KR100429198B1 - method for forming light absorption layer in panel for color CRT - Google Patents

Abstract

The present invention can significantly improve the contrast characteristics by increasing the light absorption rate, and can prevent the phenomenon that the light absorption layer having the thickness acts as a partition wall to spread to other phosphor positions when the phosphor layer is formed by a printing method. The present invention relates to the formation of a light absorption layer on a panel for a color cathode ray tube with an improved production yield due to simplicity.

According to the constitution, the light absorbing layer, the phosphor layer, and the resin film for forming the metal reflecting film are formed on the inner surface of the cathode ray tube, and the light absorbing material and the photosensitive agent mixture are applied to the panel to form a film, followed by exposure to alkali solution. This invention relates to a light absorbing layer for color cathode ray tubes, characterized in that a light absorbing layer having a film thickness of 1 to 10 µm is formed by the step of developing.

Description

Method for forming light absorption layer in panel for color CRT}

The present invention relates to the formation of a light absorbing layer on the panel for color cathode ray tubes, and in particular, by reducing the number of light absorbing layer forming process, by greatly adjusting the thickness of the light absorbing layer to increase the light absorption, and greatly improve the contrast characteristics by a printing method. When the phosphor layer is formed, the light absorbing layer having the thickness serves as a partition wall to prevent the phenomenon of spreading to another phosphor position, and the light absorbing layer structure suitable for improving the production yield by increasing the margin of the process and a method of forming the same will be.

Conventional color flat cathode ray tube is a panel (2) is fixed to the wide glass (1) having explosion-proof characteristics on the front surface as shown in Figure 1 and the funnel (3) and the funnel (fused to the front surface of the panel 2) ( 3, red, green, and blue phosphors are coated on the inner surface of the panel 2 and the electron gun 5 for emitting three electron beams 4 enclosed in 3) toward the panel 2; There is a phosphor layer 6 that emits each color by an electron beam, and the panel 2 is supported by a tensioned shadow mask 7 having numerous pores in the shape of pores to maintain a constant distance from the inner surface of the panel 2. It is comprised by the rail 8 shown. And the outside of the panel and the safety glass is covered with a band (9) to seal.

In the planar cathode ray tube configured as described above, when power is applied to the cathode of the electron gun 5, the generated R, G, B electron beams are accelerated and focused while passing through the accelerating electrode and the focusing electrode of the electron gun, and then The image is reproduced by passing through the beam passage of the shadow mask 7 in a state of deflection in the horizontal or vertical direction by the magnetic field and hitting the phosphor layer 6 applied on the inner surface of the panel 2 to emit light.

Meanwhile, in the planar cathode ray tube, a light absorption layer is formed on the inner surface of the panel to prevent diffuse reflection by external light and to absorb external light to increase color purity of each phosphor. Then, a phosphor layer for reproducing an image is formed thereon, and then a resin film is formed on the phosphor layer to form a metal reflection film for increasing phosphor emission luminance.

After the resin film is sufficiently dried, a white metal reflective film is formed on the rear surface by vacuum deposition.

Figure 2 is a conventional light absorbing layer forming process chart, after washing the inner surface of the panel with a detergent, pure water, air (water), etc. and then evenly dispersed by injecting the photosensitive liquid 10 as shown in Figure 2 (a). It is rotated at high speed to form a uniform film thickness on the inner surface of the panel and dried. At this time, the photoresist in a liquid state is carried over the rails 9, and the photoresist is buried and dried. After drying to an appropriate temperature, the light is irradiated onto a uniform pattern as shown in FIG. 2 (b), and then double exposure to block the inner surface of the rail (effective screen portion) and irradiate light to the actual surface area as shown in FIG. Do it.

Then, only the effective screen portion and the surface sensitizer, which are developed with water and absorb light by the photocuring action as shown in FIG. 2 (d), remain. Subsequently, as shown in FIG. 2E, the light absorbing material solution 11a is injected and rotated at high speed to form a uniform film thickness and dried. In this case, too, the light absorbing material liquid is dried over the rail and buried in the real surface. After drying to an appropriate temperature, the etching liquid 12 is injected thereon, and the etching liquid penetrates into the film to absorb light and chemically react with the remaining photosensitive layer. Wet it enough to cause it, and if it is actually wet, immerse it with etching solution.

Then, it is developed as water to form a light absorbing layer 11 having a predetermined pattern as shown in FIG. 2F, and the light absorbing material on the surface is also removed through chemical reaction with the photosensitive layer in the developing process. Subsequently, after forming the light absorption layer and forming the R, G, and B phosphor layers thereon, two methods are used. First, the phosphor layer is formed by using a spin method in which a phosphor is applied to a panel and exposed. Method 2 and method 2 are a method of forming a phosphor layer using a screen printing process as shown in FIG.

