Metal mask and method for manufacturing the same

Abstract

To provide a metal mask capable of further controlling a shadow, excellent in the shape uniformity of open holes and excellent in mechanical strength, and a method for efficiently manufacturing the same.SOLUTION: A metal mask has a hole area including a plurality of open holes and a peripheral area, the hole area including a plurality of open holes, the peripheral area positioned in the periphery of the hole area. The open hole includes a first depression part formed on a first surface, a second depression part formed on a second surface and a circumferential connection part for connecting the first and second depression parts; the connection part includes a plurality of corner parts and a plurality of line parts positioned between the adjacent corner parts; a distance h in the thickness direction from the first surface to the connection part changes with a position; and the maximum distance h1 in the thickness direction from the first surface to the corner part is longer than the minimum distance h2 in the thickness direction from the first surface to the line part.SELECTED DRAWING: Figure 3B

Description

[Technical field]

[0001] The present disclosure relates to a metal mask and a manufacturing method thereof. [Background technology]

[0002] The pixels of an organic EL display device are formed by depositing a material for forming the pixels on a substrate by vapor deposition using a metal mask. Therefore, improving the performance of the metal mask is important for improving the image quality of the organic EL display device. For example, Patent Document 1 discloses that, for the purpose of providing a metal mask that can suppress the variation in the film thickness of the vapor deposition pattern, the corners of the large opening are shaped to protrude outward from the edge. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6870795 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the metal mask described in Patent Document 1, the corners of the polygonal shape are projected outward, so it is expected that the deposition material entering the mask hole from the vicinity of the corners of the large opening will easily reach the small opening. However, the metal mask described in Patent Document 1 has a complex shape of the opening, and it is not easy to uniformly form multiple through holes having a complex shape. In addition, there is a concern about the effect of the complex shape on the mechanical strength.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide a metal mask that can further suppress shadows, has excellent shape uniformity of through holes, and has excellent mechanical strength, and an efficient method for manufacturing the same. [Means for solving the problem]

[0006] A metal mask according to an embodiment of the present disclosure includes: a perforated region and a peripheral region; the perforated region having a plurality of through holes; the peripheral region is located around the perforated region; the through hole has a first recess formed in a first surface, a second recess formed in a second surface, and a circumferential connecting portion connecting the first recess and the second recess, the connection portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions, a distance h in a thickness direction from the first surface to the connection portion varies depending on a position, A maximum distance h1 in the thickness direction from the first surface to the connection portion at the corner portion is longer than a minimum distance h2 in the thickness direction from the first surface to the connection portion at the linear portion.

[0007] A method for producing the metal mask according to an embodiment of the present disclosure includes the steps of: providing a metal plate having a first surface and a second surface opposite the first surface; and an etching step of forming the metal mask by etching the metal plate, The metal mask has a hole region and a surrounding region, the perforated region having a plurality of through holes; the peripheral region is located around the perforated region; the through hole has a first recess formed in a first surface, a second recess formed in a second surface, and a circumferential connecting portion connecting the first recess and the second recess, the connection portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions, a distance h in a thickness direction from the first surface to the connection portion varies depending on a position, A maximum distance h1 in the thickness direction from the first surface to the corner portion is longer than a minimum distance h2 in the thickness direction from the second surface to the linear portion. Effect of the Invention

[0008] At least one embodiment of the present disclosure provides a metal mask that can further suppress shadows, has excellent shape uniformity of through holes, and is also excellent in mechanical strength, and an efficient method for manufacturing the same. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view showing a metal mask according to an embodiment of the present disclosure. [Figure 2A] 1 is a plan view showing an example of the shape, size and position of a pattern of a deposition layer attached to a substrate. [Figure 2B] 2B is a plan view showing an example of a through hole 25 of a metal mask 20 for forming the pattern of the deposition layer shown in FIG. 2A. FIG. [Figure 2C] 2B is a plan view showing an example of a through hole 25 of a metal mask 20 for forming the pattern of the deposition layer shown in FIG. 2A. FIG. [Figure 2D] 2B is a plan view showing an example of a through hole 25 of a metal mask 20 for forming the pattern of the deposition layer shown in FIG. 2A. FIG. [Figure 3A] 1 is a perspective view showing one embodiment of a perforated region as viewed from the second surface side. FIG. [Figure 3B] FIG. 3B is an enlarged perspective view of the through hole shown in FIG. 3A. [Figure 3C] 3C is a cross-sectional view of the through hole shown in FIG. 3B taken along the line AA'. [Figure 3D] 3C is a cross-sectional view of the through hole shown in FIG. 3B along the line BB'. [Figure 3E] 1 is a perspective view showing one embodiment of a perforated region as viewed from the second surface side. FIG. [Figure 4A] 1A to 1C are schematic diagrams for explaining an example of a method for manufacturing a metal mask. [Figure 4B] 1A to 1C are diagrams illustrating an example of a process for forming a resist film on a metal plate. [Figure 4C] 1A to 1C are diagrams illustrating an example of a process for patterning a resist film. [Figure 4D]11A to 11C are diagrams illustrating an example of a first surface etching step in a hole region. [Figure 4E] 11A to 11C are diagrams illustrating an example of a second surface etching step in a holed region. [Diagram 5] FIG. 1 is a diagram showing a metal mask apparatus according to an embodiment of the present disclosure. [Figure 6] FIG. 1 is a cross-sectional view illustrating a deposition apparatus according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, the scale and the aspect ratio may be appropriately changed and exaggerated from those of the actual objects for the convenience of illustration and understanding.

[0011] In this specification and / or drawings, unless otherwise specified, the following interpretations are to be made.

[0012] Terms that refer to a material that is the basis of a certain structure do not necessarily have to be distinguished by differences in name alone. For example, terms such as "substrate," "base material," "plate," "sheet," or "film" fall under the above description.

[0013] The terms and / or values ​​that mean the shape and / or geometric conditions do not need to be bound by strict meanings, and may be interpreted as including a range within which similar functions may be expected. For example, "parallel" and / or "orthogonal" fall under the above terms. Also, "length value" and / or "angle value" fall under the above numerical values.

[0014] When a certain configuration is expressed as being "above," "below," "upper," "lower," "above," or "below" another configuration, this may include a configuration in which the certain configuration is in direct contact with the other configuration, and a configuration in which another configuration is included between the certain configuration and the other configuration. In other words, a configuration in which another configuration is included between the certain configuration and the other configuration may be expressed as a configuration indirectly in contact with the other configuration. In addition, the expressions "above," "upper side," or "upper" can be replaced with the expressions "below," "lower side," or "lower." In other words, the up-down direction may be reversed.

[0015] When the same or similar symbols are used for the same parts and / or parts having similar functions, repeated description may be omitted. In addition, the dimensional ratios in the drawings may differ from the actual ratios. In addition, part of the configuration of the embodiment may be omitted from the drawings.

[0016] One or more of the embodiments may be combined with one or more of the modified examples as long as no contradictions arise. Also, one or more of the embodiments may be combined with each other as long as no contradictions arise. Also, one or more of the modified examples may be combined with each other as long as no contradictions arise.

