JPH0646540B2 - Method for forming light absorbing film of color cathode ray tube - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for forming a light absorption film on a fluorescent surface of a color cathode ray tube.

[Prior Art] At present, a fluorescent screen of a color cathode ray tube is a Bratzmatrix fluorescent screen in which the light emitting area of the fluorescent material is limited by a light absorbing film such as a graphite film to improve the contrast of the fluorescent screen. Has been adopted. An example of the method of manufacturing the Brackmatrix phosphor screen will be described.

First, the inner surface (1a) of the glass panel (1) forming the phosphor screen of FIG. 2 (a) is washed with caustic soda and ammonium fluoride, and after this washing, rinsed with pure water and dried. Before drying, a very thin solution of polyvinyl alcohol may be sprayed and dried to form a precoat film. Then, a photosensitive resin such as a resist solution containing polyvinyl alcohol and dichromate as main components is applied by spin coating. The resist solution is dried to form a photoresist film (2).

In the next exposure step, a glass mask (1) is attached with a shadow mask (3) as a color selection electrode, and a shutter (7) is opened / closed via a correction lens (4), a light quantity adjusting filter (5), etc. Then, the mercury lamp (6) is sequentially exposed for a certain period of time at the position where the phosphor is to be formed, thereby forming a latent image on the photoresist film (2).

Next, at the position where development is to be performed and the phosphor is to be deposited,
As shown in FIG. 2B, a resist dot or a resist stripe which is a resist film pattern (2a) is formed. After drying the resist film pattern (2a), a solution of a light absorbing substance such as a graphite solution is applied onto the resist film pattern (2a) and dried to form a graphite film (9).

After this drying, the graphite film (9) is sufficiently dried and heated, and then an oxidizing agent such as 10% hydrogen peroxide solution is injected into the inner surface of the glass panel (1) to form the resist film pattern (2).
Chemically decompose a). Chemically decomposed resist film pattern (2a) and graphite film applied on it
(9) is peeled off from the glass panel (1) in the next strong development step. As a result, as shown in FIG. 2 (c), the graphite film (9) is left at a position other than the position where the phosphor is deposited and emits light, and the remaining graphite film (9) serves as a light absorbing film. It becomes a black stripe (9a).

Furthermore, it was attached to the skirt of the glass panel (1),
The graphite film (9) in the unnecessary area is removed and shaped by etching the glass surface with an aqueous solution of ammonium fluoride, and finally, washing and drying are carried out to complete the formation of the Brackmatrix.

Thereafter, similarly to the formation of the resist stripe (2a), the steps of coating, exposing, and developing are repeated for the phosphor slurries of the three primary colors, that is, green, blue, and red, and the second step is performed.
As shown in FIG. 3D, a phosphor screen on which the three primary color phosphor stripes (10) have been deposited is formed. In addition, each of the above steps,
The carrier for fixing the glass panel (1) is sequentially moved in a predetermined cycle time to a manufacturing process in which a carrier is formed into a loop.

For example, the cleaning process of the inner surface (1a) of the glass panel (1) shown in FIG. 3 with a glass etching agent is similar, and the glass panel (1) is fixed to the carrier (60). Each washing step is usually performed at 7 to 8 positions, and an example is shown in FIG. That is, in each cleaning position, the pump (62) is fed from the chemical tank or pure water tank (61) shown in FIG.
A cleaning liquid such as a chemical liquid or pure water (63) pressurized with is sprayed from several nozzles (64) in a short time, and the inner surface (1a) of the glass panel (1) is heated with hot water (73), caustic soda (71), Sequential cleaning with a solution of oxygen (72).

[Problems to be Solved by the Invention] In the above method for forming a light absorbing film, as shown in the enlarged view of the inner surface (1a) of the glass panel (1) in FIG. Partial blockage (81) occurs, which significantly reduces product quality and manufacturing process yield.

A detailed analysis of the cause of this deficiency (81) suggests that there is one cause in the manufacturing process, and various experiments and studies were conducted. As a result, it was discovered that there was a foreign substance that had adhered to the inner surface (1a) of the glass panel (1) from the beginning, and that there was a foreign substance that could not be removed by the cleaning process. As a countermeasure against this, it was found that the inner surface (1a) of the glass panel (1) is removed by wiping soft sponge or chamois moistened with water under pressure. By carrying out this, the defects (81) caused by the foreign substances are considerably reduced. However, such a manual work not only reduces the productivity of the cathode ray tube but also causes a variation in the work.
There is a problem that the quality and the yield are not sufficiently improved because the removal is insufficient or, on the contrary, the inner surface is scratched.

The present invention has been made in view of the above points, and provides a method for forming a light absorption film that is less likely to cause a decrease in manufacturability and that can significantly improve the quality and yield of color cathode ray tubes. Is intended.

[Means for Solving the Problems] In order to achieve the above object, the present invention firstly sprays water having a pressure onto the inner surface of the glass panel at least before forming the photoresist film. There are processes. The pressure of the jet water is set to 60 kg / cm ² or more.

[Operation] According to the present invention, the inner surface of the glass panel is 60 kg / cm ²
Since it is washed with the jet water having the above pressure, foreign matters are removed.

Also, because it is due to water spray, unlike manual work,
It is less likely to cause a decrease in manufacturability and does not damage the inner surface of the glass panel. Further, since the cleaning can be performed under a constant pressure, there is no fear that the removal will be insufficient.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a cleaning device. Carrier (60)
Supports the glass panel (1) at an angle θ with respect to the vertical line A and is rotated by a motor (65). Therefore, the glass panel (1) rotates at a constant speed. The angle θ is, for example, 75 °, but it may be 0 °.

