JPH0657382A - Stock for shadow mask - Google Patents

Abstract

PURPOSE:To enable the piercing of electron beam passing pores having a uniform shape and pore size by specifying the X-ray diffraction intensity ratio of the crystalline planes in the surface of an alloy sheet constituted of prescribed ratios of Ni and Fe and forming its structure into a nonrecrystallized one. CONSTITUTION:This stock for a shadow mask is formed with an Fe-Ni alloy sheet constituting of, by weight, 20 to 48% Ni, and the balance Fe. Furthermore, the X-ray diffraction intensity ratio of the crystalline planes {111}, {200}, {220} and {311} is regulated to 20 or larger (in the case the X-ray diffraction intensity of the face in which the X-ray diffraction intensity is the highest among respective faces, is regulated to 100). Then, the surface is formed into structure near the non-oriented state, and is wholly formed into a nonrecrystallized structure.

Description

Detailed Description of the Invention

[0001]

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask material suitable for the construction of a shadow mask used, for example, in a picture tube for a color television.

[0003]

[0002]

[0004]

2. Description of the Related Art A shadow mask for a picture tube for a color television is required to have a function of accurately projecting a required electron beam spot on a three-color fluorescent screen divided into minute islands. That is, the relative position, hole diameter, and hole shape of the electron beam passage hole of the shadow mask have a direct influence on the image quality of the displayed image. From this point of view, in the shadow mask, while high processing accuracy is required for the electron beam passage hole, in order to prevent the generation of scattered electrons, the surface side of the electron beam passage hole that faces the fluorescent surface has a hemispherical shape or the like. Although a special processing such as chamfering is performed, if the processing accuracy is poor, the deterioration of image quality due to so-called doming cannot be eliminated (avoided or reduced).

[0005]

In particular, in order to improve the resolution in view of the demand for "large-sized and high-definition image quality" and the development of "high-definition television system" which have been increasing in recent years, in order to improve the resolution, the shadow mask has a fine electronic structure. It is required to form a beam passage hole. In response to these trends, for example, 36 wt% Ni-Fe
Attempts have been made to use an amber alloy plate centered on.
That is, since the amber alloy has a small coefficient of thermal expansion, in use as a shadow mask, even if the shadow mask is heated by the collision of electrons, it is difficult for the electron beam passage hole to be displaced, resulting in a color shift. This is because it is easy to prevent In the formation (configuration) of the shadow mask, so-called photo-etching is used to form fine electron beam passage holes substantially uniformly (open holes).
In order to achieve this, it is desired that the crystals on the surface of the amber alloy plate be aligned (have a directivity).

[0006]

By the way, the amber alloy shadow mask material is manufactured as follows. That is, it is manufactured through the steps of melting of raw material, hot forging, hot rolling, cold rolling, intermediate annealing, adjustment rolling, recrystallization structured annealing, etc., and the amber alloy sheet thus obtained Has a state in which at least the crystal planes of the surface are uniform (uniform).

[0007]

[0005]

[0008]

However, with the development and commercialization of a large-sized, high-definition color TV, the shadow mask is required to have higher precision and electron beam passage holes to be finer or finer. Has been done. That is, in the material for the shadow mask, in addition to having a small coefficient of thermal expansion, it is also desired that the required electron beam passage holes that are fine and have no variation can be easily and highly accurately formed. However, in the shadow mask formed by forming electron beam passage holes by photoetching in the conventional Amber alloy plate, defective shape of the etching holes and so-called white unevenness were observed, resulting in sufficient improvement of image quality and the like. There is an inconvenient problem in that In other words, for example, using an amber alloy plate whose surface is aligned with the (100) plane,
When this amber alloy plate is photoetched and the required fine electron beam passage holes are drilled, even if the shape of the drilled electron beam passage holes is an ideal similar shape, In reality, the size is large and small, and the roughness of the etching surface is different, so that the white unevenness is not completely eliminated.

[0009]

[0006]

The present invention has been made in view of the above circumstances. In addition to the shape of the hole diameter, the side surface is fine and smooth, and the hole diameter is substantially uniform, and it is possible to form a fine electron beam passage hole. It is an object of the present invention to provide a shadow mask material capable of forming (configuring) a shadow mask in which unevenness is not recognized.

[0011]

[0007]

[0012]

A material for a shadow mask according to the present invention is a Fe-Ni-based material called at least an amber-based material in which Ni is 20 to 48% by weight, inevitable impurities, and the balance is Fe. It is an alloy plate, and the X-ray diffraction intensity ratio of at least the crystal planes {111}, {200}, {220} and {311} on the surface is the most X-ray among those planes.
It is characterized in that when the X-ray diffraction intensity of the surface having a strong line diffraction intensity is 100, it is 20 or more, respectively, and a non-recrystallized structure is formed.

