JPH059658A - Shadow mask material having excellent etchability - Google Patents

Abstract

PURPOSE:To offer a shadow mask material suppressing side etching and ensuring a uniform shape for holes through which electron beams are passed. CONSTITUTION:This shadow mask material having excellent etchability is an Fe-Ni alloy sheet having a higher rate of aggregation of {100} crystal faces in the central part of the sheet in the thickness direction than in the surface of the sheet. The rate of aggregation of {100} crystal faces in the central part is preferably >=30%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask material excellent in etching processability used for a shadow mask used for a display device such as a television or a computer.

[0002]

2. Description of the Related Art Aluminum-killed steel, Fe-Ni alloy and the like are used as shadow mask materials used for display devices for televisions or computers. Of these, Fe-Ni alloys containing about 36% by weight of Ni (including so-called Invar alloys and their improved alloys)
Has a particularly small coefficient of thermal expansion and can accurately maintain the positional accuracy of many through-holes that pass through the electron beam formed in the shadow mask, regardless of temperature. It is promising as a shadow mask material for computer display devices and the like that require images. To obtain a high-definition shadow mask,
Through holes having a small pitch and a uniform shape must be formed in the shadow mask material by etching. Fe
The etching property of Ni-based alloys has hitherto been noted as an important technical problem. For example, JP 61-82453 A discloses that the carbon content is restricted to 0.01% or less. Further, JP-A-84356 discloses that the etching property can be improved by controlling non-metallic inclusions. Further, in JP-A-61-19737, attention is paid to the crystal orientation and etching property of the surface of the shadow mask material, and by gathering 35% or more of {100} crystal planes on the surface of the shadow mask material, uniform etching can be achieved. It is disclosed that a through hole having a different shape can be obtained.

[0003]

The etching of the shadow mask material is usually performed from both the front and back sides. As mentioned above, it is the etching property of the shadow mask material that has undergone various improvements, but when etching progresses from the front and back of the shadow mask material, it is etched in a mortar shape from the mask surface as shown in Fig. 2. There is a problem of so-called side etching in which the surface 2 expands. With such side etching, irregular reflection 4 of the electron beam 3 is likely to occur on the etching surface, and color misregistration may occur. Further, the intersection of the etching holes from the front and back of the shadow mask material becomes the electron beam passage hole 1. Therefore, if the side etching is large, the edge of this passage hole becomes an acute angle and the shape of the passage hole 1 varies. There was a problem that occurs. An object of the present invention is to provide a shadow mask material in which the side etching described above is reduced and the electron beam passage hole shape is made uniform.

[0004]

The present invention is based on the result of studying that the etching rate of the central portion in the plate thickness direction is made faster than the surface of the plate in order to reduce the side etching of the Fe-Ni alloy. Is. When an Fe-Ni-based shadow mask material is manufactured, a considerably large amount of cold working (so-called cold rolling) is performed. Of the recrystallized aggregate composition generated at this time, only the surface layer portion is the central portion of the plate thickness. It was found that the etching uniformity was significantly improved by changing the crystal orientation to different ones. That is, according to the present invention, the etching workability is characterized in that the aggregation ratio of {100} crystal faces of an alloy thin plate made of an Fe-Ni alloy is larger in the central portion in the plate thickness direction than in the surface of the thin plate. It is an excellent shadow mask material. The greatest feature of the present invention resides in that the etching rate of the central portion of the shadow mask material is made relatively faster than the etching rate of the surface of the shadow mask material by aligning the crystal plane of the central portion of the shadow mask material with a specific orientation. As a result, the shape of the through hole formed by etching is such that it does not spread much in the plate thickness direction, diffused reflection of the electron beam can be prevented on the etching surface, and the shape of the electron beam passage hole becomes uniform. The shadow mask material of the present invention is manufactured, for example, as follows. Fe
-Ni-based alloy material is hot-rolled, then cold-rolled to give uniform strain to the material, and then recrystallized,
By adopting a recrystallized texture, the entire material has a cubic direction, that is, the crystal orientation of the plane parallel to the rolling surface is {100}.
Align. Further, by subjecting this material to light reduction rolling (for example, skin pass rolling), only the surface portion of the material is given a working action, that is, a local rotation of the crystal grains, and {100}
The gathering rate of crystal planes is reduced on the material surface, and the gathering rate is relatively higher in the central portion. In the present invention, the Fe-Ni alloy thin plate having a thickness of {1
It is preferable that the collection ratio of (00) crystal faces is 30% or more. This is because the aggregation ratio of {100} crystal faces in the center is 3
This is because the effect of increasing the etching rate at the center of the plate thickness can be clearly confirmed by setting it to 0% or more.