[0017] When a plurality of steps are disclosed for a method such as a manufacturing method, other steps that are not disclosed may be performed between the disclosed steps. In addition, the order of the steps is not limited to the extent that no contradiction occurs.

[0018] Numerical ranges expressed by the symbols "~" and / or "-" include the numerical values ​​before and after the symbols "~" and / or "-". For example, a numerical range expressed as "34 to 38% by mass" is the same as a numerical range expressed as "34% by mass or more and 38% by mass or less".

[0019] For the numerical values ​​described in this disclosure, a numerical range may be defined by combining any one of a plurality of upper limit candidate values ​​with any one of a plurality of lower limit candidate values. In addition, even if not specifically mentioned, a numerical range may be defined by combining any two of a plurality of upper limit candidate values, or a numerical range may be defined by combining any two of a plurality of lower limit candidate values.

[0020] An embodiment of the present disclosure will be described in the following paragraphs. The embodiment of the present disclosure is an example of an embodiment of the present disclosure. The present disclosure is not limited to the embodiment of the present disclosure.

[0021] The metal mask of the present disclosure can be used for various applications. For example, the metal mask of the present disclosure can be used as a metal mask used to pattern an organic material in a desired pattern on a substrate in the manufacture of an organic electroluminescence display device, without being particularly limited thereto. The metal mask is also called a deposition mask. The metal mask of the present disclosure can also enable patterning with high pixel density. Organic electroluminescence display devices that can be manufactured include displays for smartphones, televisions, and the like, as well as devices for displaying or projecting images or videos to express virtual reality (VR) or augmented reality (AR).

[0022] Unless otherwise specified in this specification and the drawings, an example of a metal mask used in manufacturing an organic EL display device and a manufacturing method thereof will be described as one embodiment of the present invention.

[0023] The first aspect of the present disclosure is a perforated region and a peripheral region; the perforated region having a plurality of through holes; the peripheral region is located around the perforated region; the through hole has a first recess formed in a first surface, a second recess formed in a second surface, and a circumferential connecting portion connecting the first recess and the second recess, the connection portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions, a distance h in a thickness direction from the first surface to the connection portion varies depending on a position, a maximum distance h1 in the thickness direction from the first surface to the connection portion at the corner portion is longer than a minimum distance h2 in the thickness direction from the first surface to the connection portion at the linear portion; It is a metal mask.

[0024] A second aspect of the present disclosure is a metal mask according to the first aspect, The linear portion includes a first linear portion and a second linear portion, The first linear portion is shorter than the second linear portion, A distance h21 in the thickness direction from the first surface to the first linear portion is longer than a distance h22 in the thickness direction from the first surface to the second linear portion.

[0025] A third aspect of the present disclosure is the metal mask of the first or second aspect described above, The maximum distance h1 is not less than 0.6 μm and not more than 8.0 μm.

[0026] A fourth aspect of the present disclosure is a metal mask according to any one of the first to third aspects described above, The minimum distance h2 is not less than 0.06 μm and not more than 4.0 μm.

[0027] A fifth aspect of the present disclosure is a metal mask according to any one of the first to fourth aspects described above, A ratio (h1 / h2) of the maximum distance h1 to the minimum distance h2 is 1.1 or more and 50 or less.

[0028] A sixth aspect of the present disclosure is a metal mask according to any one of the first to fifth aspects described above, A ratio (h1 / H) of the maximum distance h1 to a thickness H from the first surface to the second surface is equal to or greater than 0.010 and equal to or less than 0.40.

[0029] A seventh aspect of the present disclosure is a metal mask according to any one of the first to sixth aspects described above, A ratio (h2 / H) of the minimum distance h2 to a thickness H from the first surface to the second surface is equal to or greater than 0.001 and equal to or less than 0.20.

[0030] An eighth aspect of the present disclosure is providing a metal plate having a first surface and a second surface opposite the first surface; and an etching step of forming the metal mask by etching the metal plate, The metal mask has a hole region and a surrounding region, the perforated region having a plurality of through holes; the peripheral region is located around the perforated region; the through hole has a first recess formed in a first surface, a second recess formed in a second surface, and a circumferential connecting portion connecting the first recess and the second recess, the connection portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions, a distance h in a thickness direction from the second surface to the connection portion varies depending on a position, A maximum distance h1 in the thickness direction from the second surface to the corner portion is longer than a minimum distance h2 in the thickness direction from the second surface to the linear portion. A method for manufacturing a metal mask.

[0031] The metal mask 20 of the present disclosure will be described in detail below.

[0032] The metal mask 20 of the present disclosure has a perforated region 22 and a surrounding region 23. The perforated region 22 is a region in which a plurality of through holes 25 are formed. The surrounding region 23 is a region located around the perforated region 22.

[0033] Fig. 1 shows a plan view of the second surface 20b side of a metal mask 20 according to an embodiment of the present disclosure. As shown in Fig. 1, the metal mask 20 may have a substantially rectangular outline in a plan view. In this disclosure, the term "plan view" refers to viewing the metal mask 20 from a surface along the plate surface of the metal mask 20.

[0034] In the metal mask 20 of the present disclosure, one perforated region 22 may be configured to correspond to one organic EL display device. For example, as shown in Fig. 1, the metal mask 20 may have a plurality of perforated regions 22 arranged in a line at predetermined intervals along the longitudinal direction D2. In Fig. 1, a surrounding region 23 is positioned around each perforated region 22. By using such a metal mask 20, it is possible to vapor-deposit a plurality of organic EL display devices onto a substrate 92.

[0035] The material constituting the metal mask 20 is not particularly limited, but examples thereof include iron alloys containing nickel, iron alloys containing chromium such as stainless steel, nickel, and nickel-cobalt alloys.

[0036] Among these, an iron alloy containing nickel is preferable. By using an iron alloy containing nickel, the thermal expansion coefficient of the metal mask 20 can be made equal to the thermal expansion coefficient of the frame 15 and the thermal expansion coefficient of the substrate 92 (see FIG. 6). This makes it possible to suppress the occurrence of misalignment caused by differences in dimensional changes among the metal mask 20, the frame 15, and the substrate 92 during the deposition process. Therefore, it is possible to suppress a decrease in the dimensional accuracy and positional accuracy of the deposition material 98 attached to the substrate 92 caused by the misalignment.

[0037] Examples of iron alloys containing nickel include, but are not limited to, iron alloys containing 0% to 54% by mass of nickel, such as Super Invar material containing 30% to 34% by mass of nickel and further containing cobalt, Invar material containing 34% to 38% by mass of nickel, and low-thermal expansion Fe-Ni-based plating alloys containing 48% to 54% by mass of nickel.

[0038] Next, a description will be given of the surfaces of the metal mask 20 of the present disclosure. The metal mask 20 of the present disclosure has a first surface 20a and a second surface 20b as front and back surfaces.