[0013]

According to the present invention, the problem of white unevenness in the amber alloy plate depends on the precipitation of α-Fe, the variation in the etching rate of crystal grain boundaries, the crystal orientation on the plate surface, and the like. It is based on knowledge. That is, since α-Fe has poorer corrosion resistance than Amber alloy,
The diameter of the electron beam passage hole formed at the location where α-Fe is localized increases. By suppressing the precipitation of α-Fe and controlling the non-recrystallized structure and the crystal orientation, problems such as white unevenness due to the formation of the electron beam passage hole are easily and surely solved. It was confirmed that the present invention was created.

[0014]

The material for a shadow mask according to the present invention is an Fe-Ni alloy compositionally called an amber alloy,
Examples thereof include Ni-Co type and Fe-Ni-Co-Cr type (all of which include inevitable impurities). Here, the composition ratio of Ni is 20
Even if less than 48% by weight, the coefficient of thermal expansion is 7%
This is because the temperature does not ^fall below × 10 ⁻⁶ / ° C. or less, the position of the electron beam passage hole shifts due to the temperature rise due to the collision of electrons, and the desired function cannot be finally achieved. Further, when containing Co or Cr, the composition ratio of Co is 0.01 to 10% by weight, and the composition ratio of Cr is 0.01 to 10% by weight.
It is selected within the range of 7% by weight and in the relationship of Cr ≦ Co. The reason is that when the content of Co or Cr is outside the above range, the coefficient of thermal expansion becomes large in both cases.

[0015]

Further, a part (within several%) of the Ni component of the amber alloy system may be replaced with, for example, Ti, Al, Zr, Nb, Ta, Cr, Cu, etc. , For example, C is 0.02% or less by weight, Al is 0.02% or less, and S is 0.
0!% Or less, P 0.1% or less, Mo 0.02% or less, N ₂ 50
ppm or less, O ₂ 100 ppm or less, Mn as a deoxidizer of 0.
It may contain 5% or less and Si of 0.1% or less.

[0016]

Furthermore, in the X-ray diffraction intensity ratio of the crystal planes {111}, {200}, {220} and {311} on the plate surface, the plane having the strongest X-ray diffraction intensity among the respective planes. 20 when the X-ray diffraction intensity of
As described above, the values of at least two crystal planes are preferably 70 or more. In addition, the amber alloy plate according to the present invention needs to have a non-recrystallized structure. In other words, it is characterized in that the crystal structure is not re-formed by annealing (annealing). Here, at least on the surface, the crystal plane {111
}, {200}, {220} and {311} are allowed to exist (in a range) in the above-mentioned predetermined state so as not to have so-called crystal orientation, and to remain unrecrystallized structure. This is because it has been experimentally confirmed that the electron beam passage hole cannot be formed with high precision.

[0017]

Here, the reason why it is necessary that the crystal on the surface of the material is not oriented in a specific crystal orientation in performing the etching will be described. A non-oriented crystal is a state in which a fine powder is pressed and solidified, and when a non-oriented material is etched, the etching direction is not specified at all and is completely random. Therefore, macroscopically, etching proceeds uniformly in a desired direction. Therefore, the electron beam passage holes can be formed at right angles to the etching surface, and the positions and shapes of the holes can be made uniform. At this time, the finer the powder, the more effective. Further, in the material according to the present invention, the smaller the crystal grains of the non-oriented material, the more finely the electron beam passage hole can be opened. In addition,
The amber alloy plate as the material for the shadow mask according to the present invention has at least a crystal plane {111},
The X-ray diffraction intensity ratios of {200}, {220} and {311} are 20 or more, respectively, when the X-ray diffraction intensity of the surface having the strongest X-ray diffraction intensity is 100. Further, it is more preferable that the hardness (Hv) is 230 or less (or the Erichsen value is 7 or more) in consideration of workability as well as forming an unrecrystallized structure.

[0018]

The material for a shadow mask according to the present invention is manufactured by a method such as melting, forging, hot rolling, cold rolling, etc. according to a conventional method using raw materials (or alloys) selectively blended in a required composition ratio. At that time, quenching from a high temperature of 900 ℃ or more, and at least without recrystallization in the final heat treatment step,
It can be manufactured by performing softening annealing.

