Metal mask and manufacturing method thereof

Abstract

The invention provides a metal mask and a manufacturing method thereof. Shadows can be further suppressed, the shape uniformity of the through holes is excellent, and the mechanical strength is also excellent. A metal mask having a perforated region having a plurality of through-holes, and a peripheral region located around the perforated region, the through-holes having: a first recess formed in a first surface, a second recess formed in a second surface, and a third recess formed in a second surface; a second recess formed in the second surface; and a circumferential connection portion that connects the first recess and the second recess, the connection portion including a plurality of corner portions and a plurality of linear portions located between the adjacent corner portions, the distance h in the thickness direction from the first surface to the connection portion being different depending on positions, and the distance h being smaller than the distance h in the thickness direction from the first surface to the connection portion. The maximum distance h1 in the thickness direction from the first surface to the corner portion is longer than the minimum distance h2 in the thickness direction from the first surface to the linear portion.

Description

Technical Field

[0001] The present disclosure relates to a metal mask and a method for manufacturing the same. Background Art

[0002] The pixels of an organic EL display device are formed by attaching a material forming the pixels to 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 the following technology: for the purpose of providing a metal mask capable of suppressing the deviation of the film thickness of the vapor deposition pattern, the corners of the large opening are set to a shape that protrudes outward relative to the edge.

[0003] Patent Document 1: Japanese Patent No. 6870795

[0004] However, in the metal mask described in Patent Document 1, since the corners of the polygonal shape are extended toward the outside of the polygonal shape, it is expected that the evaporation material entering the mask hole from the vicinity of the corners of the large opening will easily reach the small opening. However, on the other hand, in the metal mask described in Patent Document 1, the shape of the opening is complex, and it is not easy to uniformly form multiple through holes with complex shapes. In addition, there is also concern that the complex shape may affect the mechanical strength. Summary of the invention

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a metal mask capable of further suppressing shadows, having excellent uniformity in the shape of through holes and excellent mechanical strength, and an efficient method for manufacturing the metal mask.

[0006] A metal mask according to an embodiment of the present disclosure has a hole region and a surrounding region.

[0007] The perforated area has a plurality of through holes,

[0008] The surrounding area is located around the perforated area,

[0009] The through hole has: a first recessed portion formed on the first surface; a second recessed portion formed on the second surface; and a circumferential connecting portion connecting the first recessed portion and the second recessed portion.

[0010] The connecting portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions.

[0011] The distance h from the first surface to the connecting portion in the thickness direction varies depending on the position.

[0012] A maximum distance h1 from the first surface to the connecting portion in the thickness direction at the corner portion is longer than a minimum distance h2 from the first surface to the connecting portion in the thickness direction at the linear portion.

[0013] The method for manufacturing the metal mask according to one embodiment of the present disclosure comprises:

[0014] a step of preparing a metal plate having a first surface and a second surface located on the opposite side of the first surface; and

[0015] an etching step of forming the metal mask by etching the metal plate,

[0016] The metal mask has a hole area and a surrounding area,

[0017] The perforated area has a plurality of through holes,

[0018] The surrounding area is located around the perforated area,

[0019] The through hole has: a first recessed portion formed on the first surface; a second recessed portion formed on the second surface; and a circumferential connecting portion connecting the first recessed portion and the second recessed portion.

[0020] The connecting portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions.

[0021] The distance h from the second surface to the connecting portion in the thickness direction varies depending on the position.

[0022] A maximum distance h1 from the second surface to the corner portion in the thickness direction is longer than a minimum distance h2 from the second surface to the linear portion in the thickness direction.

[0023] In at least one embodiment of the present disclosure, a metal mask capable of further suppressing shadows, having excellent uniformity in the shape of through holes, and having excellent mechanical strength, and an efficient method for manufacturing the metal mask can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is a top view showing a metal mask according to one embodiment of the present disclosure.

