EP3508285A1

EP3508285A1 - Metal mask material and production method therefor

Info

Publication number: EP3508285A1
Application number: EP17846646.2A
Authority: EP
Inventors: Akihiro Omori; Takuya Okamoto; Yasuyuki Iida
Original assignee: Hitachi Metals Ltd
Current assignee: Proterial Ltd
Priority date: 2016-08-31
Filing date: 2017-08-31
Publication date: 2019-07-10
Anticipated expiration: 2037-08-31
Also published as: EP3508285A4; KR20190030754A; CN109641248B; JP6646882B2; EP3508285B1; WO2018043642A1; KR102164912B1; JPWO2018043642A1; CN109641248A

Abstract

Provided are: a metal mask material the shape change of which after etching is suppressed and which is preferable in order to achieve good resist adhesiveness and good etching workability; and a production method for the metal mask material. The metal mask material has a surface roughness in the rolling direction and a surface roughness in a direction perpendicular to the rolling direction, which satisfy 0.05 µm≤Ra≤0.25 µm and Rz≤1.5 µm. The metal mask material has a skewness Rsk of 0 or greater in the direction perpendicular to the rolling direction. When a sample having a length of 150 mm and a width of 30 mm is cut out of the metal mask material and the thickness of the sample is reduced by 60% by etching from one side of the sample, the amount of warpage of the sample is 15 mm or less. The metal mask material has a thickness of 0.10-0.5 mm.

Description

[Technical Field]

The present invention relates to a metal mask material and a production method therefor.

[Background Art]

For example, when an organic EL display is manufactured, a metal mask is used for deposition on a substrate and generation of color patterning. For such a metal mask, a method of performing etching processing on an Fe-Ni alloy thin plate is known as one of methods of forming an opening. In order to improve etching characteristics, various methods have been proposed. For example Patent Literature 1 describes a material for etching processing in which, in order to enable formation of a high-definition etching pattern, a surface roughness measured in a direction perpendicular to a rolling direction is Ra: 0.08 to 0.20 µm, a surface roughness measured in the rolling direction is Ra: 0.01 to 0.10 µm, and the surface roughness measured in a direction perpendicular to the rolling direction has a rough surface roughness Ra exceeding the surface roughness measured in the rolling direction by 0.02 µm. In addition, Patent Literature 2 describes a metal mask material in which etching properties are improved by adjusting X-ray diffraction intensities of crystal orientations (111), (200), (220), and (311) on the rolled surface.

[Citation List]

[Patent Literature]

[Patent Literature 1]
Japanese Unexamined Patent Application Publication No. 2010-214447
[Patent Literature 2]
Japanese Unexamined Patent Application Publication No. 2014-101543

[Summary of Invention]

[Technical Problem]

In order to produce products such as a high-definition organic EL display, it is necessary to form patterns with higher precision on a mask to be used. Therefore, in addition to the surface form in which etching can uniformly progress, in order to minimize side etching, it is necessary to further improve the adhesion between a resist and a material. While Patent Literature 1 and Patent Literature 2 are excellent inventions in consideration of improvement in etching processability, there is still room for further research for improving the adhesion at the same time.
An objective of the present invention is to provide a metal mask material in which change in shape after etching is minimized and which is suitable for obtaining favorable adhesion to a resist and etching processability and a production method therefor.

[Solution to Problem]

