JPH03281756A - Fe-ni alloy sheet for shadow mask and its manufacture - Google Patents

Abstract

PURPOSE:To prevent the generation of nonuniformity in an Fe-Ni alloy sheet at the time of etching and piercing and its contact printing at the time of annealing flat masks by specifying the surface roughness of an alloy thin strip as well as the Si content in the alloy and its distribution. CONSTITUTION:This Fe-Ni alloy sheet is a one constituted of, by weight, 0.01 to 0.15% Si, 34 to 38% Ni and the balance Fe and in which the sheet thickness of the alloy steel strip is equal to that of flat masks serving for the manufacture a shadow mask including a stage of laminating many pieces of the flat masks and executing annealing treatment. Then, its surface roughness Ra is regulated to 0.3 to 0.7, its skewness Rsk, i.e., the bias index in the height direction of a roughness curve is regulated to 0.3 to 1.0 and the conditions in the inequality I are satisfied. Furthermore, the componental segregating rate of Si in the formula II on the surface of the alloy sheet immediately before etching is regulated to <=10%. For manufacturing this sheet, a dull roll is used at the time of final cold rolling or temper rolling and the above surface roughness is provided on the surface of the thin sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial Field of Application) The present invention relates to a Fe-Ni alloy thin plate for a shadow mask and a method for manufacturing the same. The present invention relates to a technique for obtaining an appropriate product with excellent etching perforation properties in a Ni-based alloy thin plate, and in particular, preventing unevenness during perforation and preventing adhesion seizure when annealing a flat mask after perforation.

(Prior art) In recent years, with the increasing quality of color televisions, Fe-
Ni-based invar alloys are attracting attention, but compared to conventional shadow mask materials made of low carbon steel, this alloy causes unevenness of the flat mask during etching and adhesion baking when annealing the flat mask after drilling. Significantly sexual.

Among these, in order to solve the former problem,
-39344 publication, (1) Japanese Patent Application Laid-Open No. 62-243780, (2) Japanese Patent Application Laid-open No. 243781, and (2) Japanese Patent Application Laid-open No. 243782.

That is, (2) obtains regularity of the aperture shape and uniformity of the apertures throughout the shadow mask by setting the surface roughness (center line average roughness Ra) of the shadow mask material to 0.1 to 0.4 μm. There is. In addition, ■ indicates that the surface roughness (Ra) of the shadow mask material is 0.2 to 0.7 ii m, S... (the average value of the unevenness interval of the cross-sectional curve showing the surface roughness within the standard length) is 100 μm or less, By setting the crystal grain size to a grain size number of 8.0 or more, a mask with high quality unevenness after etching and perforation is provided.

Furthermore, in addition to the provisions of ■, ■Re(i3 through hole diameter αl/
By setting the etching hole diameter α2) to 0.9 or more, a mask with high quality unevenness after etching is provided. Note that (■) is obtained by accumulating the texture of the etched material by intense cold rolling and recrystallization annealing, and by increasing the grain size to 8.
0 or more, and then adjust the surface roughness as described in (1) above to a degree of cold working using dull rolls of 3 to 15% to produce a mask with high quality unevenness after etching and perforation.

On the other hand, no suitable proposal has been made to solve the latter problem mentioned above.

That is, (1) the adhesion baking during annealing of a conventional low carbon steel flat mask as disclosed in JP-A No. 62-238003 is performed by optimizing the surface roughness, that is, Ra of 0.2 to 2. Outa, Rsk (
Although there have been proposals to set the index of deviation in the height direction of the roughness curve to 0 or more, there is no preferred technique for preventing adhesion seizure during annealing in flat masks of Fe--Ni-based invar alloys.