[0025] Figure 2A It is a plan view showing an example of the shape, size, and position of a pattern of a vapor-deposited layer attached to a substrate.

[0026] Figure 2B It is shown for the composition Figure 2A FIG. 1 is a plan view of an example of the through-holes 25 of the metal mask 20 having the pattern of the vapor-deposited layer shown.

[0027] Figure 2CIt is shown for the composition Figure 2A FIG. 1 is a plan view of an example of the through-holes 25 of the metal mask 20 having the pattern of the vapor-deposited layer shown.

[0028] Figure 2D It is shown for the composition Figure 2A FIG. 1 is a plan view of an example of the through-holes 25 of the metal mask 20 having the pattern of the vapor-deposited layer shown.

[0029] Figure 3A This is a perspective view showing one aspect of viewing the perforated region from the second surface side.

[0030] Figure 3B Yes Figure 3A An enlarged perspective view of the through hole is shown.

[0031] Figure 3C yes Figure 3B A cross-sectional view of the through hole taken along the line AA' is shown.

[0032] Figure 3D yes Figure 3B A cross-sectional view of a BB' section of the through hole shown.

[0033] Figure 3E This is a perspective view showing one aspect of viewing the perforated region from the second surface side.

[0034] Figure 4A This is a schematic diagram for explaining an example of a method for manufacturing a metal mask.

[0035] Figure 4B This is a diagram showing an example of a process of forming a resist film on a metal plate.

[0036] Figure 4C This is a diagram showing an example of a process of patterning a resist film.

[0037] Figure 4D This is a diagram showing an example of the first surface etching step in the hole-containing region.

[0038] Figure 4E This is a diagram showing an example of the second surface etching step in the hole-containing region.

[0039] Figure 5 is a schematic diagram showing a metal mask device according to one embodiment of the present disclosure;

[0040] Figure 6 : is a cross-sectional view which shows the vapor deposition device which concerns on one embodiment of this disclosure. DETAILED DESCRIPTION

[0041] Hereinafter, one embodiment of the present disclosure will be described with reference to the accompanying drawings. In addition, in the drawings attached to this specification, for the sake of convenience of illustration and understanding, the scale and aspect ratio of the drawings may be appropriately changed and exaggerated relative to the scale and aspect ratio of the actual objects.

[0042] Unless otherwise specified in the present specification and / or the drawings, the following explanations shall be given.

[0043] The terms indicating a substance that serves as a basis for a certain structure may not be distinguished only by the difference in name. For example, the terms such as "substrate", "base material", "plate", "sheet" or "film" belong to the above description.

[0044] The terms and / or numerical values ​​indicating the shape and / or geometric conditions do not need to be limited to the strict meaning, and can also be interpreted as including the range of the degree that the same function can be expected. For example, "parallel" and / or "orthogonal" belong to the above terms. In addition, "length value" and / or "angle value" belong to the above numerical values.

[0045] When expressing that a certain structure is "above", "below", "upper side", "lower side", "above" or "below" another structure, it can also include a method in which a certain structure is directly connected to another structure, and a method in which other structures are included between a certain structure and another structure. In other words, the method in which other structures are included between a certain structure and another structure can also be expressed as a certain structure being indirectly connected to another structure. In addition, expressions such as "above", "upper side" or "above" can be replaced with expressions such as "below", "lower side" or "below". In other words, the up and down directions can also be reversed.

[0046] When the same parts and / or parts having the same functions are marked with the same reference numerals or similar reference numerals, repeated descriptions are sometimes omitted. In addition, the dimensional ratios of the drawings are sometimes different from the actual ratios. In addition, a part of the structure of the embodiment is sometimes omitted from the drawings.

[0047] In the range that no contradiction occurs, one or more modes of the embodiment and one or more modes of the modified example may be combined together. In addition, in the range that no contradiction occurs, one or more modes of the embodiment may be combined with each other. In addition, in the range that no contradiction occurs, one or more modes of the modified example may be combined with each other.