In order to achieve the above objective, the inventors conducted extensive studies regarding various factors that influence etching processing such as a chemical composition, a surface roughness, and the residual stress. As a result, a configuration in which the adhesion to a resist can be improved and uniform etching processing is possible, and which is beneficial to minimize change in shape after etching has been found and thereby the present invention has been completed.
That is, an aspect of the present invention is a metal mask material including, by mass%, C: 0.01% or less, Si: 0.5% or less, Mn: 1.0% or less, and Ni: 30 to 50%, with the balance being made up of Fe and inevitable impurities,
wherein for the metal mask material, both a surface roughness in a rolling direction and a surface roughness in a direction perpendicular to the rolling direction are 0.05 µm≤Ra≤0.25 µm and Rz≤1.5 µm or less,
wherein the metal mask material has a skewness Rsk of 0 or more in a direction perpendicular to the rolling direction, and
wherein, when a sample with a length of 150 mm and a width of 30 mm is cut out from the metal mask material and 60% of the plate thickness of the sample is removed by etching the sample from one side, an amount of warpage is 15 mm or less, and the plate thickness is 0.10 mm or more and 0.5 mm or less.
Preferably, a skewness Rsk of the metal mask material in the rolling direction is smaller than a skewness Rsk of the metal mask material in the direction perpendicular to the rolling direction.
Preferably, a surface roughness Ra of the metal mask material in the direction perpendicular to the rolling direction is larger than a surface roughness Ra of the metal mask material in the rolling direction.
Preferably, an Rsk of the metal mask material in the direction perpendicular to the rolling direction is 1 or less.
Preferably, when a sample with a length of 150 mm and a width of 30 mm is cut out from the metal mask material and any of 20%, 30%, and 50% of the plate thickness of the sample is removed by etching the sample from one side, an amount of warpage is 15 mm or less.
Another aspect of the present invention is a production method of a metal mask material by cold rolling a cold rolling material including, by mass%, C: 0.01% or less, Si: 0.5% or less, Mn: 1.0% or less, and Ni: 30 to 50%, with the balance being made up of Fe and inevitable impurities to obtain a metal mask material, wherein:

conditions in a final pass of a finish cold rolling process for the cold rolling material are that a rolling reduction ratio is 35% or less and a bite angle of a rolling roller is 1.0° or more;
for the metal mask material, both a surface roughness in a rolling direction and a surface roughness in a direction perpendicular to the rolling direction are 0.05 µm≤Ra≤0.25 µm and Rz≤1.5 µm or less, and a skewness Rsk is 0 or more in the direction perpendicular to the rolling direction;
when a sample with a length of 150 mm and a width of 30 mm is cut out from the metal mask material and 60% of the plate thickness of the sample is removed by etching the sample from one side, an amount of warpage is 15 mm or less; and
the plate thickness of the material after finish cold rolling is 0.10 mm or more and less than 0.5 mm.

Preferably, the bite angle of the rolling roller is 3.0° or less.
Preferably, a rolling reduction ratio in the final pass of the finish cold rolling process is 15% to 35%.
Preferably, a surface roughness Ra in a direction perpendicular to a circumferential direction of a roller used in the final pass of the finish cold rolling process is 0.05 to 0.25 µm.
Preferably, a rolling speed in the finish cold rolling process is 150 m/min or less.

[Advantageous Effects of Invention]

According to the present invention having the above features, it is possible to obtain a metal mask material which has less change in shape after etching processing and is suitable for improving the adhesion to a resist.

[Description of Embodiments]

Hereinafter, the present invention will be described in detail. However, the present invention is not limited to embodiments described here, and the embodiments can be appropriately combined and modified without departing from the spirit and scope of the invention. Here, a metal mask material of the present invention includes a steel strip wound in a coil shape and a rectangular thin plate produced by cutting the steel strip.
The reasons why the metal mask material of the present invention is an Fe-Ni alloy having a chemical composition including, by mass%, C: 0.01% or less, Si: 0.5% or less, Mn: 1.0% or less, and Ni: 30 to 50%, with the balance being made up of Fe and inevitable impurities are as follows.

[C: 0.01 mass% or less]

C is an element that influences etching properties. Since etching properties deteriorate when an excess amount of C is included, the upper limit of C is set to 0.01%. There may be 0% of C, but it is incorporated in a small amount in a production process, and thus the lower limit is not particularly limited.

