JPH06260086A - Manufacture of shadow mask - Google Patents

Abstract

PURPOSE:To manufacture a shadow mask capable of effectively preventing the occurrence of rust on the shadow mask. CONSTITUTION:After the film peeling process is completed, a shadow mask material 2 is conveyed to a rustproof liquid coating mechanism 20, and it passes between a sponge roller 24 and a sponge roller 26 impregnated with a water-soluble volatile rustproof liquid. The surface of the shadow mask material 2 is coated with the rustproof liquid. The rustproof liquid applied on the shadow mask material 2 becomes a surface protective film, and the occurrence of rust can be effectively prevented.

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 shadow mask incorporated in a color CRT or the like, and more particularly to a method capable of effectively preventing rust on the surface of the shadow mask.

[0002]

2. Description of the Related Art In a color CRT, for example, an electron gun for emitting three electron beams is provided, and each electron beam from the electron gun is directed toward a phosphor. Further, a shadow mask having a plurality of through holes formed therein is arranged between the electron gun and the phosphor, and only the electron beam in the necessary direction out of the electron beams from the electron gun passes through the through holes. While being incident on the phosphor, the electron beam in an unnecessary direction is blocked by the shadow mask.

The shadow mask has a thickness of 0.1 mm, for example.
It is a shadow mask material made of low carbon aluminum killed steel of ~ 0.3 mm in which a plurality of through holes for passing electron beams are formed, and the following processes are performed before the formation of the shadow mask and the incorporation into the color CRT. .

First, a plurality of through holes are formed in a band-shaped shadow mask material (low carbon aluminum chilled steel plate) by a photo-etching method, and then the shadow mask material is cut into an appropriate size to form a shadow mask. Then, in order to inspect whether or not the shadow mask is a non-defective product, an uninspected shadow mask is stored in a case in an appropriate number of units (for example, 2000 units). Specifically, spread rust-proof paper on the inner bottom surface of the case, stack multiple uninspected shadow masks on the rust-proof paper, stack another rust-proof paper, and insert the desiccant into the case. At the same time, seal the case. The uninspected shadow mask thus stored in the case is transported to the inspection station. For convenience of description below, a process from storing an uninspected shadow mask in a case and transporting the shadow mask to the inspection station is referred to as a “transporting process”.

At the inspection station, an inspector wearing rubber gloves inspects the shadow mask by visual inspection, and determines an appropriate unit number (10
Sheets of paper, 20 sheets, etc.) are spread with anticorrosive paper, stored in a case in the same manner as above, and shipped to a color CRT manufacturer. On the other hand, for shadow masks where rust was found on the surface in the inspection stage, after removing the rust by etching the surface with nitric acid solution etc., a predetermined treatment (water washing treatment-surface treatment with sodium hydroxide solution-water washing treatment) Then, the product is stored in a case and shipped in the same manner as above. For convenience of the following description, the process of storing the inspected shadow mask in the case, shipping it to the color CRT maker, and receiving it from the maker is referred to as “shipping process”.

On the other hand, in a color CRT maker, after the shadow mask sent in is annealed and press-molded, the shadow mask is used for the purpose of enhancing the heat radiation ability of the shadow mask and reducing the reflection of electron beams. Apply blackening treatment. Then, the shadow mask that has undergone the series of processes is incorporated into the color CRT.

[0007]

By the way, a color CR
The phosphor constituting T is formed by using the through hole of the shadow mask, and the shape of the through hole has a great influence on the shape of the phosphor. Therefore, for example, rust is generated near the through hole or on the inner peripheral surface. Then, it becomes impossible to finish the phosphor into a desired shape. Further, if rust is generated and grows on the surface of the shadow mask, it adversely affects the formation of a blackening film formed by the blackening treatment. For this reason, it is important to prevent the shadow mask from rusting. In consideration of this point, conventionally, as described above, shadow masks are laid with anticorrosive paper every suitable number of sheets and hermetically housed in a case, and then transported or shipped.

However, the conventional method cannot effectively prevent the generation of rust, and in some cases, the shadow mask is rusted in the carrying process or the shipping process. In particular, during the rainy season, it became a serious problem, and rust was generated in more than half of the shadow masks during the transportation process.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a shadow mask which can effectively prevent rust from occurring in the shadow mask. And

[0010]

According to the present invention, there is provided a film forming step of forming a resist film having a predetermined pattern on the surface of a shadow mask material, and the shadow mask material is selectively used by using the resist film as an etching mask. A shadow mask including a through hole forming step of forming a through hole by etching, a film removing step of removing the resist film after the through hole forming step, and a drying step of drying the shadow mask material after the film removing step. In order to achieve the above object, in order to achieve the above-mentioned object, an anticorrosive solution is applied to the shadow mask material after the film stripping step and prior to the drying step. It further includes steps.

