JP2795028B2 - Metal sheet for shadow mask with excellent etching processability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Fe-Ni alloy excellent in etching processability, and more particularly to a thin invar alloy sheet for a shadow mask used for a color cathode ray tube.

[0002] In recent years, as the quality of color televisions has increased, alloys for shadow masks that can deal with the problem of color misregistration have been developed.
An Fe-Ni-based invar alloy containing 34 to 38 wt.% Of Ni (hereinafter referred to as "conventional Fe-Ni-based alloy") is used. This conventional Fe-Ni alloy has a significantly lower coefficient of thermal expansion than low carbon steel conventionally used as a shadow mask material. Therefore, if a shadow mask is made of a conventional Fe-Ni alloy, even if the shadow mask is heated by an electron beam, the problem of color shift due to thermal expansion of the shadow mask hardly occurs.

[0003] Such an alloy thin plate for a shadow mask is usually processed into a shadow mask by the following steps. That is, a hole for passing an electron beam (hereinafter simply referred to as a “hole”)
(Hereinafter, the alloy thin plate for a shadow mask that has been perforated by etching is referred to as a “flat mask”), and then the flat mask is annealed,
Next, the annealed flat mask is press-formed into a curved surface shape so as to match the shape of the cathode ray tube, and then assembled into a shadow mask, and the surface thereof is subjected to a blackening treatment. However, when using such a conventional Fe-Ni-based Invar alloy, this alloy is preferable in etching processability for opening a larger number of pores as compared with a conventional low carbon steel shadow mask material. Not something.

[0004] In the case of the above-mentioned invar alloy, the corrosion resistance to an etching solution is remarkably lower than that of mild steel, and the crystal grain size is larger than that of mild steel. As a result, light is transmitted through the pores formed by the etching. In addition, the flat mask also had a blurred unevenness, and the brightness of such a flat mask (brightness when light was transmitted) was inferior to that of a mild steel mask. In particular, in a high-definition mask having a fine pitch and a small hole diameter, which has been rapidly increasing in recent years, the above-mentioned unevenness is apt to occur, and the brightness of the mask is also inferior. Especially recently, there is a strong demand for screen brightness.
It is a great disadvantage that the brightness of the flat mask is inferior to such needs. The following prior arts are known to solve such a problem of the etching processability.

[0005] (a) Japanese Patent Publication No. 2-9655 discloses that a {100} crystal plane is gathered at 35% or more on the surface of an Invar alloy thin plate, thereby enabling highly accurate and uniform etching. (Hereinafter referred to as “prior art 1”
). (B) JP-A-62-243782 discloses that {100} faces are gathered on a rolled face of an Fe-Ni-based invar alloy, and the surface roughness is set to Ra 0.2 to 0.7 μm and Sm 100 μm or less. Moreover, by setting the crystal grain size to 8.0 or more, the etching speed is improved, and the quality of the unevenness is improved (hereinafter referred to as "prior art 2").

[0006]

However, in the above-mentioned prior art 1, the accuracy and uniformity of the etching of the Invar alloy are enhanced, but in fact, the flat mask obtained by this technique still has the same haze, The brightness of the flat mask was also inferior, causing a quality problem.

Further, prior art 2 attempts to increase the etching speed of the Invar alloy and improve the uneven quality, but the flat mask obtained by this technique is still inferior in terms of brightness. It was a quality problem. The grain size described in this technique is the finest grain having a grain size number of 10.0, and the grain size corresponding to this grain size number is 11 μm according to the following formula (1). is there. (Crystal grain size No.) = 16.6439-6.6439 log (Crystal grain size (μm) /1.125) ... (1)

[0008]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned circumstances, and has been devised through repeated studies.
Provided is a Fe-Ni-based Invar alloy thin plate for a shadow mask, which has excellent etching workability, enables high-precision and uniform etching perforation, and has an excellent level of brightness of a flat mask after etching perforation. It was successful, as follows:

(1) Fe—Ni containing Fe and Ni as main components
Made of Invar alloy, and the surface of the alloy plate is # 33
Each of the crystal plane densities of {1}, {210} and {211} shows the values shown in the following table, and their ratio {210} /
A metal sheet for a shadow mask excellent in etching workability, characterized in that [{331} + {211}] is 0.2 to 1.0.

