CN108048793B

CN108048793B - Metal plate, method for producing metal plate, and method for producing vapor deposition mask using metal plate

Info

Publication number: CN108048793B
Application number: CN201711267429.7A
Authority: CN
Inventors: 池永知加雄
Original assignee: Dai Nippon Printing Co Ltd
Current assignee: Dai Nippon Printing Co Ltd
Priority date: 2013-01-10
Filing date: 2014-01-10
Publication date: 2020-11-03
Anticipated expiration: 2034-01-10
Also published as: JP2014148740A; KR101761494B1; KR20170087533A; KR20150103655A; CN107858644A; CN108048793A; CN104838037A; KR102087056B9; WO2014109394A1; JP5382257B1; CN110938798A; CN104838037B; KR102087056B1

Abstract

The present invention relates to a metal plate, a method for manufacturing the metal plate, and a method for manufacturing a vapor deposition mask using the metal plate. The invention provides a metal plate capable of manufacturing a vapor deposition mask with small warpage. When a sample obtained from a metal plate after an annealing step was etched, the curvature k of the warpage of the etched sample was 0.008mm^‑1The following.

Description

Metal plate, method for producing metal plate, and method for producing vapor deposition mask using metal plate

The present application is a divisional application entitled "metal plate, method for manufacturing metal plate, and method for manufacturing vapor deposition mask using metal plate", which was originally applied under chinese national application No. 201480003438.3, application date 1/10/2014.

Technical Field

The present invention relates to a metal plate for manufacturing a vapor deposition mask by forming 2 or more through holes. The invention also relates to a method for manufacturing the metal plate. The present invention also relates to a method for manufacturing a vapor deposition mask for vapor deposition in a desired pattern using a metal plate.

Background

In recent years, a display device used in a portable device such as a smartphone or a tablet computer is required to have high definition, for example, a pixel density of 300ppi or more. In addition, in portable devices, the demand for full high-definition display is increasing, and in this case, the pixel density of a display device is required to be 450ppi or more, for example.

Organic EL display devices have attracted attention because of their good responsiveness and low power consumption. As a method for forming pixels of an organic EL display device, a method is known in which pixels are formed in a desired pattern using a vapor deposition mask including through holes arranged in a desired pattern. Specifically, first, a vapor deposition mask is brought into close contact with a substrate for an organic EL display device, and then the vapor deposition mask and the substrate brought into close contact are put into a vapor deposition device together to perform vapor deposition of an organic material or the like. The vapor deposition mask is generally produced as follows: the vapor deposition mask is manufactured by forming a through hole in a metal plate by etching using a photolithography technique (for example, patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2004-39319

Disclosure of Invention

When a vapor deposition material is formed on a substrate using a vapor deposition mask, the vapor deposition material adheres to not only the substrate but also the vapor deposition mask. For example, there is a vapor deposition material that flies toward the substrate along a direction that is greatly inclined with respect to the normal direction of the vapor deposition mask, and such a vapor deposition material reaches the wall surface of the through hole of the vapor deposition mask before reaching the substrate and adheres thereto. In this case, it is considered that the vapor deposition material is less likely to adhere to a region of the substrate located near the wall surface of the through hole of the vapor deposition mask, and as a result, the thickness of the adhering vapor deposition material is smaller than that of other portions, or a portion where the vapor deposition material does not adhere is generated. That is, it is considered that vapor deposition in the vicinity of the wall surface of the through hole of the vapor deposition mask is unstable. Therefore, when a vapor deposition mask is used to form pixels of an organic EL display device, the dimensional accuracy and positional accuracy of the pixels are reduced, and as a result, the light emission efficiency of the organic EL display device is reduced.

In order to solve such a problem, it is considered to reduce the thickness of a metal plate used for manufacturing a vapor deposition mask. This is because the height of the wall surface of the through hole of the vapor deposition mask can be reduced by reducing the thickness of the metal plate, and the proportion of the vapor deposition material adhering to the wall surface of the through hole in the vapor deposition material can be reduced. However, in order to obtain a metal plate having a small thickness, it is necessary to increase the rolling reduction when rolling a base metal to produce the metal plate. Here, the rolling reduction is a value calculated by (thickness of base material — metal plate)/(thickness of base material). When heat treatment such as annealing is performed after rolling, the stress remaining in the metal sheet, that is, the residual stress, is generally increased as the rolling reduction is increased. If the residual stress is large, when a through hole is formed in the metal plate by etching, the residual stress is removed on the side of the metal plate where etching is performed, and as a result, the resulting vapor deposition mask is warped. When the warpage is large, the vapor deposition mask cannot be sufficiently adhered to the substrate for the organic EL display device, and as a result, the dimensional accuracy and positional accuracy of the pixels of the obtained organic EL display device are degraded.

The present invention has an object to provide a metal plate, a method for manufacturing the metal plate, and a method for manufacturing a vapor deposition mask, which can effectively solve the above problems.

The present invention relates to a method for manufacturing a metal plate having 2 or more through holes formed therein for manufacturing a vapor deposition mask, wherein the through holes of the vapor deposition mask are formed by etching the metal plate, the method comprising: a rolling step of rolling the base material to obtain a material having a thickness t₀The above metal plate of (1); and an annealing step of annealing the metal plate to remove internal stress of the metal plate, wherein the metal plate has a 1 st surface and a 2 nd surface, the 1 st surface and the 2 nd surface being orthogonal to and opposed to each other in a thickness direction of the metal plate, and when a sample obtained from the metal plate after the annealing step is etched, a curvature k of a warp of the sample after etching is 0.008mm^-1The curvature k is the following value: first, the sample having a length of 170mm and a width of 30mm was taken from the metal plate after the annealing step, and then, a region having a length of 150mm and a width of 30mm except regions within 10mm from both ends in the longitudinal direction in the sample was set as an etched region, and the sample was etched over the entire etched region of the sample from the 1 st surface side until the thickness of the etched region reached 1/3 × t₀Above and 2/3 × t₀The curvature k is determined by placing the etched sample on a predetermined placing table so that the side surface of the sample is horizontal, measuring the distance x (mm) between the ends of the sample in the longitudinal direction of the region to be etched and the depth y (mm) of the warp of the region to be etched of the sample, and substituting the distance x between the ends and the depth y into the following equation,

k＝1/ρ、ρ＝(y/2)+(x²/8y)。

in the method for manufacturing a metal plate according to the present invention, the annealing step may be performed while the metal plate is stretched in the longitudinal direction.

In the method for manufacturing a metal plate according to the present invention, the annealing step may be performed in a state where the metal plate is wound around a core member.

In the method for producing a metal plate according to the present invention, it is preferable that the base material has a coefficient of thermal expansion equal to a coefficient of thermal expansion of a substrate on which a vapor deposition material is formed with a vapor deposition mask made of the metal plate interposed therebetween.

In the method for manufacturing a metal plate according to the present invention, the metal plate may contain an invar alloy material.

The present invention described in claim 2 relates to a metal plate for manufacturing a vapor deposition mask by forming 2 or more through holes, wherein the metal plate has a thickness t₀The metal plate has a 1 st surface and a 2 nd surface, the 1 st surface and the 2 nd surface being orthogonal to each other in a thickness direction of the metal plate and facing each other, and when a sample obtained from the metal plate is etched, a curvature k of a warp of the sample after etching is 0.008mm^-1The curvature k is the following value: first, the sample having a length of 170mm and a width of 30mm was taken from the metal plate, and then, a region having a length of 150mm and a width of 30mm except regions within 10mm from both ends in the longitudinal direction of the sample was set as an etched region, and the sample was etched over the entire etched region of the sample from the 1 st surface side to the thickness of the etched regionThe degree reaches 1/3 × t₀Above and 2/3 × t₀The curvature k is determined by placing the etched sample on a predetermined placing table so that the side surface of the sample is horizontal, measuring the distance x (mm) between the ends of the sample in the longitudinal direction of the region to be etched and the depth y (mm) of the warp of the region to be etched of the sample, and substituting the distance x between the ends and the depth y into the following equation,

k＝1/ρ、ρ＝(y/2)+(x²/8y)。

the thermal expansion coefficient of the metal plate according to the present invention is preferably the same as the thermal expansion coefficient of a substrate on which a vapor deposition material is formed via a vapor deposition mask made of the metal plate.

