JP6988565B2 - A base material for a vapor deposition mask, a method for manufacturing a base material for a vapor deposition mask, a method for manufacturing a vapor deposition mask, and a method for manufacturing a display device. - Google Patents

Description

The present invention relates to a base material for a vapor deposition mask, a method for manufacturing a base material for a vapor deposition mask, a method for manufacturing a vapor deposition mask, and a method for manufacturing a display device.

The vapor deposition mask includes a first surface and a second surface. The first surface faces an object such as a substrate, and the second surface is located on the opposite side to the first surface. The hole penetrating from the first surface to the second surface includes a first opening located on the first surface and a second opening located on the second surface. The vapor-filmed substance that enters the hole from the second opening forms a pattern that follows the position of the first opening and the shape of the first opening on the object (see, for example, Patent Document 1).

JP-A-2015-055007

The holes provided in the vapor deposition mask have a cross-sectional area that expands from the first opening to the second opening, thereby increasing the amount of vapor deposition material entering the holes through the second opening and reaching the first opening. Secure the quantity of substances. On the other hand, a part of the vapor-filmed substance that enters the hole from the second opening does not reach the first opening and adheres to the wall surface that partitions the hole. The vapor-deposited material adhering to the wall surface prevents the passage of holes by other thin-film-deposited materials and reduces the accuracy of the dimensions of the pattern.

In recent years, it has been studied to reduce the thickness of the vapor deposition mask and reduce the area of the wall surface itself for the purpose of reducing the volume of the vapor deposition substance adhering to the wall surface. Then, as a technique for reducing the thickness of the vapor deposition mask, it is considered to reduce the thickness of the metal plate itself, which is a base material for manufacturing the vapor deposition mask.

On the other hand, in the etching process of forming holes in a metal plate, the thinner the metal plate, the smaller the volume of metal to be removed. Therefore, the permissible range is narrowed depending on the processing conditions such as the time for supplying the etching solution to the metal plate and the temperature of the etching to be supplied, and as a result, sufficient accuracy can be obtained for the dimensions of the first opening and the second opening. I want to. In particular, in the technique for manufacturing a metal plate, rolling in which the base metal is stretched by a roller and electrolysis in which the metal plate deposited on the electrode is peeled off from the electrode are used, and a wavy shape is formed on the metal plate itself. In the metal plate having such a shape, the contact time between the metal plate and the etching solution is greatly different, for example, between the wavy peaks and the wavy valleys, and the allowable range is narrowed. The decrease in accuracy is further exacerbated. As described above, the technique of reducing the thickness of the vapor deposition mask reduces the amount of the vapor deposition substance adhering to the wall surface, thereby improving the accuracy of the pattern dimensions in the repeated vapor deposition. It introduces a new problem that it is difficult to obtain the accuracy required for pattern dimensions.

An object of the present invention is to provide a base material for a vapor deposition mask, a method for manufacturing a base material for a vapor deposition mask, a method for manufacturing a vapor deposition mask, and a method for manufacturing a display device, which can improve the accuracy of a pattern formed by vapor deposition. That is.

The base material for a vapor deposition mask for solving the above-mentioned problems is a base material for a vapor deposition mask, which is a metal plate having a strip shape in which a plurality of holes are formed by etching and is used for manufacturing the vapor deposition mask. The shapes along the width direction of the metal plate at each position in the length direction of the plate are different from each other, and each shape has a wave repeating in the width direction of the metal plate, and one of the waves. The length of a straight line in the width direction connecting one valley to the other valley is the length of the wave, and the percentage of the height of the wave to the length of the wave is the unit steepness, and the unit length in the length direction is the unit length. The maximum value of the unit steepness in the metal plate having the unit length is 500 mm, the first steepness is the first steepness, and the first steepness is 0.5% or less.

A method for manufacturing a base material for a vapor deposition mask for solving the above problems is a method for manufacturing a base material for a vapor deposition mask, which is a metal plate having a band shape and is used for manufacturing a vapor deposition mask in which a plurality of holes are formed by etching. Including rolling the base metal to obtain the metal plate, the shapes of the metal plate along the width direction at each position in the length direction of the metal plate are different from each other. The shape has waves that repeat in the width direction of the metal plate, and the length of a straight line in the width direction connecting one valley to the other valley in the wave is the length of the wave, with respect to the length of the wave. The percentage of the height of the wave is the unit steepness, the unit length in the length direction is 500 mm, and the maximum value of the unit steepness in the metal plate of the unit length is the first steepness. The base metal is rolled so that the first steepness is 0.5% or less.

A method for manufacturing a vapor deposition mask for solving the above problems is to form a resist layer on a metal plate having a band shape and to form a plurality of holes in the metal plate by etching using the resist layer as a mask to form a mask. It is a method of manufacturing a vapor deposition mask including forming a portion, and the shapes along the width direction of the metal plate at each position in the length direction of the metal plate are different from each other, and each shape is formed. Has a wave that repeats in the width direction of the metal plate, and the length of a straight line in the width direction connecting one valley to the other valley in the wave is the length of the wave, and is the length of the wave. The percentage of the wave height is the unit steepness, the unit length in the length direction is 500 mm, and the maximum value of the unit steepness in the metal plate of the unit length is the first steepness. The first steepness is 0.5% or less.

According to the above-mentioned thin-film deposition mask base material, the maximum value of the steepness in the width direction of the metal plate in the unit length is 0.5 or less, so that the surface of the thin-film deposition mask base material conveyed in the length direction Even if the liquid is supplied, it is easy to flow the liquid uniformly on the surface of the substrate for the vapor deposition mask. As a result, the liquid supplied to the surface of the substrate for the vapor deposition mask, which is conveyed in the length direction, is prevented from stagnation in a part in the length direction. Then, the uniformity of processing in the length direction using the treatment with a liquid such as an etching solution, that is, the uniformity in the length direction of the pores of the substrate for the vapor deposition mask, and by extension, the pattern formed by the vapor deposition. It is possible to improve the accuracy.

In the base material for vapor deposition mask, the maximum value of the unit steepness in the width direction of the metal plate at each position in the length direction of the metal plate is the second steepness, and the metal of the unit length. The average value of the second steepness on the plate may be 0.25% or less. According to this thin-film deposition mask substrate, the steepness in the width direction is suppressed in the entire unit length, so that the accuracy of the pattern can be further improved.

In the base material for vapor deposition mask, the number of waves contained in the width direction of the metal plate at each position in the length direction of the metal plate is a wave number, which is the wave number of the metal plate having the unit length. The maximum value may be 4 or less. According to this thin-film deposition mask base material, the number of waves contained in the width direction is 4 or less, and the unit steepness of each wave is 0.5% or less. It is possible to further suppress the stagnation of the liquid in.

In the base material for vapor deposition mask, the number of waves contained in the width direction of the metal plate at each position in the length direction of the metal plate is a wave number, which is the wave number of the metal plate having the unit length. The average value may be 2 or less. According to this thin-film deposition mask substrate, the wave number in the width direction is suppressed over the entire unit length, so that the accuracy of the pattern can be further improved.

In the method for manufacturing a vapor deposition mask, forming the mask portion means forming a plurality of the mask portions on a single metal plate, and each mask portion has the plurality of holes1. Two side surfaces are separately provided, and the side surface of each mask portion and one frame portion are joined to each other so that the plurality of holes are surrounded by the one frame portion for each mask portion. Further may be included. According to this method for manufacturing a thin-film deposition mask, since the side surface of each mask portion and one frame portion are joined, the stability of the shape of each mask portion is improved in the vapor-filming mask provided with a plurality of mask portions. It will also be possible.

A method for manufacturing a display device for solving the above problems includes preparing a vapor deposition mask according to the method for manufacturing a vapor deposition mask and forming a pattern by vapor deposition using the vapor deposition mask.

According to each of the above configurations, the accuracy of the pattern formed by the vapor deposition can be improved.

The perspective view which shows the base material for a vapor deposition mask. The plan view which shows the base material for measurement. The figure which shows the graph for demonstrating the steepness together with the cross-sectional structure of the base material for measurement. The plan view which shows the planar structure of a mask device. The cross-sectional view which shows an example of the cross-sectional structure of a mask part partially. A cross-sectional view partially showing another example of the cross-sectional structure of the mask portion. A cross-sectional view partially showing an example of a joint structure between the edge of the mask portion and the frame portion. FIG. 6 is a cross-sectional view partially showing another example of the joint structure between the edge of the mask portion and the frame portion. (A) A plan view showing an example of a planar structure of a vapor deposition mask, and (b) a cross-sectional view showing an example of a cross-sectional structure of a vapor deposition mask. (A) A plan view showing another example of the plan structure of the vapor deposition mask, (b) a cross-sectional view showing another example of the cross-sectional structure of the vapor deposition mask. The process chart which shows the rolling process for manufacturing the base material for a vapor deposition mask. The process drawing which shows the heating process for manufacturing the base material for a vapor deposition mask. The process drawing which shows the etching process for manufacturing a mask part. The process drawing which shows the etching process for manufacturing a mask part. The process drawing which shows the etching process for manufacturing a mask part. The process drawing which shows the etching process for manufacturing a mask part. The process drawing which shows the etching process for manufacturing a mask part. The process drawing which shows the etching process for manufacturing a mask part. (A)-(h) A process diagram illustrating an example of a method for manufacturing a vapor deposition mask. (A)-(e) A process diagram illustrating an example of a method for manufacturing a vapor deposition mask. (A)-(f) A process diagram illustrating an example of a method for manufacturing a vapor deposition mask. The plan view which shows the planar structure of the measuring base material in each Example together with the dimension.