(11) is a pump for cleaning water (13) in the main tank (12)
The air is sucked in through the second filter (14) and the pipe (15) and ejected from the nozzle (16). Reference numeral (17) is a cleaning water supply pipe, and (18) is a heater for keeping the temperature of the cleaning water at 15 to 40 ° C. It should be noted that if the temperature is close to 60 ° C. to 70 ° C., it is not preferable in terms of durability of the pump (11) and the like.

In the cross section including the center line C of rotation of the carrier (60), the jet angle θ1 of the high-pressure jet water (13A) from the nozzle (16) is 2
It is set at 5 °. The nozzle (16) injects high-pressure water (13A) in a range from the center (1b) of the inner surface (1a) of the glass panel (1) to one end (1c). Therefore, when the glass panel (1) rotates once, the high-pressure jet water (13A) is jetted onto the entire inner surface (1a) of the glass panel (1). Here, the injection angle θ1 is preferably 15 ° to 45 °. The reason is that if the injection angle is smaller than 15 °, the above center (1
This is because the range from b) to the end (1c) cannot be jetted, and when the jet angle is larger than 45 °, the surface pressure of the high pressure jet water (13A) on the glass panel (1) becomes too small.

High-pressure jet water (13A) that contacts the center (1b) and this center
The angle θ2 formed by the tangent to the inner surface (1a) of the glass panel (1) in (1b) is preferably set in the range of 20 ° to 45 °, for example. The reason is that if the angle θ2 is smaller than 20 °, the surface pressure becomes too small.
This is because the injection range becomes too narrow when the angle θ2 is larger than 45 °.

The injection pressure from the nozzle (16) is set to 60 kg / cm ² or more. The reason is that if it is less than 60 kg / cm ² , a sufficient cleaning effect cannot be obtained.

The injection pressure is preferably in the range of 100 kg / cm ² to 110 kg / cm ² . The reason is that at 100 kg / cm ² or more, the cleaning effect does not differ much, but the durability of the pump (11) decreases.

(19) is a cover that prevents the high-pressure jet water (13A) from scattering,
It is intended to improve the recovery rate of high-pressure jet water (13A) and prevent the work environment from deteriorating. (20) is a sub-tank, which is washing water that drops from the drain port (19a) of the cover (19).
(13) is collected. This sub-tank (20) has a first filter (21) at the top, and a glass panel
The foreign matter removed from (1) is filtered out. The sub tank (20) communicates with the main tank (12) and supplies purified cleaning water (13) to the main tank (12).

Next, the operation of the above configuration will be described.

First, the glass panel (1) is conveyed to this cleaning position by the carrier (60). After this conveyance, the motor (65) is rotated, the glass panel (1) is rotated, and the pump (11) is activated, so that the high-pressure jet water (13A) is applied to the inner surface (1a) of the glass panel (1). Is jetted. This makes the glass panel
The inner surface (1a) of (1) is washed to remove foreign matter. The removed foreign matter is removed by the first filter (21), and purified cleaning water (13) is supplied to the main tank (12).

After the above washing, the glass panel (1) is transferred to the next washing step, and is washed with a glass etching agent such as caustic alkali hydrofluoric acid or ammonium acid fluoride as in the conventional step. The subsequent steps are as described in the conventional example, and the description thereof is omitted.

In the above-mentioned configuration, since the present invention cleans with the high-pressure jet water (13A), unlike the manual work, the workability of the cleaning is good, and therefore the productivity of the cathode ray tube does not decrease. Further, since it is not a manual work, there is no risk of variations in the cleaning state, so there is no risk of insufficient removal of foreign matter or damage to the inner surface (1a). Therefore, the quality and yield of the cathode ray tube are greatly improved.

By the way, in this embodiment, the injection angle θ of the high-pressure jet water (13A) is
1 is one end (1c) from the center (1b) of the glass panel (1)
It is set in the range up to. Therefore, by rotating the glass panel (1) with the motor (65), the inner surface (1a) of the glass panel (1) can be automatically cleaned.

By the way, in this example, high-pressure jet water (13A) was used for cleaning before cleaning with the above-mentioned etching agent. But,
In the present invention, cleaning with high-pressure water jet (13A),
It may be performed at least before forming the photoresist film.

Needless to say, the number of nozzles (16) and the components of the cleaning water (13) may be set appropriately.

[Effects of the Invention] As described above, according to the present invention, the inner surface of the glass panel is washed with high-pressure jet water of 60 kg / cm ² or more before at least the photoresist film is formed. The quality and yield of the color cathode ray tube can be significantly improved without inviting it.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a cleaning device according to the present invention, and FIG.
(a) to FIG. 2 (d) are longitudinal sectional views showing a conventional manufacturing process of the Brackmatrix phosphor screen, FIG. 3 is a schematic configuration diagram of the cleaning device, FIG. 4 is a block diagram showing the cleaning process, and FIG. FIG. 5 is a plan view of a glass panel showing a conventional defect. (1) …… glass panel, (1a) …… inner surface, (2) …… photoresist film, (2a) …… resist film pattern, (9a) …… light absorbing film (black stripe), (13A) …… (High pressure) water spray. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A step of cleaning an inner surface of a glass panel of a color cathode ray tube with a glass etching agent, a step of forming a photoresist film made of a photosensitive resin, and a step of exposing and developing the photoresist film to form a resist film pattern. A color having a step of forming, a step of applying a solution of a light absorbing substance to the inner surface of the glass panel on which the resist film pattern is formed, and a step of disassembling and removing the photoresist film to form a light absorbing film. A method for forming a light-absorbing film for a cathode ray tube, which comprises a step of spraying water having a pressure of 60 kg / cm ² or more onto the inner surface of the glass panel at least before forming the photoresist film. Method for forming light absorption film of cathode ray tube.