The metal plate according to the present invention may contain an invar alloy material.

The present invention of claim 3 relates to a method for manufacturing a vapor deposition mask including an effective region in which 2 or more through holes are formed and a peripheral region located around the effective region, the method including: a step of preparing a metal plate having a thickness t₀A 1 st surface and a 2 nd surface, the 1 st surface and the 2 nd surface being orthogonal to the thickness direction of the metal plate and facing each other; and a recess forming step of etching the metal plate from the 1 st surface side, forming a recess for cutting the through hole from the 1 st surface side in a region of the metal plate for forming the effective region, and when a sample obtained from the metal plate is etched, a curvature k of a warp of the sample after etching is 0.008mm^-1The curvature k is the following value: first, the sample having a length of 170mm and a width of 30mm was taken from the metal plate, and then, a region having a length of 150mm and a width of 30mm except regions within 10mm from both ends in the longitudinal direction of the sample was set as an etched region, and the sample was etched over the entire etched region of the sample from the 1 st surface side until the thickness of the etched region reached 1/3 × t₀Above and 2/3 × t₀Within the following range, thereafterThe curvature k is obtained by placing the etched sample on a predetermined placing table so that the side surface thereof is horizontal, measuring the distance x (mm) between the ends of the sample in the longitudinal direction of the region to be etched and the depth y (mm) of the warp of the region to be etched of the sample, and substituting the distance x between the ends and the depth y into the following equation,

k＝1/ρ、ρ＝(y/2)+(x²/8y)。

in the recess forming step in the method for manufacturing a vapor deposition mask according to the present invention, the metal plate may be etched over the entire 1 st surface from the 1 st surface side.

In the recess forming step of the method for manufacturing a vapor deposition mask according to the present invention, the metal plate may be etched over the entire 1 st surface from the 1 st surface side until the etching thickness reaches 1/3 × t₀Above and 2/3 × t₀Within the following ranges.

In the method for producing a vapor deposition mask according to the present invention, it is preferable that the coefficient of thermal expansion of the metal plate is equal to the coefficient of thermal expansion of a substrate on which a vapor deposition material is formed with a vapor deposition mask made of the metal plate interposed therebetween.

In the method for manufacturing a vapor deposition mask according to the present invention, the metal plate may contain an invar alloy material.

According to the present invention, a vapor deposition mask with less warpage can be obtained. Therefore, the vapor deposition mask can be sufficiently closely attached to the substrate, and as a result, the dimensional accuracy and positional accuracy of the vapor deposition material adhering to the substrate can be improved.

Drawings

Fig. 1 is a view for explaining an embodiment of the present invention, and is a schematic perspective view showing an example of a vapor deposition mask device including a vapor deposition mask.

Fig. 2 is a diagram for explaining a method of performing vapor deposition by using the vapor deposition mask device shown in fig. 1.

Fig. 3 is a partial plan view showing the vapor deposition mask shown in fig. 1.

Fig. 4 is a sectional view taken along line IV-IV of fig. 3.

Fig. 5 is a sectional view taken along line V-V of fig. 3.

Fig. 6 is a sectional view taken along line VI-VI of fig. 3.

Fig. 7(a) is a view showing a step of obtaining a metal plate having a desired thickness by rolling a base material, and fig. 7(b) is a view showing a step of annealing the metal plate obtained by rolling.

Fig. 8(a) is a view showing a sample cut out from the metal plate obtained by the steps shown in fig. 7(a) and (b), and fig. 8(b) is a view showing an etched sample obtained by etching the 1 st surface of the sample shown in fig. 8 (a).

Fig. 9(a) and (b) are a perspective view and a plan view showing how the etched sample shown in fig. 8(b) is mounted on the mounting table.

Fig. 10 is a schematic view for explaining an example of the method of manufacturing the vapor deposition mask shown in fig. 1 as a whole.

Fig. 11 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and shows a long metal plate in a cross section along a normal direction.

Fig. 12 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and shows a long metal plate in a cross section along a normal direction.

Fig. 13 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and shows a long metal plate in a cross section along a normal direction.

Fig. 14 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and shows a long metal plate in a cross section along a normal direction.

Fig. 15 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and shows a long metal plate in a cross section along a normal direction.

Fig. 16 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and shows a long metal plate in a cross section along a normal direction.

Fig. 17 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and shows a long metal plate in a cross section along a normal line direction.

Fig. 18 is a diagram for explaining a modification of the vapor deposition mask and the vapor deposition mask device.

Fig. 19(a) to (c) are diagrams for explaining a method of obtaining a sample from a metal plate in the example.

Detailed Description

An embodiment of the present invention will be described below with reference to the drawings. In the drawings attached to the present specification, the actual scale, the aspect ratio, and the like are appropriately changed and exaggerated for the convenience of illustration and easy understanding.

Fig. 1 to 17 are diagrams for explaining an embodiment according to the present invention. In the following embodiments and modifications thereof, a method of manufacturing a vapor deposition mask for patterning an organic material on a substrate in a desired pattern in the manufacture of an organic EL display device will be described as an example. However, the present invention is not limited to such an application, and can be applied to a method for manufacturing a vapor deposition mask for various applications.

In this specification, the terms "plate", "sheet" and "film" are not distinguished from each other only by the difference in designation. For example, "plate" is a concept that also includes a member that may be referred to as a sheet or a film, and thus, for example, "metal plate" is indistinguishable from a member referred to as "metal sheet" or "metal film" only in terms of a difference in designation.

The "plate surface (sheet surface, film surface)" refers to a surface of a plate-like member (sheet-like member, film-like member) as a target in a planar direction when the plate-like member (sheet-like member, film-like member) as a target is viewed as a whole or substantially. The normal direction used for a plate-shaped (sheet-shaped or film-shaped) member means a normal direction to a plate surface (sheet surface or film surface) of the member.

Terms used in the present specification such as "parallel", "orthogonal", "identical" and "equivalent" specifying the conditions and physical properties of the shape and geometry and the degree thereof, and the length, angle, value of the physical property and the like are not limited to strict meanings, but are interpreted to include ranges of degrees where the same functions can be expected.

(vapor deposition mask device)

First, an example of a vapor deposition mask device including a vapor deposition mask to be subjected to a manufacturing method will be described mainly with reference to fig. 1 to 6. Here, fig. 1 is a perspective view showing an example of a vapor deposition mask device including a vapor deposition mask, and fig. 2 is a view for explaining a method of using the vapor deposition mask device shown in fig. 1. Fig. 3 is a plan view showing the vapor deposition mask from the 1 st surface side, and fig. 4 to 6 are sectional views of the respective positions in fig. 3.

The vapor deposition mask device 10 shown in fig. 1 and 2 includes a vapor deposition mask 20 formed of a rectangular metal plate 21, and a frame 15 attached to a peripheral portion of the vapor deposition mask 20. The vapor deposition mask 20 is provided with a large number of through holes 25, and the large number of through holes 25 are formed by etching at least the 1 st surface 21a of the metal plate 21 having the 1 st surface 21a and the 2 nd surface 21b facing each other. As shown in fig. 2, the vapor deposition mask device 10 is supported in a vapor deposition device 90 so that a vapor deposition mask 20 faces a lower surface of a substrate to be vapor deposited, for example, a glass substrate 92, and is used for vapor deposition of a vapor deposition material on the substrate.

In the vapor deposition device 90, the vapor deposition mask 20 is brought into close contact with the glass substrate 92 by a magnetic force from a magnet not shown. In the vapor deposition device 90, a crucible 94 for containing a vapor deposition material (an organic light emitting material, for example) 98 and a heater 96 for heating the crucible 94 are disposed below the vapor deposition mask device 10. The evaporation material 98 in the crucible 94 is vaporized or sublimated by heating from the heater 96 and adheres to the surface of the glass substrate 92. As described above, a large number of through holes 25 are formed in the vapor deposition mask 20, and the vapor deposition material 98 adheres to the glass substrate 92 through the through holes 25. As a result, the vapor deposition material 98 is formed on the surface of the glass substrate 92 in a desired pattern corresponding to the position of the through hole 25 of the vapor deposition mask 20.