An embodiment of a base material for a vapor deposition mask, a method for manufacturing a base material for a vapor deposition mask, a method for manufacturing a vapor deposition mask, and a method for manufacturing a display device will be described with reference to FIGS. 1 to 22.

[Construction of base material for vapor deposition mask]
As shown in FIG. 1, the base material 1 for a vapor deposition mask is a metal plate having a band shape. The base material 1 for a vapor deposition mask has a wave shape having waves repeated in the width direction DW at each position in the length direction DL which is the length direction. Each position of the substrate 1 for a vapor deposition mask in the length direction DL has a wave shape different from each other. In different wave shapes, the number of waves (unevenness) included in the wave shape, the length of the wave, the height of the wave, etc. are different from each other. In addition, in FIG. 1, in order to explain the shape of the substrate 1 for a vapor deposition mask, the wave shape is exaggerated from the actual shape. The thickness of the substrate 1 for a vapor deposition mask is 10 μm or more and 50 μm or less. The thickness uniformity of the thin-film mask substrate 1 is, for example, the ratio of the difference between the maximum value and the minimum thickness to the average value of the thickness is 5% or less.

The material constituting the base material 1 for the vapor deposition mask is nickel or an iron-nickel alloy, for example, an iron-nickel alloy containing 30% by mass or more of nickel, particularly 36% by mass nickel and 64% by mass iron. It is preferably composed of an alloy as a main component, that is, an inver. When the main component is an alloy of 36% by mass nickel and 64% by mass iron, the residue contains additives such as chromium, manganese, carbon and cobalt. When the material constituting the vapor deposition mask base material 1 is Invar, the coefficient of thermal expansion of the vapor deposition mask base material 1 is, for example, ^{about 1.2 × 10 −6} / ° C. In the case of the thin-film deposition mask base material 1 having such a coefficient of thermal expansion, the size changes due to the thermal expansion of the mask manufactured from the vapor-film deposition mask base material 1 and the thermal expansion of the glass substrate or the polyimide sheet. Since the change in size is about the same, it is preferable to use a glass substrate or a polyimide sheet as an example of the vapor deposition target.

[Steepness]
The position (height) of the surface of the vapor deposition mask base material 1 with respect to the horizontal plane is the surface position in the state where the vapor deposition mask base material 1 is placed on the horizontal plane.
As shown in FIG. 2, in the measurement of the surface position, first, the metal plate is cut so that the dimension of the rolled or electrolytically produced metal plate in the width direction DW is the width W, and the metal plate is formed into a strip shape. The base material 1 for a vapor deposition mask, which is a metal plate having the above, is wound in a roll shape. Next, a slit step is performed in which the thin-film deposition mask base material 1 is cut in the entire width direction DW (total width), and the measurement base material 2M is cut out as a part of the vapor deposition mask base material 1 in the length direction DL. Is done. The width W of the measurement base material 2M in the width direction DW is equal to the dimension of the vapor deposition mask base material 1 in the width direction DW. Next, with respect to the surface 2S of the measuring base material 2M, the surface position at each position in the width direction DW is measured at predetermined intervals in the length direction DL. The range in which the surface position is measured is the measurement range ZL.

The measurement range ZL is a range excluding the non-measurement range ZE, which is both ends of the measurement base material 2M in the length direction DL. The measurement range ZL is also a range excluding a non-measurement range (not shown) which is both ends of the measurement base material 2M in the width direction DW. In the slit step of cutting the vapor deposition mask base material 1, a new wave shape different from that of the vapor deposition mask base material 1 can be formed on the measurement base material. The length of each non-measurement range ZE in the length direction DL is a range in which such a new wave shape can be formed, and is a range excluded from the measurement of the surface position. The length of each non-measurement range ZE in the length direction DL is, for example, 100 mm. Also in the width direction, the length in the width direction DW of the non-measurement range is, for example, 10 mm from the end of the width direction DW in order to exclude the new wave shape due to the slit process.

FIG. 3 is a graph showing an example of the surface position of the measurement base material 2M at each position in the width direction DW, and is a diagram showing the surface position together with the cross-sectional structure of the measurement base material 2M in the cross section including the width direction DW. Is. Note that FIG. 3 shows an example of a portion having three waves in the width direction DW among each portion in the length direction DL.

As shown in FIG. 3, the positions of the DW in the width direction in which the surface position is measured are arranged at intervals capable of copying the wave shape of the substrate 1 for the vapor deposition mask. The positions of the DW in the width direction in which the surface position is measured are arranged in the DW in the width direction at intervals of 1 mm or more and 20 mm or less, for example. The line LC connecting the surface positions of each position in the width direction DW is regarded as a line along the surface of the vapor deposition mask base material 1, and the length of the line LC is the creepage distance on the surface of the vapor deposition mask base material 1. Is. In each wave included in the line LC, the length of the straight line in the width direction DW connecting one valley to the other valley in the wave is the wave lengths L1, L2, and L3. In each wave included in the line LC, the height with respect to the straight line connecting the valleys in the wave is the wave heights HW1, HW2, HW3. The unit steepness of the base material 1 for the vapor deposition mask is a percentage of the height of the wave with respect to the length of the wave. In the example shown in FIG. 3, the height HW1 / length L1 × 100 (%), height HW2 / The length is L2 × 100 (%), and the height is HW3 / the length is L3 × 100 (%). When the peak of the wave is located at the end of the DW in the width direction, the length of the wave is estimated as twice the length from the peak to the valley of the wave in the DW in the width direction.

The unit length of the substrate 1 for the vapor deposition mask in the length direction DL is 500 mm.
The first steepness of the substrate 1 for the vapor deposition mask is the maximum value in the unit length and the unit steepness of all the waves included in the width W.
The second steepness of the substrate 1 for the vapor deposition mask is the maximum value of the unit steepness in all the waves included in each position in the length direction DL. That is, the first steepness of the substrate 1 for the vapor deposition mask is also the maximum value of the second steepness in the unit length.
The wave number of the substrate 1 for the vapor deposition mask is the number of all waves at each position in the length direction DL.

The first steepness of the substrate 1 for the vapor deposition mask satisfies the following [Condition 1]. Regarding the steepness of the substrate 1 for the vapor deposition mask in the width direction DW, it is preferable that the second steepness satisfies the following [Condition 2] and the wave numbers satisfy [Condition 3] and [Condition 4].
[Condition 1] The first steepness is 0.5% or less.
[Condition 2] The average value of the second steepness is 0.25% or less.
[Condition 3] The maximum value of the wave number per unit length is 4 or less.
[Condition 4] The average value of the wave number per unit length is 2 or less.

In the thin-film mask substrate 1 satisfying [Condition 1], the maximum value of the unit steepness, which is the steepness in the width direction DW, is 0.5% or less, so that the inclination is steep when viewed from the DL in the length direction. There are no waves due to protrusions or depressions. In protrusions and dents with steep slopes, the liquid supplied to them tends to stagnate compared to the surroundings, and whether or not such waves exist is information that cannot be obtained from the average value of unit steepness. Therefore, even if the liquid for processing is supplied to the surface of the thin-film mask base material 1 conveyed in the DL in the length direction, the liquid does not stagnate around the protruding wave, and the same processing is performed in the DL in the length direction. Even if it is repeated, it is easy to uniformly flow the liquid on the surface of the substrate 1 for the vapor deposition mask. As a result, the liquid supplied to the surface of the substrate for the vapor deposition mask is prevented from stagnation in a part of the DL in the length direction. Then, the uniformity of processing in the length direction DL using the treatment with a liquid such as an etching solution, that is, the uniformity in the length direction DL of the pores of the substrate 1 for the vapor deposition mask, and eventually formed by the vapor deposition. It is possible to improve the accuracy of the pattern.

Further, in the roll-to-roll method in which the substrate 1 for the vapor deposition mask is pulled out from the roll and the substrate 1 for the vapor deposition mask is conveyed, the tension for pulling out the substrate 1 for the vapor deposition mask is the length of the substrate 1 for the vapor deposition mask. It acts on the directional DL. The tension acting on the DL in the length direction stretches the bending and the dent in the substrate 1 for the vapor deposition mask in the DL in the length direction. On the other hand, the part where such tension starts to act is a part in the base material 1 for vapor deposition mask immediately before being pulled out from the roll, and the larger the elongation difference ratio in the width direction DW, the more the degree of stretching varies. be. Then, the time when the stretching due to the tension is likely to occur and the time when the stretching due to the tension is difficult to occur are repeated each time the roll rotates, and the thin-film deposition mask base material 1 transported in the length direction DL is displaced. Causes wrinkles and the like. As a result, the large elongation difference ratio in the width direction DW tends to cause transport deviation in the roll-to-roll method, and when another film such as a dry film resist is attached to the substrate 1 for a vapor deposition mask. Is likely to cause misalignment due to wrinkles and deterioration of adhesion. In this respect, according to the configuration satisfying [Condition 1], it is possible to suppress the transfer deviation, the positional deviation and the wrinkles, and it is also possible to improve the accuracy of the pattern formed by the vapor deposition.

The liquid supplied to the surface of the vapor deposition mask base material 1 is, for example, a developer for developing a resist layer located on the surface of the vapor deposition mask base material 1 and a cleaning liquid for removing the developing liquid from the surface. .. The liquid supplied to the surface of the thin-film deposition mask base material 1 is, for example, an etching solution for etching the vapor-film deposition mask base material 1 and a cleaning liquid for removing the etching liquid from the surface. Further, the liquid supplied to the surface of the thin-film deposition mask base material 1 is, for example, for removing the peeling liquid and the peeling liquid for peeling the resist layer remaining after etching on the surface of the thin-film deposition mask base material 1 from the surface. Cleaning liquid.