(Problems to be Solved by the Invention) Fran during the above-mentioned etching drilling! - None of the techniques (1) to (3) above, which aim to improve the quality of mask unevenness, have achieved adhesion 2 prevention of seizure during annealing before curved surface pressing. In addition, as mentioned above, the method only prevents adhesion seizure during annealing of conventional low carbon steel flat masks, but the actual strength of the invar alloy is higher than that of low carbon steel, and the annealing temperature before curved pressing is Cathode ray tube manufacturers have to anneal low-carbon steel flat masks at temperatures of 810 to 1100°C by stacking dozens to hundreds of Fe-Ni invar alloy flat masks. The current situation is that it is performed at a considerably higher temperature than the actual temperature. At such an annealing temperature, the above technique (1) cannot prevent seizure during annealing of an invar alloy flat mask.

Therefore, no technology has been established for preventing the occurrence of J and cavities during etching and perforation in conventional Fe--Ni-based invar alloy shadow mask materials, and for appropriately preventing adhesion seizure during annealing after perforation.

"Structure of the Invention" (Means for Solving the Problems) In view of the above-mentioned circumstances, the present invention has excellent etching perforation properties, particularly prevents unevenness during perforation, and anneals a flat mask after perforation. F that prevents adhesion seizure when
In order to obtain a material for a shadow mask made of an e-Ni-based invar alloy, the invention was developed after repeated studies, and is as follows.

1. Si: 0.01-0.15wt%, Ni: 34
~38-1χ, with the remainder consisting of Fe and unavoidable impurities, and the plate thickness of the alloy steel strip is a flat mask used for manufacturing a shadow mask, which includes a step of stacking and annealing a large number of flat masks. and the surface roughness (Ra) is 0.3 to 0.7μ,
Moreover, the skewness (Rsk), which is an index of deviation in the height direction of the roughness curve, is 0.3 to 1.0, and the conditions of (Ra)≧1/3 (Rsk) +9.5 are satisfied, and Si on the surface of the alloy plate just before etching
A Pe-Ni alloy thin plate for a shadow mask, characterized in that the component segregation rate is 0% or less; 2. It has the components and surface roughness of item 1 above, and the surface? The degree of anisotropy is expressed by the following formula, Ra (L) - Ra (c) l ≦0.1/
JmRsk (L) Rsk (c) l
≦0.2 However, Ra(L) and Rsk(L) are measured values in the rolling direction, and Ra(c) and Rsk(e) are measured values in a direction perpendicular to the rolling direction.

F for a shadow mask characterized by satisfying the relationship
e-Ni alloy thin plate; 3. Ra (c) and Rsk (c) are the measured values when manufacturing a thin plate having the components listed in item 1 above. A method for producing a Fe-Ni alloy thin plate for a shadow mask, characterized in that the thin plate is coated with the thin plate having the components listed in item 1 above. ) is a method for producing a Fe--Ni alloy thin plate for a shadow mask, characterized in that a dull roll is used during rolling to give the surface of the thin plate the surface roughness of item 2 above.

(Function) To explain the present invention as described above, the present invention targets an invar alloy for shadow masks, and has an average coefficient of thermal expansion (30
~100°C) is set at 2.0x l Q -6/°C, and this thermal expansion characteristic depends on Nil, and the component range is -t% (hereinafter simply referred to as %) as it satisfies the above-mentioned condition for the average coefficient of thermal expansion. ), and the Ni content is 34 to 38%, so the Ni content of the alloy of the present invention is set to 34 to 38%. The amount of Ni is appropriately selected within the range -F depending on the required coefficient of thermal expansion.

Next, the etching properties and prevention of adhesion seizure during flat mask annealing, which are the goals of the present invention, can only be achieved when the surface roughness and the amount and distribution of Si in the alloy are optimized at the same time. That is, Si is an element effective in preventing adhesion seizure during annealing in Fe--Ni based invar alloys, and when this Si is 0.01% or more, an oxide film effective in preventing this seizure is formed.