(vapor deposition mask)

The vapor deposition mask 20 will be described in detail below. As shown in fig. 1, in the present embodiment, the vapor deposition mask 20 is formed of a metal plate 21, and has a substantially quadrangular shape in plan view, more precisely, a substantially rectangular outline in plan view. The metal plate 21 of the vapor deposition mask 20 includes an effective region 22 in which through holes 25 are formed and which are regularly arranged, and a peripheral region 23 surrounding the effective region 22. The peripheral region 23 is a region for supporting the active region 22, and is not a region through which an evaporation material to be evaporated on the substrate passes. For example, in the vapor deposition mask 20 used for vapor deposition of an organic light-emitting material for an organic EL display device, the effective region 22 is a region in the vapor deposition mask 20 facing a region on the substrate (glass substrate 92) for forming pixels by vapor deposition of the organic light-emitting material, that is, a region in the vapor deposition mask 20 facing a region on the substrate for forming the display surface of the substrate for the organic EL display device to be produced. However, a through hole or a recess may be formed in the peripheral region 23 for various purposes. In the example shown in fig. 1, each effective region 22 has a substantially quadrangular shape in plan view, and more precisely has a substantially rectangular outline in plan view.

In the illustrated example, 2 or more effective regions 22 are arranged at predetermined intervals along one direction parallel to one side of the vapor deposition mask 20, and at predetermined intervals along another direction orthogonal to the one direction. In the illustrated example, one effective region 22 corresponds to one organic EL display device. That is, according to the vapor deposition mask device 10 (vapor deposition mask 20) shown in fig. 1, vapor deposition can be repeated segment by segment (multi-surface vapor deposition).

As shown in fig. 3, in the illustrated example, 2 or more through holes 25 formed in each effective region 22 are arranged at predetermined intervals in the effective region 22 along two directions orthogonal to each other. An example of the through-hole 25 formed in the metal plate 21 will be described in further detail with reference to fig. 3 to 6.

As shown in fig. 4 to 6, 2 or more through holes 25 extend between a 1 st surface 20a and a 2 nd surface 20b of the vapor deposition mask 20, the 1 st surface 20a being one side of the vapor deposition mask 20 along the normal line direction, and the 2 nd surface 20b being the other side of the vapor deposition mask 20 along the normal line direction, and penetrate through the vapor deposition mask 20. In the illustrated example, as will be described in detail later, the 1 st recess 30 is formed in the metal plate 21 by etching from the 1 st surface 21a side of the metal plate 21 which is one side in the normal direction of the vapor deposition mask, the 2 nd recess 35 is formed in the metal plate 21 from the 2 nd surface 21b side which is the other side in the normal direction of the metal plate 21, and the through-hole 25 is formed by the 1 st recess 30 and the 2 nd recess 35.

As shown in fig. 3 to 6, the sectional area of each 1 st recess 30 in the cross section along the plate surface of the vapor deposition mask 20 is gradually reduced from the 1 st surface 20a side to the 2 nd surface 20b side of the vapor deposition mask 20 at each position of the vapor deposition mask 20 along the normal line direction. As shown in fig. 3, the wall surface 31 of the 1 st recess 30 extends in a direction intersecting the normal direction of the vapor deposition mask 20 over the entire region thereof, and is exposed to one side along the normal direction of the vapor deposition mask 20. Similarly, at each position of the vapor deposition mask 20 along the normal direction, the sectional area of each 2 nd concave portion 35 in the cross section along the plate surface of the vapor deposition mask 20 may be gradually smaller from the 2 nd surface 20b side to the 1 st surface 20a side of the vapor deposition mask 20. The wall surface 36 of the 2 nd recessed portion 35 extends in a direction intersecting the normal direction of the vapor deposition mask 20 over the entire region thereof, and is exposed to the other side along the normal direction of the vapor deposition mask 20.

As shown in fig. 4 to 6, the wall surface 31 of the 1 st recess 30 and the wall surface 36 of the 2 nd recess 35 are connected by a circumferential connecting portion 41. The connection portion 41 is defined by a ridge line of a protrusion formed by joining the wall surface 31 of the 1 st recess 30 inclined with respect to the normal direction of the vapor deposition mask and the wall surface 36 of the 2 nd recess 35 inclined with respect to the normal direction of the vapor deposition mask. The connecting portion 41 defines a through portion 42 having the smallest area of the through hole 25 in a plan view of the vapor deposition mask 20.

As shown in fig. 4 to 6, two through holes 25 adjacent to each other are spaced apart from each other along the plate surface of the vapor deposition mask on the other surface of the vapor deposition mask along the normal direction, that is, the 2 nd surface 20b of the vapor deposition mask 20. That is, as in the manufacturing method described later, when the 2 nd concave portions 35 are formed by etching the metal plate 21 from the 2 nd surface 21b side of the metal plate 21 corresponding to the 2 nd surface 20b of the vapor deposition mask 20, the 2 nd surface 21b of the metal plate 21 remains between the two adjacent 2 nd concave portions 35.

On the other hand, as shown in fig. 4 to 6, two adjacent 1 st recesses 30 are connected to one side of the vapor deposition mask along the normal direction, that is, the 1 st surface 20a side of the vapor deposition mask 20. That is, as in the manufacturing method described later, when the 1 st recess 30 is formed by etching the metal plate 21 from the 1 st surface 21a side of the metal plate 21 corresponding to the 1 st surface 20a of the vapor deposition mask 20, the 1 st surface 21a of the metal plate 21 does not remain between the adjacent two 1 st recesses 30. That is, the 1 st surface 21a of the metal plate 21 is etched in the entire effective region 22. When the vapor deposition mask 20 is used such that the 1 st surface 20a of the vapor deposition mask 20 formed by the 1 st recessed portion 30 faces the vapor deposition material 98 as shown in fig. 2, the use efficiency of the vapor deposition material 98 can be effectively improved.

As shown in fig. 2, when the vapor deposition mask device 10 is housed in the vapor deposition device 90, as shown by the two-dot chain line in fig. 4, the 1 st surface 20a of the vapor deposition mask 20 is positioned on the crucible 94 side holding the vapor deposition material 98, and the 2 nd surface 20b of the vapor deposition mask 20 faces the glass substrate 92. Therefore, the vapor deposition material 98 adheres to the glass substrate 92 through the 1 st recess 30 whose cross-sectional area is gradually reduced. As indicated by arrows in fig. 4, the vapor deposition material 98 may move from the crucible 94 to the glass substrate 92 not only in the normal direction of the glass substrate 92 but also in a direction greatly inclined with respect to the normal direction of the glass substrate 92. At this time, when the thickness of the vapor deposition mask 20 is large, a large amount of the vapor deposition material 98 that moves obliquely reaches the wall surface 31 of the 1 st concave portion 30 and adheres thereto before it passes through the through hole 25 and reaches the glass substrate 92. In addition, in the region facing through hole 25 on glass substrate 92, a region where vapor deposition material 98 easily reaches and a portion where it is difficult to reach are generated. Therefore, in order to improve the utilization efficiency of the vapor deposition material (film formation efficiency: the ratio of deposition onto the glass substrate 92), save an expensive vapor deposition material, and stably and uniformly perform film formation using the expensive vapor deposition material in a desired region, it is important to configure the vapor deposition mask 20 so that the vapor deposition material 98 that is moved obliquely reaches the glass substrate 92 as much as possible. That is, in the cross-section of fig. 4 to 6 in which the vapor deposition mask 20 is orthogonal to the sheet surface, it is advantageous to sufficiently increase the minimum angle θ 1 (see fig. 4) formed by the straight line L1 with respect to the normal direction of the vapor deposition mask 20, and the straight line L1 passes through the connection portion 41, which is a portion having the minimum cross-sectional area, of the through-hole 25 and any other position of the wall surface 31 of the 1 st recess 30.