If the above configuration is such that the flow of the liquid supplied to the surface of the substrate 1 for the vapor deposition mask in the length direction DL is less likely to stagnate, the uniformity of processing using the treatment with the liquid can be obtained for the vapor deposition mask. It can be enhanced within the surface of the substrate 1. Moreover, if the average value of the second steepness satisfies [Condition 2], the unit steepness can be suppressed in the entire length direction DL, so that the accuracy of the pattern can be further improved. Then, it is possible to secure the adhesion between the vapor deposition mask base material 1 conveyed in the DL in the length direction and the resist layer such as a dry film, and the accuracy of exposure to the resist layer. That is, if the configuration satisfies the conditions 1 and 2, it is possible to improve the accuracy of the exposure, so that the flow of the liquid in the length direction DL is less likely to stagnate, and the uniformity of processing is improved. It will be possible to further increase it.

Further, in the vapor deposition mask base material 1 satisfying [Condition 3], the maximum value of the wave number per unit length is 4 or less, so that the vapor deposition mask base material 1 is included in the vapor deposition mask base material 1 when viewed from the DL in the length direction. Does not contain many waves. Therefore, even if the liquid for treatment is supplied to the surface of the vapor deposition mask base material 1 transported in the length direction DL, the liquid may stagnate due to the large wave number in a part of the length direction DL. Even if the same process is repeated in the length direction DL, the liquid can be more evenly flowed on the surface of the vapor deposition mask base material 1.

Further, in the vapor deposition mask base material 1 satisfying [Condition 4], since the average value of the wave numbers per unit length is 2 or less, it is possible to suppress the wave numbers in the entire length direction DL. Become. Therefore, it is possible to further secure the adhesion between the vapor deposition mask base material 1 conveyed in the DL in the length direction and the resist layer such as a dry film, and the accuracy of exposure to the resist layer.

As described above, the configuration satisfying the conditions 1 to 4 and the effect obtained by the configuration are problems in surface processing using a liquid generated by the vapor deposition mask base material 1 conveyed in the DL in the length direction. It is derived only by recognizing the problem and by recognizing the problem in which the influence of the tension acting on the DL in the length direction is taken into consideration.

[Mask device configuration]
FIG. 4 shows a schematic planar structure of a masking apparatus including a vapor deposition mask manufactured by using the vapor deposition mask base material 1. FIG. 5 shows an example of the cross-sectional structure of the mask portion included in the vapor deposition mask, and FIG. 6 shows another example of the cross-sectional structure of the mask portion included in the vapor deposition mask. The quantity of the vapor deposition mask included in the mask device and the quantity of the mask portion included in the vapor deposition mask 30 are examples.

As shown in FIG. 4, the mask device 10 includes a mainframe 20 and three thin-film deposition masks 30. The main frame 20 has a rectangular frame shape that supports a plurality of vapor deposition masks 30, and is attached to a vapor deposition apparatus for performing vapor deposition. The mainframe 20 has a mainframe hole 21 that penetrates the mainframe 20 over almost the entire range in which each vapor deposition mask 30 is located.

Each vapor deposition mask 30 includes a plurality of frame portions 31 having a strip shape, and each frame portion 31 includes three mask portions 32. The frame portion 31 has a strip plate shape that supports the mask portion 32, and is attached to the main frame 20. The frame portion 31 has a frame hole 33 penetrating the frame portion 31 over almost the entire range in which the mask portion 32 is located. The frame portion 31 has a higher rigidity than the mask portion 32, and has a frame shape surrounding the frame hole 33. Each mask portion 32 is fixed to the inner edge portion of the frame portion 31 that partitions the frame hole 33 one by one by welding or adhesion.

As shown in FIG. 5, an example of the mask portion 32 is composed of a mask plate 323. The mask plate 323 may be a single plate member formed from the vapor deposition mask base material 1, or may be a laminate of a single plate member formed from the vapor deposition mask base material 1 and a resin plate. There may be. In addition, in FIG. 5, it is shown as one plate member formed from the base material 1 for a vapor deposition mask.

The mask plate 323 includes a first surface 321 (lower surface of FIG. 5) and a second surface 322 (upper surface of FIG. 5) which is a surface opposite to the first surface 321. The first surface 321 faces the vapor deposition target such as a glass substrate in a state where the mask device 10 is attached to the vapor deposition device. The second surface 322 faces the vapor deposition source of the vapor deposition apparatus. The mask portion 32 has a plurality of holes 32H penetrating the mask plate 323. The wall surface of the hole 32H has an inclination in a cross-sectional view with respect to the thickness direction of the mask plate 323. As shown in FIG. 6, the shape of the wall surface of the hole 32H may be a semicircular shape protruding toward the outside of the hole 32H, or may be a complicated curved shape having a plurality of bending points. You may.

The thickness of the mask plate 323 is 1 μm or more and 50 μm or less, preferably 2 μm or more and 20 μm or less. When the thickness of the mask plate 323 is 50 μm or less, the depth of the holes 32H formed in the mask plate 323 can be 50 μm or less. As described above, with the thin mask plate 323, it is possible to reduce the area of the wall surface of the hole 32H itself and reduce the volume of the vapor-deposited substance adhering to the wall surface of the hole 32H.

The second surface 322 includes a second opening H2 which is an opening of the hole 32H, and the first surface 321 includes a first opening H1 which is an opening of the hole 32H. The second opening H2 is larger than the first opening H1 in a plan view. Each hole 32H is a passage through which the vapor-deposited substance sublimated from the vapor-film deposition source passes, and the thin-film vapor-deposited substance sublimated from the vapor-film deposition source advances from the second opening H2 to the first opening H1. If the second opening H2 is a hole 32H larger than the first opening H1, the amount of the vapor-deposited substance entering the hole 32H from the second opening H2 can be increased. The area of the hole 32H in the cross section along the first surface 321 may be monotonically increased from the first opening H1 to the second opening H2 from the first opening H1 to the second opening H2. A portion that becomes substantially constant may be provided on the way from the first opening H1 to the second opening H2.

As shown in FIG. 6, another example of the mask portion 32 has a plurality of holes 32H penetrating the mask plate 323. The second opening H2 is larger than the first opening H1 in a plan view. The hole 32H is composed of a large hole 32LH having a second opening H2 and a small hole 32SH having a first opening H1. The cross-sectional area of the large hole 32LH decreases monotonically from the second opening H2 toward the first surface 321. The cross-sectional area of the small hole 32SH decreases monotonically from the first opening H1 toward the second surface 322. The wall surface of the hole 32H has a shape protruding inward of the hole 32H at a portion where the large hole 32LH and the small hole 32SH are connected, that is, in the middle of the thickness direction of the mask plate 323 in a cross-sectional view. The distance between the portion protruding from the wall surface of the hole 32H and the first surface 321 is the step height SH. In the example of the cross-sectional structure described with reference to FIG. 5, the step height SH is zero. From the viewpoint of easily securing the amount of the vapor-filmed substance that reaches the first opening H1, a configuration in which the step height SH is zero is preferable. In the configuration for obtaining the mask portion 32 having zero step height SH, the thickness of the mask plate 323 is so thin that the holes 32H are formed by wet etching from one side of the vapor deposition mask base material 1, for example, at 50 μm or less. be.

[Joint structure of mask part]
FIG. 7 shows an example of the cross-sectional structure of the joint structure of the mask portion 32 and the frame portion 31. FIG. 8 shows another example of the cross-sectional structure of the joint structure of the mask portion 32 and the frame portion 31.

As in the example shown in FIG. 7, the outer edge portion 32E of the mask plate 323 is a region not provided with the hole 32H. The portion of the second surface 322 of the mask plate 323 that is included in the outer edge portion 32E of the mask plate 323 is an example of the side surface of the mask portion and is joined to the frame portion 31. The frame portion 31 includes an inner edge portion 31E that partitions the frame hole 33. The inner edge portion 31E includes a joint surface 311 (lower surface in FIG. 7) facing the mask plate 323 and a non-joint surface 312 (upper surface in FIG. 7) opposite to the joint surface 311. The thickness T31 of the inner edge portion 31E, that is, the distance between the joint surface 311 and the non-joint surface 312 is sufficiently thicker than the thickness T32 of the mask plate 323, whereby the frame portion has higher rigidity than the mask plate 323. 31 has. In particular, the frame portion 31 has high rigidity against the fact that the inner edge portion 31E hangs down due to its own weight and the inner edge portion 31E is displaced toward the mask portion 32. The joint surface 311 of the inner edge portion 31E includes a joint portion 32BN joined to the second surface 322.

The joint portion 32BN is continuously or intermittently located over almost the entire circumference of the inner edge portion 31E. The joint portion 32BN may be a welding mark formed by welding the joint surface 311 and the second surface 322, or may be a joint layer for joining the joint surface 311 and the second surface 322. The frame portion 31 joins the joining surface 311 of the inner edge portion 31E and the second surface 322 of the mask plate 323, and applies a stress F such that the mask plate 323 is pulled toward the outside of the mask plate 323. Add.