[0039] In the present disclosure, the first surface 20a and the second surface 20b of the metal mask 20 are distinguished from each other by the diameter of the through holes 25 on the front and back surfaces of the perforated region 22. Specifically, as shown in Figs. 3A and 3B, the first surface 20a refers to a surface in the perforated region 22 where the opening area of ​​the through holes 25 is small, and the second surface 20b refers to a surface where the range S3 of the through holes 25 is large. Also, as shown in Fig. 3E, when the second wall surfaces 36 of the second recesses 35 of adjacent through holes 25 join on the second surface 20b, the range S3 closed by the ridge line 33 surrounding one through hole 25 may be regarded as the opening of the through hole 25. In this case, the range closed by the ridge line 33 is the opening area.

[0040] Furthermore, from the viewpoint of the deposition process, the first surface 20a may be the surface of the metal mask 20 facing the substrate 92 when the metal mask device 10 is housed in the deposition device 90 (see FIG. 6). Furthermore, the second surface 20b may be the surface of the metal mask 20 located on the side of the crucible 94 holding the deposition material 98 when the metal mask device 10 is housed in the deposition device 90 (see FIG. 6).

[0041] Next, the pattern of the deposition layer to be attached to the substrate 92 and the pattern of the through holes 25 in the perforated region 22 of the metal mask 20 for forming the deposition layer will be described.

[0042] FIG. 2A shows a plan view illustrating an example of the shape, size, and position of a pattern of a deposition layer attached to a substrate 92. In FIG. 2A, the rectangles labeled with the letters RGB are deposition layers of different colors, red R, green G, and blue B, respectively. When different types of deposition materials 98 are deposited according to pixels such as RGB, the deposition materials 98 may be formed on the surface of the substrate 92 using different metal masks 20 according to the types of the deposition materials 98. For example, the deposition material 98 for red, the deposition material 98 for green, and the deposition material 98 for blue may be deposited on the substrate 92 in order. Alternatively, the deposition material 98 for red, the deposition material 98 for green, and the deposition material 98 for blue may be deposited in order by gradually moving the metal mask 20 (metal mask device 10) and the substrate 92 relative to each other along the arrangement direction of the through holes 25 (the aforementioned one direction).

[0043] 2A, when the pattern in which the deposition material 98 is attached differs depending on the type of deposition material 98, a metal mask 20 having a different pattern of through holes 25 can be used depending on the type of deposition material 98. When the pattern in which the deposition material 98 is attached is the same regardless of color, such as red R and blue B in FIG. 2A, the same metal mask 20 may be used. In this case, deposition materials 98 of different colors can be attached in the same pattern by moving the metal mask 20 and the substrate 92 relative to each other.

[0044] 2B to 2D show the formation pattern of through holes 25 in the perforated region 22 of the metal mask 20 to form the deposition layer pattern shown in FIG. 2A. All of FIGS. 2B to 2D show the perforated region 22 as viewed from the first surface 20a side. The solid lines in FIGS. 2B to 2D indicate the connection portion 41 of the through holes 25a, 25b, and 25c. The dashed lines in FIGS. 2B to 2D indicate, for reference, the positions of other deposition layers formed by other metal masks. In other words, the dashed line portion is the first surface 20a of the metal plate where no through holes actually exist.

[0045] The through holes 25 penetrate the metal mask 20 in the thickness direction N from the first surface 20a to the second surface 20b. In the deposition process, the deposition material 98 passes through the through holes 25 and is deposited on the substrate 92. That is, each through hole 25 defines a location where the deposition material is deposited on the substrate 92. The pattern of the through holes 25 in the perforated region 22 corresponds to the pattern in which the deposition material 98 is deposited.

[0046] FIG. 2B shows a metal mask 20 having through holes 25a passing through a blue vapor deposition material 98. In the example shown in FIG. 2B, the through holes 25a have connection parts 41 that are substantially square in plan view. The through holes 25a are arranged in two predetermined directions, sandwiching a portion (dashed rectangular line) where a vapor deposition layer of green G is formed. The connection parts 41 of the through holes 25a have linear parts 41a and corner parts 41b. In FIG. 2B, the connection parts 41 of the through holes 25a are shown as quadrangles that are substantially close to a square, but are not limited thereto, and the connection parts 41 of the through holes 25a may be polygonal, such as a triangle, a pentagon, a hexagon, or an octagon.

[0047] In the present disclosure, a "corner" refers to a corner of a polygon formed by the connection portion 41, and is an intersection point of two linear portions 41a extending in different directions. The corner portion 41b may have an angular shape, or may have a rounded shape having a predetermined radius of curvature. The radius of curvature of the corner portion 41b is preferably 1 μm or more and 40 μm or less. The radius of curvature of the corner portion 41b is preferably 40 μm or less, 30 μm or less, 20 μm or less, or 15 μm or less. The radius of curvature of the corner portion 41b is preferably 1 μm or more, 3 μm or more, or 5 μm or more.

[0048] In addition, in the present disclosure, the "linear portion" refers to a side of a polygon formed by the connection portion 41, and connects adjacent corners 41b. The linear portion 41a includes not only straight lines, but also rounded lines having a predetermined or greater radius of curvature. The radius of curvature of the linear portion 41a is preferably 100 μm or more, 200 μm or more, or 300 μm or more. The linear portion 41a includes straight lines, and the upper limit of the radius of curvature is not particularly limited, but may be 10,000 μm or less.

[0049] Fig. 2C shows a metal mask 20 having through holes 25b passing through a green vapor deposition material 98. In the example shown in Fig. 2C, the through holes 25b have connection parts 41 that are substantially rectangular in plan view. In Fig. 2C, the through holes 25b are arranged in the short axis direction, sandwiching a part (dashed square line) where a vapor deposition layer of blue B is formed, and are also arranged in the long axis direction, sandwiching a part (dashed square line) where a vapor deposition layer of red R is formed.

[0050] The connection portion 41 of the through hole 25b has a linear portion 41a and a corner portion 41b. As shown in FIG. 2C, the linear portion 41a of the through hole 25b has a first linear portion 41a1 and a second linear portion 41a2. The first linear portion 41a1 is shorter than the second linear portion 41a2. The first linear portion 41a1 and the second linear portion 41a2 may have a relationship in which a distance h21 in the thickness direction from the first surface 20a to the first linear portion 41a1 is greater than a distance h22 in the thickness direction from the first surface 20a to the second linear portion 41a2. This point will be described in detail later.

[0051] As shown in FIG. 2C, when the connection portion 41 of the through hole 25b is substantially rectangular, the short side is the first linear portion 41a1, and the long side is the second linear portion 41a2. Furthermore, without being limited thereto, the connection portion 41 of the through hole 25b may be a polygon such as a triangle, a pentagon, a hexagon, or an octagon. When the connection portion 41 of the through hole 25b has such a polygon, the connection portion 41 may include three or more linear portions 41a having different lengths. Even in that case, two linear portions 41a arbitrarily selected from the three or more linear portions 41a can be recognized as the first linear portion 41a1 and the second linear portion 41a2 according to their lengths. And, it is preferable that the arbitrarily selected first linear portion 41a1 and second linear portion 41a2 have a relationship in which the distance h21 is greater than the distance h22. In other words, in the polygonal linear portion 41a, the longer the length of the linear portion 41a, the smaller the distance in the thickness direction from the first surface 20a to the linear portion 41a may be.