On the other hand, if this Si exceeds 0.15%, the occurrence of unevenness during etching becomes significant, so this is set as the upper limit, and based on these, it is 0.01 to 0. .15%. Note that even if the amount of Si is within this range, S on the surface of the alloy plate
If the component variation of i is large, problems such as localized unevenness due to differences in etching and perforation conditions and differences in the properties of the oxide film formed during annealing will occur, resulting in localized seizures. Such component fluctuations must be controlled. Therefore, in the present invention, in addition to the above-mentioned specifications for SiN, the segregation rate of Si on the alloy plate surface immediately before etching is set to 1.
By setting it to 0% or less, local deterioration of etching perforability due to component fluctuations and local seizure during annealing can be solved. Even if the Si component segregation rate is 10% or less, if it is less than 0.401% in the minimum concentration area or exceeds 0.15% in the maximum concentration area, it may cause seizing during annealing or during etching or drilling. Therefore, control is required to prevent this from occurring.

In order to achieve the anti-seizure effect during annealing and the suppression of unevenness during etching and perforation as intended by the present invention, it is necessary to optimize the surface roughness in addition to the above-mentioned component specifications. That is, in FIG. 1, S≦0.0025%, Si: 0, O1~0.15%
(St is 0.01 to 0.15% at any location within the plate surface.
), etching perforation and adhesion seizure during annealing were investigated for alloy plates with a St component segregation rate ≦10%, and the area satisfying both of them was determined by the surface roughness parameter R.
a and Rsk. No matter what value Rsk is, if Ra exceeds 0.7μ-, unevenness during etching becomes noticeable;
If the Ra value is less than 0.5, adhesion seizure will occur on the entire surface during flat mask annealing, and the flat mask will have poor uniform adhesion, so the range of Ra in the present invention is 0.3 to 0.7.
μ Make it ugly.

In addition to such optimization of Ra, it is also necessary to optimize Rsk in order to prevent scorching during annealing. That is, even if Ra is in the range of 0.3 to 0.7 and crm, Rsk is +0.
When Rsk is less than 3, adhesion occurs over the entire surface during flat mask annealing, while when Rsk exceeds 11.0, localized seizure occurs during flat mask annealing. Also,
Under the conditions of Ra < 1/a Rsk 10.5, adhesion during flat mask annealing occurs over the entire surface.

From the above, the surface particle size conditions for obtaining the effects intended in the present invention are Ra: 0.3 to O-7utm, Rs
k: 0, 3 to 1.0 and (Ra)≧-1/3 (Rsk
) +0.5.

As described above, by optimizing the amount and distribution of Si and optimizing the surface roughness, it is possible to prevent etching perforation and adhesion seizure during annealing when applying Fe-Ni invar alloy to a thin plate for a shadow mask. However, if you are trying to reduce the cost of annealing by increasing the number of flat masks laminated in one annealing process than before, in addition to the above surface roughness specifications, the surface roughness In-plane anisotropy must be kept below a specific value. That is, the anisotropy of surface roughness is expressed as Ra
(L)-Ra (c) l ≦0.1μmR
sk (L)”−Rsk (c) l ≦0.
2, it is possible to avoid partial burn-in even when the number of laminated flat masks is increased compared to the conventional one.

In addition to specifying the above-mentioned components and surface roughness, it is effective to reduce S in order to raise the critical temperature at which contact annealing does not occur during flat mask annealing.
, Rsk, Si and Si segregation rate are within the range of the present invention and s31 is changed by changing the annealing temperature,
The state of contact seizure was investigated. By reducing the amount of S, the critical annealing temperature at which seizure does not occur can be increased.

Although the clear mechanism of the effect of such a reduction in S is not necessarily clear, the formation of a Si oxide film effective for preventing adhesion, which is formed on the surface during pre-press annealing in an Invar alloy with a Si content within the range of the present invention, It is surmised that this is because surface segregation of S occurs in competition with the surface.