[0048] When a plurality of steps are disclosed in 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 within the scope of not causing contradiction.

[0049] Numerical ranges expressed by symbols such as “to” and / or “-” include numerical values ​​placed before and after the symbols such as “to” and / or “-”. For example, a numerical range expressed as “34 to 38 mass %” is the same as a numerical range expressed as “34 mass % or more and 38 mass % or less”.

[0050] For the numerical values ​​described in this disclosure, the numerical range can be limited by combining any one of multiple upper limit candidate values ​​and any one of multiple lower limit candidate values. In addition, even if not specifically mentioned, the numerical range can be defined by combining any two of multiple upper limit candidate values, and the numerical range can be defined by combining any two of multiple lower limit candidate values.

[0051] An embodiment of the present disclosure is described in the following paragraphs. An 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.

[0052] The metal mask disclosed in the present invention can be used for various purposes. There is no particular limitation. For example, the metal mask of the present invention can be used as such a metal mask: it is used to pattern the organic material on the substrate in the desired pattern in the manufacture of the organic EL display device. The metal mask is also called a vapor deposition mask. In addition, the metal mask disclosed in the present invention can achieve a high pixel density composition. In the organic EL display device that can be manufactured, in addition to the display of a smartphone or a television, it also includes a device for displaying or projecting images and videos for expressing virtual reality (VR) and augmented reality (AR).

[0053] In addition, in this specification and the drawings, unless otherwise specified, an example of a metal mask used when manufacturing an organic EL display device and a method for manufacturing the same will be described as one embodiment of the present invention.

[0054] A first aspect of the present disclosure is a metal mask, wherein:

[0055] The metal mask has a hole area and a surrounding area,

[0056] The perforated area has a plurality of through holes,

[0057] The surrounding area is located around the perforated area,

[0058] The through hole has: a first recessed portion formed on the first surface; a second recessed portion formed on the second surface; and a circumferential connecting portion connecting the first recessed portion and the second recessed portion.

[0059] The connecting portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions.

[0060] The distance h from the first surface to the connecting portion in the thickness direction varies depending on the position.

[0061] A maximum distance h1 from the first surface to the connecting portion in the thickness direction at the corner portion is longer than a minimum distance h2 from the first surface to the connecting portion in the thickness direction at the linear portion.

[0062] A second aspect of the present disclosure is, based on the metal mask of the first aspect,

[0063] The linear portion includes a first linear portion and a second linear portion,

[0064] The first linear portion is shorter than the second linear portion,

[0065] A distance h21 from the first surface to the first linear portion in the thickness direction is longer than a distance h22 from the first surface to the second linear portion in the thickness direction.

[0066] A third aspect of the present disclosure is, in addition to the metal mask of the first aspect or the second aspect,

[0067] The maximum distance h1 is greater than or equal to 0.6 μm and less than or equal to 8.0 μm.

[0068] A fourth aspect of the present disclosure is the metal mask according to any one of the first to third aspects described above.

[0069] The minimum distance h2 is greater than or equal to 0.06 μm and less than or equal to 4.0 μm.

[0070] A fifth aspect of the present disclosure is the metal mask according to any one of the first to fourth aspects,

[0071] A ratio of the maximum distance h1 to the minimum distance h2, that is, h1 / h2, is greater than or equal to 1.1 and less than or equal to 50.

[0072] A sixth aspect of the present disclosure is the metal mask according to any one of the first to fifth aspects,

[0073] A ratio of the maximum distance h1 to the thickness H from the first surface to the second surface, that is, h1 / H, is greater than or equal to 0.010 and less than or equal to 0.40.

[0074] A seventh aspect of the present disclosure is, in addition to the metal mask of any one of the first to sixth aspects,

[0075] A ratio of the minimum distance h2 to the thickness H from the first surface to the second surface, that is, h2 / H, is greater than or equal to 0.001 and less than or equal to 0.20.