The frame portion 31 is also subjected to a stress such that it is pulled toward the outside by the main frame 20 to the same degree as the stress F on the mask plate 323. Therefore, in the vapor deposition mask 30 removed from the main frame 20, the stress due to the joining between the main frame 20 and the frame portion 31 is released, and the stress F applied to the mask plate 323 is also relaxed. The position of the joint portion 32BN on the joint surface 311 is preferably a position where the stress F is isotropically applied to the mask plate 323, and is appropriately selected based on the shape of the mask plate 323 and the shape of the frame hole 33. Will be done.

The joint surface 311 is a plane on which the joint portion 32BN is located, and extends from the outer edge portion 32E of the second surface 322 toward the outside of the mask plate 323. In other words, the inner edge portion 31E has a surface structure in which the second surface 322 is pseudo-extended to the outside thereof, and extends from the outer edge portion 32E of the second surface 322 toward the outside of the mask plate 323. Therefore, in the range where the joint surface 311 is widened, a space V corresponding to the thickness of the mask plate 323 is likely to be formed around the mask plate 323. As a result, it is possible to suppress physical interference between the vapor deposition target S and the frame portion 31 around the mask plate 323.

Also in the example shown in FIG. 8, the outer edge portion 32E of the second surface 322 includes a region in which the hole 32H is not formed. The outer edge portion 32E of the second surface 322 is joined to the joining surface 311 included in the frame portion 31 through the joining by the joining portion 32BN. Then, the frame portion 31 applies a stress F such that the mask plate 323 is pulled toward the outside of the mask plate 323, and a space corresponding to the thickness of the mask plate 323 in the range where the joint surface 311 spreads. Form V.

The mask plate 323 in a state where the stress F does not act may have a wavy shape to some extent, like the vapor deposition mask base material 1. Then, the mask plate 323 in the state where the above-mentioned stress F acts, that is, the mask plate 323 mounted on the vapor deposition mask 30, may be deformed so as to lower the height of the wave. In this respect, in the case of the thin-film deposition mask base material 1 satisfying the above conditions, even if deformation due to stress F occurs, it is suppressed to an allowable extent, and as a result, the deformation of the holes 32H in the thin-film deposition mask 30 is caused. It is also possible to suppress it and improve the accuracy of the position and shape of the pattern.

[Quantity of mask part]
FIG. 9 shows an example of the relationship between the number of holes 32H included in the vapor deposition mask 30 and the number of holes 32H included in the mask portion 32. Further, FIG. 10 shows another example of the relationship between the number of holes 32H included in the vapor deposition mask 30 and the number of holes 32H included in the mask portion 32.

As the example of FIG. 9A shows, the frame portion 31 has three frame holes 33 (33A, 33B, 33C). As the example of FIG. 9B shows, the vapor deposition mask 30 includes one mask portion 32 (32A, 32B, 32C) in each frame hole 33. The inner edge portion 31E that partitions the frame hole 33A is joined to one mask portion 32A, and the inner edge portion 31E that partitions the frame hole 33B is joined to another mask portion 32B to partition the frame hole 33C. The inner edge portion 31E is joined to another mask portion 32C.

Here, the vapor deposition mask 30 is repeatedly used for a plurality of vapor deposition targets. Therefore, each hole 32H included in the vapor deposition mask 30 is required to have higher accuracy in terms of the position of the hole 32H, the structure of the hole 32H, and the like. If the desired accuracy cannot be obtained in the position of the hole 32H or the structure of the hole 32H, the mask portion 32 should be replaced as appropriate regardless of whether the vapor deposition mask 30 is manufactured or the vapor deposition mask 30 is repaired. Is desired.

In this regard, if the number of holes 32H required for one frame portion 31 is shared by the three mask portions 32 as in the configuration shown in FIG. 9, it is tentatively replaced with one mask portion 32. Even if it is desired, it is sufficient to replace only one of the three mask portions 32. That is, of the three mask portions 32, two mask portions 32 can be continuously used. Therefore, if the structure is such that separate mask portions 32 are joined to each frame hole 33, it is possible to suppress the consumption of various materials required for the production of the vapor deposition mask 30 and the repair of the vapor deposition mask 30. It also becomes. The thinner the mask plate 323 and the smaller the hole 32H, the easier it is for the yield of the mask portion 32 to decrease, and the greater the request for replacement of the mask portion 32. Therefore, the above configuration in which each frame hole 33 is provided with a separate mask portion 32 is particularly suitable for the vapor deposition mask 30 that requires high resolution.

It is preferable that the inspection regarding the position of the hole 32H and the structure of the hole 32H is performed in a state where the stress F is applied, that is, in a state where the mask portion 32 is joined to the frame portion 31. From this point of view, it is preferable that the above-mentioned joint portion 32BN is intermittently present in, for example, a part of the inner edge portion 31E so that the mask portion 32 can be replaced.

As the example of FIG. 10A shows, the frame portion 31 has three frame holes 33 (33A, 33B, 33C). As the example of FIG. 10B shows, the vapor deposition mask 30 can also include one mask portion 32 common to each frame hole 33. At this time, the inner edge portion 31E for partitioning the frame hole 33A, the inner edge portion 31E for partitioning the frame hole 33B, and the inner edge portion 31E for partitioning the frame hole 33C are joined to one mask portion 32 common to these.

If the number of holes 32H required for one frame portion 31 is borne by one mask portion 32, the number of mask portions 32 joined to the frame portion 31 should be one. Therefore, it is possible to reduce the load required for joining the frame portion 31 and the mask portion 32. The thicker the mask plate 323 constituting the mask portion 32 and the larger the size of the hole 32H, the higher the yield of the mask portion 32 is likely to be, and the smaller the request for replacement of the mask portion 32 is. Therefore, the configuration including the mask portion 32 common to each frame hole 33 is particularly suitable for the vapor deposition mask 30 that requires low resolution.

[Manufacturing method of base material for vapor deposition mask]
Next, a method for manufacturing a base material for a vapor deposition mask will be described. In the method for manufacturing the base material for a vapor-deposited mask, a form using rolling and a form using electrolysis are separately exemplified. First, a form using rolling will be described, and then a form using electrolysis will be described. 11 and 12 show an example of using rolling.

In the manufacturing method using rolling, as shown in FIG. 11, first, a base material 1a formed from Invar or the like and extending in the length direction DL is prepared. Next, the base metal 1a is conveyed toward the rolling apparatus 50 so that the DL in the length direction of the base metal 1a and the conveying direction for conveying the base metal 1a are parallel to each other. The rolling apparatus 50 includes, for example, a pair of rolling rollers 51 and 52, and the base metal 1a is rolled by the pair of rolling rollers 51 and 52. As a result, the base material 1a is stretched in the length direction DL to form the rolled material 1b. The rolled material 1b is cut so that the dimension in the width direction DW is the width W. The rolled material 1b may be wound around the core C, for example, or may be handled in a strip-shaped state. The thickness of the rolling material 1b is, for example, 10 μm or more and 50 μm or less. It is also possible to use a method using a plurality of pairs of rolling rollers, and FIG. 12 shows a method using a pair of rolling rollers as an example.

Next, as shown in FIG. 12, the rolling material 1b is transferred to the annealing device 53. The annealing device 53 heats the rolling material 1b while pulling it in the length direction DL. As a result, the accumulated residual stress is removed from the inside of the rolling material 1b, and the substrate 1 for the vapor deposition mask is formed. At this time, the pressing force between the rolling rollers 51 and 52, the rotation speed of the rolling rollers 51 and 52, the annealing temperature of the rolling material 1b, and the like are set so that the above [condition 1] is satisfied. Preferably, the pressing force between the rolling rollers 51 and 52, the rotational speed of the rolling rollers 51 and 52, and the rolling rollers 51 and 52 so that the above [Condition 2] to [Condition 4] are satisfied together with [Condition 1]. The pressing temperature at, the annealing temperature of the rolling material 1b, and the like are set. The rolled material 1b may be cut after annealing so that the dimension in the width direction DW is the width W.

In the manufacturing method using electrolysis, the base material 1 for a vapor deposition mask is formed on the surface of the electrode used for electrolysis, and then the base material 1 for the vapor deposition mask is released from the surface of the electrode. At this time, for example, another electrode is used in which the electrolytic drum electrode having a mirror surface as the surface is immersed in the electrolytic bath and the electrolytic drum electrode is received downward and faces the surface of the electrolytic drum electrode. Then, a current is passed between the electrolytic drum electrode and the other electrodes, and the vapor deposition mask base material 1 is deposited on the electrode surface, which is the surface of the electrolytic drum electrode. At the timing when the electrolytic drum electrode rotates and the vapor deposition mask base material 1 has a desired thickness, the vapor deposition mask base material 1 is peeled off from the surface of the electrolytic drum electrode and wound up.

When the material constituting the vapor deposition mask substrate 1 is Invar, the electrolytic bath used for electrolysis includes an iron ion feeder, a nickel ion feeder and a pH buffer. The electrolytic bath used for electrolysis may contain a stress relieving agent, a Fe ³⁺ ion masking agent, a complexing agent such as malic acid or citric acid, and is a weakly acidic solution adjusted to a pH suitable for electrolysis. The iron ion feeder is, for example, ferrous sulfate heptahydrate, ferrous chloride, iron sulfamate and the like. Nickel ion feeders are, for example, nickel sulfate (II), nickel chloride (II), nickel sulfamate, nickel bromide. The pH buffer is, for example, boric acid or malonic acid. Malonic acid ^{also functions as a Fe 3+} ion masking agent. The stress relaxation agent is, for example, saccharin sodium. The electrolytic bath used for electrolysis is, for example, an aqueous solution containing the above-mentioned additives, and the pH is adjusted to be, for example, 2 or more and 3 or less by a pH adjusting agent such as 5% sulfuric acid or nickel carbonate. .. If necessary, an annealing step may be added.