Referring to the method of forming the phosphor layer using the screen printing process, the screen on which the green phosphor layer 6G pattern to be formed is formed on the panel 2 on which the light absorbing layer 11 is formed, as shown in FIG. 4. The green phosphor layer 6G is formed on the light absorbing layer 11 when the mask 13 is placed and the green phosphor paste 14 is pushed to the glass panel by applying a predetermined pressure using the squeegee 15. The blue phosphor layer 6B and the red phosphor film 6R are also formed in the same manner as described above.

When the above method is used, the amount of phosphor used can be reduced, and the phosphor layer can be formed more simply, so that economic production is possible.

However, the conventional light absorbing layer forming method has to go through a complicated process as shown in FIG. 2, and causes various defects during the process and increases the manufacturing cost due to the use of many equipment and materials in manufacturing. When the absorption layer is formed, the chemical reaction between the double exposure and the etching solution is used to remove the photoresist and the light absorbing material on the surface, but it is not completely removed and must be manually washed again.The cleaning solution splashes into the effective screen part during re-washing by hand. If not completely cleaned, such as causing a problem that is mixed with the slurry to cause a defect due to the foreign matter.

In addition, when the light absorbing material is not completely removed, welding defects occur when the shadow mask is welded after forming the metal reflection film, and when the panel and the funnel are fused with the frit glass, the fusing leak occurs and the shrinkage occurs in the exhaust process. There is a fatal problem, and there are problems such as a decrease in production yield and an increase in processing cost.

In addition, if foreign matter enters the inside of the panel during cleaning, foreign matter does not come out after the shadow mask welding, which causes fatal problems such as mask clogging and electron gun stray defect in the post-process.

In addition, when the film is formed by the conventional light absorbing layer forming method, it is impossible to form the film thickness of the light absorbing layer more than 1 μm. This is because first, after forming a photoresist film pattern, a liquid containing a light absorbing material is injected and rotated thereon to form a constant film thickness, and then a material for etching through the chemical reaction with the photoresist film is injected thereon for a sufficient time. The photoresist film and the etchant should be chemically reacted. And then sprayed with water at a pressure of 5kg / cm ² to form a light absorption layer film.

If the light absorbing layer on the photoresist film is formed to be 1 μm or more, the etching is not performed, and thus the light absorbing layer may not be formed, and thus the current film thickness is about 0.5 μm. When the phosphor layer is formed by a printing method on the light absorbing layer having a thickness of about 1 μm or less, the phosphor layer 6 printed as shown in FIG. 5B crosses the light absorbing layer 11 having a thickness of 1 μm or less to another color. There are many cases of smearing, which makes it difficult to print precisely in its own position, and the production margin is reduced due to reduced process margin. If invaded into the other phosphor region as described above it is mixed with other phosphors causing a fatal problem in the color of the cathode ray tube.

This phenomenon causes more and more problems toward the high-definition cathode ray tube, and eventually it becomes impossible to form the phosphor layer by the printing method.

The present invention is to solve the above-mentioned problems, the process of reducing the light absorbing layer forming process, and by adjusting the thickness of the light absorbing layer to greatly increase the light absorption rate to significantly improve the contrast characteristics when forming the phosphor layer by printing method The purpose of the present invention is to obtain a light absorbing layer having improved production yield by simplifying the process diagram, such that the light absorbing layer having the thickness serves as a partition wall and prevents the phenomenon of spreading to another phosphor location.

1 is a structural diagram of a color cathode ray tube

Figure 2 is a conventional light absorption layer forming process diagram

3 is a light absorption layer forming process chart of the present invention

4 is a view of forming a fluorescent film using screen printing

5A is a state of forming a fluorescent film according to the light absorption layer thickness (1 to 10㎛)

5B is a view illustrating a fluorescent film forming state according to a light absorption layer thickness (0.5 μm)

Explanation of symbols for main parts of the drawings

2 panel 16 light absorption layer

In order to achieve the above object, the present invention provides a light absorbing layer, a phosphor layer, and a resin film for forming a metal reflective film on an inner surface of a cathode ray tube, wherein the film is formed by applying a light absorbing material and a photosensitive agent mixture to a panel to form a film. The light absorbing layer is formed on the cathode ray tube panel, wherein the light absorbing layer has a uniform pattern.

Figure 3 shows the light absorbing layer forming process of the present invention, first clean the inner surface of the panel using the cleaning chemicals, and then the panel is mounted on the rotating equipment and slowly rotating while injecting a light absorbing material liquid (16a) containing a photosensitive agent After a certain time, the film is formed by rotating with a rotational force capable of forming a desired film thickness (FIG. 3 (a)).