[0076] An eighth aspect of the present disclosure is a method for manufacturing a metal mask, wherein:

[0077] The method for manufacturing the metal mask comprises:

[0078] a step of preparing a metal plate having a first surface and a second surface located on the opposite side of the first surface; and

[0079] an etching step of forming the metal mask by etching the metal plate,

[0080] The metal mask has a hole area and a surrounding area,

[0081] The perforated area has a plurality of through holes,

[0082] The surrounding area is located around the perforated area,

[0083] The through hole has: a first recessed portion formed on the first surface; a second recessed portion formed on the second surface; and a circumferential connecting portion connecting the first recessed portion and the second recessed portion.

[0084] The connecting portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions.

[0085] The distance h from the second surface to the connecting portion in the thickness direction varies depending on the position.

[0086] A maximum distance h1 from the second surface to the corner portion in the thickness direction is longer than a minimum distance h2 from the second surface to the linear portion in the thickness direction.

[0087] Hereinafter, the metal mask 20 of the present disclosure will be described in detail.

[0088] The metal mask 20 of the present disclosure includes a hole region 22 and a peripheral region 23. The hole region 22 is a region where a plurality of through holes 25 are formed. In addition, the peripheral region 23 is a region located around the hole region 22.

[0089] Figure 1 FIG. 2 shows a top view of the second surface 20b side of the metal mask 20 according to one embodiment of the present disclosure. Figure 1 As shown, the metal mask 20 may have a substantially rectangular outline in a plan view. In addition, in the present disclosure, “plan view” means observing the metal mask 20 from a plane along the plate surface of the metal mask 20 .

[0090] In the metal mask 20 of the present disclosure, one porous region 22 may also be configured to correspond to one organic EL display device. Figure 1As shown in FIG. 2 , the metal mask 20 may include a plurality of perforated regions 22 arranged in a row at predetermined intervals along the longitudinal direction D2. Figure 1 In the embodiment, the peripheral region 23 is located around each of the perforated regions 22. By using such a metal mask 20, a plurality of organic EL display devices can be deposited on the substrate 92.

[0091] The material constituting the metal mask 20 is not particularly limited, and examples thereof include iron alloys containing nickel, iron alloys containing chromium such as stainless steel, nickel, and nickel-cobalt alloys.

[0092] Among them, an iron alloy containing nickel is preferred. 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 or the thermal expansion coefficient of the substrate 92 (see Figure 6 ). Thus, during the vapor deposition process, it is possible to suppress the occurrence of positional deviation due to the difference in the size changes of the metal mask 20, the frame 15, and the substrate 92. Therefore, it is possible to suppress the reduction in the dimensional accuracy or positional accuracy of the vapor deposition material 98 attached to the substrate 92 caused by the positional deviation.

[0093] There is no particular limitation on the nickel-containing iron alloy, and examples thereof include: a super Invar alloy material containing cobalt in addition to 30% by mass to 34% by mass of nickel; an Invar alloy material containing 34% by mass to 38% by mass of nickel; a low thermal expansion Fe-Ni plated alloy containing 48% by mass to 54% by mass of nickel; and an iron alloy containing 0% by mass to 54% by mass of nickel.

[0094] Next, the surfaces of the metal mask 20 of the present disclosure will be described. The metal mask 20 of the present disclosure has a first surface 20a and a second surface 20b as the front surface and the back surface.

[0095] In the present disclosure, the first surface 20a and the second surface 20b of the metal mask 20 are distinguished by the diameter of the through hole 25 on the front and back surfaces of the hole area 22. Specifically, Figure 3A , Figure 3B As shown in FIG. 1 , the first surface 20a refers to a surface where the opening area of ​​the through hole 25 is smaller in the hole region 22, and the second surface 20b refers to a surface where the range S3 of the through hole 25 is larger. Figure 3E As shown in the figure, in the second surface 20b, when the second wall surfaces 36 of the second recessed portions 35 of the adjacent through holes 25 merge, the range S3 enclosed by the ridgeline 33 surrounding one through hole 25 can also be regarded as the opening of the through hole 25. In this case, the range enclosed by the ridgeline 33 becomes the opening area.