[0052] FIG. 2D shows a metal mask 20 having through holes 25c passing through a red vapor deposition material 98. In the example shown in FIG. 2D, similar to FIG. 2B, the through holes 25c have connection parts 41 that are substantially square in plan view. The through holes 25c are arranged in two predetermined directions, sandwiching a portion (dashed rectangular line) where a vapor deposition layer of green G is formed. The connection parts 41 of the through holes 25c have linear parts 41a and corner parts 41b. In FIG. 2D, the connection parts 41 of the through holes 25c are shown as quadrangles that are substantially close to a square, but are not limited thereto, and the connection parts 41 of the through holes 25c may be polygonal, such as a triangle, a pentagon, a hexagon, or an octagon.

[0053] The pattern of the through holes 25 of the metal mask shown in Fig. 2D is the same as the pattern of the through holes 25 of the metal mask shown in Fig. 2B. Therefore, the metal mask shown in Fig. 2B may be used as the metal mask shown in Fig. 2D, and the metal mask 20 and the substrate 92 may be moved relatively to each other, so that deposition materials 98 of different colors may be attached in the same pattern.

[0054] The through holes 25 may be formed in a desired pattern other than the patterns exemplified in Figures 2B to 2D. For example, the through holes 25 may be arranged in a lattice pattern at a predetermined pitch along two mutually intersecting directions. The through holes 25 may also be arranged in a staggered pattern at a predetermined pitch along two mutually intersecting directions.

[0055] The two directions may correspond to the longitudinal direction D2 or the width direction D1 of the metal mask 20. The pitch of the through holes 25 in the perforated region 22 is not particularly limited. For example, when the metal mask 20 is used to produce displays (approximately 0.5 inches to 32 inches) for mobile phones, digital cameras, etc., the pitch of the through holes 25 may be approximately 20 μm to 254 μm in both the width direction D1 and the longitudinal direction D2.

[0056] As described above, the perforated region 22 of the metal mask 20 has a plurality of through holes 25 of any shape and in any pattern. Next, the shape of the through holes 25 in the perforated region 22 will be described in more detail.

[0057] Fig. 3A shows an example of a perspective view of perforated region 22 as viewed from second surface 20b. Fig. 3B shows an enlarged perspective view of through hole 25 shown in Fig. 3A. Fig. 3C shows a cross-sectional view of through hole 25 shown in Fig. 3B along A-A', and Fig. 3D shows a cross-sectional view of through hole 25 shown in Fig. 3B along B-B'.

[0058] 3A and 3B, the through hole 25 has a first recess 30 formed on the first surface 20a, a second recess 35 formed on the second surface 20b, and a circumferential connection portion 41 connecting the first recess 30 and the second recess 35. The through hole 25 is formed by connecting the first recess 30 on the first surface 20a side to the second recess 35 on the second surface 20b side. The portion where the first recess 30 and the second recess 35 communicate with each other is the connection portion 41. The first wall surface 31 of the first recess 30 and the second wall surface 36 of the second recess 35 are connected via the circumferential connection portion 41.

[0059] The area of ​​the first recess 30 in a plan view may be gradually decreased from the first surface 20a to the second surface 20b. The area of ​​the second recess 35 in a plan view may be gradually decreased from the second surface 20b to the first surface 20a. The first recess 30 may be configured as a recess having a smaller diameter than the second recess 35.

[0060] Furthermore, at the connection portion 41, the direction in which the wall surface of the through hole 25 expands changes discontinuously. In general, the opening area of ​​the through hole 25 in a plan view is minimized at the connection portion 41. Here, from the viewpoint of suppressing shadows, it is preferable that the distance h in the thickness direction N from the first surface 20a to the connection portion 41 is small.

[0061] The shadow is a phenomenon in which a part of the deposition material 98 that has reached the metal mask 20 from the deposition source collides with the second wall surface 36 of the second recess 35 of the metal mask 20 and cannot reach the substrate 92, resulting in an insufficient area or thickness of the layer of the deposition material 98 on the substrate 92. In particular, since the connection portion 41 is a portion where the opening area of ​​the through hole 25 is the smallest in a plan view, the closer the connection portion 41 is to the substrate 92, the more likely the deposition material 98 will reach the substrate 92 in the same shape as the connection portion 41, and the less likely the shadow will occur. On the other hand, the farther the connection portion 41 is from the substrate 92, the more the deposition material 98 is blocked by the second wall surface 36 or the like at a position farther from the substrate. Therefore, the area or thickness of the layer of the deposition material 98 that has reached the substrate 92 tends to be insufficient, and the shadow tends to occur easily.

[0062] Therefore, from the viewpoint of suppressing the shadow, it is preferable to make the distance h smaller overall. However, if the distance h is made smaller overall, the mechanical strength of the metal mask decreases, and the metal mask is likely to deform or break. In addition, in order to make the distance h smaller, the first recess 30 can be made larger, but it is difficult to perform such etching precisely. Therefore, there is a risk of variation in the shape of the through hole.

[0063] Incidentally, it is also conceivable to form the through-hole 25 by etching only one side in order to reduce the distance h. However, in that case, the variation in the shape and size of the through-hole 25 becomes large. Therefore, in the second-side etching process described later, the h1 of the corner 41b of the connection part 41 is made slightly larger, and the h21 and h22 of the linear part 41a are made close to 0. If the h1 of the corner 41b of the connection part 41 is made close to 0, the shape accuracy of the linear part 41a decreases, so by making the h1 slightly larger, it is possible to make the h21 and h22 close to 0 while maintaining the shape accuracy of the linear part 41a. This makes it possible to improve the shape accuracy of the linear part 41a of the connection part 41. Specifically, it is possible to improve the linearity of the linear part 41a. In addition, in the evaluation of the linearity of the linear part 41a, the through-hole 25 is photographed from the thickness direction of the metal mask 20 using a scanning electron microscope, and the shape of the connection part 41 when viewed in a plan view is photographed. When the linear portion 41a is curved toward the outside or inside of the through hole 25, the distance (μm) between the straight line connecting both ends of the linear portion 41a and the apex of the curved mountain of the linear portion 41a is measured. This distance is also referred to as "straightness" in this specification. As the scanning electron microscope, for example, a scanning electron microscope ULTRA55 manufactured by ZEISS can be used.

[0064] In contrast to this, in the present disclosure, the distance h in the thickness direction from the first surface 20a to the connection portion 41 is varied depending on the position, and the shape of the through hole 25 is adjusted so that the maximum distance h1 in the thickness direction N from the first surface 20a to the connection portion 41 at the corner portion 41b is longer than the minimum distance h2 in the thickness direction N from the first surface 20a to the connection portion 41 at the linear portion 41a.

[0065] Here, the maximum distance h1 is the distance at which the distance h is the longest among the corners 41b. When there are multiple corners 41b, the longest distance h among all the corners 41b is the maximum distance h1.