[Si: 0.5 mass% or less, Mn: 1.0 mass% or less]

Si and Mn are generally used for the purpose of deoxidation and are contained in a small amount in the Fe-Ni alloy. However, when an excessive amount thereof is contained, since segregation easily occurs, Si: 0.5% or less, and Mn: 1.0% or less are set. Preferably, an amount of Si and an amount of Mn are Si: 0.1% or less, and Mn: 0.5% or less. The lower limits of Si and Mn can be set to, for example, 0.05% for Si and 0.05% for Mn.

[Ni: 30 to 50 mass%]

Ni is an element that has a function of allowing adjustment of a coefficient of thermal expansion and greatly influences low thermal expansion characteristics. Since there is no effect of lowering a coefficient of thermal expansion when a content is less than 30% or exceeds 50%, a range for Ni is set to 30 to 50%. Preferably, an amount of Ni is 32 to 45%.
Components other than the above elements are Fe and inevitable impurities.
First, the metal mask material of the present invention will be described.

(Surface roughness)

Regarding a surface roughness of a metal mask material of the present invention, an arithmetic average roughness Ra (according to JIS-B-0601-2001) is 0.05 to 0.25 µm, and a maximum height Rz (according to JIS-B-0601-2001) is 1.5 µm or less. When Ra and Rz are within the above ranges, the material of the present invention can be etched with high precision. When Ra exceeds 0.25 µm, since the surface of the material is too rough, variations occur during etching, and etching processing with high precision becomes difficult. When Ra is less than 0.05 µm, the adhesion to a resist is likely to be lowered. In addition, when Rz exceeds 1.5 µm even if Ra is within the above range, this is not preferable because a large peak part in a roughness curve is formed in a part of the surface of the material, etching progresses from the peak part and this causes etching unevenness. The lower limit of Rz is not particularly limited. However, in order to obtain higher adhesion, the lower limit of Rz is preferably set to 0.3 µm. The upper limit of Ra is more preferably 0.20 µm, and the upper limit of Rz is more preferably 1.2 µm. In order to minimize local etching unevenness, it is preferable that these restrictions on the surface roughness be satisfied for both a surface roughness in a direction perpendicular to a rolling direction (hereinafter referred to as a "width direction" or "direction perpendicular to a rolling direction") and a surface roughness in the rolling direction (hereinafter referred to as a "longitudinal direction") of the metal mask material. In addition, a surface roughness in the width direction of the metal mask material in the present embodiment is preferably larger than a surface roughness measured in the rolling direction. Accordingly, a rolling oil is easily discharged from between the roller and the material, and it is possible to minimize an oil pit formed by biting of the rolling oil. Specifically, Ra in the width direction is preferably a value that is higher than Ra in the rolling direction by 10% or more because the above effect of minimizing an oil pit is easily obtained. Here, the surface roughness can be measured using a contact type or non-contact type roughness meter that is generally used.
The metal mask material of the present embodiment has a skewness Rsk (according to JIS-B-0601-2001)≥0 in a direction perpendicular to the rolling direction of the material in addition to the above surface roughness. When the above numerical value range is satisfied, since many peak parts with a sharp shape are formed in the roughness curve of the surface of the material, it is possible to obtain an excellent anchoring effect. Accordingly, it is possible to improve the adhesion between the metal mask material and the resist, and it is possible to minimize side etching that is caused when an etching solution enters a boundary between the material and the resist. Since there is a possibility of uniform progress of etching being inhibited when a value of Rsk is excessively high, the upper limit of Rsk is preferably 1.0 and more preferably 0.5. In addition, when Rsk in the rolling direction of the material is set to be smaller than an Rsk in the width direction, it is possible to improve the above effect of minimizing occurrence of oil pits. When Rsk in the rolling direction is smaller than the value of Rsk in the width direction, it may be a value of less than 0 (negative value). Here, the metal mask material of the present embodiment is applied to a material with a plate thickness of 0.5 mm or less in order to sufficiently obtain the above effect of Rsk. Preferably, the plate thickness is 0.2 mm or less. In addition, the lower limit of the plate thickness is set to 0.10 mm in order for a bite angle to be described below to be easily adjusted to 1.0° or more.