[0096] In addition, from the perspective of the vapor deposition process, the first surface 20a may be a surface of the metal mask 20 that faces the substrate 92 when the metal mask device 10 is accommodated in the vapor deposition device 90 (see Figure 6 ). In addition, the second surface 20b may be a surface of the metal mask 20 located on the side of the crucible 94 holding the evaporation material 98 when the metal mask device 10 is accommodated in the evaporation device 90 (see Figure 6 ).

[0097] Next, the pattern of the vapor-deposited layer 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 vapor-deposited layer will be described.

[0098] exist Figure 2A 1 is a top view showing an example of the shape, size, and position of the pattern of the vapor-deposited layer attached to the substrate 92. Figure 2A In the figure, rectangles with RGB characters are respectively vapor-deposited layers of different colors, red R, green G, and blue B. When different types of vapor-deposited materials 98 are vapor-deposited according to pixels such as RGB, different metal masks 20 can be used according to the types of vapor-deposited materials 98, and the vapor-deposited materials 98 can be formed into films on the surface of the substrate 92. For example, the vapor-deposited material 98 for red, the vapor-deposited material 98 for green, and the vapor-deposited material 98 for blue can be vapor-deposited on the substrate 92 in sequence. In addition, the metal mask 20 (metal mask device 10) and the substrate 92 can be relatively moved little by little along the arrangement direction of the through holes 25 (one of the aforementioned directions), and the vapor-deposited material 98 for red, the vapor-deposited material 98 for green, and the vapor-deposited material 98 for blue can be vapor-deposited in sequence.

[0099] In addition, if Figure 2A As shown in FIG. 1 , when the pattern of the deposition material 98 is different depending on the type of the deposition material 98, a metal mask 20 having a different pattern of through holes 25 can be used depending on the type of the deposition material 98. Figure 2A The same metal mask 20 may be used when the pattern of the deposition material 98 is the same regardless of the color, such as red R and blue B. In this case, by moving the metal mask 20 and the substrate 92 relative to each other, the deposition materials 98 of different colors can be deposited in the same pattern.

[0100] Figure 2B to Figure 2D Shown is the Figure 2A The pattern of the vapor deposition layer shown is a formation pattern of the through holes 25 in the perforated region 22 of the metal mask 20 . Figure 2B to Figure 2D Each of the figures shows the perforated region 22 as viewed from the first surface 20 a side. Figure 2B to Figure 2D The solid line in represents the connection portion 41 of the through holes 25a, 25b, and 25c. Figure 2B to Figure 2DThe dotted lines in 0 are used as references to indicate the positions of other vapor-deposited layers formed by other metal masks. That is, the dotted line portion is the first surface 20a of the metal plate where no through-holes actually exist.

[0101] In addition, the through holes 25 penetrate from the first surface 20a to the second surface 20b of the metal mask 20 in the thickness direction N. In the evaporation process, the evaporation material 98 is attached to the substrate 92 through the through holes 25. That is, each through hole 25 defines a portion where the evaporation material is attached to the substrate 92. The pattern of the through holes 25 in the perforated region 22 corresponds to the pattern for attaching the evaporation material 98.

[0102] Figure 2B FIG. 2 shows a metal mask 20 having through holes 25a through which a blue vapor deposition material 98 passes. Figure 2B In the example shown, the through hole 25a has a substantially square connection portion 41 in a plan view. In addition, the through holes 25a are arranged in two predetermined directions with the portion (rectangular dotted line) of the vapor-deposited layer forming the green G sandwiched therebetween. The connection portion 41 of the through hole 25a has a linear portion 41a and a corner portion 41b. Figure 2B In the figure, the connection portion 41 of the through hole 25a is represented by a quadrilateral close to a substantially square, but the present invention is not limited thereto. The connection portion 41 of the through hole 25a may be a polygon such as a triangle, a pentagon, a hexagon, or an octagon.