As one of the methods for increasing the angle θ 1, it is conceivable to reduce the height of the wall surface 31 of the 1 st recess 30 and the wall surface 36 of the 2 nd recess 35 by reducing the thickness of the vapor deposition mask 20. That is, it can be said that as the metal plate 21 constituting the vapor deposition mask 20, it is preferable to use a metal plate 21 having a thickness as small as possible within a range in which the strength of the vapor deposition mask 20 can be ensured.

As another method for increasing the angle θ 1, it is also conceivable to optimize the profile of the 1 st recess 30. For example, according to the present embodiment, the angle θ 1 can be made larger by the merging of the wall surfaces 31 of the adjacent two 1 st recesses 30 than a recess having a wall surface (contour) indicated by a broken line which is not merged with another recess. The reason for this will be described below.

As will be described later in detail, the 1 st recess 30 is formed by etching the 1 st surface 21a of the metal plate 21. The wall surface of the recess formed by etching is generally curved, and the curved protrusion faces the erosion direction. Therefore, the wall surface 31 of the recess formed by etching is steep in the region on the etching start side, and is greatly inclined with respect to the normal direction of the metal plate 21 in the region on the opposite side to the etching start side, that is, the deepest side of the recess. On the other hand, in the illustrated vapor deposition mask 20, since the wall surfaces 31 of the two adjacent 1 st concave portions 30 meet at the etching start side, the outer contour of the portion 43 where the front end edges 32 of the wall surfaces 31 of the two 1 st concave portions 30 meet is not a sharp shape but a chamfered shape. Therefore, the wall surface 31 of the 1 st recess 30 forming most of the through-hole 25 can be effectively inclined with respect to the normal direction of the vapor deposition mask. That is, the angle θ 1 may be increased.

With the vapor deposition mask 20 according to the present embodiment, the inclination angle θ 1 formed by the wall surface 31 of the 1 st recess 30 and the normal direction of the vapor deposition mask can be effectively increased over the entire effective region 22. This can effectively improve the utilization efficiency of the vapor deposition material 98, and can perform vapor deposition in a desired pattern with high accuracy and stability.

In addition, as described in the manufacturing method described later, when the 1 st recess 30 is formed by etching the metal plate 21 from the 1 st surface 21a side of the metal plate 21 corresponding to the 1 st surface 20a of the vapor deposition mask 20, the 1 st surface 21a of the metal plate 21 is eroded by the etching over the entire area of the metal plate 21 that forms the effective region 22 of the vapor deposition mask 20. That is, the maximum thickness Ta in the effective region 22 of the vapor deposition mask along the normal direction is less than 100% of the maximum thickness Tb in the peripheral region 23 of the vapor deposition mask along the normal direction. In this way, it is preferable to reduce the thickness of the entire effective region 22 in order to improve the utilization efficiency of the vapor deposition material. On the other hand, from the viewpoint of the strength of the vapor deposition mask, the maximum thickness Ta in the effective region 22 of the vapor deposition mask along the normal direction is preferably 50% or more of the maximum thickness Tb in the peripheral region 23 of the vapor deposition mask along the normal direction. When the maximum thickness Ta in the effective region 22 is 50% or more of the maximum thickness Tb in the peripheral region 23, deformation of the vapor deposition mask 20 in the effective region 22 can be effectively suppressed when the vapor deposition mask 20 is placed on the frame 15 in tension, and thus vapor deposition in a desired pattern can be effectively performed.

However, in order to obtain a metal plate 21 having a small thickness, it is necessary to increase the rolling reduction in producing the metal plate 21 by rolling the base material. However, as the rolling reduction is increased, the stress remaining in the metal plate, that is, the residual stress is also increased. If the residual stress is large, when the metal plate 21 is etched to produce the vapor deposition mask 20, the residual stress is eliminated on the side of the metal plate 21 where the etching is performed, and as a result, the resulting vapor deposition mask 20 is warped. It is considered that when the warpage is large, the vapor deposition mask 20 cannot be made sufficiently dense with respect to the substrate 92, and as a result, the positional accuracy of vapor deposition is lowered. In the present embodiment, as described above, the vapor deposition mask 20 is produced by etching the wide region, for example, the entire region of the effective region 22 of the 1 st surface 21a of the metal plate 21. Therefore, the degree of residual stress to be removed on the 1 st surface 21a side of the metal plate 21 is higher than that in the case where only the 1 st surface 21a is partially etched, and as a result, the possibility of occurrence of warpage is also higher. Therefore, as described later, it is important to screen out and use the metal plate 21 that is less likely to warp when used as the vapor deposition mask 20.

As described above, in the present embodiment, the through holes 25 are arranged in a predetermined pattern in each effective region 22. When color display is to be performed, the vapor deposition mask 20 (vapor deposition mask device 10) and the glass substrate 92 may be moved relative to each other little by little along the arrangement direction of the through holes 25 (the above-described one direction), and the red organic light-emitting material, the green organic light-emitting material, and the blue organic light-emitting material may be sequentially vapor deposited.

The frame 15 of the vapor deposition mask device 10 is attached to the peripheral portion of the rectangular vapor deposition mask 20. The frame 15 holds the vapor deposition mask 20 in a tensioned state so as not to deflect the vapor deposition mask. The vapor deposition mask 20 and the frame 15 are fixed to each other by, for example, spot welding.

The vapor deposition process is performed inside the vapor deposition device 90 in a high-temperature atmosphere. Therefore, during the vapor deposition process, the vapor deposition mask 20, the frame 15, and the substrate 92 held inside the vapor deposition device 90 are also heated. At this time, the vapor deposition mask, the frame 15, and the substrate 92 exhibit behavior based on dimensional changes in the respective thermal expansion coefficients. In this case, if the difference in the thermal expansion coefficients of the vapor deposition mask 20, the frame 15, and the substrate 92 is large, a displacement occurs due to the difference in the dimensional changes of these components, and as a result, the dimensional accuracy and positional accuracy of the vapor deposition material adhering to the substrate 92 are lowered. In order to solve such a problem, the thermal expansion coefficients of the vapor deposition mask 20 and the frame 15 are preferably equal to the thermal expansion coefficient of the substrate 92. For example, when the glass substrate 92 is used as the substrate 92, an invar alloy material, which is an alloy obtained by adding 36% of nickel to iron, may be used as the material of the vapor deposition mask 20 and the frame 15.

The operation and effect of the present embodiment having such a configuration will be described below. First, a method for manufacturing a metal plate for use in manufacturing a vapor deposition mask will be described. Next, a method for manufacturing a vapor deposition mask using the obtained metal plate will be described. Next, a method of performing vapor deposition of a vapor deposition material on a substrate using the obtained vapor deposition mask will be described.

(method for producing Metal plate)

First, a method for manufacturing a metal plate will be described with reference to fig. 7(a) and 7(b), fig. 8(a) and 8(b), and fig. 9(a) and 9 (b). Fig. 7(a) is a view showing a step of obtaining a metal plate having a desired thickness by rolling a base material, and fig. 7(b) is a view showing a step of annealing the metal plate obtained by rolling. Fig. 8(a) is a view showing a sample cut out from the metal plate obtained by the steps shown in fig. 7(a) and 7(b), and fig. 8(b) is a view showing an etched sample obtained by etching the 1 st surface of the sample shown in fig. 8 (a). Fig. 9(a) and (b) are a perspective view and a plan view, respectively, showing how a sample cut out from a metal plate is mounted on a mounting table.

[ Rolling Process ]

First, as shown in fig. 7(a), a base material 55 containing an invar alloy material is prepared, and the base material 55 is transferred to a rolling apparatus 56 including a pair of rolling

rolls

56a and 56 b. The base material 55 that has reached between the pair of rolling

rolls

56a and 56b is rolled by the pair of rolling

rolls

56a and 56b, and as a result, the base material 55 is stretched in the conveying direction while being reduced in thickness. Thereby, the thickness t can be reached₀The long metal plate 64. As shown in fig. 7(a), the long metal sheet 64 may be wound around the core 61 to form a wound body 62.