In addition, as a means of reducing Si segregation, for example, a steel ingot or a continuous casting (CC) slab is heated at 1200°C x 20 hr, and the area is subjected to blooming at a cross-sectional area reduction rate of 20 to 60% in the primary blooming. Rolling is carried out and the light blooming slab is heated at 1200℃ x 20
Examples include a step of heating at 100 hr, followed by blooming rolling at a cross-sectional area reduction rate of 30 to 50% in secondary blooming, and slow cooling. This process involves reducing the segregation of Si in the steel ingot through primary heating and soaking, promoting the reduction of Si ingot segregation and micro-segregation through processing in the primary blooming process and subsequent heating and soaking, and secondary blooming. The homogenization of Si has been achieved through the synergistic effect of homogenization in the three main steps, namely processing and further promotion of the reduction of Si ingot segregation and microsegregation in the subsequent slow cooling process. The heating before blooming is as follows:
The content of 8 in the atmosphere was kept as low as 80 ppm or less to suppress grain boundary embrittlement during heating, and consideration was given to suppressing the occurrence of surface flaws in the blooming slab.

Furthermore, the thin plate for shadow masks that is featured in the present invention is not limited to those with a manufacturing history as described above. The effects of the present invention can be fully exerted even when the cold-rolled material is produced through rolling and light rolling. Further, production of an invar alloy material for a shadow mask having such a surface can be accomplished by rolling using dull rolls during final cold rolling or temper rolling.

In addition, in order to improve the etching perforation properties of the amber alloy, especially the quality of the hole interface after etching, and to reduce the contamination of the etching solution during the etching process and improve etching workability, it is necessary to The composition of the metal inclusions is shown in FIG. 3.

Points 1, 2, 3, 4 of the CuOMgO system ternary phase diagram. It is necessary to control the composition to outside the area surrounded by the pentagon connecting 5 and 5. In other words, by controlling the composition of such inclusions, the nonmetallic inclusions immediately before etching are reduced to size 3.
The inclusions are mainly spherical inclusions of μm or less in size, and there are very few linear inclusions that have extensibility and extend in the rolling direction (as a result, the formation of focal points caused by inclusions at the interface of the etching hole is suppressed, and the Contamination of the etching solution due to inclusions in the etching solution is also greatly reduced.

Electric discharge machining, laser machining, etc. can be used to obtain the dull roll as described above, but it is preferable to dull the roll by the John de blasting method. In this case, 5KH (hardness Hs 85 to 95) is used as the roll material, Further, it is appropriate to use a diameter of 100 to 125 inches. The roll processing conditions for the shot blasting method are Al2O~#240 steel grisotho (Hv
400 to 950), and the projected energy was Al
Use a low grade for 2O and a high grade for #240.

To obtain an appropriate roll surface roughness, Ra:
0.1. Ra: 0.4-0.9 +17m% Rsk after processing for f7m or less (Rsk<O)
: <0.2, more preferably ~0.5,
As such a roll roughness, a surface roughness within the range of the present invention can be appropriately obtained.

Regarding rolling, in final cold rolling or gP1 quality rolling, Jl) 10% or more per pass with a dull roll as described above,
Moreover, by employing a total of two or more passes and applying a rolling reduction of 10% or more per pass, the roll roughness is sufficiently transferred, and by using two or more passes, a predetermined R3 can be effectively obtained.

More specifically, the rolling oil used in rolling is one with a temperature of 10 to 50°C and a viscosity of 7 to 8 cst, and a viscosity of 0.1 to 0.
．． It is used by discharging at 5 kg/crA, and the rolling speed is 3
0~200mpm, tension during rolling is 15~45k at the front
g/kenlt, the rear is about 10-40kg/12,
The rolling blade per unit width is 0.15 to 0.25) n/
Preferably a dragon. The above-mentioned rolling oil discharge pressure is 0
．． less than 1 kg/ct or 0.5 k
If it exceeds 0.5 kg/cffl, it is difficult to obtain the surface roughness of the thin alloy plate targeted by the present invention even if other conditions are appropriate, and if it exceeds 0.5 kg/cat, unevenness occurs in the surface roughness. Further, by optimizing the tension conditions during rolling as described above, the flatness of the rolled alloy thin plate can be brought to a good level.