[0103] In addition, in the present disclosure, a "corner" is the corner of a polygon formed by the connecting portion 41, and is the intersection of two linear portions 41a extending in different directions. Regarding the corner 41b, in addition to an angular shape, it also includes a shape with an arc having a specified radius of curvature. The radius of curvature of the corner 41b is preferably greater than 1 μm and less than 40 μm. The radius of curvature of the corner 41b is preferably less than 40 μm, less than 30 μm, less than 20 μm, and less than 15 μm. In addition, the radius of curvature of the corner 41b is preferably greater than 1 μm, greater than 3 μm, and greater than 5 μm.

[0104] In addition, in the present disclosure, the "linear portion" is the side of the polygon formed by the connecting portion 41, which connects the adjacent corner portions 41b. Regarding the linear portion 41a, in addition to the straight line, it also includes a line with an arc having a curvature radius greater than a specified value. The curvature radius of the linear portion 41a is preferably greater than 100 μm, greater than 200 μm, or greater than 300 μm. In addition, the linear portion 41a includes a straight line, and the upper limit of the curvature radius is not particularly limited, and can be less than 10000 μm.

[0105] Figure 2C FIG. 2 shows a metal mask 20 having through holes 25b through which a green vapor deposition material 98 passes. Figure 2CIn the example shown, the through hole 25b has a substantially rectangular connection portion 41 in a plan view. Figure 2C In the figure, the through holes 25b are arranged in the short axis direction sandwiching the portion of the vapor deposition layer forming blue B (the dotted line of the square), and are also arranged in the long axis direction sandwiching the portion of the vapor deposition layer forming red R (the dotted line of the square).

[0106] The connecting portion 41 of the through hole 25b has a linear portion 41a and a corner portion 41b. Figure 2C As shown, 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 also have such a relationship that a distance h21 from the first surface 20a to the first linear portion 41a1 in the thickness direction is greater than a distance h22 from the first surface 20a to the second linear portion 41a2 in the thickness direction. This will be described in detail later.

[0107] In such Figure 2C When the connecting portion 41 of the through hole 25b is roughly rectangular as shown, the short side becomes the first linear portion 41a1, and the long side becomes the second linear portion 41a2. In addition, without limitation thereto, the connecting portion 41 of the through hole 25b may also be a polygon such as a triangle, a pentagon, a hexagon, an octagon, etc. When the connecting portion 41 of the through hole 25b has these polygons, the connecting portion 41 may include more than three linear portions 41a of different lengths. In this case, two linear portions 41a arbitrarily selected from the three or more linear portions 41a can also be identified as the first linear portion 41a1 and the second linear portion 41a2 according to their lengths. Moreover, the arbitrarily selected first linear portion 41a1 and the second linear portion 41a2 preferably have a relationship in which the distance h21 is greater than the distance h22. In other words, in the polygonal linear portion 41 a , the longer the length of the linear portion 41 a is, the smaller the distance from the first surface 20 a to the linear portion 41 a in the thickness direction may be.

[0108] Figure 2D The metal mask 20 having the through hole 25c through which the vapor deposition material 98 for red passes is shown. Figure 2D In the example shown, Figure 2B Similarly, the through hole 25c has a substantially square connection portion 41 when viewed from above. In addition, the through holes 25c are arranged in two predetermined directions with the portion of the vapor-deposited layer forming the green G (rectangular dotted line) sandwiched therebetween. The connection portion 41 of the through hole 25c has a linear portion 41a and a corner portion 41b. Figure 2DIn the figure, the connection portion 41 of the through hole 25c is represented by a quadrilateral close to a substantially square, but the present invention is not limited thereto. The connection portion 41 of the through hole 25c may be a polygon such as a triangle, a pentagon, a hexagon, or an octagon.