[0011]

According to the present invention, a water-soluble vaporizable rust preventive liquid is applied to the shadow mask material and is adsorbed on the surface of the shadow mask material to form a surface protective film for the shadow mask material, which effectively causes rusting of the shadow mask. To be prevented.

[0012]

FIG. 1 is a diagram showing a main part of a shadow mask manufacturing apparatus to which the shadow mask manufacturing method according to the present invention can be applied. As shown in the figure, this apparatus is provided with a plurality of conveyance rollers R so that the strip-shaped shadow mask material 2 is continuously conveyed in a predetermined direction (from the left-hand direction to the right-hand direction in the figure) X. Is configured.
In addition, along the transport path of the shadow mask material 2 from the upstream side (the left-hand side in the figure) to the downstream side (the right-hand side in the figure), the etching chamber 4, the etching water washing tank 6, the water washing spray 8, the film stripping tank 10 are provided. , Peeling water washing tank 12, hot water spray 14,
Pure water washing tank 16, pure water spray 18, rust preventive liquid coating mechanism 2
0, the drying chamber 22 is arranged in this order.

FIG. 2 is a schematic perspective view showing the structure of the anticorrosive liquid coating mechanism 20. In the antirust coating mechanism 20, for example, P
VA (polyvinyl alcohol) type sponge roller 2
4, 26 are arranged so as to sandwich the shadow mask material 2 as shown in FIG. Further, a rust preventive liquid tank 28 is provided above the sponge rollers 24, 26, and a rust preventive liquid such as a fatty acid amine salt system of benzotriazole or an amine salt system of fatty acid ester, that is, a water-soluble vaporization preventive solution. A rust solution (hereinafter referred to as "water-soluble vaporizable rust preventive solution") is stored. This tank 28 includes pipes 30a,
Pumps 32a, 32b, 32c by 30b, 30c
And the pumps 32a, 32
By operating b and 32c, the rust prevention liquid tank 28
The water-soluble vaporizable rust preventive liquid in each pump 32a, 32b,
32c, then pumps 32a, 32b, 3
It is configured to be dropped on the sponge roller 24 via the pipes 34a, 34b, 34c extending from 2c.

Next, the manufacturing process of the shadow mask by the shadow mask manufacturing apparatus configured as described above will be described. First, after forming a resist film having a predetermined pattern on the front and back surfaces of the shadow mask material 2 at a processing station (not shown), the shadow mask material 2 is transferred into the etching chamber 4. Here, the resist film forming step, that is, the “film forming step” is performed as follows, as is well known in the art. That is, after the surface treatment (degreasing and washing with water) is performed on the shadow mask material 2, a photosensitive liquid (for example, a resist containing milk casein and ammonium dichromate is applied to both front and back main surfaces of the shadow mask material 2). ),
After drying, a photoresist film having a thickness of several μm is deposited. Then, contact exposure is carried out using a master pattern having an image corresponding to a through hole through which the electron beam passes,
Further, the film is developed with warm water or the like, dipped in a solution of chromic anhydride for hardening treatment, and then burned. Thus
A resist film having a pattern corresponding to the through holes is formed on both main surfaces of the shadow mask material 2.

In the etching chamber 4, an etching solution such as an aqueous solution of ferric chloride is sprayed on both main surfaces of the shadow mask material 2 on which a resist film has been deposited to form a plurality of through holes in the shadow mask material 2. To do. When the through hole forming step is completed in this way, the shadow mask material 2 is conveyed to the etching water washing tank 6 and is immersed and washed, and is further spray washed by the water washing spray 8.

Next, the shadow mask material 2 is conveyed to the film stripping tank 10. The stripping tank 10 has, for example, 90 ° C.
A 5% sodium hydroxide solution is stored, and the resist film is removed by immersing the shadow mask material 2 in this solution (this process is referred to as "film stripping process").