(Amount of warpage)

Regarding the metal mask material of the present embodiment, a sample with a length of 150 mm and a width of 30 mm is cut out, the sample is etched from one side, and an amount of warpage when 60% of the plate thickness of the sample is removed is 15 mm or less. As described above, even if the vicinity of the center of the plate thickness in which the balance of the stress further breaks down is etched, by reducing the residual stress in a region of 60% of the plate thickness, it is possible to minimize deformation and etching processing can progress favorably. Therefore, half etching with various depths can be performed and it is possible to increase a degree of freedom of etching pattern. Preferably, an amount of warpage when any of 20%, 30%, and 50% of the plate thickness of the sample is removed is 15 mm or less. More preferably, amounts of warpage when any of 20, 30, and 50% of the plate thickness of the sample is removed are all 15 mm or less. The amount of warpage is preferably 13 mm or less, more preferably 11 mm or less, and still more preferably 9 mm or less. Most preferably, an amount of warpage when 50% of the plate thickness of the sample is removed, in which the balance of the stress easily breaks and large warpage is likely to occur, is 9 mm or less, and an amount of warpage when 20% or 30% of the plate thickness is removed is preferably 7 mm or less. In the present embodiment, the sample is cut so that a longitudinal direction corresponds to the rolling direction, and the warpage is measured. Here, in a method of measuring an amount of warpage in the present embodiment, after removal by etching from one side of a sample, the sample is hung of which an upper end of the cut sample is in contact with a vertical surface plate, and a horizontal distance between a lower end of the cut sample separated from the vertical surface plate due to warpage and the vertical surface plate is measured as an amount of warpage.
Subsequently, a production method of a metal mask material of the present invention will be described.
In the production method of the present embodiment, for example, processes of vacuum melting-hot forging-hot rolling-cold rolling can be applied. As necessary, a homogenization heat treatment is performed at about 1,200 °C in a step before cold rolling, and during the cold rolling process, in order to reduce the hardness of the cold rolled material, annealing at 800 to 950 °C can be performed at least once. In the cold rolling process, a polishing process of removing scale on the surface and an ear trimming process of removing an off-gauge part (a part with a thick plate thickness) at the end of the material and removing an ear wave part generated in rolling processing may be performed. As a furnace used during the heat treatment process, existing furnaces such as a vertical type furnace and a horizontal type furnace (a horizontal furnace) may be used. However, in order to prevent breaking while passing a plate through and further increase the steepness of the material, a vertical type furnace in which deflection due to an own weight is unlikely to occur is preferably used.
In the production method of the present embodiment, a rolling reduction ratio in a final pass of a finish cold rolling process is adjusted to 35% or less. When the rolling reduction ratio exceeds 35%, the residual distortion of the material increases and the occurrence of deformation during etching processing tends to increase. Preferably, the upper limit of the rolling reduction ratio is 30%. Here, since it is difficult to adjust the surface roughness to be in the above range when the rolling reduction ratio is excessively low, the lower limit of the rolling reduction ratio is preferably set to 15%. More preferably, the lower limit of the rolling reduction ratio is 18%, and most preferably, the lower limit of the rolling reduction ratio is 20%. Here, the number of passes in the finish cold rolling is not particularly limited, and it may be performed a plurality of times (for example, three times or more). However, in order to perform rolling so that polishing marks to be described below are prevented from being crushed, finish rolling is preferably performed in one pass.
In the production method of the present embodiment, as a roller used in the finish cold rolling, a roller having a surface roughness Ra of 0.05 to 0.25 µm in a direction perpendicular to a circumferential direction (a direction in which a roller rotates) of the roller can be used. Preferably, the upper limit of Ra is 0.15 µm. Thereby, a desired roughness can be imparted to the metal mask material. The material of the roller is not particularly limited. For example, an alloy tool steel roller defined in JIS-G4404 can be used. In addition, when a roughness with which oil during rolling easily passes between the surface of the rolling material and the roller is imparted to the roller, it is possible to minimize the occurrence of an oil pit. Therefore, on the surface of the roller in the production method according to the present invention, a polishing mark is preferably formed on the roller in the circumferential direction. In order to form the polishing mark, a grindstone having a roughness at which a roughness in a direction perpendicular to the circumferential direction of the roller can be set to Ra: 0.05 to 0.25 µm is prepared, and the grindstone is pressed while rolling the roller for formation. More preferably, a difference between a roughness in the circumferential direction of the roller in the present embodiment and a surface roughness in a direction perpendicular to the circumferential direction is an Ra of 0.02 µm or more according to the polishing mark. With this feature, a difference can be intentionally provided between the surface roughness in a direction perpendicular to a rolling direction of the metal mask material and a surface roughness in the rolling direction, and rolling oil is more easily discharged, and thus it is possible to further minimize the occurrence of an oil pit.
In the production method according to the present invention, in the finish cold rolling, a bite angle which is an angle at which the rolled material and a work roller start to come in contact with each other is set to 1.0° or more. When the bite angle is adjusted in this manner, it is possible to minimize an excess occurrence of oil pit and obtain a desired surface roughness. Here, since there is a possibility of a desired rolling shape not being obtained due to an excess rolling load when the bite angle is too large, the upper limit of the bite angle can be set to 3.0°. Preferably, the upper limit of the bite angle is 2.0°. In addition, these restrictions on the bite angle are preferably applied to all passes of the finish cold rolling. Here, when the bite angle is θ in the present embodiment, the bite angle can be derived from a calculation formula θ=180/π·arccos((R-(h₀-h₁)/2)/R). Here, R indicates the radius of the roller, h₀ indicates the plate thickness of the material before rolling, and h₁ indicates the plate thickness of the material after rolling.
In the production method of the present embodiment, a rolling speed is preferably set to 150 m/min or less. When the rolling speed is set to 150 m/min or less, an amount of a rolling oil introduced between the work roller and the metal mask material is reduced, the occurrence of an oil pit is minimized, and it is possible to adjust Rsk to have a positive value more reliably. More preferably, the upper limit of the rolling speed is 120 m/min. Most preferably, the upper limit is set to 100 m/min. Here, the lower limit of the rolling speed is not particularly set, but since the production efficiency is lowered if the rolling speed is too low, 20 m/min can be set. 30 m/min is preferable.
In the production method of the present embodiment, distortion relief annealing may be performed in order to remove distortion remaining in an etching processing material after finish rolling and minimize shape defects occurring in the material. The distortion relief annealing is preferably performed at a temperature of about 400 to 700 °C. Here, an annealing time is not particularly limited. However, when the time is too long, characteristics such as the tensile strength significantly deteriorate, and when the time is too short, an effect of removing the distortion is not obtained. Therefore, about 0.5 to 3.0 min is preferable. More preferably, the lower limit of the distortion relief annealing time is 1.2 min and most preferably the lower limit of the distortion relief annealing time is 1.5 min.