[0010]

[Table 1]

(2) The composition described in (1) and the degree of integration of each crystal plane on the surface of the alloy plate and their ratio, and the crystal grain size in the thickness direction of the alloy plate is 10 μm.
A metal sheet for a shadow mask excellent in etching workability, characterized in that:

[0012]

The present invention as described above will be further described. The present invention is characterized in that when a fine pattern is formed by photoetching on an alloy thin plate made of an Fe-Ni-based Invar alloy, the size and shape are made uniform over the entire surface. In order to provide this, it is necessary that the etching rate be constant and fast over the entire surface, and for this purpose, it is important to increase the etching factor, and this is because a specific crystal plane on the etched surface (alloy plate surface) is required. By controlling the ratio of the degree of integration and controlling the crystal grain size in the thickness direction of the alloy plate.

Further, in order to obtain an excellent level of brightness of the flat mask after the etching perforation, it is important that the surface roughness (Ra) of the interface of the etching hole is not more than a specific value. This is achieved by controlling the degree of integration of a specific crystal plane on the etched surface (alloy plate surface).
The present invention focuses on the above two points.

The reasons for limiting the degree of crystal plane integration and the crystal grain size of the Fe—Ni-based Invar alloy sheet for a shadow mask according to the present invention will be described. First, the Fe—Ni-based Invar alloy used in the present invention prevents color shift from occurring. Has an effect,
In order to exhibit this effect, the upper limit of the average thermal expansion coefficient in the temperature range of 30 to 100 ° C. needs to be about 2.0 × 10 ⁻⁶ / ° C. The average coefficient of thermal expansion depends on the amount of nickel.
It is in the range of 4-38%.

In the case where 0.01 to 6% of cobalt is contained, the amount of Ni satisfying the above average thermal expansion coefficient is 3%.
It may be in the range of 0-37%.

In the present alloy, (1)
11), (200), (220), (311), (33)
The X-ray diffraction intensities of the diffraction planes 1), (420) and (422) are obtained, and the degree of integration of the crystal orientation can be measured based on these. That is, the degree of integration of the {331} crystal plane is (331) and the relative X-ray intensity ratio of the diffraction plane is (111).
(200), (220), (311), (331),
It was obtained by dividing by the sum of the relative X-ray intensity ratios of the diffraction planes of (420) and (422).

Here, the relative X-ray diffraction intensity ratio is obtained by dividing the X-ray diffraction intensity measured on each diffraction surface by the theoretical X-ray intensity of the diffraction surface. For example, the relative X-ray diffraction intensity ratio of the (111) diffraction surface is obtained by dividing the X-ray diffraction intensity of the (111) diffraction surface by the theoretical X-ray diffraction intensity of the (111) diffraction surface. Also, the degree of integration of each of the crystal planes {210} and {211} is (420), (42)
The relative X-ray diffraction intensity ratio of the diffraction surface of (2) was as described above (11
It was determined by dividing by the sum of the relative X-ray diffraction intensity ratios of the seven diffraction planes from 1) to (422).

By controlling the degree of integration of {331}, {210}, and {211} crystal planes on the surface of an Invar alloy thin plate and the ratio of the degree of integration of these crystal planes, the present inventors have proposed an etching factor. And the surface roughness (Ra) of the etching hole interface can be reduced, and the brightness level of the flat mask can be improved. That is, FIG. 1 shows {331}, {210}, and {21}.
1｝ Invar alloy thin plates with various degrees of integration of crystal planes on the alloy plate surface are photo-etched, the light transmission of the obtained flat mask is measured, and this value is perforated with the same dimensions as the above-mentioned Invar alloy. The light transmittance of the conventional flat mask made of mild steel is divided by the light transmittance of the flat mask, which is defined as the light transmittance of the flat mask. The relationship between the transmittance and the surface roughness (Ra) of the interface between the etching and the hole is plotted. The method for measuring the surface roughness was determined by the method described in Example 1 described later.