Under the electrolysis conditions used for electrolysis, the temperature, current density, and electrolysis time of the electrolysis bath are appropriately adjusted according to the thickness of the base material 1 for the vapor deposition mask, the composition ratio of the base material 1 for the vapor deposition mask, and the like. The anodes applied to the above-mentioned electrolytic baths are, for example, pure iron and nickel. The cathode applied to the above-mentioned electrolytic bath is, for example, a stainless steel plate such as SUS304. The temperature of the electrolytic bath is, for example, 40 ° C. or higher and 60 ° C. or lower. The current density is, for example, 1 A / dm ² or more and 4 A / dm ² or less. At this time, the current density on the electrode surface is set so that the above [Condition 1] is satisfied. Preferably, the current density on the electrode surface is set so that the above [Condition 2] to [Condition 4] are satisfied together with [Condition 1].

The thin-film deposition mask base material 1 by electrolysis and the thin-film deposition mask base material 1 by rolling may be further thinned by chemical polishing, electrical polishing, or the like. The polishing liquid used for chemical polishing is, for example, a chemical polishing liquid for iron-based alloys containing hydrogen peroxide as a main component. The electrolytic solution used for electrical polishing is a perchloric acid-based electrolytic polishing solution or a sulfuric acid-based electrolytic polishing solution. At this time, since the above conditions are satisfied, it is possible to suppress variations in the surface of the substrate 1 for the vapor deposition mask with respect to the result of polishing with the polishing liquid and the result of cleaning the polishing liquid with the cleaning liquid.

[Manufacturing method of mask part]
The process for manufacturing the mask portion 32 shown in FIG. 6 will be described with reference to FIGS. 13 to 18. The step for manufacturing the mask portion 32 described with reference to FIG. 5 is a step for manufacturing the mask portion 32 described with reference to FIG. 6 in order to form a large hole 32LH with the small hole 32SH as a through hole. Since it is the same as the process in which the process of is omitted, the duplicated explanation is omitted.

As shown in FIG. 13, when manufacturing the mask portion, first, a vapor deposition mask base material 1 including the first surface 1Sa and the second surface 1Sb, and a first dry film resist attached to the first surface 1Sa ( A dry film resist (DFR) 2 and a second dry film resist (DFR) 3 to be attached to the second surface 1Sb are prepared. Each of DFR2 and 3 is formed separately from the substrate 1 for a vapor deposition mask. Next, the first DFR2 is attached to the first surface 1Sa, and the second DFR3 is attached to the second surface 1Sb. At this time, since the above conditions are satisfied, when the vapor deposition mask base material 1 transported in the length direction DL and the DFRs 2 and 3 transported along the vapor deposition mask base material 1 are bonded to each other, the transport deviation is caused. The occurrence of misalignment and wrinkles is suppressed.

As shown in FIG. 14, a portion of DFRs 2 and 3 other than the portion forming a hole is exposed to develop the DFR after exposure. As a result, the first through hole 2a is formed in the first DFR2, and the second through hole 3a is formed in the second DFR3. When developing the DFR after exposure, for example, an aqueous sodium carbonate solution is used as the developing solution. At this time, since the above conditions are satisfied, variations in the surface of the vapor deposition mask base material 1 with respect to the result of development with the developing solution and the result of cleaning with the cleaning solution can be suppressed. Further, since the occurrence of transport deviation, positional deviation, and wrinkles is suppressed in the above-mentioned bonding, the exposure position deviation caused by these can be suppressed, and the exposure accuracy can be improved. As a result, it is possible to improve the uniformity of the shape and size of the first through hole 2a and the shape and size of the second through hole 3a in the surface of the substrate 1 for the vapor deposition mask.

As shown in FIG. 15, for example, the first surface 1Sa of the substrate 1 for a vapor deposition mask is etched with a ferric chloride solution using the developed first DFR2 as a mask. At this time, the second protective layer 61 is formed on the second surface 1Sb so that the second surface 1Sb is not etched at the same time as the first surface 1Sa. The material of the second protective layer 61 has chemical resistance to ferric chloride solution. As a result, a small hole 32SH recessed toward the second surface 1Sb is formed on the first surface 1Sa. The small hole 32SH has a first opening H1 that opens to the first surface 1Sa. At this time, since the above conditions are satisfied, it is possible to suppress variations in the surface of the vapor deposition mask base material 1 with respect to the result of etching with the etching solution and the result of cleaning with the cleaning solution. As a result, it is possible to improve the uniformity of the shape and size of the small holes 32SH in the surface of the thin-film deposition mask base material 1.

The etching solution for etching the substrate 1 for the vapor deposition mask is an acidic etching solution, and if the substrate 1 for the vapor deposition mask is composed of the inver, the etching solution can etch the inver. good. The acidic etching solution is, for example, any of perchloric acid, hydrochloric acid, sulfuric acid, formic acid and acetic acid with respect to the ferric perchloric acid solution and the mixed solution of the ferric perchloric acid solution and the ferric chloride solution. It is a mixed solution. The method for etching the vapor deposition mask base material 1 may be a dip type in which the vapor deposition mask base material 1 is immersed in an acidic etching solution, or a spray type in which the vapor deposition mask base material 1 is sprayed with an acidic etching solution. It may be.

Next, as shown in FIG. 16, the first DFR2 formed on the first surface 1Sa and the second protective layer 61 in contact with the second DFR3 are removed. Further, the first protective layer 4 for preventing further etching of the first surface 1Sa is formed on the first surface 1Sa. The material of the first protective layer 4 has chemical resistance to the ferric chloride solution.

Next, as shown in FIG. 17, the second surface 1Sb is etched with the ferric chloride solution using the developed second DFR3 as a mask. As a result, a large hole 32LH recessed toward the first surface 1Sa is formed on the second surface 1Sb. The foramen magnum 32LH has a second opening H2 that opens into the second surface 1Sb. The second opening H2 is larger than the first opening H1 in a plan view facing the second surface 1Sb. At this time, since the above conditions are satisfied, variations in the surface of the vapor deposition mask base material 1 with respect to the result of etching with the etching solution and the result of cleaning the etching solution with the cleaning solution can be suppressed. As a result, it is possible to improve the uniformity of the shape and size of the large hole 32LH in the surface of the substrate 1 for vapor deposition mask. The etching solution used at this time is also an acidic etching solution, and when the substrate 1 for the vapor deposition mask is composed of Invar, it may be an etching solution capable of etching Invar. The method of etching the base material 1 for the vapor deposition mask may also be a dip type in which the base material 1 for the vapor deposition mask is immersed in an acidic etching solution, or a spray that sprays the base material 1 for a vapor deposition mask with an acidic etching solution. It may be an expression.

Next, as shown in FIG. 18, by removing the first protective layer 4 and the second DFR3 from the vapor deposition mask base material 1, a plurality of small holes 32SH and large holes 32LH connected to each small hole 32SH are formed. The mask portion 32 is obtained.

In the manufacturing method using rolling, metal oxides such as aluminum oxide and magnesium oxide are contained in the vapor deposition mask base material 1 in no small amount. That is, when the above-mentioned base material 1a is formed, a deoxidizing agent such as granular aluminum or magnesium is usually mixed with the raw material in order to prevent oxygen from being mixed into the base material 1a. Then, aluminum and magnesium remain in the base material 1a as metal oxides such as aluminum oxide and magnesium oxide. In this respect, according to the manufacturing method using electrolysis, it is possible to prevent the metal oxide from being mixed with the mask portion 32.

[Manufacturing method of thin-film mask]
Each example of the manufacturing method of the vapor deposition mask will be described. In addition, an example (the first manufacturing method) of the method of forming a hole by wet etching will be described with reference to FIG. Further, with reference to FIG. 20, an example (second manufacturing method) of the method of forming holes by electrolysis will be described. In addition, another example (third manufacturing method) of the method of forming pores by electrolysis will be described with reference to FIG. 21.

[First manufacturing method]
The method of manufacturing the thin-film deposition mask including the mask portion 32 described in FIG. 5 and the method of manufacturing the thin-film deposition mask including the mask portion 32 described in FIG. 6 are modes of etching performed on the base material 32K. However, the other steps are almost the same. In the following, a method for manufacturing a thin-film deposition mask including the mask portion 32 described with reference to FIG. 5 will be mainly described, and the duplicate description of the method for manufacturing a vapor-film deposition mask with the mask portion 32 described with reference to FIG. 6 will be omitted.

As in the example shown in FIGS. 19 (a) to 19 (h), in one example of the method for manufacturing a vapor deposition mask, first, a base material 32K is prepared (see FIG. 19 (a)). The base material 32K is the above-mentioned vapor deposition mask base material 1 processed as a mask plate 323, and is a support SP for supporting the vapor deposition mask base material 1 in addition to the vapor deposition mask base material 1. It is preferable to further provide. The first surface 321 (lower surface of FIG. 19) of the base material 32K corresponds to the first surface 1Sa, and the second surface 322 (upper surface of FIG. 19) of the base material 32K corresponds to the second surface 1Sb. do.

First, a resist layer PR is formed on the second surface 322 of the base material 32K (see FIG. 19B), and the resist layer PR is exposed and developed to form a resist mask RM on the second surface 322. (See FIG. 19 (c)). Next, holes 32H are formed in the base material 32K by wet etching from the second surface 322 using the resist mask RM (see FIG. 19 (d)).