Examples

The present invention will be described in further detail with reference to the following examples
Chemical compositions of metal mask materials of this example are shown in Table 1. An Fe-Ni alloy of this example was subjected to and a finishing process to have a thickness of 2 to 3 mm according to vacuum melting-hot forging-homogenization heat treatment-hot rolling, and was then subjected to cold rolling. The Fe-Ni alloy after hot rolling was subjected to cold rolling including annealing twice, and an Fe-Ni alloy cold rolled material was produced. The thickness of the Fe-Ni alloy cold rolled materials before the final pass of the finish cold rolling were 0.125 mm (sample No. 1) and 0.275 mm (sample No. 2), respectively, and rolling conditions were adjusted so that sample No. 1 had a thickness of 0.10 mm (a rolling reduction ratio of 20%) after the finish cold rolling and sample No. 2 had a thickness of 0.20 mm (rolling reduction ratio of 27%) after the finish cold rolling. In this case, a bite angle of the roller of sample No. 1 was 1.28°. In addition, a bite angle of the roller of sample No. 2 was 2.22°. In addition, in sample No. 1 and sample No. 2, a rolling speed during the finish cold rolling was about 100 m/min. In addition, a roller having a roughness Ra in a range of 0.08 to 0.25 µm in a direction perpendicular to a circumferential direction (a direction in which a roller rotates) of the roller used for finish cold rolling was used. After the finish cold rolling, distortion relief annealing was performed on sample No. 1 at a temperature of 600 °C for 2 minutes and on sample No. 2 at a temperature of 630 °C for 1 minute. In addition, as a comparative example, a sample No. 11 in which a bite angle of a roller was adjusted to less than 1.0° by adjusting rolling conditions was prepared. A chemical composition, a final plate thickness, and distortion relief annealing condition of the sample No. 11 were the same as those of sample No. 1. [Table 1]