[0005]

EXAMPLES Examples of the present invention will be described in detail below. Fe containing 36% by weight of Ni and the balance Fe
-Ni alloy (so-called Invar alloy) ingot was hot-rolled and cold-rolled, and in the final cold-rolling step, thin plates having the thicknesses of Samples No. 1 to No. 5 shown in Table 1 were prepared. This was finally annealed at 800 ° C. X-ray diffraction analysis was performed on the obtained collection rate of the {100} planes of the material after the final annealing and the collection rate of the {100} planes of the etched surface of the central portion of the material obtained by etching this material from the surface. Sought by. The results are shown in Table 1. Sample No. 1 from this same material
Materials No. 3 to No. 5 were prepared, skin pass rolling was performed to a plate thickness of 0.15 mm, and then strain relief annealing was performed at a temperature not higher than the recrystallization temperature to obtain a shadow mask material.

The shadow mask material obtained by light reduction rolling is also the same as in Table 1, and the {100} of the surface and the central part
The collection ratio of faces was calculated. The results are shown in Table 2. For the shadow mask materials of Samples No. 1 to No. 5, the shadow mask material 5 was masked with 0.3 mm round holes so that the front side and the back side were aligned with each other, and then etching treatment was performed to measure the shape of the through holes. In the comparative example, the sheet thickness of 0.15 mm was obtained by the final rolling without performing the skin pass rolling (Sample No.
4) and a large reduction in the skin pass rolling process (Sample No. 5), which are also shown in Tables 1 and 2.
Electron beam passage hole 1 shown in FIG. 1 for these materials
Was measured, and d1 corresponding to the maximum diameter of the etching start surface was measured. Table 2 shows these results and the values of d1 / d2. Note that these values are averages of 20 points. Samples No. 1 to No. 3 in Table 2 are examples of the present invention, and the shadow mask material of the present invention has a large ratio (d1 / d2) of the maximum diameter of the etching start surface to the electron beam passage hole, and diffuse reflection of the etching surface. It can be seen that can be reduced. Further, the variation of the maximum diameter d1 of the electron beam passage hole 1 was 4 to 5% in the comparative example, but was 3 in the present invention example.
% Or less, and it was confirmed that etching with extremely high precision was possible.

[0007]

[Table 1]

[0008]

[Table 2]

[0009]

By forming through holes in the shadow mask material of the present invention through which the electron beam passes by etching, it is possible to prevent so-called side etching in which the etching surface spreads like a mortar, and the electron beam is diffusely reflected on the etching surface. Therefore, it is possible to prevent the occurrence of color misregistration. Further, there is little variation in the shape of the through hole to be created, and etching with extremely high accuracy becomes possible. Therefore, it is extremely useful as a material for a high-definition shadow mask.

[Brief description of drawings]

FIG. 1 is a schematic view of a through hole formed in a shadow mask material of the present invention.

FIG. 2 is an explanatory diagram of a shadow mask through hole.

[Explanation of symbols]

1 Electron beam passage hole 2 Etching surface 3 electron beam 4 diffuse reflection 5 shadow mask

Claims (2)

[Claims] 1. An etching workability, characterized in that a ratio of {100} crystal faces of an alloy thin plate made of a Fe--Ni alloy is larger in a central portion in a plate thickness direction than in a surface of the thin plate. Excellent shadow mask material. 2. The excellent etching workability according to claim 1, wherein the Fe—Ni alloy thin sheet has a central portion in the thickness direction of the {100} crystal planes in an aggregate ratio of 30% or more. Shadow mask material.