[0019]

[0014]

[0020]

The material for a shadow mask according to the present invention has a state in which at least the surface (layer) of the plate is close to so-called non-directional (non-directional), and has a non-recrystallized structure as a whole. , By photo etching, for example diameter
When drilling electron beam passage holes of about mm, not only the shape but also the hole diameter is almost uniform, and it is possible to make fine electron beam passage holes. Can be formed. In other words, by suppressing the precipitation of α-Fe, and by controlling the non-recrystallized structure and the crystal orientation, even when an electron beam passage hole is formed by etching, it is possible to easily and reliably obtain a uniform and fine hole diameter. It can be said that it becomes possible to form electron beam passage holes, which will greatly contribute to the realization of a high-definition color television with high resolution.

[0021]

[0015]

[0022]

EXAMPLES Examples of the present invention will be described below.

[0023]

Example 1 and Comparative Examples 1 to 4 An amber alloy having a weight ratio of 36% Ni and the balance substantially consisting of Fe was melted (melted) as a target component, and a plurality of 5 ton ingots (thickness 150 mm × A width of 600 mm and a length of 10 m) was obtained.
After heating this ingot at 1200 ° C for 4 hours, it was hot-rolled to a thickness of 3 mm × width of 600 mm × length of 200 m. Then 1
Heat treatment at 100 ℃ for 4 hours, cold rolling and thickness 0.7mm
After being thinned, the sheet was annealed continuously at 900 ° C. After that, cold rolling is further performed to make a thin plate with a thickness of 0.25 mm, and 620 ° C.
Continuous annealing was performed and then flattening was performed by skin pass to obtain a shadow mask material having an unrecrystallized structure. The working ratio in the cold rolling process in this manufacturing process is 50% or more.

[0024]

The entire surface of the shadow mask material (plate) obtained above was subjected to X-ray diffraction, and as shown in FIG. 1, {111}, {200}, {220} and {311} Xs were obtained.
When the X-ray diffraction intensity is remarkable, and the X-ray diffraction intensity of {200} is 100, the X-ray diffraction intensity ratio is {111}.
In the case of 72, {220}, it was 98, and in the case of {311}, it was 42. Further, the crystal structure of the shadow mask material (plate) is as shown in FIG. 2, that is, a micrograph (Photo A) and an electron micrograph (Photo B), respectively, and is a fine crystal including an unrecrystallized structure, The dislocation density is also high.

[0025]

The shadow mask material (plate) has a designed hole diameter of 1.7 by a conventional photo-etching method.
× 0.7 mm long hole (large hole side) electron beam passage hole
When the holes were opened, electron beam passage holes (holes) of uniform shape and size were formed and opened over the entire surface, and a shadow mask without white unevenness was obtained. The shadow mask material (plate) according to the present invention is made into a shadow mask in this manner, and then recrystallized to be incorporated into a color television.

[0026]

For comparison, the ingot was placed at 1300 ° C.
After heating for an hour, it was forged to have dimensions of thickness 3 mm × width 600 mm × length lm. After that, heat treatment was performed at 1100 ° C. for 4 hours, cold rolling was performed to form a thin plate having a thickness of 0.7 mm, and then intermediate annealing was performed at 1000 ° C. for 10 minutes. After that, further cold rolling is performed to a thickness of 0.
A 25 mm thin plate was annealed at 800 ° C. for 10 minutes and then flattened by a skin pass to obtain a shadow mask material having a recrystallized structure (Comparative Example 1). When X-ray diffraction was performed on the entire surface of the shadow mask material (plate) obtained above,
As shown in FIG. 2, the X-ray diffraction intensities of {111} and {200} are remarkable, the X-ray diffraction intensities of {220} and {311} are small, and the X-ray diffraction intensity of {111} is 100. When each X-ray diffraction intensity ratio is {200} 84, {220} 1
In the case of 2, {311}, it was 9. Further, the crystal structures of the shadow mask material (plate) are as shown in FIG. 4, that is, a micrograph (photograph a) and an electron micrograph (photograph b), respectively, and the crystal is recrystallized. It was coarser than the shadow mask material according to (1) and had a low dislocation density.

[0027]

Further, in Comparative Example 1, two kinds of Comparative Examples (Comparative Example 2 and Comparative Example 3) were similarly prepared except that the working ratio of cold rolling during the manufacturing process and the final annealing temperature were changed.
Further, one kind of comparative example (Comparative Example 4) was manufactured in the same manner except that the cold rolling working ratio in the manufacturing process of Comparative Example 1 was set to 50%. X in Comparative Examples 2 to 4
The line diffraction intensity and the state of the crystal structure were the same as those in Comparative Example 1. In the shadow mask material (plate) of each of these comparative examples, a long hole (large hole side) electron beam passage hole having a design hole diameter of 1.4 × 0.7 mm was formed and opened by a conventional photoetching method. However, a shadow mask was obtained that was inferior to the case of Example 1 in etching accuracy and white spots.