Ironing rolls, anti-crimping rolls, etc. are used for thin counter-rolling, and continuous annealing furnaces for mild steel, HIz?, are used for intermediate annealing and SR annealing. fi degree 5-15%, DP
-10~-30℃ atmosphere gas) or bright annealing furnace (H
z concentration of 15 to 100%, DP of 20 to -50°C), etc. are used.

(Example) A specific example of the invention according to the above-mentioned embodiment will be shown, and details of its operation and effect will be explained as follows.

Example I.

Alloys No. 1 to A having the composition shown in Table 1 below were tapped in an electric furnace and then ladle refined to obtain a 7-ton steel ingot.

In addition, in the ladle refining after tapping, CaO: 40% or less M
A ladle made of gO-CaO-based refractory is used, and the slag is (Cab)/(CaO)+(JV20:
1) is 0.45% or less, MgO is 25% or less, 5iOz
is less than 15%, and metal oxides with weaker oxidizing power than Si are 3
% or less of CaOAl2O:+MgO, and by processing with this, alloys having the chemical compositions shown in Table 1 and those shown in Table 2 to be described later were obtained.

After cleaning each steel ingot obtained as described above, 12
Heating at 00℃ for 20 hours, the area reduction rate was 60 in the primary blooming.
%, followed by heating at 1200°C for 20 hours, secondary blooming with a cross-section reduction rate of 45%, and slow cooling. Test materials were obtained, and alloy number 2 was prepared as test material g, alloy Il & 13 was prepared as test material h, and alloy number 4 was prepared as test material i, respectively. The material for the test material is a 7-ton steel ingot, heated at 1200℃ for 15 hours, subjected to primary blooming with a cross-section reduction rate of 78%, and slowly cooled to prepare a slab. did.

After cleaning these slabs and coating them with an antioxidant, they were heated at a heating temperature of 1100° C. and then hot rolled. At this time, the total rolling reduction rate at 1000°C or higher was 82%,
The total rolling reduction at 850°C or higher was 98%, and the winding temperature of the hot-rolled coil was 550 to 750°C.

After descaling the hot-rolled coil obtained as above,
Cold rolling and annealing were repeated, and alloy plates with thicknesses of 0 and 25 ml having surface roughness shown in Table 3, which will be described later, were prepared by rolling using dull rolls during final cold rolling or temper rolling, respectively. The morphology and size classification of inclusions in the etching test material were measured in the thickness section of the original sheet in the rolling direction. The measurement method is to use a 6012-microscope at 800x magnification and measure the thickness and length of all inclusions within the field of view.(Length/Thickness)≦3
are classified as spherical inclusions, (length/thickness)〉3 as linear inclusions, and the number of these inclusions by size (111
(hit).

The dull weight of the roll used was # for a roll of diameter 120 made of material SKH (Hs 90) by shot blasting.
120 Steel Griso H (II v400~95
0), and the surface roughness after processing is Ra: 0.3-0,
85, Rsk knee of 0.2 to -1.1. In this example, during the final skin pass rolling, the dull roll was used to roll the first pass to 18.6% and the second pass to 12.3%. (The total rolling reduction was 28.6%.The viscosity of the rolling oil used for this rolling was ?5 cst, the rolling speed was 100 mpm, and the tension at the time of rolling was 20 mpm.
kg/am', rear 15 kg/Kinho 2.

The rolling blade per unit width used in this rolling was 0.20 mm/■1, and the discharge pressure of rolling oil was 0.4 kg.
/cd, the rolling process could be carried out smoothly, and the flatness and other properties of the obtained alloy plate could be obtained at a good level.

The segregation rate of Si on the plate surface of each alloy plate as described above is E
This was investigated using a PMA mufping analyzer.