When the film stripping process is completed, the shadow mask material 2 is conveyed to the film stripping water washing tank 12 side and subjected to immersion cleaning,
It is spray washed with hot water (for example, 60 ° C.) from the hot water spray 14. Following that, shadow mask material 2
Is conveyed to the pure water rinsing tank 16 side, and is subjected to immersion cleaning in the pure water rinsing tank 16 and spray cleaning with the pure water spray 18 to clean both main surfaces of the shadow mask material 2 (this step is referred to as "water rinsing step". ")).

After the washing process is completed, the shadow mask material 2 is further conveyed between the sponge rollers 24 and 26. At this time, the pump 3 is previously attached to the sponge roller 24.
The water-soluble vaporizable rust preventive liquid is dripped by 2a, 32b and 32c, and the entire sponge roller 24 is impregnated with the rust preventive liquid. Therefore, when the shadow mask material 2 passes between the sponge rollers 24 and 26, the water-soluble vaporizable rust preventive liquid is uniformly applied to the surface side of the shadow mask material 2. In this way, the water-soluble vaporizable anticorrosive liquid is continuously applied to the shadow mask material 2 simultaneously with the transportation of the shadow mask material 2 (this step is referred to as "rust preventive solution applying step").

Next, when the above-mentioned rust preventive liquid application step is completed, the shadow mask material 2 is further conveyed to the drying chamber 22 side, heated to about 120 ° C. and dried (this step is referred to as "drying step"). ")).

A plurality of through holes are formed as described above,
The shadow mask material 2 carried out from the drying chamber 22 is conveyed to the next processing station, cut into an appropriate size to form a shadow mask, and then stored in the case as described above and conveyed to the inspection station. It Further, the subsequent steps are similar to those of the conventional example, and therefore the description thereof is omitted here. As described above, the rust preventive liquid on the surface of the shadow mask remains until the color CRT maker anneals it, which prevents rust on the surface of the shadow mask while the anneal treatment is performed. It is completely sublimated so that it does not affect the blackening process, which is a post process.

As described above, in this embodiment, after the film stripping process and the water washing process are completed, the surface of the shadow mask material 2 is coated with a water-soluble vaporizable rust preventive solution and adsorbed on the surface of the shadow mask material 2. Since this is done, this serves as a surface protective film, and it is possible to effectively prevent the generation of rust on the shadow mask. Further, since this rust preventive solution is water-soluble, it has good wettability with the shadow mask material and can form a uniform surface protective film.

In this embodiment, a plurality of shadow masks are stored in a case in a stacked state in the shadow mask transporting step and the shipping step, so that only one main surface (front surface) of the shadow mask material 2 is accommodated. Although the water-soluble vaporizable rust preventive solution is applied, it may be applied only to the back surface or both main surfaces.

In the above embodiment, the sponge roller 2 is used.
A water-soluble vaporizable rust preventive solution is dropped onto 4 to impregnate the rust preventive solution, and the sponge roller 24 is brought into contact with the shadow mask material 2 to apply the rust preventive solution to the shadow mask material 2. However, as in the case of the etching water washing tank 6 and the like, a coating tank containing a rust preventive liquid is provided in a subsequent step of the pure water spray 18, and the shadow mask material 2 is immersed in the coating tank, and then a sponge roller, an air knife, etc. You may make it apply | coat a water-soluble vaporizable rust preventive liquid by draining by.

The pure water washing tank 16 and the pure water spray 1
8 may be replaced with an antirust liquid tank and an antirust liquid spray.

[0025]

According to the method for producing a shadow mask according to the present invention, since a water-soluble vaporizable rust preventive liquid is applied to the shadow mask material to form a surface protective film for the shadow mask material, the shadow mask material is protected from rust. Occurrence can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a view showing a main part of a shadow mask manufacturing apparatus to which a shadow mask manufacturing method according to the present invention can be applied.

FIG. 2 is a schematic perspective view showing a configuration of a rust preventive liquid coating mechanism.

[Explanation of symbols]

 2 shadow mask

Claims (1)

[Claims] 1. A film forming step of forming a resist film having a predetermined pattern on the surface of a shadow mask material, and using the resist film as an etching mask, the shadow mask material is selectively etched to form through holes. A method of manufacturing a shadow mask, comprising: a through hole forming step; a film removing step of removing the resist film after the through hole forming step; and a drying step of drying the shadow mask material after the film removing step. A method for producing a shadow mask, further comprising a step of applying a rust preventive liquid that applies a water-soluble vaporizable rust preventive liquid to the shadow mask material after the step and prior to the drying step.