and when the sheet resistance is more than 900 Å, the surface reflection of the panel becomes large and the image becomes difficult to see.

In order to suppress the surface reflection of the panel,
It is effective to form an antireflection film having a lower refractive index than the ZnO film. As the antireflection film, a SiO ₂ film is preferable because it is inexpensive, has high film strength, and has stable performance. The refractive index of the SiO ₂ film is
Since it is 1.46, which is lower than the refractive index of the ZnO film, it is possible to suppress reflection due to the light interference effect. As a method for forming this SiO ₂ film, any one of a spin coating method, a dip coating method and a spray coating method is suitable.
Further, the film thickness is preferably in the range of 500 to 1500Å because the surface reflection due to the interference effect of light can be minimized.

Further, by forming a SiO ₂ film having fine irregularities on such an antireflection film, diffuse reflection becomes large and conversely reflection becomes small when a light ray is irradiated from the outside. It is also possible to obtain an excellent antiglare effect. Such a SiO ₂ film can be formed by a spray coating method.

[0018]

EXAMPLES Hereinafter, a method of manufacturing a cathode ray tube panel of the present invention will be described in detail based on Examples and Comparative Examples.

(Embodiment 1) FIG. 1 is a schematic vertical sectional view showing a panel 1 for a cathode ray tube of an embodiment manufactured by the method of the present invention.

This panel glass (refractive index 1.536) 1
On the outer surface of 0, a ZnO film (refractive index 2.0) 11 having a film thickness of 270 Å is formed.

In this cathode ray tube panel 1, first, the panel glass 10 is preheated to about 450 ° C., and zinc acetylacetonate vapor is sprayed on the outer surface of the panel glass 10 to obtain a CV under normal pressure.
It was manufactured by forming the ZnO film 11 by the D method.

The sheet resistance of the thus obtained panel 1 for cathode ray tube was measured and found to be 3 × 10 ² Ω / □, which was excellent in electromagnetic wave shielding property.

(Embodiment 2) FIG. 2 is a schematic vertical sectional view showing a cathode ray tube panel 2 of another embodiment manufactured by the method of the present invention.

This panel glass (refractive index 1.536) 2
A ZnO film (refractive index 2.0) 21 having a film thickness of 270Å is formed on the outer surface of 0, and a SiO ₂ film (refractive index 1.46) 22 having a film thickness of 1000Å is formed thereon. Further, a SiO ₂ film (refractive index 1.46) 23 having fine irregularities is formed thereon.

The cathode ray tube panel 2 was manufactured as follows.

First, the panel glass 20 is preheated to about 450 ° C., zinc acetylacetonate vapor is sprayed on the outer surface of the panel glass 20, and the ZnO film 21 is formed by the atmospheric pressure CVD method.
Was formed. Next, while the panel glass 20 is preheated to about 30 ° C., while being rotated, a SiO ₂ -containing alcohol solution is dripped almost at the center of the ZnO film 21, and naturally dried and then baked to obtain SiO 2. _Two films 22 were formed. Then, on the SiO ₂ film 22, SiO
By spraying an ethanol solution containing ₂ by a spray coating method, a SiO ₂ film 2 having fine irregularities is formed.
3 was formed.

The sheet resistance of the cathode ray tube panel 2 thus produced was measured and found to be 3 × 10 ² Ω / □, which also had an excellent electromagnetic wave shielding property.

Further, with respect to the cathode ray tube panel 2 and the cathode ray tube panel (comparative example) in which no film was formed on the outer surface side, the reflectance at a wavelength of 400 to 700 nm was measured, and the result is shown in FIG. Indicated.

As is apparent from FIG. 3, the cathode ray tube panel of Example 2 has a low reflectance over a wide wavelength range and excellent antireflection properties, but the cathode ray tube panel of the comparative example is It had a high reflectance around 4.5% over the entire wavelength range.

[0030]

As described above, the panel for a cathode ray tube manufactured by the method of the present invention has an excellent electromagnetic wave shielding property and a reaction between a ZnO film which is a transparent conductive film and an alkaline component in the panel glass. Since it is suppressed, it is not necessary to provide an undercoat made of a SiO ₂ film under the ZnO film.

Further, in the present invention, by forming a film made of a low refractive index material such as SiO ₂ on the ZnO film, antireflection property is imparted, and further, SiO having fine irregularities is formed thereon. By forming _two films, it is possible to impart an antiglare effect.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a cathode ray tube panel of an example.

FIG. 2 is a schematic vertical sectional view showing a panel for a cathode ray tube of another embodiment.

FIG. 3 is a graph showing the reflectance of the cathode ray tube panels of Example 2 and Comparative Example.

[Explanation of symbols]

1, 2 Cathode ray tube panel 10, 20 Panel glass 11, 21 ZnO film 22 SiO ₂ film 23 SiO ₂ film having fine irregularities

Claims (3)

[Claims] 1. A method of manufacturing a panel for a cathode ray tube, which comprises using a halogen-free Zn organic compound as a chemical source and forming a ZnO film on the outer surface by a CVD method. 2. A halogen-free Zn organic compound,
It is zinc acetylacetonate, The manufacturing method of the panel for cathode ray tubes of Claim 1 characterized by the above-mentioned. 3. The method for manufacturing a cathode ray tube panel according to claim 1, wherein the ZnO film has a film thickness of 100 to 900 Å.