[0066] Furthermore, the minimum distance h2 is the distance at which the distance h is the smallest among the linear portions 41a. When there are multiple linear portions 41a, the minimum distance h2 is the smallest distance h among all the linear portions 41a. For example, when distances h21 and h22 exist for each of the linear portions 41a of different lengths, the minimum distance h2 is the minimum value.

[0067] In this way, by making the distance h relatively small in the linear portion 41a, shadows are further suppressed, and by making the distance h relatively large in the corner portion 41b, the mechanical strength of the metal mask is improved. In addition, since it is not necessary to make the corners protrude, the shape of the through holes is excellent in uniformity.

[0068] For the same reason, it is preferable that the maximum distance h2' in the thickness direction N from the first surface 20a to the connection portion 41 in the linear portion 41a is smaller than the maximum distance h1.

[0069] Furthermore, as shown in FIG. 2C, when the linear portion 41a of the through hole 25b has a relatively short first linear portion 41a1 and a relatively long second linear portion 41a2, the distance h21 in the thickness direction from the first surface 20a to the first linear portion 41a1 may be the same as the distance h22 in the thickness direction from the first surface 20a to the second linear portion 41a2, or the distance h21 may be longer than the distance h22, or the distance h21 may be shorter than the distance h22. Among these, it is preferable that the distance h21 is longer than the distance h22. As a result, the distance h22 of the longer part (second linear portion 41a2) of the linear portion 41a is short, so that the shadow tends to be suppressed more. Also, the distance h21 and the distance h22 may be approximately the same, but by making the distance h21 longer, the mechanical strength of the metal mask tends to be improved more. From this viewpoint, it is preferable that the distance h1, the distance h21, and the distance h22 satisfy the relationship h1>h21>h22.

[0070] 2C, when the linear portion 41a has a relatively short first linear portion 41a1 and a relatively long second linear portion 41a2, the minimum distance h2 in the linear portion 41a is the distance h22. This also applies when the linear portion 41a includes three or more linear portions 41a of different lengths, and the linear portion 41a having the shortest distance h is set to the minimum distance h2.

[0071] The formation of such through holes 25 may be adjusted by the etching conditions when forming the first recess 30 and the second recess 35 and the shape of the photoresist mask used.

[0072] The maximum distance h1 is preferably 0.6 μm or more and 8.0 μm or less, 0.8 μm or more and 6.0 μm or less, or 1.0 μm or more and 4.0 μm or less. The maximum distance h1 is preferably 0.6 μm or more, 0.8 μm or more, 1.0 μm or more, and 1.2 μm or more. Furthermore, the maximum distance h1 is preferably 8.0 μm or less, 6.0 μm or less, 4.0 μm or less, 3.0 μm or less, and 2.0 μm or less. The range of the maximum distance h1 may be determined by a combination of any one of the above-mentioned multiple lower limit candidate values ​​and any one of the above-mentioned multiple upper limit candidate values.

[0073] By setting the maximum distance h1 to 0.6 μm or more, the mechanical strength of the metal mask tends to be improved. Also, by setting the maximum distance h1 to 8.0 μm or less, shadows tend to be suppressed.

[0074] The minimum distance h2 is preferably 0.06 μm or more and 4.0 μm or less, 0.08 μm or more and 3.0 μm or less, or 0.10 μm or more and 2.0 μm or less. The minimum distance h2 is preferably 0.06 μm or more, 0.08 μm or more, 0.10 μm or more, 0.25 μm or more, or 0.50 μm or more. The minimum distance h2 is preferably 4.0 μm or less, 3.0 μm or less, 2.0 μm or less, 1.5 μm or less, or 1.0 μm or less. The range of the minimum distance h2 may be determined by a combination of any one of the above-mentioned multiple lower limit candidate values ​​and any one of the above-mentioned multiple upper limit candidate values.

[0075] When the minimum distance h2 is 0.06 μm or more, the mechanical strength of the deposition mask tends to be further improved. Also, when the minimum distance h2 is 4.0 μm or less, the shadow tends to be further suppressed.

[0076] The ratio (h1 / h2) of the maximum distance h1 to the minimum distance h2 is preferably 1.1 or more and 50 or less, 1.2 or more and 45 or less, or 1.5 or more and 40 or less. The ratio (h1 / h2) is preferably 1.1 or more, 1.2 or more, 1.5 or more, 1.8 or more, 2.0 or more, 3.0 or more, or 4.0 or more. The ratio (h1 / h2) is preferably 50 or less, 45 or less, 40 or less, 35 or less, 30 or less, 25 or less, or 20 or less. The range of the ratio (h1 / h2) may be determined by a combination of any one of the above-mentioned multiple lower limit candidate values ​​and any one of the above-mentioned multiple upper limit candidate values.

[0077] By making the ratio (h1 / h2) 1.1 or more, the shape precision of the linear portion tends to be further improved. Also, by making the ratio (h1 / h2) 50 or less, the shadow tends to be further suppressed.

[0078] The thickness H from the first surface 20a to the second surface 20b is preferably 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, or may be 20 μm or less. By reducing the thickness H, the holed region 22 can be made thinner by etching or the like, and adhesion of the deposition material 98 to the second wall surface 36 of the second recess 35 in the deposition process tends to be suppressed.

[0079] The thickness H is preferably 5 μm or more, and may be 10 μm or more, or 15 μm or more. Increasing the thickness H tends to further improve the strength of the metal mask 20. This tends to further suppress deformation or breakage of the perforated region 22, for example.

[0080] The ratio (h1 / H) of the maximum distance h1 to the thickness H is preferably 0.010 or more and 0.40 or less, 0.015 or more and 0.30 or less, or 0.020 or more and 0.20 or less. The ratio (h1 / H) is preferably 0.010 or more, 0.015 or more, 0.020 or more, and 0.025 or more. The ratio (h1 / H) is preferably 0.40 or less, 0.30 or less, 0.20 or less, and 0.15 or less. The range of the ratio (h1 / H) may be determined by a combination of any one of the above-mentioned multiple lower limit candidate values ​​and any one of the above-mentioned multiple upper limit candidate values.

[0081] When the ratio (h1 / H) is 0.010 or more, the mechanical strength of the metal mask tends to be improved, and when the ratio (h1 / H) is 0.40 or less, shadows tend to be suppressed.

[0082] The ratio (h2 / H) of the minimum distance h2 to the thickness H is preferably 0.001 to 0.20, 0.002 to 0.10, 0.004 to 0.080, or 0.004 to 0.080. The ratio (h2 / H) is preferably 0.001 or more, 0.002 or more, 0.003 or more, or 0.004 or more. The ratio (h2 / H) is preferably 0.20 or less, 0.10 or less, 0.080 or less, or 0.060 or less. The range of the ratio (h2 / H) may be determined by a combination of any one of the above-mentioned multiple lower limit candidate values ​​and any one of the above-mentioned multiple upper limit candidate values.