At this time, the second opening H2 is formed on the second surface 322 where the wet etching is started, and the first opening H2 smaller than the second opening H2 is formed on the first surface 321 where the etching is performed later than that. H1 is formed. Next, the resist mask RM is removed from the second surface 322 to form the mask portion 32 (see FIG. 19E). Finally, the outer edge portion 32E on the second surface 322 is joined to the inner edge portion 31E of the frame portion 31, and the support SP is released from the mask portion 32, whereby the vapor deposition mask 30 is manufactured (FIG. 19 (FIG. 19). f) to (h)).

In the method for manufacturing a vapor deposition mask including the mask portion 32 described with reference to FIG. 6, the above-mentioned steps are applied to the surface of the substrate 32K corresponding to the first surface 321 in the substrate 32K having no support SP. The pores 32SH are formed thereby. Next, a resist or the like for protecting the small hole 32SH is filled in the small hole 32SH. Subsequently, the above-mentioned steps are applied to the surface of the base material 32K corresponding to the second surface 322, whereby the mask portion 32 is manufactured.

In the example shown in FIG. 19 (f), resistance welding is used as a method of joining the outer edge portion 32E of the second surface 322 to the inner edge portion 31E of the frame portion 31. At this time, a plurality of holes SPH are formed in the support SP having an insulating property. Each hole SPH is formed in a portion of the support SP that faces the portion that becomes the joint portion 32BN. Then, electricity is applied through each hole SPH to form an intermittent joint portion 32BN. As a result, the outer edge portion 32E and the inner edge portion 31E are welded together.

Further, in the example shown in FIG. 19 (g), laser welding is used as a method of joining the outer edge portion 32E of the second surface 322 to the inner edge portion 31E of the frame portion 31. At this time, the support SP having light transmission is used, and the laser beam L is irradiated to the portion to be the joint portion 32BN through the support SP. Then, the laser beam L is intermittently irradiated around the outer edge portion 32E to form an intermittent joint portion 32BN. Alternatively, by continuously irradiating the laser beam L around the outer edge portion 32E, a continuous joint portion 32BN is formed over the entire circumference of the outer edge portion 32E. As a result, the outer edge portion 32E and the inner edge portion 31E are welded together.

Further, in the example shown in FIG. 19 (h), ultrasonic welding is used as a method of joining the outer edge portion 32E of the second surface 322 to the inner edge portion 31E of the frame portion 31. At this time, the outer edge portion 32E and the inner edge portion 31E are sandwiched by a clamp CP or the like, and ultrasonic waves are applied to the portion to be the joint portion 32BN. The member to which ultrasonic waves are directly applied may be the frame portion 31 or the mask portion 32. When ultrasonic welding is used, crimping marks are formed on the frame portion 31 and the support SP by the clamp CP.

In each of the above-mentioned joints, welding or welding can be performed on the mask portion 32 in a state where stress is applied to the outside of the mask portion 32. Further, when the support SP supports the mask portion 32 in a state where the stress toward the outside of the mask portion 32 is applied, it is possible to omit the application of the stress to the mask portion 32. Is.

[Second manufacturing method]
The vapor deposition mask described with reference to FIGS. 7 and 8 can be manufactured by other examples shown in FIGS. 20 (a) to 20 (e) in addition to the first manufacturing method.
As in the examples shown in FIGS. 20 (a) to 20 (e), first, a resist layer PR is formed on the electrode surface EPS, which is the surface of the electrode EP used for electrolysis (see FIG. 20 (a)). Next, a resist mask RM is formed on the electrode surface EPS by exposing and developing the resist layer PR (see FIG. 20 (b)). The resist mask RM has an inverted cone shape in a cross section orthogonal to the electrode surface EPS, and the larger the distance from the electrode surface EPS, the larger the area in the cross section along the electrode surface EPS. Next, electrolysis is performed using the electrode surface EPS having the resist mask RM, and the mask portion 32 is formed in the region other than the resist mask RM in the electrode surface EPS (see FIG. 20 (c)).

At this time, since the mask portion 32 is formed in a space other than the space occupied by the resist mask RM, a hole having a shape following the shape of the resist mask RM is formed in the mask portion 32. That is, the holes 32H of the mask portion 32 are formed in the mask portion 32 in a self-aligned manner. The surface in contact with the electrode surface EPS functions as the first surface 321 having the first opening H1, and the outermost surface having the second opening H2, which is an opening larger than the first opening H1, is used as the second surface 322. Function.

Next, only the resist mask RM is removed from the electrode surface EPS to form a hole 32H in which the first opening H1 to the second opening H2 are hollow (see FIG. 20D). Finally, the joint surface 311 of the inner edge portion 31E is joined to the outer edge portion 32E of the second surface 322 having the second opening H2, and then the stress for peeling the mask portion 32 from the electrode surface EPS is applied to the frame portion 31. Add. As a result, the vapor deposition mask 30 in a state where the mask portion 32 is bonded to the frame portion 31 is manufactured (see FIG. 20 (e)).

In the second manufacturing method, the mask portion 32 is formed without etching the vapor deposition mask base material 1. At this time, if the outer edge portion 32E is configured to satisfy the above condition 1 with the direction along one side of the mask portion 32 as the width direction, it is possible to improve the accuracy of the position at the joint between the frame portion 31 and the mask portion 32. It is also possible to increase the strength in joining.

[Third manufacturing method]
The vapor deposition mask described with reference to FIGS. 7 and 8 can be manufactured by other examples shown in FIGS. 21 (a) to 21 (e) in addition to the first manufacturing method.
As in the examples shown in FIGS. 21 (a) to 21 (f), first, a resist layer PR is formed on the electrode surface EPS used for electrolysis (see FIG. 21 (a)). Next, a resist mask RM is formed on the electrode surface EPS by exposing and developing the resist layer PR (see FIG. 21 (b)). The resist mask RM has a frustum shape in a cross section orthogonal to the electrode surface EPS, and the larger the distance from the electrode surface EPS, the smaller the area in the cross section along the electrode surface EPS. Next, electrolysis is performed using the electrode surface EPS having the resist mask RM, and the mask portion 32 is formed in the region other than the resist mask RM in the electrode surface EPS (see FIG. 21 (c)).

Here, too, since the mask portion 32 is formed in a space other than the space occupied by the resist mask RM, a hole having a shape following the shape of the resist mask RM is formed in the mask portion 32. That is, the holes 32H in the mask portion 32 are self-aligned in the mask portion 32. The surface in contact with the electrode surface EPS functions as the second surface 322 having the second opening H2, and the outermost surface having the first opening H1 which is an opening smaller than the second opening H2 is used as the first surface 321. Function.

Next, only the resist mask RM is removed from the electrode surface EPS to form a hole 32H in which the first opening H1 to the second opening H2 are hollow (see FIG. 21D). Then, the intermediate transfer base material TM is bonded to the first surface 321 having the first opening H1, and then stress for peeling the mask portion 32 from the electrode surface EPS is applied to the intermediate transfer base material TM. As a result, the second surface 322 is separated from the electrode surface EPS in a state where the mask portion 32 is bonded to the intermediate transfer base material TM (see FIG. 21 (e)). Finally, the joining surface 311 of the inner edge portion 31E is joined to the outer edge portion 32E of the second surface 322, and the intermediate transfer base material TM is removed from the mask portion 32. As a result, the vapor deposition mask 30 in a state where the mask portion 32 is bonded to the frame portion 31 is manufactured (see FIG. 21 (f)).

Also in the third manufacturing method, the mask portion 32 is formed without etching the vapor deposition mask base material 1. At this time, if the outer edge portion 32E is configured to satisfy the above condition 1 with the direction along one side of the mask portion 32 as the width direction, it is possible to improve the accuracy of the position at the joint between the frame portion 31 and the mask portion 32. It is also possible to increase the strength in joining.

In the method of manufacturing a display device using the vapor deposition mask 30 described above, first, the mask device 10 equipped with the vapor deposition mask 30 is mounted in the vacuum chamber of the vapor deposition device. At this time, the mask device 10 is attached so that the vapor deposition target such as a glass substrate faces the first surface 321 and the vapor deposition source and the second surface 322 face each other. Then, the vapor deposition target is carried into the vacuum chamber of the vapor deposition apparatus, and the vapor deposition material is sublimated by the vapor deposition source. As a result, a pattern having a shape following the first opening H1 is formed on the vapor deposition target facing the first opening H1. The vapor-deposited substance is, for example, an organic light emitting material constituting a pixel of a display device, a pixel electrode constituting a pixel circuit of the display device, or the like.

[Example]
Each embodiment will be described with reference to FIG.
First, a rolling process is performed on the base material 1a using Inver as a material to form a metal plate, and then a slitting process for cutting the metal plate is performed so that a desired size can be obtained in the width direction DW, and the rolling material is rolled. 1b was formed. Subsequently, the rolling material 1b was subjected to an annealing step to obtain a substrate 1 for a vapor deposition mask of Example 1 having a length of DW in the width direction of 500 mm and a thickness of 20 μm.

Further, by changing the rotational speed and pressing force of the rolling rollers 51 and 52 from the first embodiment and setting other conditions in the same manner as those of the first embodiment, the length of the DW in the width direction is 500 mm. Moreover, the substrate 1 for a vapor deposition mask of Example 2 having a thickness of 20 μm was obtained.