(mass%)

Sample No. C Si Mn Ni Balance

1 0.002 0.024 0.22 35.8 Fe and inevitable impurities

2 0.002 0.024 0.27 35.8 Fe and inevitable impurities

Subsequently, a surface roughness and a warpage of the obtained sample were measured. Surface roughnesses Ra, Rz, and Rsk were measured according to measurement methods shown in JIS B0601 and JIS B0651, three places were randomly selected, and surface roughnesses in the longitudinal direction and the width direction were measured. A stylus type roughness meter was used as a measurement device and measurement was performed under conditions of an evaluation length of 4 mm, a measurement speed of 0.3 mm/s, and a cutoff value of 0.8 mm. Table 2 shows average values at three places. In addition, for measurement of warpage, a cut sample with a length of 150 mm and a width of 30 mm was prepared, and etched from one side so that the plate thickness became 2/5 (60% of the plate thickness was removed), and an amount of warpage when the cut sample was hung on a vertical upper board was then measured and evaluated. Here, the cut sample was collected from the central part in the width direction from the prepared so that the length direction corresponded to the rolling direction. A ferric chloride aqueous solution was used as an etching solution, and the etching solution with a liquid temperature of 50 °C was sprayed thereon and thus a test piece corroded. The results are shown in Table 2.

[Table 2]

Sample No.	Surface roughness						Amount of warpage (mm)
	Ra (µm)		Rz (µm)		Rsk
	Width direction	Longitudinal direction	Width direction	Longitudinal direction	Width direction	Longitudinal direction
1	0.10	0.08	0.69	0.55	0.23	-0.93	5
2	0.10	0.08	0.70	0.46	0.16	-0.50	6
11	0.10	0.09	0.73	0.54	-0.14	-0.78	-

According to the results in Table 2, it was confirmed that sample No. 1 and sample No. 2 as metal mask materials of the example of the present invention had an optimal surface state such that it exhibited favorable adhesion and uniform etching processability, and it was possible to minimize change in shape after deep etching exceeding half of the plate thickness. On the other hand, it was confirmed that sample No. 11 as a comparative example had adhesion that was highly likely to be lower than that of the example of the present invention because Rsk in the width direction was a negative value.

(Example 2)

Next, a plurality of cut samples with a length of 150 mm and a width of 30 mm of sample No. 1 and sample No. 2 were prepared, samples Nos. 3 to 8 of the example of the present invention in which an amount of removal due to etching was changed as shown in Table 3 were prepared, and an amount of warpage was measured. In Table 3, samples Nos. 3 to 5 were samples prepared from sample No. 1, and samples Nos. 6 to 8 were samples prepared from sample No. 2. A method of measuring an amount of warpage and an etching solution used were the same as those used in Example 1. The results are shown in Table 3. [Table 3]

Sample No. Amount of removal due to etching (with respect to initial plate thickness) Amount of warpage (mm)

3 20% 3

4 30% 5

5 50% 2

6 20% 10

7 30% 6

8 50% 14
According to the results in Table 3, it was confirmed that, even if an etching depth was changed, it was possible to minimize an amount of warpage in the metal mask material of the present invention. In particular, when an amount of the material removed due to etching was 50% of the plate thickness, the balance between the compressive residual stress and the tensile residual stress broke down, and excess warpage was likely to occur, but excess warpage did not occur in the material of the example of the present invention, and it was confirmed that the material was suitable for etching application. In addition, it was confirmed that samples Nos. 3 to 5 has smaller warpage than samples Nos. 6 to 8. It is thought that this is because, when samples were prepared, since a distortion relief annealing time of samples Nos. 6 to 8 was shorter than that of samples Nos. 3 to 5, an amount of the remaining distortion slightly increased.