[0083] When the ratio (h2 / H) is 0.001 or more, the mechanical strength of the metal mask tends to be improved, and when the ratio (h2 / H) is 0.20 or less, shadows tend to be suppressed.

[0084] Furthermore, when the distance h21 and the distance h22 exist, the ratio (h21 / h22) of the distance h21 to the distance h22 is preferably more than 1.00 and not more than 10, 1.03 or more and not more than 8.0, 1.05 or more and not more than 6.0, or 1.07 or more and not more than 4.0. Moreover, the ratio (h21 / h22) is preferably more than 1.00, 1.05 or more, 1.1 or more, 1.2 or more, or 1.3 or more. Moreover, the ratio (h21 / h22) is preferably 10 or less, 8.0 or less, 6.0 or less, 4.0 or less, or 2.0 or less. The range of the ratio (h21 / h22) may be determined by a combination of any one of the above-mentioned multiple lower limit candidate values ​​and any one of the above-mentioned multiple upper limit candidate values.

[0085] As shown in FIG. 3A, the edge of the first recess 30 is referred to as a ridge line 33 in this disclosure. The ridge line 33 is a portion that separates the adjacent through holes 25. In other words, each through hole 25 is surrounded by the ridge line 33. In FIG. 3A, the adjacent through holes 25 are spaced apart by a certain distance or more, and the second surface 20b that is not etched remains between the adjacent second recesses 35. In FIG. 3A, this remaining portion of the second surface 20b becomes the ridge line 33 that separates the adjacent through holes 25. In this case, the ridge line 33 may be the first surface 51a of the metal plate 51 that remains between the adjacent first recesses 30. In this case, the height of the ridge line 33 may be constant.

[0086] 3E shows another example of a perspective view of the perforated region 22 as viewed from the second surface 20b side. In FIG. 3E, the distance between adjacent through holes 25 is short. Therefore, the second wall surfaces 36 of adjacent second recesses 35 join together by etching, and the joined second wall surfaces 36 form a ridge line 33. Therefore, in FIG. 3E, no second surface 51b of the metal plate 51 constituting the metal mask 20 remains between adjacent second recesses 35.

[0087] 3E, the height of ridge line 33 formed by the joined second wall surfaces 36 is not constant and may vary depending on the distance from the center of through hole 25. For example, the longer the distance from the center of through hole 25 to ridge line 33, the higher the height of ridge line 33 may be.

[0088] Such through holes 25 may be formed by etching the metal plate 51 so that the second surface 51b of the metal plate 51 does not remain between adjacent second recesses 35, as in a manufacturing method described later. The first surface 51a of the metal plate 51 corresponds to the first surface 20a of the metal mask 20, and the second surface 51b of the metal plate 51 corresponds to the second surface 20b of the metal mask 20.

[0089] The peripheral region 23 is a region located around the perforated region 22. The peripheral region 23 may be located so as to surround the perforated region 22. The peripheral region 23 may be a region that supports the perforated region 22 by being located around the perforated region 22.

[0090] The surrounding region 23 may also be a region through which the deposition material 98 is not intended to pass. From this perspective, the surrounding region 23 may mainly have a non-porous surface in which no through-holes are formed. However, for various purposes, the surrounding region 23 may have through-holes that are not intended for the deposition material to pass through locally in parts other than the non-porous surface while having a non-porous surface. In the present disclosure, the "non-porous surface" refers to a surface that does not have through-holes.

[0091] As described below, the metal mask 20 is fixed to the frame 15 to constitute the metal mask device 10. The surrounding region 23 may have an end portion 23a fixed to the frame 15. When the metal mask 20 is in the shape of a long stick as shown in Fig. 1, the end portion 23a may be located at both ends in the longitudinal direction D2. Furthermore, the end portion 23a may have a U-shaped notch or the like.

[0092] The end 23a may be configured so that a portion of it can be cut off after the metal mask 20 is fixed to the frame 15. Furthermore, the end 23a may be configured integrally with the other surrounding region 23 as shown in Fig. 1, or may be configured of a member separate from the other surrounding region. In this case, the end may be joined to the other portion of the surrounding region by, for example, welding.

[0093] Finally, a method for producing a metal mask according to an embodiment of the present disclosure will be described.

[0094] A method for manufacturing a metal mask according to one embodiment of the present disclosure includes a preparation step of preparing a metal plate 51 having a first surface 51a and a second surface 51b located opposite the first surface 51a, and an etching step of forming the metal mask 20 by etching the metal plate 51.

[0095] In the following, a method for manufacturing the metal mask 20 by etching will be described, however, the metal mask 20 may be formed by etching, by laser processing, or by electroforming.

[0096] A method for manufacturing a metal mask 20 according to an embodiment of the present disclosure will be described mainly with reference to FIGS. 4A to 4E. FIG. 4A is a schematic diagram showing a manufacturing apparatus 70 for manufacturing a metal mask 20 using a metal sheet 51, together with the processing sequence. FIG. 4A shows an example in which the metal sheet 51 is continuously supplied from a resist film forming apparatus 71 to a stripping apparatus 74. However, the manufacturing method for a metal mask 20 according to the present disclosure is not limited thereto, and for example, the metal sheet 51 may be wound into a wound body after each processing in each apparatus. Furthermore, when the metal sheet 51 is supplied to each apparatus, the metal sheet 51 may be unwound from the wound body and supplied.

[0097] Each step of the method for producing the metal mask 20 will be described in detail below.

[0098] First, a metal plate 51 having a desired thickness is prepared (preparation step). The metal plate 51 may be in the form of a wound body 50 wound around a core 52. The method for producing the metal plate 51 having a desired thickness is not particularly limited, but examples thereof include a rolling method and a plating film formation method.

[0099] Next, resist films 53a, 53b are formed on the first surface 51a and the second surface 51b of the metal plate 51 using a resist film forming apparatus 71 (FIG. 4B). Specifically, the resist films 53a, 53b may be formed by attaching a dry film resist to the first surface 51a and the second surface 51b. Alternatively, the resist films 53a, 53b may be formed by applying a coating liquid containing a photosensitive resist material to the first surface 51a and the second surface 51b and drying the coating liquid.

[0100] The dry film resist and the coating liquid are not particularly limited, and conventionally known ones can be used. The resist films 53a and 53b thus formed may be either negative resist or positive resist. Of these, negative resists are preferably used.

[0101] The thickness of the resist films 53a, 53b is preferably 15 μm or less, 10 μm or less, 6 μm or less, or may be 4 μm or less. The thickness of the resist films 53a, 53b is preferably 1 μm or more, 3 μm or more, 5 μm or more, or may be 7 μm or more. The range of the thickness of the resist films 53a, 53b may be determined by a combination of any one of the above-mentioned multiple upper limit candidate values ​​and any one of the above-mentioned multiple lower limit candidate values.

[0102] Next, the resist films 53a, 53b are exposed and developed using an exposure / development device 72. As a result, as shown in Fig. 4C, a first resist pattern 53c is formed on the first surface 51a, and a second resist pattern 53d is formed on the second surface 51b. For example, when a negative resist film is used, a photomask that does not transmit light to the area of ​​the resist film that is to be removed may be placed on the resist film, the resist film may be exposed through the photomask, and the resist film may be developed.