Further, by changing the pressing force between the rolling rollers 51 and 52 from the first embodiment and setting other conditions in the same manner as those of the first embodiment, the length of the DW in the width direction is 500 mm and the length is 500 mm. , A substrate 1 for a vapor deposition mask of Example 3 having a thickness of 50 μm was obtained.

Further, by changing the quantity of the rolling rollers 51 and 52 from the first embodiment and setting other conditions in the same manner as those of the first embodiment, the length of the DW in the width direction is 500 mm and the thickness is increased. A substrate 1 for a vapor deposition mask of Example 4 having a length of 20 μm was obtained.

Next, by changing the quantity and temperature of the rolling rollers 51 and 52 from the first and fourth embodiments and setting other conditions in the same manner as those of the first embodiment, the length of the DW in the width direction is 500 mm. Further, a substrate 1 for a vapor deposition mask of Comparative Example 1 having a thickness of 20 μm was obtained.

Further, by changing the quantity and pressing force of the rolling rollers 51 and 52 from the first and third embodiments and setting other conditions in the same manner as those of the first embodiment, the length of the DW in the width direction can be increased. A substrate 1 for a vapor deposition mask of Comparative Example 2 having a thickness of 500 mm and a thickness of 20 μm was obtained.

Further, by changing the quantity and pressing force of the rolling rollers 51 and 52 from the first embodiment and setting other conditions in the same manner as those of the first embodiment, the length of the DW in the width direction is 500 mm and the length is 500 mm. A substrate 1 for a vapor deposition mask of Comparative Example 3 having a thickness of 20 μm was obtained.

Next, as shown in FIG. 22, the measurement base material 2M having a length DL in the length direction of 700 mm is used as the vapor deposition mask base material 1 of each example and the vapor deposition mask base material 1 of each comparative example. Cut out from. Subsequently, the steepness of each of the cut out measuring base materials 2M in the width direction DW was measured over the entire measurement range ZL. At this time, the following conditions were used as the measurement conditions for the steepness in the width direction DW.
Measuring device: CNC image measuring system VMR-6555 manufactured by Nikon Corporation
Measurement range ZL length direction DL length: 500 mm (unit length)
Non-measurement range ZE length direction DL length: 100 mm
Measurement interval of DL in the length direction: 20 mm
Measurement interval of DW in the width direction: 20 mm

The measurement in the width direction was carried out in the range of 480 mm in the width direction DW except for 10 mm from both ends of the width direction DW in order to exclude a new wave shape due to the slit process. That is, 25 points were measured along the width direction DW, and 26 lines were measured in the length direction DL with these 25 points as one line. In each measurement interval of each Example and each Comparative Example, the DL in the length direction is the direction in which the base metal 1a is stretched by rolling.
Table 1 shows the measurement results of the first steepness, the average value of the second steepness, the maximum value of the wave number, and the average value of the wave number for each Examples 1 to 4 and Comparative Examples 1 to 3.

As shown in Table 1, the first steepness of Example 1 was 0.43%, and it was confirmed that [Condition 1] was satisfied. Regarding 4 lines out of the 26 lines in Example 1, the minimum value of the unit steepness was 0%, and it was confirmed that almost no wave was observed in the width direction DW. The average value of the second steepness in Example 1 was 0.20%, and it was confirmed that [Condition 2] was satisfied. At this time, it was found that the standard deviation σ of the second steepness was 0.12%. The maximum value of the wave number in Example 1 was 4, and it was confirmed that [Condition 3] was satisfied. Further, the average value of the wave number in Example 1 was 1, and it was confirmed that [Condition 4] was satisfied.

The first steepness of Example 2 was 0.29%, and it was confirmed that [Condition 1] was satisfied. Regarding 5 lines out of the 26 lines in Example 2, the minimum value of the unit steepness was 0%, and it was confirmed that almost no wave was observed in the width direction DW. The average value of the second steepness in Example 2 was 0.12%, and it was confirmed that [Condition 2] was satisfied. At this time, it was found that the standard deviation σ of the second steepness was 0.09%. The maximum value of the wave number in Example 2 was 3, and it was confirmed that [Condition 3] was satisfied. Further, the average value of the wave number in Example 2 was 1, and it was confirmed that [Condition 4] was satisfied.

The first steepness of Example 3 was 0.37%, and it was confirmed that [Condition 1] was satisfied. Regarding 7 of the 26 lines in Example 3, the minimum value of the unit steepness was 0%, and it was confirmed that almost no wave was observed in the width direction DW. The average value of the second steepness in Example 3 was 0.11%, and it was confirmed that [Condition 2] was satisfied. At this time, it was found that the standard deviation σ of the second steepness was 0.12%. The maximum value of the wave number in Example 3 was 3, and it was confirmed that [Condition 3] was satisfied. Further, the average value of the wave number in Example 3 was 1, and it was confirmed that [Condition 4] was satisfied.

The first steepness of Example 4 was 0.44%, and it was confirmed that [Condition 1] was satisfied. Regarding one of the 26 lines in Example 4, the minimum value of the unit steepness in Example 4 was 0%, and it was confirmed that almost no wave was observed in the width direction DW. The average value of the second steepness in Example 4 was 0.22%, and it was confirmed that [Condition 2] was satisfied. At this time, it was found that the standard deviation σ of the second steepness was 0.11%. The maximum value of the wave number in Example 4 was 5, and it was confirmed that [Condition 3] was not satisfied. Further, the average value of the wave numbers in Example 4 was 2, and it was confirmed that [Condition 4] was satisfied.

The first steepness of Comparative Example 1 was 0.90%, and it was confirmed that [Condition 1] was not satisfied. It was found that the minimum value of the unit steepness in Comparative Example 1 was 0.11%. The average value of the second steepness in Comparative Example 1 was 0.33%, and it was confirmed that [Condition 2] was not satisfied. At this time, it was found that the standard deviation σ of the second steepness was 0.18%. The maximum value of the wave number in Comparative Example 1 was 8, and it was confirmed that [Condition 3] was not satisfied. Further, the average value of the wave numbers in Comparative Example 1 was 5, and it was confirmed that [Condition 4] was not satisfied. It was found that the minimum value of the wave number in Comparative Example 1 was three.

The first steepness of Comparative Example 2 was 1.39%, and it was confirmed that [Condition 1] was not satisfied. It was found that the minimum value of the unit steepness in Comparative Example 2 was 0.06%. The average value of the second steepness in Comparative Example 2 was 0.28%, and it was confirmed that [Condition 2] was not satisfied. At this time, it was found that the standard deviation σ of the second steepness was 0.29%. The maximum value of the wave number in Comparative Example 2 was 5, and it was confirmed that [Condition 3] was not satisfied. Further, the average value of the wave numbers in Comparative Example 2 was 2, and it was confirmed that [Condition 4] was satisfied. It was found that the minimum value of the wave number in Comparative Example 2 was one.

The first steepness of Comparative Example 3 was 0.58%, and it was confirmed that [Condition 1] was not satisfied. It was found that the minimum value of the unit steepness in Comparative Example 3 was 0.06%. The average value of the second steepness in Comparative Example 3 was 0.31%, and it was confirmed that [Condition 2] was not satisfied. At this time, it was found that the standard deviation σ of the second steepness was 0.14%. The maximum value of the wave number in Comparative Example 3 was 6, and it was confirmed that [Condition 3] was not satisfied. Further, the average value of the wave numbers in Comparative Example 3 was 4, and it was confirmed that [Condition 4] was not satisfied. It was found that the minimum value of the wave number in Comparative Example 3 was one.

[Pattern accuracy]
Using the vapor deposition mask base material 1 of Examples 1 to 4 and Comparative Examples 1 to 3, the first DFR2 having a thickness of 10 μm was attached to the first surface 1Sa of the vapor deposition mask base material 1. Next, an exposure step of contacting and exposing the first DFR2 with an exposure mask and then a developing step were performed to form a plurality of through holes 2a having a diameter of 30 μm in a grid pattern on the first DFR2. Subsequently, etching using the first DFR2 as a mask was performed on the first surface 1Sa to form a plurality of holes 32H located in a grid pattern on the substrate 1 for a vapor deposition mask. Then, the opening diameter of the substrate 1 for the vapor deposition mask in the width direction DW was measured for each hole 32H. Table 1 shows the variation in the opening diameter of each hole 32H in the width direction DW. In Table 1, among the opening diameters of each hole 32H, a circle is shown at a level where the difference between the maximum value of the opening diameter and the minimum value of the opening diameter is 2.0 μm or less, and the maximum opening diameter is shown. The x mark is shown at the level where the difference between the value and the minimum value of the opening diameter is larger than 2.0 μm.

As shown in Table 1, in Examples 1 to 4, it was found that the variation in the opening diameter was 2.0 μm or less. Further, among Examples 1 to 4, it was found that the variations in the opening diameters of Examples 1 to 3 were further smaller than those of Examples 4. On the other hand, in Comparative Examples 1 to 3, it was found that the variation in the opening diameter was larger than 2.0 μm. As a result, from the comparison between Examples 1 to 4 and Comparative Examples 1 to 3, the variation in the opening diameter varies when the first steepness is 0.5% or less, that is, when [Condition 1] is satisfied. It was found to be suppressed. It was also found that the variation in the opening diameter can be suppressed by satisfying the average value of the second steepness of 0.25% or less, that is, [Condition 2].

Further, from the comparison between Examples 1, 2 and 3 and Example 4, the variation in the opening diameter is further increased by the fact that the wave number per unit length is 4 or less, that is, when [Condition 3] is satisfied. It was found to be suppressed. Further, it was found that the variation in the opening diameter was further suppressed by the fact that the average value of the wave numbers per unit length was 2 or less, that is, that [Condition 4] was satisfied.