[0109] in addition, Figure 2D The pattern of the through holes 25 of the metal mask shown is similar to Figure 2B The pattern of the through holes 25 of the metal mask shown in FIG. Figure 2B The metal mask shown as Figure 2D The metal mask shown is used, and the metal mask 20 and the substrate 92 are relatively moved, thereby allowing the vapor deposition materials 98 of different colors to be attached in the same pattern.

[0110] The through hole 25 may also be Figure 2B to Figure 2D A desired pattern other than the illustrated pattern is formed. For example, the through holes 25 may be arranged in a grid shape at a predetermined pitch along two directions intersecting each other. In addition, the through holes 25 may be arranged in a staggered shape at a predetermined pitch along two directions intersecting each other.

[0111] The above two directions may also be consistent with the length direction D2 or the width direction D1 of the metal mask 20. The pitch of the through holes 25 in the perforated area 22 is not particularly limited. For example, when the metal mask 20 is used to make a display (about 0.5 inches or more and 32 inches or less) of a mobile phone, a digital camera, etc., the pitch of the through holes 25 in the width direction D1 and the length direction D2 may be about 20 μm or more and 254 μm or less, respectively.

[0112] As described above, the perforated region 22 of the metal mask 20 has a plurality of through holes 25 in an arbitrary shape and an arbitrary pattern. Next, the shape of the through holes 25 in the perforated region 22 will be described in more detail.

[0113] Figure 3A An example of a three-dimensional view of the hole region 22 viewed from the second surface 20b side is shown. Figure 3B Shows the Figure 3A The through hole 25 is shown in an enlarged perspective view. Figure 3C Shows Figure 3B The cross-sectional view of the through hole 25 taken along the AA' section is shown. Figure 3D Shows Figure 3B A cross-sectional view of a through hole 25 taken along the line BB′ is shown.

[0114] like Figure 3A and Figure 3BAs shown in the figure, the through hole 25 has a first recessed portion 30 formed on the first surface 20a, a second recessed portion 35 formed on the second surface 20b, and a circumferential connecting portion 41 connecting the first recessed portion 30 and the second recessed portion 35. The through hole 25 is formed by connecting the first recessed portion 30 on the first surface 20a side and the second recessed portion 35 on the second surface 20b side. Moreover, the portion where the first recessed portion 30 and the second recessed portion 35 are connected is the connecting portion 41. The first wall surface 31 of the first recessed portion 30 and the second wall surface 36 of the second recessed portion 35 are connected via the circumferential connecting portion 41.

[0115] The area of ​​the first recessed portion 30 when viewed from above may also gradually decrease from the first surface 20a toward the second surface 20b. In addition, the area of ​​the second recessed portion 35 when viewed from above may also gradually decrease from the second surface 20b toward the first surface 20a. In addition, the first recessed portion 30 may also be configured as a recessed portion having a smaller diameter than the second recessed portion 35.

[0116] In addition, in the connection portion 41, the expansion direction of the wall surface of the through hole 25 changes discontinuously. Usually, in the connection portion 41, the opening area of ​​the through hole 25 when viewed from above is the smallest. Here, from the viewpoint of suppressing shadows, it is preferred that the distance h from the first surface 20a to the connection portion 41 in the thickness direction N is small.