[ annealing step ]

Thereafter, in order to eliminate the residual stress accumulated in the long metal plate 64 by rolling, the long metal plate 64 is annealed by using the annealing device 57 as shown in fig. 7 (b). As shown in fig. 7(b), the annealing step may be performed while the long metal plate 64 is stretched in the conveyance direction (longitudinal direction). As a result, the thickness t with residual stress removed to some extent can be obtained₀The long metal plate 64. As shown in fig. 7(b), the long metal sheet 64 may be wound around the core 61 to form a wound body 62. The thickness t is₀Generally equal to the maximum thickness Tb in the surrounding area 23 of the vapor deposition mask 20.

The form of the rolling step and the annealing step is not particularly limited to the form shown in fig. 7(a) and (b). For example, the rolling process may be performed by 2 or more pairs of rolling

rolls

56a and 56 b. The thickness t may be produced by repeating the rolling step and the annealing step 2 or more times₀The long metal plate 64. In fig. 7(b), an example is shown in which the annealing step is performed while the long metal plate 64 is stretched in the longitudinal direction, but the annealing step is not limited to this, and may be performed in a state in which the long metal plate 64 is wound around the core member 61. When the annealing step is performed in a state where the long metal sheet 64 is wound around the core 61, there is a problem that the long metal sheet 64 is warped according to the winding diameter of the wound body 62. Therefore, depending on the winding diameter of the wound body 62 and the material constituting the base material 55, it is advantageous to perform the annealing step while drawing the long metal plate 64 in the longitudinal direction.

[ inspection Process ]

Thereafter, an inspection step of inspecting the degree of warpage of the obtained long metal plate 64 is performed. First, as shown in FIG. 8(a), a length l, a width w and a thickness t are cut out from a long metal plate 64₀ Sample 75 of (2). In fig. 8(a), the 1 st and 2 nd surfaces of the sample 75 are denoted by

reference numerals

75a and 75b, respectively. The 1 st surface 75a and the 2 nd surface 75b are surfaces orthogonal to the thickness direction of the sample 75 and are surfaces facing each other. In fig. 8, a pair of side surfaces located between the 1 st surface 75a and the 2 nd surface 75b and extending in the longitudinal direction of the sample 75 are denoted by

reference numerals

75c and 75d, respectively. Length l, width w and thickness t₀As described later, the thickness can be determined appropriately according to the size of the vapor deposition mask 20 obtained from the long metal plate 64, for example, the length l is 170mm, the width w is 30mm, and the thickness t is₀Is in the range of 0.020mm to 0.100 mm.

Next, as shown in fig. 8(b), the sample 75 is etched from the 1 st surface 75a side over the entire area of the etched region 75f of the 1 st surface 75a until the etched region 75f of the sample 75 has a thickness t₁. The etched region 75f is an etched region in the sample 75. For example, the etched regions 75f are the ends of the sample 75 except the longitudinal direction75g1, 75g2 ml₁、l₂The region outside the inner region. Length l near both ends 75g1, 75g2₁、l₂All the regions of (a) are regions that are not etched. As described later, such an unetched region plays a role in securing stability of the sample 75 when the sample 75 is placed on the mounting table.

As is clear from FIG. 8(b), the length l of the etched region 75f in the longitudinal direction of the sample 75₃Is to subtract the length l from the length l of the sample 75₁And length l₂The latter length. Length l₁And length l₂The thickness is determined appropriately so as to ensure the stability of the sample 75 when the sample 75 is placed on the placement table, and is, for example, 10mm each. In this case, the length l of the etched region 75f in the longitudinal direction₃Is 150 mm.

Thickness t of etched sample 75₁Is appropriately determined according to the degree of etching performed to produce the vapor deposition mask 20, for example, the thickness t₁Is 1/3 Xt₀Above and 2/3 × t₀Within the following ranges. Here, since the residual stress is accumulated to some extent in the sample 75, the sample 75 is warped by etching the sample 75 from the 1 st surface 75a side. The following describes a step of measuring the curvature of warpage.

As a method for evaluating the warpage of a sample, a method is known in which one end of a sample is supported and the sample is suspended in the air, and the curvature of the warpage of the sample is calculated. However, in this case, the measurement result of the curvature of the warp reflects not only the element due to the residual stress relief but also the element due to the self weight of the sample. Therefore, it is considered that the warpage of the sample due to the residual stress cannot be accurately evaluated. Here, according to the present embodiment, as shown in fig. 9(a), the specimen 75 is placed on a predetermined placing table 76 so that the side surface 75c of the specimen 75 is horizontal, and the curvature of the warp of the specimen 75 is calculated in this state. Therefore, according to the present embodiment, the warpage of the sample 75 due to the residual stress can be evaluated more accurately. The length l remained near the ends 75g1 and 75g2 of the sample 75₁、l₂Tool (A)Has original thickness t₀Thus, the sample 75 can be stably placed on the mounting table 76. In addition, both ends 75g1 and 75g2 of the specimen 75 were easily held by hand. Further, as described later, when the operation of obtaining the sample 75 includes a step of cutting a part of the metal plate, the influence of the strain due to cutting is given by having the original thickness t₀The etched region 75f can be prevented or suppressed from being affected by the strain due to the cut.

A specific method for calculating the curvature k of the warpage of the sample 75 is explained below. Fig. 9(b) is a plan view showing sample 75 in a state of being warped in the longitudinal direction when viewed from above. In fig. 9(b), a pair of ends in the longitudinal direction of an etched region 75f of a sample 75 is indicated by reference numeral 75 e. First, the distance x (mm) between the ends in the longitudinal direction of the etched region 75f of the sample 75 and the depth y (mm) of warpage of the etched region 75f of the sample 75 were measured. The warp depth y is the maximum value of the distance between the etched region 75f of the sample 75 and a straight line connecting the pair of end portions 75e of the etched region 75f of the sample 75. Next, the curvature radius ρ corresponding to the warpage of the etched region 75f of the sample 75 was calculated based on the following equation.

ρ＝(y/2)+(x²/8y)

Next, the curvature k of the warpage of sample 75 was calculated based on the following equation.

k＝1/ρ

Thus, the curvature k (mm) of the warpage of the sample 75 was obtained^-1)。

Thereafter, based on the obtained value of the curvature k, the long metal plate 64 is screened. Here, the long metal plates 64 of the samples 75 having the curvature k value of the reference value or less are selected, and the long metal plates 64 are screened by using only the long metal plates 64 in the manufacturing process of the vapor deposition mask 20 described later. The reference value is appropriately determined according to the positional accuracy required for vapor deposition using the vapor deposition mask 20, and the value of the curvature k is selected to be 0.008mm, for example^-1The long metal plate 64 of the following sample 75 was determined as good. By performing such screening, the vapor deposition mask 20 is etched in the manufacturing process thereofWhen warpage occurs in the die 20, the degree of warpage may be set within an allowable range. This improves the characteristics of the produced vapor deposition mask 20. Further, the yield in the manufacturing process of the vapor deposition mask 20 can be improved.

As shown in fig. 9(a), means for facilitating the distance measurement, such as a checkered paper 77, may be provided between the mounting table and the sample 75. This makes it easy to measure the distance x (mm) between the ends and the depth y (mm) of warpage, and makes it possible to calculate the curvature k quickly.

As shown in fig. 9(a), a hollow portion 76b may be formed in the mounting table 76 so that the mounting surface 76a on which the sample 75 is mounted can vibrate in the vertical direction. In this case, first, the specimen 75 is placed on the mounting table 76 or the checkered paper 77 disposed on the mounting table 76, and then the mounting surface 76a is vibrated in the vertical direction by, for example, hitting the mounting surface 76a, whereby the frictional force generated between the specimen 75 and the mounting table 76 or the checkered paper 77 can be eliminated or reduced. This can suppress the influence of the frictional force on the curvature measurement result. The dimensions of the mounting table 76, the hollow portion 76b, and the like are not particularly limited, and for example, the width and length of the mounting table 76 are both 300mm, and the thickness of the mounting table 76 is 50 mm. The hollow portion 76b of the mounting table 76 may be formed such that the thickness of the mounting surface 76a and the thickness of the bottom surface of the mounting table 76 are 5mm, respectively. The material constituting the mounting table 76 is not particularly limited, and the mounting table 76 may be made of an acrylic resin, for example.

