JPH07811B2 - Method for manufacturing shadow mask material - Google Patents

Description

The present invention relates to a method for manufacturing a material for a sheer mask.

[Conventional technology]

Usually, aluminum killed steel is used as the material for the sheer mask, but recently, color cathode ray tubes are widely used for various OA equipment displays, computer terminals, and the like. In these applications, many static images are used, which causes the electron beam to locally heat the shadow mask.
The thermal expansion causes a so-called doming phenomenon in which a part of the sheer dough mask expands into a dome shape, causing a problem that the image is disturbed. In order to solve this problem, the material of the shear mask should have a small coefficient of thermal expansion, and as a material having a low coefficient of thermal expansion, nickel-iron alloy amber type alloy (hereinafter referred to as amber material) is known. Therefore, it is considered that amber material may be used as the material for the sheer mask. However, commercially available amber materials usually contain C <0.1% and Mn <0.5%, have poor perforation properties, and the corrosion rate of iron and nickel is different, so that the etching surface does not become smooth. As a result, a good hole shape cannot be obtained, and the unevenness level of the entire shadow mask is lowered.

[Problems to be solved by the invention]

Therefore, a problem to be solved by the present invention is to provide a nickel-iron alloy material for a shear mask, which can form a good hole by photo etching and can obtain a smooth etching surface.

[Means for solving problems]

As a result of research to solve the above problems, the present inventor regulated the C content to 0.001 to 0.008% by weight and the final reduction rate in the cold rolling step to 40 to 70%. It has been found that the photo-etching suitability is improved, good holes can be formed by photo-etching, a smooth etching surface can be obtained, and the unevenness level of the entire shadow mask can be improved, and the present invention was completed based on such findings. It is a thing.

Immediately, the manufacturing method of the material for the shadow mask according to the present invention,
In a method for producing a material for a shadow mask, which comprises, as a main component, nickel and iron, which are obtained by subjecting a hot-rolled steel sheet made of a nickel-iron alloy as a raw material to cold rolling and annealing one or more times to give a predetermined thickness, Of 0.001 to 0.008% by weight, and
It is characterized in that the final rolling reduction in the cold rolling process is restricted to 40 to 70%.

The production method of the present invention will be described in detail below.

As the material of the material for the shadow mask in the present invention,
Amber material which is a conventionally known nickel-iron alloy is used. Specifically, the known "36% Ni-Fe alloy" defined in the Military Standard of the United States can be used. In this case, the 36% Ni-Fe alloy contains 35 to 37% by weight of Ni, and the balance is Fe and inevitable impurities.

Nickel-iron alloy is subjected to decarburization treatment by a vacuum degassing device after melting in a converter, but various treatment conditions such as vacuum degree, molten steel temperature and treatment time are selected and the C content is 0.001 to 0.008% by weight. Adjust to. Molten steel is cast into a mold to form a hot-rolled steel strip (plate) by hot rolling, and then cold rolling and annealing are performed one or more times to obtain a predetermined plate thickness. In the cold rolling process, the final reduction rate is 40%.
Regulate to ~ 70%. The C content is regulated to 0.001 to 0.008% by weight because when the C content exceeds 0.008% by weight, the carbides in the material increase and precipitate at the grain boundaries of the etching surface during photo-etching, resulting in uneven etching surface. This is because if the C content is less than 0.001% by weight, the amount of oxygen in the alloy will be high, and the amount of oxide inclusions will be such that the perforability is impaired during photoetching. The final rolling reduction was regulated to 40-70% because at a rolling reduction of 40% or less, the crystal grain size is large, so grain boundaries will appear prominently on the etching surface during photo-etching, and the etching surface will become uneven. With a reduction rate of 70% or more, it becomes difficult to make the plate shape uniform, and after annealing in a tube maker for press molding after connecting with a shear mask, the growth of crystal grains is poor and stable press molding is performed. This is because the sex cannot be obtained.

[Operation] In the present invention, the C content of the nickel-iron alloy is 0.001 to 0.008.
It is possible to reduce carbides that are harmful to the piercing properties during photo-etching by controlling the weight percentage, and the final rolling reduction is controlled to 40 to 70% to reduce the crystal grain size and to reduce the crystal size on the etching surface. The remarkable appearance of grain boundaries is eliminated, and the etching surface becomes smooth. As a result, holes having a good shape are formed, and the unevenness level of the entire shadow mask is improved.

〔Example〕

 Next, examples of the present invention will be described.

Two kinds of nickel-iron alloys having different C contents and final rolling reductions were subjected to the photo etching process under the same conditions to compare the etching conditions. Table 1 shows the components of the two types of samples, the final reduction rate, and the like. Sample 1 has C content
0.018 wt%, final rolling reduction is 20%, but as a result of observing the etching surface of the sample under test with a scanning electron microscope, grain boundaries appear as sticking on the etching surface and the etching surface becomes uneven. It has been found. For this reason, the unevenness level of the shadow mask is getting worse. On the other hand, sample 2 which is an example of the present invention has a C content of 0.004 wt% and a final reduction rate of 55%, but the etching surface is smooth, and the unevenness level of the shed shadow mask is also improved.

(Etching conditions) A large number of large circular dot-shaped openings (0.150 m diameter) arranged in 0.25 mm pitch on one side of a nickel-iron alloy material.
m) is provided on the other surface of the first resist pattern.
A second resist pattern having a large number of small circular dot-shaped openings (0.090 mm diameter) arranged in 0.25 mm pitch was provided, and 20 Kg / cm ² was used with a 46 ° Be′FeCl ₃ corrosive liquid with a liquid temperature of 60 ° C.
Spray etching was performed from both sides with the spray pressure of No. 2, and a large number of holes having a diameter of 0.220 mm and a small hole of 0.110 mm were etched to obtain a product.

〔The invention's effect〕

As described above in detail, according to the manufacturing method of the present invention, a nickel mask for a shadow mask capable of forming a good hole by photo etching and obtaining a smooth etching surface.
An iron alloy material can be provided, thereby improving the unevenness level of the entire sheer dough mask.

Claims (1)

[Claims] 1. A method for producing a material for a shadow mask, which comprises, as a main component, nickel and iron, which are obtained by subjecting a hot-rolled steel sheet made of a nickel-iron alloy as a raw material to cold rolling and annealing one or more times to a predetermined thickness. 2. The method for producing a material for a shadow mask, wherein the C content is regulated to 0.001 to 0.008% by weight and the final rolling reduction in the cold rolling step is regulated to 40 to 70%.