According to the above embodiment, the effects listed below can be obtained.
(1) It is possible to improve the accuracy of the hole shape and the hole size of the mask portion 32, and to improve the accuracy of the pattern formed by the vapor deposition. The method of exposing the resist is not limited to the method of bringing the exposure mask into contact with the resist, and may be an exposure in which the exposure mask is not brought into contact with the resist. In the method of bringing the exposure mask into contact with the resist, the substrate for the vapor deposition mask is pressed against the surface of the exposure mask, so that the deterioration of the exposure accuracy due to the wave shape of the substrate for the vapor deposition mask can be suppressed. Regardless of the exposure method, the accuracy in the process of processing the surface with a liquid can be improved, and by extension, the accuracy of the pattern formed by the vapor deposition can be improved.

(2) It is possible to suppress variations in the surface of the thin-film deposition mask base material 1 with respect to the result of development with a developing solution and the result of cleaning with the cleaning solution. As a result, the uniformity of the shape and size of the first through hole 2a and the second through hole 3a formed through the exposure step and the developing step can be enhanced in the surface of the substrate 1 for the vapor deposition mask. It will be possible.

(3) It is possible to suppress variations in the surface of the substrate 1 for the vapor deposition mask with respect to the result of etching with the etching solution and the result of cleaning the etching solution with the cleaning solution. Further, it is possible to suppress variations in the surface of the vapor deposition mask base material 1 with respect to the result of peeling of the resist layer by the stripping liquid and the result of cleaning the stripping liquid with the cleaning liquid. As a result, it is possible to improve the uniformity of the shape and size of the small hole 32SH and the shape and size of the large hole 32LH in the surface of the substrate 1 for the vapor deposition mask.

(4) For example, three mask portions 32 bear the quantity of holes 32H required for one frame portion 31. That is, the total area of the mask portion 32 required for one frame portion 31 is divided into, for example, three mask portions 32. Therefore, even if a part of the mask portion 32 is deformed in one frame portion 31, it is not necessary to replace all the mask portions 32 in one frame portion 31. Then, the size of the new mask portion 32 to be replaced with the deformed mask portion 32 can be reduced to about 1/3 as compared with the configuration in which one mask portion 32 is provided in one frame portion 31. It will also be possible.

(5) In the measurement of steepness using the measuring base material 2M, both ends of the measuring base material 2M in the length direction DL and both ends of the measuring base material 2M in the width direction DW. The part is excluded from the measurement target of steepness as a non-measurement range. Each non-measurement range is a range having a possibility of having a wave shape different from that of the vapor deposition mask base material 1 due to cutting of the vapor deposition mask base material 1. Therefore, if the measurement excludes the non-measurement range ZE from the measurement target, it is possible to improve the accuracy of the steepness.

The above embodiment can be changed as follows.
[Manufacturing method of base material for vapor deposition mask]
-In the rolling process, it is also possible to use a rolling apparatus provided with a plurality of pairs of rolling rollers to roll the base metal 1a with a plurality of pairs of rolling rollers. If the method uses a plurality of pairs of rolling rollers, it is possible to increase the degree of freedom regarding the control parameters for satisfying the above conditions 1 to 3.

-In the annealing step, it is also possible to anneal the roll-shaped rolling material 1b wound around the core C, instead of performing annealing while pulling the rolling material 1b in the length direction DL. In the method of annealing the roll-shaped rolling material 1b, the substrate 1 for a vapor deposition mask may have a habit of warping according to the roll diameter. Therefore, depending on the material of the substrate 1 for the vapor deposition mask and the size of the roll diameter when wound around the core C, it is preferable to anneal the rolled material 1b while pulling it.
-It is also possible to manufacture the base material 1 for a vapor deposition mask by alternately repeating the rolling process and the annealing process a plurality of times.

The base material 1 for a vapor deposition mask by electrolysis and the base material 1 for a vapor deposition mask by rolling may be further thinned by chemical polishing or electrical polishing. At this time, it is also possible to set conditions such as the composition of the polishing liquid and the method of supplying the polishing liquid so that the above conditions 1 to 3 are satisfied including the polishing step. The vapor-film mask substrate 1 obtained by polishing can also be annealed in response to a request to relieve internal stress.

C ... core, F ... stress, S ... vapor deposition target, V ... space, W ... width, CP ... clamp, DL ... length direction, DW ... width direction, EP ... electrode, H1 ... first opening, H2 ... second Opening, PC ... center, PR ... resist layer, RC ... center, RE ... edge, RM ... resist mask, SH ... step height, SP ... support, TM ... intermediate transfer substrate, ZE ... non-measurement range, ZL ... Measurement range, EPS ... Electrode surface, 1 ... Deposition mask base material, 1a ... Base material, 1b ... Rolling material, 1Sa, 321 ... First surface, 1Sb, 322 ... Second surface, 2 ... Measurement base material, 2a ... 1st through hole, 2S ... surface, 3a ... 2nd through hole, 4 ... first protective layer, 10 ... mask device, 20 ... main frame, 21 ... main frame hole, 30 ... vapor deposition mask, 31 ... frame part , 31E ... Inner edge, 32, 32A, 32B, 32C ... Mask, 32BN ... Join, 32E ... Outer edge, 32H ... Hole, 32K ... Base material, 32LH ... Large hole, 32SH ... Small hole, 33, 33A, 33B, 33C ... Frame hole, 50 ... Rolling device, 51, 52 ... Rolling roller, 53 ... Annealing device, 61 ... Second protective layer, 311 ... Bonded surface, 312 ... Non-bonded surface, 323 ... Mask plate.

Claims (8)

A base material for a vapor deposition mask, which is a metal plate having a strip shape and has a plurality of holes formed by etching and is used for manufacturing a vapor deposition mask.
The material constituting the metal plate is nickel or an iron-nickel alloy.
The thickness of the metal plate is 10 μm or more and 50 μm or less.
The shapes along the width direction of the metal plate at each position in the length direction of the metal plate are different from each other, and each shape has a wave repeating in the width direction of the metal plate.
The length of a straight line in the width direction connecting one valley to the other in the wave is the length of the wave.
The percentage of the height of the wave with respect to the length of the wave is the unit steepness.
The unit length in the length direction is 500 mm, and the unit length is 500 mm.
The maximum value of the unit steepness in the metal plate having the unit length is the first steepness.
A base material for a vapor deposition mask having a first steepness of 0.5% or less. At each position in the length direction of the metal plate, the maximum value of the unit steepness in the width direction of the metal plate is the second steepness.
The base material for a vapor deposition mask according to claim 1, wherein the average value of the second steepness of the metal plate having the unit length is 0.25% or less. At each position in the length direction of the metal plate, the number of waves included in the width direction of the metal plate is the wave number.
The base material for a vapor deposition mask according to claim 1 or 2, wherein the maximum value of the wave number in the metal plate having the unit length is 4 or less. At each position in the length direction of the metal plate, the number of waves included in the width direction of the metal plate is the wave number.
The base material for a vapor deposition mask according to any one of claims 1 to 3, wherein the average value of the wave numbers in the metal plate having the unit length is 2 or less. A method for manufacturing a base material for a thin-film deposition mask, which is a metal plate having a strip shape, in which a plurality of holes are formed by etching and used for manufacturing a thin-film deposition mask.
Including rolling the base metal to obtain the metal plate
The material constituting the metal plate is nickel or an iron-nickel alloy.
The thickness of the metal plate is 10 μm or more and 50 μm or less.
The shapes along the width direction of the metal plate at each position in the length direction of the metal plate are different from each other, and each shape has a wave repeating in the width direction of the metal plate.
The length of a straight line in the width direction connecting one valley to the other in the wave is the length of the wave.
The percentage of the height of the wave with respect to the length of the wave is the unit steepness.
The unit length in the length direction is 500 mm, and the unit length is 500 mm.
The maximum value of the unit steepness in the metal plate having the unit length is the first steepness.
A method for producing a base material for a thin-film deposition mask, in which the base metal is rolled so that the first steepness is 0.5% or less. Forming a resist layer on a strip-shaped metal plate and
A method for manufacturing a vapor-deposited mask, which comprises forming a mask portion by forming a plurality of holes in the metal plate by etching using the resist layer as a mask.
The material constituting the metal plate is nickel or an iron-nickel alloy.
The thickness of the metal plate is 10 μm or more and 50 μm or less.
The shapes along the width direction of the metal plate at each position in the length direction of the metal plate are different from each other, and each shape has a wave repeating in the width direction of the metal plate.
The length of a straight line in the width direction connecting one valley to the other in the wave is the length of the wave.
The percentage of the height of the wave with respect to the length of the wave is the unit steepness.
The unit length in the length direction is 500 mm, and the unit length is 500 mm.
The maximum value of the unit steepness in the metal plate having the unit length is the first steepness.
A method for manufacturing a thin-film deposition mask in which the first steepness is 0.5% or less. Forming the mask portion means forming a plurality of the mask portions on a single metal plate.
Each mask portion separately comprises one side surface having the plurality of holes.
The sixth aspect of claim 6 further comprises joining the side surface of each mask portion and one frame portion to each other so that the plurality of holes are surrounded by the one frame portion for each mask portion. How to make a vapor deposition mask. Preparing a vapor deposition mask according to the method for manufacturing a vapor deposition mask according to claim 6 or 7.
A method for manufacturing a display device, which comprises forming a pattern by vapor deposition using the vapor deposition mask.

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