[0028]

Table 1 shows the X-rays of the crystal planes {111}, {200}, {220} and {311} on the plate surface for each of the shadow mask materials (plates) of Example 1 and Comparative Examples 1 to 4 above. The diffraction intensity ratio, the etching property of fine holes, the state of white unevenness, etc. are collectively displayed. In Table 1, the etching characteristics are excellent when the hole dimension accuracy of the electron beam passage hole is within 2%, good when it is within 5%, and white unevenness is evaluated by visual inspection and the crystalline structure is evaluated. Are determined by the photograph of the metal structure of the cross section. And Table 1
As a reference example, a sample of metal powder (standard sample) that constitutes the composition and composition ratio of the material (plate) for the shadow mask
The X-ray diffraction intensity ratio of is also shown.

[0029]

[0022]

[0030]

[Table 1] Examples 2 to 4 Fe-32% Ni-5Co was prepared by the same method as in Example 1 above.
Alloy (Example 2), Fe-36% Ni-0.2Co-0.02Cr alloy (Example 3), Fe-32% Ni-5Co-0.2Cr alloy (Example 4) -based shadow mask material (plate) ) Were produced respectively. The final annealing temperature in these manufacturing steps was set to 640 ° C in the case of Example 2, 600 ° C in the case of Example 3, and 620 ° C in the case of Example 4.

[0031]

For each of these three types of shadow mask materials (plates), as in the case of Example 1, X-ray diffraction of the crystal planes (111), (200), (220) and (311) on the plate surface was performed. Table 2 shows the results of evaluation of the strength ratio, the etching property of the fine pores, the white unevenness generation state, the crystal structure, and the like.

[0032]

[0024]

[0033]

[Table 2]

[0034]

[0025]

[0035]

As described above, in the shadow mask material according to the present invention, at least the plate surface is nearly non-directional and the crystal structure is also a non-recrystallized structure or state. When a large electron beam passage hole is formed and opened by photoetching, the directionality of the etching is greatly reduced or eliminated, so it is easy to achieve a uniform diameter and uniform size. It is possible to pierce and open the hole. That is, it is possible to obtain a highly reliable shadow mask that is suitable for etching of a color television that requires high-quality image quality, has no uneven whiteness, and is suitable for etching. The shadow mask material can also be used for applications such as etching, for example, as lead frames.

[Brief description of drawings]

FIG. 1 is a characteristic diagram showing an example of an X-ray diffraction pattern of a shadow mask material according to the present invention.

FIG. 2 is a crystal structure diagram of a material for a shadow mask according to the present invention, in which (A) is a micrograph and (B) is an electron micrograph.

FIG. 3 is a characteristic diagram showing an example of an X-ray diffraction pattern of a conventional shadow mask material.

FIG. 4 is a crystal structure diagram of a conventional shadow mask material,
(a) is a micrograph and (b) is an electron micrograph.

[Explanation of symbols]

 None

[Table-1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Fukuda 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Inside the Toshiba Research Institute, Inc. (72) Inventor Michihiko Inaba Komu-shi Toshiba-cho, Kawasaki-shi, Kanagawa No. 1 Incorporated company Toshiba Research Institute (72) Inventor Emiko Higashi Nakagawa 1 Komukai Toshiba-cho, Sachi-ku Kawasaki City Kanagawa Prefecture Incorporated Toshiba Research Institute (72) Inventor Yasuhisa Otake 1-chome Harara-cho, Fukaya-shi, Saitama No. 9 No. 2 Toshiba Fukaya Electronics Factory (72) Inventor Eiichi Akiyoshi 50 Kamamibe, Yobu Ward, Himeji City, Hyogo Prefecture Stock Company Toshiba Himeji Factory

Claims (1)

[Claims] 1. An Fe-Ni alloy plate comprising at least Ni by weight of 20 to 48%, unavoidable impurities, and the balance being Fe, the crystal plane of which is at least the surface {111},
The X-ray diffraction intensity ratios of {200}, {220}, and {311} are each 20 or more when the X-ray diffraction intensity of the surface with the highest X-ray diffraction intensity is 100, and A material for shadow masks, which is characterized by having an unrecrystallized structure.