According to FIG. 1 described above, according to FIG.
When the degree of integration on each of the crystal planes of {1}, {210}, and {211} is 14% or less, 10% or less, and 10% or less, respectively, the surface roughness (Ra) of the etching hole interface is 0.90 μm.
The transmission ratio of light of the flat mask is 1.0 or less.
From the above, it can be seen that brightness equal to or higher than the light transmission amount of the conventional mild steel flat mask can be obtained. Regarding the relationship between the brightness of the flat mask and the surface roughness of the interface of the etching hole, the correlation with other roughness parameters was also examined, but the one showing the strongest correlation was the center line average roughness (Ra). .

From the above, the conditions for setting the brightness of the flat mask to an excellent level are as follows: {331} crystal plane integration ≦ 14%, {210} crystal plane integration ≦ 10%,
The degree of integration of the {211} crystal plane was determined to be ≦ 10%. Note that the degree of integration of the {331} crystal plane> 14% and / or {21}
When the degree of integration of the 0 crystal plane is greater than 10% and / or the degree of integration of the {211} crystal plane is greater than 10%, microscopic pits (irregularities) are generated on the entire surface of the etching hole interface when viewed microscopically. Therefore, the roughness (Ra) of the etching hole interface is 0.9.
It is considered that the reason why the thickness exceeds 0 μm is due to the generation of such pits.

{331}, {210},
Control of the ratio of the degree of integration of the {211} crystal plane is necessary for improving the etching factor. That is, FIG. 2 shows the relationship between {210} / [{331} + {211}] and the etching factor and unevenness quality of the Invar alloy thin plate. The etching factor is the same as that shown in Example 1 described later. Asked in the same way. Also $ 21
The degree of integration of the {0}, {331}, and {211} crystal planes was determined by the X-ray diffraction technique as described above. The non-uniformity grade was determined by visual observation, and the non-uniformity was A, the non-uniformity was severe and practically problematic was E, and B to D were A and E
Are ranked, and A to C have no practical problem. The {210} / [$ 33
[1} + {211}], the etching factor was increased.

In the present invention, 1.8 is set as the value of the etching factor which has no practical problem, and {210} / [{331} + ｛2
0.2 was determined as the lower limit of [11 °]. Note that {210}
If / [{331} + {211}] is more than 1.0, the quality of the unevenness deteriorates and there is a practical problem. As described above, {210} / [{331} + {2} in which the unevenness quality is as good as A to C and the high etching factor intended in the present invention can be obtained.
11 °] is set to 0.2 to 1.0.

In the present invention, the etching factor can be improved by controlling the ratio of the degree of integration of a specific crystal plane on the surface of the alloy plate as described above. In order to further improve the etching factor, it is necessary to reduce the crystal grain size in the thickness direction of the alloy plate to 10 μm smaller than the conventional level.
The following (with a grain size of 10.3 or more)
As shown in FIG. 3, the same {210} / [{331} +
Even with the value of {211}, the etching factor can be further increased.

Based on the above relationship, the upper limit of the crystal grain size in the thickness direction of the alloy plate for increasing the etching factor was set to 10 μm. Note that FIG. 4 shows that {210} / [{331} + {211}] = 0.2 in FIG.
It shows the relationship between the etching factor and the crystal grain size in the thickness direction of the alloy plate when it is 5 (constant).

However, the shadow mask Fe of the present invention
-Ni-based Invar alloy is Fe-Ni or
The basic composition of Fe-Ni-Co is characterized by defining the degree of integration of crystal planes on the alloy plate surface and its ratio, and the crystal grain size in the plate thickness direction of the alloy plate, respectively. Other C: 0.0050% or less, Mn: 0.35% or less, Si: 0.0
5% or less, Cr: 0.05% or less, N: 0.0015% or less,
O: Desirably 0.0020% or less.