[0103] Subsequently, the metal plate 51 is etched using the etching device 73 with the first resist pattern 53c and the second resist pattern 53d as a mask (etching step). The etching step may include a first surface etching step and a second surface etching step.

[0104] 4D is a schematic diagram showing an example of the first-surface etching step in the hole region 22. In the first-surface etching step, the region of the first surface 51a that is not covered by the first resist pattern 53c is etched using an etching solution. At this time, the second surface 51b may be covered with a resin or the like that is resistant to the etching solution.

[0105] The etching solution erodes the first surface 51a that is not covered by the first resist pattern 53c (FIG. 4D). As a result, a large number of first recesses 30 are formed on the first surface 51a. The etching of the metal plate 51 can proceed isotropically in various directions from the holes in the resist pattern. Therefore, the cross-sectional areas of the first recesses 30 and the second recesses 35 at each position along the thickness direction of the metal mask 20 become gradually smaller as they progress from the surface in the thickness direction.

[0106] 4E is a schematic diagram showing an example of the second-side etching step in the hole region 22. In the second-side etching step, the region of the second side 51b that is not covered by the second resist pattern 53d is etched using an etching solution. At this time, a film or the like that covered the second side 51b in the first-side etching step may be peeled off in advance. In addition, the first side 51a may be covered with a resin 54 or the like that is resistant to the etching solution.

[0107] The etching solution erodes the second surface 51b that is not covered by the second resist pattern 53d (FIG. 4E). As a result, the second recess 35 is formed on the second surface 51b. The first recess 30 and the second recess 35 communicate with each other, thereby forming the through hole 25.

[0108] The etching solution is not particularly limited as long as it is a conventionally known solution, and examples thereof include those containing ferric chloride solution and hydrochloric acid.

[0109] In the second surface etching step, etching may be performed until adjacent second recesses 35 are connected as shown in FIG. 4E. At the points where adjacent second recesses 35 are connected, the adjacent second recesses 35 join together to form ridge lines 33. In addition, ridge lines 33 are separated from second resist pattern 53d, and erosion by etching progresses in the thickness direction of metal plate 51 at the tops of ridge lines 33. As a result, second resist pattern 53d is peeled off from metal plate 51. Note that the second surface 51b may be partially left between adjacent second recesses 35.

[0110] Furthermore, a peeling device 74 is used to peel off the resist pattern, the resin 54 having resistance to the etching solution, and the like from the metal plate 51. Then, a separation device 75 is used to cut the long metal plate 51, thereby performing a separation step in which the metal mask 20 made of a sheet-like metal plate is separated from the metal plate 51. In this manner, the metal mask 20 can be obtained.

[0111] A metal mask apparatus 10 according to an embodiment of the present disclosure includes a frame 15 and the above-mentioned metal mask 20 placed on the frame 15. The metal mask 20 may be placed on the frame 15 with the second surface 20b in contact with the frame 15. Fig. 5 shows a plan view of the metal mask apparatus 10 as viewed from the side of the first surface 20a of the metal mask 20. Fig. 6 shows a cross-sectional view of the deposition apparatus.

[0112] In the metal mask device 10 of the present disclosure, multiple metal masks 20 may be attached to one frame ( FIG. 5 ). In this case, the multiple metal masks 20 may be lined up in a width direction D1 that intersects with the longitudinal direction D2 of the metal mask 20. Furthermore, each metal mask 20 may be fixed to the frame 15 at both ends 23a of the metal mask 20 in the longitudinal direction D2.

[0113] The method of fixing to the frame 15 is not particularly limited, but may be, for example, welding.

[0114] The metal mask device 10 may include a member that is fixed to the frame 15 and partially overlaps the metal mask 20 in the thickness direction of the metal mask 20. Examples of such a member are not particularly limited, but include a member that extends in a direction intersecting the longitudinal direction of the metal mask 20 and supports the metal mask 20, and a member that overlaps a gap between two adjacent metal masks.

[0115] Next, a method for manufacturing an organic EL display device using the metal mask 20 according to the present disclosure will be described with reference to Fig. 6. The organic EL display device may include a substrate 92 and a deposition layer including a deposition material 98 provided in a pattern, which are laminated together.

[0116] The method for manufacturing the organic EL display device according to an embodiment of the present disclosure is not particularly limited, but includes, for example, a deposition step of depositing a deposition material 98 on a substrate such as the substrate 92 using a metal mask 20.

[0117] In the vapor deposition process, first, the metal mask device 10 is arranged so that the metal mask 20 faces the substrate 92. At this time, as shown in Fig. 6, the first surface 20a of the metal mask 20 may face the substrate 92. Here, the substrate 92 is a vapor deposition target such as a glass substrate.

[0118] 6, when the metal mask device 10 is housed in the deposition device 90, the surface of the metal mask 20 facing the substrate 92 is the first surface 20a, and the surface of the metal mask 20 located on the crucible 94 side holding the deposition material 98 is the second surface 20b. In the deposition device 90, the metal mask 20 is disposed on the surface of the substrate 92 facing the crucible 94. Here, the metal mask 20 and the substrate 92 may be brought into close contact with each other by magnetic force.

[0119] In the deposition device 90, a crucible 94 for accommodating a deposition material 98 and a heater 96 for heating the crucible 94 may be disposed below the metal mask device 10. Here, the deposition material 98 may be, for example, an organic light-emitting material. The deposition material 98 in the crucible 94 is vaporized or sublimated by heating from the heater 96. The vaporized or sublimated deposition material 98 adheres to the substrate 92 through the through-holes 25 of the metal mask 20. As a result, the deposition material 98 is formed on the surface of the substrate 92 in a desired pattern corresponding to the positions of the through-holes 25 of the metal mask 20. Note that the inside of the deposition device 90 may be a vacuum atmosphere in the deposition process.

[0120] When it is desired to deposit different types of deposition materials according to pixels such as RGB, the deposition materials 98 may be formed on the surface of the substrate 92 using different metal masks 20 according to the colors of the deposition materials 98. For example, the deposition material 98 for red, the deposition material 98 for green, and the deposition material 98 for blue may be deposited in order on the substrate 92. Alternatively, the deposition material 98 for red, the deposition material 98 for green, and the deposition material 98 for blue may be deposited in order by gradually moving the metal mask 20 (metal mask device 10) and the substrate 92 relative to each other along the arrangement direction of the through holes 25 (the aforementioned one direction).

[0121] The method for manufacturing an organic EL display device may include various steps other than the deposition step of depositing a deposition material 98 on a substrate such as the substrate 92 using the metal mask 20. For example, the method for manufacturing an organic EL display device may include a step of forming a first electrode on the substrate. A deposition layer is formed on the first electrode. The method for manufacturing an organic EL display device may include a step of forming a second electrode on the deposition layer. The method for manufacturing an organic EL display device may include a sealing step of sealing the first electrode, the deposition layer, and the second electrode provided on the substrate 92.