(method for manufacturing vapor deposition mask)

Next, a method of manufacturing the vapor deposition mask 20 using the long metal plate 64 screened as described above will be described with reference mainly to fig. 10 to 17. In the method for manufacturing the vapor deposition mask 20 described below, as shown in fig. 10, a long metal plate 64 is supplied, the through-holes 25 are formed in the long metal plate 64, and the long metal plate 64 is further cut, thereby obtaining the vapor deposition mask 20 made of the sheet-like metal plate 21.

More specifically, the method for manufacturing the vapor deposition mask 20 includes: a step of supplying a long metal plate 64 extended in a band shape; a step of forming the 1 st recess 30 on the long metal plate 64 from the 1 st surface 64a side by applying etching using a photolithography technique to the long metal plate 64; and a step of forming the 2 nd recessed portion 35 on the long metal plate 64 from the 2 nd surface 64b side by applying etching using a photolithography technique to the long metal plate 64. The 1 st concave portion 30 and the 2 nd concave portion 35 formed in the long metal plate 64 communicate with each other, and the through hole 25 is formed in the long metal plate 64. In the example shown in fig. 10, the step of forming the 2 nd concave portion 35 is performed before the step of forming the 1 st concave portion 30, and a step of sealing the produced 2 nd concave portion 35 is further provided between the step of forming the 2 nd concave portion 35 and the step of forming the 1 st concave portion 30. The respective steps are explained in detail below.

Fig. 10 shows a manufacturing apparatus 60 for manufacturing the vapor deposition mask 20. As shown in fig. 10, first, a wound body 62 is prepared by winding a long metal sheet 64 around a core 61. Then, the core member 61 is rotated to unwind the wound body 62, thereby supplying the elongated metal plate 64 elongated in a band shape as shown in fig. 10. After the through holes 25 are formed in the long metal plate 64, the sheet-like metal plate 21 and the vapor deposition mask 20 are formed.

The fed long metal plate 64 is conveyed to an etching device (etching unit) 70 by a conveying roller 72. The etching unit 70 performs the processes shown in fig. 11 to 17. First, as shown in fig. 11, a resist pattern (also simply referred to as a resist) 65a is formed on the 1 st surface 64a of the long metal plate 64, and a resist pattern (also simply referred to as a resist) 65b is formed on the 2 nd surface 64b of the long metal plate 64. Specifically, the procedure is as follows. First, a negative photosensitive resist material is applied to the 1 st surface 64a (the lower surface in the paper of fig. 11) and the 2 nd surface 64b of the long metal plate 64, and a resist film is formed on the long metal plate 64. Then, a glass dry plate is prepared, and the glass dry plate is arranged on the resist film so that light does not pass through the region to be removed in the resist film. Thereafter, the resist film was exposed to light through a glass dry plate, and the resist film was further developed. In this way, a resist pattern (also simply referred to as a resist) 65a is formed on the 1 st surface 64a of the long metal plate 64, and a resist pattern (also simply referred to as a resist) 65b is formed on the 2 nd surface 64b of the long metal plate 64.

As the photosensitive resist material, a positive photosensitive resist material can be used. In this case, an exposure mask that transmits light to a region to be removed in the resist film is used as the exposure mask.

Next, as shown in fig. 12, the resist pattern 65b formed on the long metal plate 64 is etched from the 2 nd surface 64b side of the long metal plate 64 using an etching solution (for example, an iron (III) chloride solution) as a mask. For example, the etching solution is sprayed onto the 2 nd surface 64b of the long metal plate 64 through the resist pattern 65b from a nozzle disposed on the side facing the 2 nd surface 64b of the long metal plate 64 being conveyed. As a result, as shown in fig. 12, erosion by the etching solution progresses in the region of the long metal plate 64 not covered with the resist pattern 65 b. In this way, a large number of the 2 nd recessed portions 35 are formed in the long metal plate 64 from the 2 nd surface 64b side.

Thereafter, as shown in fig. 13, the formed 2 nd concave portion 35 is covered with a resin 69 having resistance to an etching solution. That is, the 2 nd concave portion 35 is sealed with the resin 69 having resistance to the etching solution. In the example shown in fig. 13, the film of the resin 69 is formed so as to cover not only the formed 2 nd recessed portion 35 but also the 2 nd surface 64b (resist pattern 65 b).

Next, as shown in fig. 14, the 2 nd etching is performed on the long metal plate 64. In the 2 nd etching, the long metal plate 64 is etched only from the 1 st surface 64a side, and the formation of the 1 st concave portion 30 advances from the 1 st surface 64a side. Since the 2 nd surface 64b side of the long metal plate 64 is coated with the resin 69 having resistance to the etching solution, the shape of the 2 nd concave portion 35 formed into a desired shape by the 1 st etching is not damaged.

Etching-based erosion proceeds in a portion of the long metal plate 64 that is in contact with the etching liquid. Therefore, the erosion proceeds not only in the normal direction (thickness direction) of the long metal plate 64 but also in the direction along the plate surface of the long metal plate 64. As a result, as shown in fig. 15, the etching proceeds in the normal direction of the long metal plate 64, and the 1 st concave portion 30 and the 2 nd concave portion 35 are connected, and not only does the etching proceed in the normal direction of the long metal plate 64, but also the two 1 st concave portions 30 formed at positions facing the two adjacent holes 66a of the resist pattern 65a merge inside the bridge portion 67a located between the two holes 66 a.

As shown in fig. 16, the etching from the 1 st surface 64a side of the long metal plate 64 further proceeds. As shown in fig. 16, the merged part 43 where the adjacent two 1 st recesses 30 are merged is separated from the resist pattern 65a, and erosion by etching also proceeds in the normal direction (thickness direction) of the metal plate 64 in the merged part 43 located below the resist pattern 65 a. Thereby, the merging portions 43 sharpened toward the side along the normal direction of the vapor deposition mask are etched from the side along the normal direction of the vapor deposition mask, and chamfered as shown in fig. 16. This increases the inclination angle θ 1 formed by the wall surface 31 of the 1 st recess 30 with respect to the normal direction of the vapor deposition mask.

In this manner, the erosion of the 1 st surface 64a of the long metal plate 64 based on the etching progresses in the entire area of the long metal plate 64 for forming the effective region 22. Thereby, the maximum thickness Ta of the long metal plate 64 in the normal direction in the region for forming the effective region 22 becomes thinner than the maximum thickness Tb of the long metal plate 64 before etching.

As described above, the etching of the long metal plate 64 from the 1 st surface 64a side is advanced by a predetermined amount, and the 2 nd etching of the long metal plate 64 is completed. At this time, the 1 st concave portion 30 extends along the thickness direction of the long metal plate 64 to a position reaching the 2 nd concave portion 35, so that the through hole 25 is formed in the long metal plate 64 by the 1 st concave portion 30 and the 2 nd concave portion 35 communicating with each other.

Thereafter, as shown in fig. 17, the resin 69 is removed from the long metal plate 64. The resin film 69 can be removed by using, for example, an alkali-based stripping liquid. When an alkali-based stripping solution is used, the resist

patterns

65a and 65b are also removed together with the resin 69 as shown in fig. 17.

The long metal plate 64 having the large number of through holes 25 formed therein is conveyed to a cutting device (cutting unit) 73 by conveying

rollers

72 and 72 rotating while sandwiching the long metal plate 64. The long metal sheet 64 is fed from the roll 62 by rotating the feeding core 61 by the tension (tensile force) applied to the long metal sheet 64 by the rotation of the

feed rollers

72 and 72.

Thereafter, the long metal plate 64 formed with the large number of recesses 61 is cut into a predetermined length by a cutting device (cutting means) 73, thereby obtaining the sheet metal plate 21 formed with the large number of through holes 25.