{331} on the surface of the Invar alloy sheet,
In order to reduce the degree of integration of the crystal planes of {210} and {211} to the value specified in the present invention or less, from solidification to hot working and subsequent cold rolling / annealing in the production of alloy thin plates This is achieved by adopting manufacturing conditions that minimize the formation of these crystal planes in the process. For example, when the alloy is produced from a hot-rolled steel strip obtained by subjecting an ingot or a continuously cast slab to slab rolling and hot rolling, after hot rolling,
Appropriate hot-rolled sheet annealing requires {331}, # 21
It is effective for suppressing the formation of the {0} and {211} crystal planes. At this time, the annealing temperature of the hot rolled sheet is 910-99.
It is first necessary to select an appropriate temperature in the range of 0 ° C.

Also, {331}, {210}, and {21}
In order to keep the ratio of the degree of integration of 1｝ crystal planes within the range of the present invention, {331}, {210},
Depending on the degree of integration of the {211} crystal planes, the cold rolling and the annealing conditions (temperature, time) , Heating rate) and a series of steps of finish cold rolling are optimally combined.

The effect of the hot-rolled sheet annealing described above is exerted when the hot-rolled steel strip of the present alloy is sufficiently recrystallized before hot-rolled sheet annealing. Further, in order to obtain the degree of integration of the three crystal planes intended in the present invention, it is not preferable to perform the heat treatment for homogenizing the slab after the slab rolling in producing the present alloy. For example, the above-mentioned homogenization heat treatment is 1200 ° C. or more,
If the treatment is performed under the condition of 10 Hr or more, such a treatment must be avoided since the degree of integration of the above three crystal planes exceeds the prescribed value of the present invention.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below. (Example 1) An ingot of an alloy having the chemical components shown in Table 2 below was obtained by ladle refining. After cleaning these ingots,
Blast rolling, surface flaw removal, hot rolling (heating is 1100 ° C x
A hot-rolled steel strip that had passed 3 hours) was used.

[0030]

[Table 2]

Next, the hot-rolled steel strip is subjected to hot-rolled sheet annealing at 910 to 990 ° C., and thereafter, the cold rolling, annealing conditions and finish cold rolling conditions are changed to obtain crystal faces as shown in Table 3 below. (Material Nos. 1 to 21) having a degree of integration and a crystal grain size in the thickness direction of the alloy plate. Note that {331},
The degree of integration of the {210} and {211} crystal planes was determined by the above-described X-ray diffraction technique.

[0032]

[Table 3]

Next, a resist pattern was provided on the surface of each alloy plate obtained as described above, and the etching factor at a resist opening diameter of 135 μm was measured.
In this etching factor measurement, the above sample was measured for 45 minutes.
Baume, ferric chloride solution, liquid temperature 40 ° C, spray pressure 2.5
After etching at kg / cm ^{2 for} 50 seconds, calculation was performed by a measurement method as shown in FIG. Further, a similar alloy plate is used as a flat mask by photoetching, the amount of transmitted light is measured, and this value is divided by the amount of transmitted light of a conventional flat mask made of mild steel perforated with the same dimensions as the above-mentioned Invar alloy. This was defined as the light transmittance of the flat mask.

The surface roughness of the interface between the etching holes in these flat masks was measured by a non-contact type laser roughness meter. The cutoff value was 0.02 mm, and the tapered portion at the hole interface was removed as a waviness component to extract a roughness curve, and the center line average roughness (Ra) was determined from this curve. The unevenness quality of the flat mask was determined by visual observation, and was determined based on the same standard as in FIG.

As is clear from the results shown in Table 3 above, {311}, {210}, and {2} within the scope of the present invention.
Degree of integration of 11 crystal plane and {210} / [{331}
+ {211}], the surface roughness (Ra) of the etching hole interface is 0.90 μm.
m, and the light transmittance of the flat mask is 1.0 or more, and it is understood that a brightness higher than the light transmission of the conventional mild steel flat mask can be obtained. Further, these materials have an etching factor of 1.8 or more, and the level of unevenness of the flat mask is at a level that does not cause any practical problem.