In addition, holes were etched into these thin alloy coils, flat masks were made, and the occurrence of unevenness was investigated. Furthermore, the interface of the etching hole was observed using a scanning electron microscope.
The presence or absence of bits was checked, and the presence of etching liquid was checked by checking the amount of residue after etching. Furthermore, regarding adhesion baking during annealing, 30 flat masks as described above were laminated and annealed at a temperature of 900° C., and then the adhesion was investigated. Each village of Alloy Nos. 1 to 4 has the composition of inclusions as shown in Table 2 below, and these inclusions have a melting point of 1600°C or more, which is the liquidus temperature, and the alloy thin plate immediately before etching. The inclusions were spherical in shape and were mainly 3 μm or less in width, and no pits were observed at the pore interface in terms of etching porosity.
There is very little staining of the etching solution, and the etching properties are excellent. That is, the alloy materials contemplated by the present invention are basically those having excellent etching perforation properties.

The results of each of the above-mentioned investigations are shown in Table 3 below, and for each alloy 11hl to 4, the results are as shown in Table 3 above.
In the figure A/203-CaO-MgO system ternary phase diagram ■～■
It was shown as

That is, the materials of test materials a and g have the following characteristics: Si amount, Si segregation rate,
Ra (L), Ra (C), Rsk (L), Rsk
The values of (C) and (Ra) +1/3 (Rsk) are both within the range of the present invention, and neither unevenness during etching nor adhesion seizure during annealing is observed.

On the other hand, although the surface roughness parameters of sample materials i and b are within the range of the present invention, the amount of Si is below the lower limit of the range specified by the present invention, and the upper limit thereof is within the range of the present invention. or the segregation rate exceeds the upper limit, and problems are recognized in one or two of unevenness during etching and perforation and adhesion burning during annealing.

Although the Si content and the Si segregation rate of sample materials c, d, e, and f are all within the specified range of the present invention, the upper limit of Ra in the present invention, (Ra) + 1/3 ( Rs.
k) The value is outside the value of -0.5, the lower limit of Rsk, and the upper limit of Rsk, and the performance is unfavorable in one or more of unevenness during etching and perforation and adhesion and seizure during annealing.

That is, it is understood that the effects aimed at by the present invention can only be achieved by optimizing the surface roughness in addition to taking into account the composition of the amount of Si and the segregation rate of Si.

Example 2 After descaling the hot-rolled coil used to produce sample material a of Example 1 and the hot-rolled coil used to produce sample material g, cold rolling and annealing were repeated to final cold rolling. Or an alloy plate of 0.25 mm thickness (sample material j, (!, m opening and 0) was obtained.

The Si segregation rate on the plate surface of these test materials is as shown in Example 1.
The results were investigated using the same method as above, and all results were in the range of 4 to 7%.

In addition, flat masks were made by etching holes in these alloy thin plate coils, and the occurrence of unevenness was investigated. Furthermore, for adhesion baking during annealing, 50 sheets of the above-mentioned flat masks were stacked and annealed at the temperatures shown in Table 4, and the adhesion conditions thereafter were investigated. All of these results are shown in Table 4 below.

Note that the dull roll used in this example, rolling conditions, etc. are the same as those described in Example 1 above, but the surface roughness of the roll is Ra after processing.
:0.45~0.70 μm, Rsk knee O, 4~
-10.9.

In other words, the amount of Si, the segregation rate of Si, and the surface roughness of the sample j are all within the range specified by the present invention, and the Si content is 0.0005%, and there is no unevenness during etching and drilling. Even under the example annealing conditions, no contact seizure occurred.

On the other hand, sample material 0 has a Si amount, Si segregation rate, and surface roughness within the specified range of the present invention, and has a Si content of 0.00.
25%, and no unevenness occurs during etching and perforation, but adhesion seizure occurs in some areas during annealing. As described above, it is understood that even if the constituent requirements of the present invention are satisfied, if the annealing temperature is higher than that of Example 1, the occurrence of adhesion seizure can be prevented by lowering the Si content.