In this manner, the vapor deposition mask 20 including the metal plate 21 having the large number of through holes 25 formed therein can be obtained. Here, according to the present embodiment, the 1 st surface 21a of the metal plate 21 is etched in the entire effective region 22. Therefore, the outer contour of the portion 43 where the leading edges 32 of the wall surfaces 31 of the two 1 st recesses 30 formed on the 1 st surface 21a side meet can be chamfered while reducing the thickness of the effective region 22 of the vapor deposition mask 20. Therefore, the angle θ 1 can be increased, and thus, the utilization efficiency of the vapor deposition material and the positional accuracy of vapor deposition can be improved.

However, etching the 1 st surface 21a of the metal plate 21 over the entire effective region 22 increases the difference between the degree of etching on the 1 st surface 21a side and the degree of etching on the 2 nd surface 21b side. That is, the residual stress to be eliminated is not uniform between the 1 st surface 21a side and the 2 nd surface 21b side, and the metal plate 21, that is, the deposition mask 20 is warped. Here, according to the present embodiment, the long metal plates 64 previously screened based on the degree of warpage of the sample 75 as described above are used. Therefore, even when there is a difference in the degree of etching between the 1 st surface 21a side and the 2 nd surface 21b side, the degree of warpage generated in the vapor deposition mask 20 can be made within the allowable range. Therefore, according to the present embodiment, by reducing the thickness of the vapor deposition mask 20 and increasing the inclination angle θ 1 of the wall surface 31 of the 1 st recess 30 of the vapor deposition mask 20, it is possible to improve the utilization efficiency of the vapor deposition material and the positional accuracy of vapor deposition, to optimize the profile, to reduce the warpage of the vapor deposition mask 20, and to improve the yield of the manufacturing process of the vapor deposition mask 20. Therefore, the vapor deposition mask 20 having excellent characteristics can be stably provided.

(vapor deposition method)

Next, a method of depositing a vapor deposition material on the substrate 92 using the obtained vapor deposition mask 20 will be described. First, as shown in fig. 2, the vapor deposition mask 20 is brought into close contact with the substrate 92. At this time, the vapor deposition mask 20 is placed on the frame 15 in tension so that the surface of the vapor deposition mask 20 is parallel to the surface of the substrate 92. Here, according to the present embodiment, the long metal plate 64 screened in advance based on the degree of warping of the sample 75 is used. Therefore, the degree of warping of the vapor deposition mask 20 is uniformly reduced as compared with the case where such screening is not performed. Therefore, by applying an appropriate tension to the vapor deposition mask 20, the vapor deposition mask 20 can be held parallel to the substrate 92. That is, in order to correct the warpage due to the elimination of the internal stress (residual stress), it is not necessary to apply a high tension to the vapor deposition mask 20 to such an extent that the vapor deposition mask 20 is wrinkled. Therefore, the vapor deposition mask 20 can be sufficiently brought into close contact with the substrate 92, and thereby the vapor deposition material can be deposited on the substrate 92 with high positional accuracy. Therefore, when the pixels of the organic EL display device are formed by vapor deposition, the dimensional accuracy and positional accuracy of the pixels of the organic EL display device can be improved. Thus, a high-definition organic EL display device can be manufactured.

In the example described above in the present embodiment, the 2 or more effective regions 22 of the vapor deposition mask 20 are arranged at predetermined intervals along one direction parallel to one side of the vapor deposition mask 20, and at predetermined intervals along the other direction orthogonal to the one direction. However, as shown in fig. 18, the vapor deposition mask 20 may include 2 or more effective regions 22 aligned in a line along one direction, and the vapor deposition mask device 10 may include 2 or more vapor deposition masks 20 aligned in a direction orthogonal to the longitudinal direction (one direction) and attached to the frame 15. A method for producing such a vapor deposition mask 20 is not particularly limited. For example, the vapor deposition mask 20 can be manufactured using the metal plate 21, which is a long metal plate 64 having a width corresponding to the vapor deposition mask 20 shown in fig. 18. Alternatively, the vapor deposition mask 20 shown in fig. 18 may be produced by forming 2 or more effective regions 22 along one direction and the other direction of the long metal plate 64, that is, the metal plate 21, and then cutting the metal plate 21 along the longitudinal direction thereof.

Examples

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the descriptions of the following examples as long as the gist of the present invention is not exceeded.

(preparation of sample)

First, the base material containing the invar alloy material was subjected to the rolling step and the annealing step described above to produce a steel sheet having a width of 500mm and t₀A long metal plate of the thickness of (1) is wound to form a wound body. Thereafter, the 1 st wound body was cut out to a length of 300mm, thereby obtaining a metal plate 63 shown in fig. 19 (a). In fig. 19(a), an arrow D1 corresponds to the conveying direction in the rolling step, i.e., the rolling direction, and an arrow D2 corresponds to the width direction in the rolling step.

Next, as shown in fig. 19(b), a plurality of samples 75 were taken from the metal plate 63. The dimensions of sample 75 were 170mm long by 30mm wide. The longitudinal direction of the sample 75 is a direction parallel to the arrow D1, and the width direction of the sample 75 is a direction parallel to the arrow D2. The number of samples 75 taken from 1 metal plate 63 was 15. As a method of taking out the plurality of samples 75 from the metal plate 63, etching was used. Specifically, first, resist patterns are provided on both the 1 st surface side and the 2 nd surface side of the metal plate 63 so as to cover the region to be the sample 75 and the outer frame portion 63a of the metal plate 63. Next, the metal plate 63 is etched from both the 1 st surface side and the 2 nd surface side using the resist pattern as a mask. As a result, as shown in fig. 19(b), a through-hole 63b is formed between the outer frame portion 63a of the metal plate 63 and the region of the metal plate 63 to be the sample 75. The etching is performed so that the outer frame portion 63a of the metal plate 63 and the connecting portion 63c of the sample 75 are left. The connecting portion 63c has a length of about 3mm × a width of about 1 mm.

Next, as shown in FIG. 19(c), the sample 75 was etched over the entire area of the etched region 75f of the 1 st surface 75a from the 1 st surface 75a side of the sample 75 until the thickness of the etched region 75f of the sample 75 reached (1/2-8/100). times.t.₀Above and (1/2+8/100) × t₀Within the following ranges. Thereafter, the etched 15 is taken out from the metal plate 63 by cutting the connecting portion 63cSheet sample 75. In order to prevent the etched region 75f from being affected by the strain due to cutting, precision scissors may be used as a means for cutting the connecting portion 63 c.

The through hole 63b described above was formed in the metal plate 63, and the thickness of the etched region 75f of the sample 75 was set to (1/2-8/100) × t₀Above and (1/2+8/100) × t₀All of the following ranges can be simultaneously performed by the same etching process.

(calculation of curvature of sample)

Next, as in the case of the inspection step described above, the curvature k (mm) of the warpage in each of the etched samples 75 was sequentially obtained^-1). Specifically, first, the sample 75 is placed on the placement surface 76a of the placement stage 76 having the hollow portion 76b formed therein via the checkered paper 77 so that the side surface 75c of the sample 75 is horizontal. Next, vibration was applied to the mounting surface 76a of the mounting table 76 until the state of warpage of the sample 75 was not changed visually. Thereafter, the distance x (mm) between the ends in the longitudinal direction of the etched region 75f and the depth y (mm) of the warp of the etched region 75f of the sample 75 were read by the scale of the checkered paper 77. Next, the curvature radius ρ corresponding to the warpage of the etched region 75f of the sample 75 is calculated based on the following formula.

ρ＝(y/2)+(x²/8y)

k＝1/ρ

In the measurement result of the curvature k of the warpage in 15 samples 75 obtained from the 1 st wound body, the maximum value was 7.6 × 10^-3mm^-1。

(evaluation of Effect 1 time)

Using the above-described method for manufacturing a vapor deposition mask, a vapor deposition mask was manufactured from the long metal plate of the 1 st roll. Then, the curl of the obtained vapor deposition mask was measured. The curl is the maximum value of the fluctuation of the vapor deposition mask in the vertical direction which is exhibited when the vapor deposition mask is placed on a horizontal plane. As a result, the curl of the vapor deposition mask obtained from the long metal plate of the 1 st roll was 0.25 mm.