Claims

A metal mask material, the metal mask material is characterised by including, by mass%, C: 0.01% or less, Si: 0.5% or less, Mn: 1.0% or less, and Ni: 30 to 50%, with the balance being made up of Fe and inevitable impurities,
wherein for the metal mask material, both a surface roughness in a rolling direction and a surface roughness in a direction perpendicular to the rolling direction are 0.05 µm≤Ra≤0.25 µm and Rz≤1.5 µm or less,
wherein the metal mask material has a skewness Rsk of 0 or more in a direction perpendicular to the rolling direction, and
wherein, when a sample with a length of 150 mm and a width of 30 mm is cut out from the metal mask material and 60% of the plate thickness of the sample is removed by etching the sample from one side, an amount of warpage is 15 mm or less, and the plate thickness is 0.10 mm or more and 0.5 mm or less.
The metal mask material according to claim 1,
wherein a skewness Rsk of the metal mask material in the rolling direction is smaller than a skewness Rsk of the metal mask material in the direction perpendicular to the rolling direction.
The metal mask material according to claim 1 or 2,
wherein a surface roughness Ra of the metal mask material in the direction perpendicular to the rolling direction is larger than a surface roughness Ra of the metal mask material in the rolling direction.
The metal mask material according to any one of claims 1 to 3,
wherein an Rsk of the metal mask material in the direction perpendicular to the rolling direction is 1.0 or less.
The metal mask material according to any one of claims 1 to 4,
wherein, when a sample with a length of 150 mm and a width of 30 mm is cut out from the metal mask material and any of 20%, 30%, and 50% of the plate thickness of the sample is removed by etching the sample from one side, an amount of warpage is 15 mm or less.
A production method of a metal mask material, the production method of a metal mask material is characterised by cold rolling a cold rolling material including, by mass%, C: 0.01% or less, Si: 0.5% or less, Mn: 1.0% or less, and Ni: 30 to 50%, with the balance being made up of Fe and inevitable impurities to obtain a metal mask material, wherein:
conditions in a final pass of a finish cold rolling process for the cold rolling material are that a rolling reduction ratio is 35% or less and a bite angle of a rolling roller is 1.0° or more;

for the metal mask material, both a surface roughness in a rolling direction and a surface roughness in a direction perpendicular to the rolling direction are 0.05 µm≤Ra≤0.25 µm and Rz≤1.5 µm or less, and a skewness Rsk is 0 or more in the direction perpendicular to the rolling direction;

when a sample with a length of 150 mm and a width of 30 mm is cut out from the metal mask material and 60% of the plate thickness of the sample is removed by etching the sample from one side, an amount of warpage is 15 mm or less; and

the plate thickness of the material after finish cold rolling is 0.10 mm or more and 0.5 mm or less.
The production method of a metal mask material according to claim 6,
wherein the bite angle of the rolling roller is 3.0° or less.
The production method of a metal mask material according to claim 6 or 7,
wherein a rolling reduction ratio in the final pass of the finish cold rolling process is 15% to 35%.
The production method of a metal mask material according to any one of claims 6 to 8,
wherein a surface roughness Ra in a direction perpendicular to a circumferential direction of a roller used in the final pass of the finish cold rolling process is 0.05 to 0.25 µm.
The production method of a metal mask material according to any one of claims 6 to 9,
wherein a rolling speed in the finish cold rolling process is 150 m/min or less.