[0122] The deposition layer formed on a substrate such as the substrate 92 using the metal mask 20 is not limited to the light-emitting layer formed by depositing the organic light-emitting material described above, and may include other layers. For example, the deposition layer may include, in order from the first electrode side, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and the like. In this case, a deposition process using the metal mask 20 corresponding to each layer may be performed.

[0123] It should be noted that various modifications can be made to the above-described embodiment. Below, the modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above-described embodiment will be used for parts that can be configured in the same manner as in the above-described embodiment, and duplicated descriptions will be omitted. Also, if it is clear that the effects obtained in the above-described embodiment can also be obtained in the modified examples, the description may be omitted. EXAMPLES

[0124] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0125] (Example) Using the above-mentioned method for manufacturing a metal mask, a metal mask was manufactured having a through hole consisting of a first recess and a second recess, and a third recess in a metal plate. In this case, the maximum distance h1 at the corner portion and the minimum distance h2 at the linear portion were set to have a predetermined relationship. In addition, the metal plate used as the raw material for the metal mask was an Invar material. Example A shows an embodiment in which the through hole is substantially square in plan view, and Example B shows an embodiment in which the through hole is substantially rectangular in plan view.

[0126] (Comparative Example) Metal masks were obtained in the same manner as in the examples, except that the maximum distance h1 at the corners and the minimum distance h2 at the linear portions were set to have the predetermined relationship shown in Table 1. Comparative Example A shows a through hole having a substantially square shape in plan view, and Comparative Example B shows a through hole having a substantially rectangular shape in plan view.

[0127] (Evaluation of the shape of the connection) For the linear parts of the connections, those with a straightness within ±2μm were rated as OK, and those exceeding ±2μm were rated as NG. The straightness was measured by photographing the connections using a scanning electron microscope (ZEISS, ULTRA55).

[0128] Specifically, the "straightness" was measured by photographing the shape of connection part 41 in a plan view using a scanning electron microscope, and measuring the distance (μm) between the straight line connecting both ends of linear part 41a and the apex of the curved mountain of linear part 41a as the straightness. When the straight line connecting both ends of linear part 41a coincides with linear part 41a, it was measured as "0 μm", when linear part 41a is curved outward from through hole 25, it was measured as "+", and when linear part 41a is curved inward, it was measured as "-".

[0129] (Shadow evaluation) Next, a deposition process was carried out in which a deposition material was attached onto the substrate using a metal mask to form a deposition layer. Tris(8-quinolinolato)aluminum, an organic light-emitting material, was used as the deposition material. A glass substrate was used as the substrate. The conditions of the deposition process were set so that the thickness of the deposition layer would be 40 nm.

[0130] Next, the deposition layer on the substrate was observed using a LEICA optical microscope DMRX HX DC300F and a Hitachi High-Technologies scanning white light interference microscope Birdscan. Based on the observation results, the area ratio V of the deposition layer was calculated. The area ratio V of the deposition layer is the ratio (V2 / V1) of the effective area V2 of the deposition layer to the area V1 of the through holes.

[0131] The effective area V2 is the area of ​​the region of the deposited layer having a thickness of 95% or more of the target thickness. When the target thickness is 40 nm, the effective area V2 is the area of ​​the region of the deposited layer having a thickness of 38 nm or more.

[0132] The area ratio V was calculated for each of the 30 deposition layers on the substrate. If the area ratio V was 0.70 or more for all of the 30 deposition layers on the substrate, it was evaluated as "OK", and if even one of the deposition layers had an area ratio V less than 0.70, it was evaluated as "NG".

[0133] [Table 1]

[0134] [Table 2] *Distance h22 was used as the minimum distance h2. [Industrial Applicability]

[0135] The metal mask of the present invention has industrial applicability, such as a metal mask used in the manufacture of organic EL display devices. [Explanation of symbols]

[0136] 10...metal mask device, 15...frame, 20...metal mask, 20a...first surface, 20b...second surface, 22...perforated area, 23...peripheral area, 23a...edge, 25...through hole, 25a...through hole, 25b...through hole, 25c...through hole, 30...first recess, 31...first wall surface, 33...ridge line, 35...second recess, 36...second wall surface, 41...connection portion, 41a...linear portion, 41a1...first linear portion, 41a2...second linear portion, 41b...corner portion, 50 ...wound body, 51...metal plate, 51a...first surface, 51b...second surface, 52...core, 53a...resist film, 53b...resist film, 53c...first resist pattern, 53d...second resist pattern, 54...resin, 70...manufacturing equipment, 71...resist film forming equipment, 72...exposure / developing equipment, 73...etching equipment, 74...peeling equipment, 75...separating equipment, 90...evaporation equipment, 92...substrate, 94...crucible, 96...heater, 98...evaporation material.

Claims

1. a perforated region and a peripheral region; the perforated region having a plurality of through holes; the peripheral region is located around the perforated region; the through hole has a first recess formed in a first surface, a second recess formed in a second surface, and a circumferential connecting portion connecting the first recess and the second recess, the connection portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions, a distance h in a thickness direction from the first surface to the connection portion varies depending on a position, a maximum distance h1 in the thickness direction from the first surface to the connection portion at the corner portion is longer than a minimum distance h2 in the thickness direction from the first surface to the connection portion at the linear portion; Metal mask.

2. The linear portion includes a first linear portion and a second linear portion, The first linear portion is shorter than the second linear portion, A distance h21 in a thickness direction from the first surface to the first linear portion is longer than a distance h22 in a thickness direction from the first surface to the second linear portion. The metal mask according to claim 1 .

3. The maximum distance h1 is 0.6 μm or more and 8.0 μm or less. The metal mask according to claim 1 .

4. The minimum distance h2 is 0.06 μm or more and 4.0 μm or less. The metal mask according to claim 1 .

5. a ratio (h1 / h2) of the maximum distance h1 to the minimum distance h2 is 1.1 or more and 50 or less; The metal mask according to claim 1 .

6. a ratio (h1 / H) of the maximum distance h1 to a thickness H from the first surface to the second surface is 0.010 or more and 0.40 or less; The metal mask according to claim 1 .

7. a ratio (h2 / H) of the minimum distance h2 to a thickness H from the first surface to the second surface is 0.001 or more and 0.20 or less; The metal mask according to claim 1 .

8. A method for manufacturing a metal mask, comprising the steps of: providing a metal plate having a first surface and a second surface opposite the first surface; and an etching step of forming the metal mask by etching the metal plate, The metal mask has a hole region and a surrounding region, the perforated region having a plurality of through holes; the peripheral region is located around the perforated region; the through hole has a first recess formed in a first surface, a second recess formed in a second surface, and a circumferential connecting portion connecting the first recess and the second recess, the connection portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions, a distance h in a thickness direction from the second surface to the connection portion varies depending on a position, A maximum distance h1 in a thickness direction from the second surface to the corner portion is longer than a minimum distance h2 in a thickness direction from the second surface to the linear portion. A method for manufacturing a metal mask.

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