(evaluation of Effect 2 times)

The vapor deposition material was vapor-deposited on the substrate using a vapor deposition mask made of a long metal plate of the 1 st roll. The pattern of a large number of through holes formed in the vapor deposition mask used was a stripe pattern corresponding to a pixel density of 300 ppi. As the vapor deposition material, a green organic light emitting material that emits green light is used. Thereafter, the center coordinate position and the line width dimension of each of 2 or more green light emitting layers formed of the green organic light emitting material deposited on the substrate were measured. Further, the measured center coordinate position and the measured line width are respectively calculated as the deviation from the design value. And determines whether the deviation amount is equal to or less than an allowable value. In this case, the allowable value of the amount of deviation of the center coordinate position is ± 4 μm, and the allowable value of the amount of deviation of the line width dimension is ± 2 μm. As a result, the amount of deviation of either the center coordinate position or the line width dimension is below the allowable value. That is, the positional accuracy and the dimensional accuracy of the vapor deposition material are both good (OK).

Table 1 shows the measurement results of the curvature of the sample obtained from the 1 st roll and the evaluation results of the above-described 1 st order effect and 2 nd order effect with respect to the vapor deposition mask produced from the long metal plate of the 1 st roll. Further, similarly to the case of the 1 st wound body, the 2 nd to 20 th wound bodies are manufactured from the base material containing the invar alloy material. Further, as in the case of the 1 st roll, the 2 nd to 20 th rolls were subjected to measurement of the curvature of the sample obtained from each roll and evaluation of the above-described 1 st and 2 nd effects with respect to the vapor deposition mask made of the long metal plate of each roll. The results are shown together in Table 1.

[ TABLE 1 ]

As shown in Table 1, the curvatures of the samples obtained from the 1 st to 10 th wound bodies were all 0.008mm^-1The following. The vapor deposition masks made of the long metal plates of the 1 st to 10 th wound bodies each have a curl of 0.25mm or less. Further, in vapor deposition using a vapor deposition mask made of a long metal plate of the 1 st to 10 th wound bodies, both the positional accuracy and the dimensional accuracy of the vapor deposition material were good (OK).

On the other hand, the curvature of the samples obtained from the 11 th to 20 th wound bodies exceeded 0.008mm^-1. The vapor deposition masks made of the long metal plates of the 11 th to 20 th wound bodies had a curl exceeding 0.25 mm. Further, in vapor deposition using a vapor deposition mask made of a long metal plate of the 11 th to 20 th wound bodies, positional accuracy of a part of the vapor deposition material and all dimensional accuracy are defective (NG), and overall, all are defective (NG). That is, the position and size of the vapor deposition material deposited on the substrate are out of the allowable range from the design.

From this, it can be considered that the curvature of the obtained sample was 0.008mm^-1The following wound body can provide a vapor deposition mask having excellent vapor deposition characteristics.

Description of the symbols

20 vapor deposition mask

20a vapor deposition mask No. 1

20b second surface of vapor deposition mask

21 metal plate

21a No. 1 surface of metal plate

21b No. 2 surface of metal plate

22 effective area

23 surrounding the area

25 through hole

30 st recess

31 wall surface

35 nd 2 nd recess

36 wall surface

55 base material

56 rolling device

57 annealing device

61 core material

62 wound body

64 long metal plate

Surface 1 of 64a long metal plate

Face 2 of 64b long metal plate

75 samples

75a sample No. 1

75b sample side 2

75c, 75d side

75f etched region

76 stage

76a carrying surface

76b hollow part

77 chequered paper

Claims

1. A method for manufacturing a metal plate for manufacturing a vapor deposition mask by forming 2 or more through holes,

the through hole of the vapor deposition mask is formed by etching the metal plate,

the method for manufacturing a metal plate comprises the following steps:

a rolling step of rolling the base material to obtain a material having a thickness t₀The metal plate of (a); and

an annealing step of annealing the metal plate to remove internal stress of the metal plate,

the metal plate has a 1 st surface and a 2 nd surface, the 1 st surface and the 2 nd surface being orthogonal to the thickness direction of the metal plate and facing each other,

etching a sample obtained from the metal plate after the annealing step, measuring a curvature k of a warp of the etched sample, screening the metal plate based on the obtained curvature k value, and selecting a curvature k value of 0.008mm^-1The following metal plate is made of a metal plate,

the curvature k is a value obtained as follows: first, the sample having a length of 170mm and a width of 30mm was taken from the metal plate after the annealing step, and then 10 was taken from both ends of the sample except for the longitudinal directionA region having a length of 150mm and a width of 30mm other than the region within mm was defined as an etched region, and the sample was etched over the entire etched region of the sample from the 1 st surface side until the thickness of the etched region reached 1/3 × t₀Above and 2/3 × t₀The curvature k is determined by placing the etched sample on a predetermined mounting table so that the side surface of the sample is horizontal, applying vibration to the mounting table, measuring the distance x (mm) between the ends of the sample in the longitudinal direction of the region to be etched and the depth y (mm) of the warp of the region to be etched of the sample, and substituting the distance x between the ends and the depth y into the following equation,

k＝1/ρ、ρ＝(y/2)+(x²/8y)，

the base material comprises an invar alloy material.

2. The method of manufacturing a metal plate according to claim 1, wherein the annealing step is performed while the metal plate is stretched in a longitudinal direction.

3. The method of manufacturing a metal plate according to claim 1, wherein the annealing step is performed in a state where the metal plate is wound around a core material.

4. The method of manufacturing a metal plate according to any one of claims 1 to 3, wherein the base material has a thermal expansion coefficient equal to that of a substrate on which a vapor deposition material is formed via a vapor deposition mask manufactured from the metal plate.

5. A method for manufacturing a vapor deposition mask including an effective region in which 2 or more through holes are formed and a peripheral region located around the effective region, the method comprising:

a step of preparing a metal plate having a thickness t₀Having a 1 st surface and a 2 nd surface, the 1 st surface and the 2 nd surface being opposite to the thickness of the metal plateThe directions are orthogonal and opposite to each other; and

a recess forming step of etching the metal plate from the 1 st surface side to form a recess for cutting out the through hole from the 1 st surface side in a region of the metal plate for forming the effective region;

etching a sample obtained from the metal plate after the annealing step, measuring the curvature k of the warpage of the etched sample, screening the metal plate based on the obtained curvature k value, and selecting the curvature k value of 0.008mm^-1The following metal plate is made of a metal plate,

the curvature k is a value obtained as follows: first, the sample having a length of 170mm and a width of 30mm was taken from the metal plate, and then, a region having a length of 150mm and a width of 30mm except regions within 10mm from both ends in the longitudinal direction of the sample was set as an etched region, and the sample was etched over the entire etched region of the sample from the 1 st surface side until the thickness of the etched region reached 1/3 × t₀Above and 2/3 × t₀The curvature k is determined by placing the etched sample on a predetermined mounting table so that the side surface of the sample is horizontal, applying vibration to the mounting table, measuring the distance x (mm) between the ends of the sample in the longitudinal direction of the region to be etched and the depth y (mm) of the warp of the region to be etched of the sample, and substituting the distance x between the ends and the depth y into the following equation,

k＝1/ρ、ρ＝(y/2)+(x²/8y)，

the metal plate contains an invar alloy material.

6. The method of manufacturing a vapor deposition mask according to claim 5, wherein in the recess forming step, the metal plate is etched over the entire 1 st surface from the 1 st surface side.

7. The method of manufacturing a vapor deposition mask according to claim 6, wherein in the recess forming step, the first surface is located on the 1 st surface sideEtching the metal plate in the whole area of the 1 st surface until the etching thickness reaches 1/3 × t₀Above and 2/3 × t₀Within the following ranges.

8. The method of manufacturing a vapor deposition mask according to any one of claims 5 to 7, wherein the coefficient of thermal expansion of the metal plate is equal to the coefficient of thermal expansion of a substrate on which a vapor deposition material is formed with the vapor deposition mask made of the metal plate interposed therebetween.