In general, the film thickness of the light absorption layer has the best cathode ray tube characteristics at 0.1 to 50㎛, and the film thickness is determined by the characteristics of the liquid including the light absorption liquid and the rotational force to form the film. The film thickness in the present invention is used by adjusting the characteristics and rotational force of the light absorbing layer liquid so as to form a light absorbing layer between 1 and 10 mu m. The light absorbing material used in the present invention applies to those known in the art.

Following the above process, the light absorbing layer should be infrared dried to dry quickly without damaging the light absorbing layer material. If the drying is delayed, the uniformly formed film thickness is changed to cause exposure failure due to film unevenness during exposure, so that a uniform light absorbing layer pattern cannot be formed. In addition, rapid drying causes cracks due to heat of the photosensitizer in the light absorption layer, and thus a film having a uniform pattern cannot be obtained.

After sufficiently drying as above, it is placed on the glass on which a constant pattern is formed and irradiated with light to perform exposure (FIG. 3B). It exposes using the light quantity of about 100-1000m J / cm <2> at the time of exposure. The panel temperature during exposure has a big influence on the pattern width and should be managed thoroughly. Exposure is performed between 30-50 degreeC which is normal temperature.

The exposed panel is then sprayed with a constant pressure of alkali solution to develop. At this time, the temperature and spray pressure of the alkaline solution is an important factor for forming the light absorption layer and needs to be properly adjusted to form a uniform film.

After developing with an alkali solution as described above, the light absorbing layer 16 having a constant pattern is formed by heating and drying with a heater (FIG. 3C), and then R, G, and B fluorescent films are formed thereon.

The reason why the thickness of the light absorption layer film cannot be formed by 1 μm or more in the existing process is that, as shown in the conventional process of the above-mentioned limit 2, first, after forming the photoresist film pattern, the liquid containing the light absorbing material is injected thereon and rotated. It should be formed to a certain film thickness, and the material to be etched through the chemical reaction with the photoresist film is injected thereon to give sufficient etching time to cause the chemical reaction between the photoresist film and the etching solution. When the light absorbing layer on the photoresist film is formed at 1 μm or more, the etching reaction is not performed, and thus the light absorbing layer formation itself is impossible.

On the other hand, when the thickness of the light absorbing layer is formed to be 1 μm or less, when the phosphor layer is formed by the printing method, the phosphor layer often crosses the light absorbing layer and spreads to other colors. Production yield is lowered. In addition, as shown in FIG. 5B, when invading into another phosphor region, the mixture is mixed with other phosphors, causing a fatal problem in color implementation of the cathode ray tube.

When the light absorbing layer thickness is formed to be 10 μm or more, the light absorbing layer thickness is not exposed to the bottom of the light absorbing layer during exposure, and thus pattern formation is impossible. In the present invention, the light absorbing layer thickness is 1 to 10 μm.

As described above, according to the present invention, as the thickness of the light absorption layer is formed to 1 to 10 μm, the phosphor layer may be printed so as not to invade to another position between the light absorption layers, and the margin of the process may be increased, including R, G, When forming the B phosphor layer, the light absorbing layer may serve as a partition wall to improve the printability and to prevent invasion of other colors to prevent defects.

As described above, the present invention forms a film by applying a light absorbing material and a photosensitive agent mixture to a panel, and forms a thick light absorbing layer by a simple process such as developing with an alkali solution, thereby greatly improving the light absorption and improving the contrast characteristics. In addition, when the phosphor layer is formed by printing, the light absorbing layer having the thickness acts as a partition wall to prevent the phenomenon of spreading to another phosphor position, and the light absorbing layer is applied to the panel for color cathode ray tube with improved production yield by simplifying the process diagram. Can be formed.

Claims (3)

In a color cathode ray tube having a light absorption layer, a phosphor layer and a metal reflection film formed on an inner surface of a panel, The light absorption layer structure for a color cathode ray tube, characterized in that the thickness of the light absorption layer is 1 ~ 10㎛. In the light absorption layer, the phosphor layer and the metal reflective film formed on the inner surface of the panel of the cathode ray tube, Rotating the panel mounted on the rotating equipment while applying a light absorbing material mixture containing a photosensitive agent to the inner surface of the panel while applying to form a light absorbing coating layer, followed by drying, irradiating and exposing light, spraying alkaline solution And developing to form a light absorbing layer having a thickness of 1 to 10 μm after drying. The method of claim 2, The phosphor layer is formed by the screen printing method, characterized in that the light absorbing layer for forming a color cathode ray tube.