In particular, the values of {210} / [{331} + {211}] for each of the materials No. 6, No. 9 to No.
25 to 0.26, but compared to No. 6 No. 9 to No. 1
The crystal grain size in the thickness direction of the alloy plate of each material of No. 4 is 10 μm or less, which is smaller than the conventional level, the etching factor shows a higher value, and it is clear that the etching property is more excellent. Further, the materials No. 9 to No. 14
Among the above materials, the material having a smaller crystal grain size in the thickness direction of the alloy plate has a higher etching factor, and in order to increase the etching factor, the crystal grain size in the thickness direction of the alloy plate is reduced. It is understood that is important.

With respect to these invention examples, material Nos.
o. Each of the materials of No. 3 has a {331} crystal plane exceeding the present invention, a {210} crystal plane exceeding the present invention, and a {211} crystal plane exceeding the present invention. The surface roughness (Ra) of the interface of the etching hole is 0.90μ
m, and the light transmittance of the flat mask is less than 1.0, which is lower than that of the invention. Furthermore, material No. 4 is {210}
/ [{331} + {211}] exceeds the upper limit specified in the present invention, and the uneven quality of the flat mask is inferior to that of the present invention. No. 5 is {210} /
The value of [{331} + {211}] is less than the lower limit of the present invention, and the level intended in the present invention is not obtained when the etching factor is less than 1.80.

As is apparent from the above description, the surface roughness (Ra) at the interface of the etching hole is determined by setting the degree of integration of the {331}, {210}, and {211} crystal planes within the range of the present invention. {210} to control the light transmittance of the flat mask to an excellent level and within the scope of the present invention.
/ [{331} + {211}],
The etching factor and the uneven quality of the flat mask can be made excellent, and the etching factor can be further increased by further reducing the crystal grain size in the thickness direction of the alloy plate within the range of the present invention. It is possible. That is, according to the present invention, it is apparent that an Fe—Ni-based Invar alloy thin plate for a shadow mask having excellent etching workability can be obtained.

[0039]

According to the present invention as described above, the etching process is excellent, the etching factor is high, the brightness of the flat mask is excellent, and the uneven quality of the flat mask is excellent. The present invention can provide an Fe-Ni-based Invar alloy thin plate for a shadow mask, and has an industrially advantageous effect, and is an invention having a large effect.

[Brief description of the drawings]

FIG. 1 is a table showing the relationship between the light transmittance of a flat mask and the surface roughness (Ra) of the interface of an etching hole.

FIG. 2 Etching factor, uneven quality and {210}
It is a chart showing the relationship of / [{331} + {211}].

FIG. 3 shows an etching factor and {210} / [$ 33]
1} + {211}], and a table showing the relationship with the crystal grain size (D) in the thickness direction of the alloy plate.

FIG. 4 is a table summarizing the relationship between the etching factor and the crystal grain size in the thickness direction of the alloy plate.

FIG. 5 is an explanatory diagram showing a method of measuring an etching factor.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomoyoshi Ohkita 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (72) Yoshiaki Shimizu 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan (56) References JP-A-59-40443 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23F 1/00 H01J 29/07 C22C 38 / 00,38 / 08

Claims (2)

(57) [Claims] The present invention comprises an Fe-Ni-based Invar alloy containing Fe and Ni as main components, and {331} on an alloy plate surface.
The degree of integration of each crystal plane of {210} and {211} shows the values in the following table, respectively, and their ratio {210} / [{3
31｝ + {211}] is 0.2 to 1.0, and is a metal sheet for a shadow mask excellent in etching workability. 2. The composition according to claim 1, which has the degree of integration of each crystal plane on the surface of the alloy plate and the ratio thereof, and the crystal grain size in the thickness direction of the alloy plate is 10 μm or less. Metal sheet for shadow mask with excellent etching processability.