In addition, the sample material n is within the specified range of the present invention except for the in-plane anisotropy of RaO and the in-plane anisotropy of Rsk. In this case, contact seizure did not occur. On the other hand, sample material m is obtained by annealing the flood mask of sample material n at 950° C., and in this case, contact seizure occurred over the entire surface during annealing.

In addition, in the sample material, each village of l also has an in-plane anisotropy of Ra, Rs
Although the properties other than kO in-plane anisotropy are within the specified range of the present invention, even in these materials, adhesion seizure occurs in some parts when annealed at 950°C. For these test materials, for l and m,
In sample material j, all of the in-plane anisotropy of RaO and the in-plane anisotropy of Rsk are within the range specified by the present invention,
In this case, no contact seizure occurred even at an annealing temperature of 950°C.

Even in materials where annealing adhesion does not occur at 850°C, when the annealing temperature is increased to a higher temperature, Ra and Rs
It is necessary to optimize the in-plane anisotropy of k.

``Effects of the Invention'' The present invention as explained above has excellent etching perforation properties, accurately prevents unevenness during perforation, and prevents contact baking when annealing the flat mask after perforation. To provide a thin plate for a shadow mask made of an Fe-Ni-based invar alloy that is appropriately prevented from causing damage, and to obtain a preferable manufacturing method for manufacturing a high-quality flat mask at a high yield.
This invention has the effect of making it possible to reduce costs.This invention has great industrial effects.

[Brief explanation of drawings]

The drawings show the technical content of the present invention, and FIG. 1 is a chart showing the relationship between Ra and Rsk and the occurrence of unevenness during etching and perforation in a flat mask, adhesion seizure during annealing, and Ra and Rsk. Figure 3 is a diagram showing the relationship between the annealing adhesion of flat masks and Si for the case where 30 flat masks are stacked during annealing. The alloys used in the examples are shown as 1 to 4, and FIG. 4 is a ternary phase diagram showing their general relationship.

Claims (1)

[Claims] 1. Si: 0.01 to 0.15 wt%, Ni: 34 to 3
8 wt%, the balance being Fe and unavoidable impurities, and the plate thickness of the alloy steel strip is substantially the same as that of the flat mask used in the production of a shadow mask, which includes a process of stacking and annealing a large number of flat masks. The surface roughness (Ra) is 0.3 to 0.7 μm, and the skewness (Rsk), which is an index of deviation in the height direction of the roughness curve, is 0.3 to 1.0. In addition, the condition of (Ra)≧-1/3(Rsk)+0.5 is satisfied, and the Si component segregation rate on the surface of the alloy plate immediately before etching | (component concentration in segregation area - average component concentration)/ An Fe-Ni alloy thin plate for a shadow mask, characterized in that the average component concentration |×100 is 10% or less. 2. It has the component and surface roughness of claim 1, and the anisotropy of the surface roughness is expressed by the following formula: |Ra(L)-Ra(c)|≦0.1μm |Rsk(L)- Rsk(c)|≦0.2 However, Ra(L) and Rsk(L) are measured values in the rolling direction, and Ra(c) and Rsk(c) are measured values in a direction perpendicular to the rolling direction. F for a shadow mask characterized by satisfying the relationship
e-Ni alloy thin plate. 3. A shadow characterized in that in producing a thin plate having the components of claim 1, a dull roll is used during final cold rolling or temper rolling to impart the surface roughness of claim 1 to the surface of the thin plate. A method for producing a Fe-Ni alloy thin plate for masks. 4. A shadow characterized in that in producing a thin plate having the components of claim 1, a dull roll is used during final cold rolling or temper rolling to impart the surface roughness of claim 2 to the surface of the thin plate. A method for producing a Fe-Ni alloy thin plate for masks.