[0117] Shadow refers to a phenomenon in which a portion of the vapor deposition material 98 that reaches the metal mask 20 from the vapor 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, thereby the area or thickness of the layer of the vapor deposition material 98 on the substrate 92 becomes insufficient. In particular, the connection portion 41 is the portion where the opening area of ​​the through hole 25 becomes the smallest when viewed from above. Therefore, the closer the connection portion 41 is to the substrate 92, the easier it is for the vapor deposition material 98 to reach the substrate 92 in the same shape as the connection portion 41, and the less likely it is to generate a shadow. On the other hand, the farther the connection portion 41 is from the substrate 92, the more the vapor deposition material 98 is blocked by the second wall surface 36 at a position farther from the substrate. Therefore, the area or thickness of the layer of the vapor deposition material 98 that reaches the substrate 92 is likely to be insufficient, and there is a tendency that shadows are likely to be generated.

[0118] Therefore, from the perspective of suppressing shadows, it is preferred to reduce the distance h as a whole. However, if the distance h is reduced as a whole, the mechanical strength of the metal mask is reduced, and the metal mask is easily deformed, broken, etc. In addition, in order to reduce the distance h, a solution of further increasing the first recess 30 can be cited, but it is difficult to perform such etching accurately. Therefore, the shape of the through hole may be deviated.

[0119] However, in order to reduce the distance h, it is also possible to etch only from one side to form the through hole 25. However, in this case, the deviation of the shape and size of the through hole 25 becomes larger. Therefore, in the second surface etching process described later, the corner 41b of the connecting portion 41 makes h1 slightly larger, so that h21 or h22 of the linear portion 41a is close to 0. If the corner 41b of the connecting portion 41 is to make h1 close to 0, the shape accuracy of the linear portion 41a is reduced. Therefore, by slightly increasing h1, h21 or h22 can be made close to 0 while maintaining the shape accuracy of the linear portion 41a. Thus, the shape accuracy of the linear portion 41a of the connecting portion 41 can be improved. Specifically, the linearity of the linear portion 41a can be improved. In addition, in the evaluation of the linearity of the linear portion 41a, the through hole 25 is photographed from the thickness direction of the metal mask 20 using a scanning electron microscope, thereby photographing the shape of the connecting portion 41 when viewed from above. Furthermore, when the linear portion 41a is bent toward the outside or inside of the through hole 25, the distance (μm) between the straight line connecting the two ends of the linear portion 41a and the top of the peak of the bending of the linear portion 41a is measured. This distance is also referred to as "straightness" in this specification. As a scanning electron microscope, for example, a scanning electron microscope ULTRA55 manufactured by ZEISS can be used.

[0120] In contrast, in the present disclosure, the distance h in the thickness direction from the first surface 20a to the connecting portion 41 is made different 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 connecting portion 41 at the corner 41b is longer than the minimum distance h2 in the thickness direction N from the first surface 20a to the connecting portion 41 at the linear portion 41a.

[0121] Here, the maximum distance h1 is a distance at which the distance h becomes the largest in the corner 41b. When there are a plurality of corners 41b, the maximum distance h in all the corners 41b becomes the maximum distance h1.

[0122] In addition, the minimum distance h2 refers to the distance at which the distance h becomes the minimum in the linear portion 41a. When there are multiple linear portions 41a, the minimum distance h among all the linear portions 41a is the minimum distance h2. For example, when there are distances h21 and h22 for each linear portion 41a of different lengths, the minimum value is the minimum distance h2.

[0123] Thus, 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 there is no need to make the corner portion protruding, the shape uniformity of the through hole is also excellent.

[0124] In addition, for the same reason, the maximum distance h2 ′ in the thickness direction N from the first surface 20 a to the connecting portion 41 in the linear portion 41 a is preferably smaller than the maximum distance h1 .

[0125] Furthermore, in Figure 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 as shown, the distance h21 from the first surface 20a to the first linear portion 41a1 in the thickness direction and the distance h22 from the first surface 20a to the second linear portion 41a2 in the thickness direction may be the same, the distance h21 may be longer than the distance h22, or the distance h21 may be shorter than the distance h22. Preferably, the distance h21 is longer than the distance h22. Thus, the distance h22 of the longer portion (the second linear portion 41a2) in the linear portion 41a is shorter, so there is a tendency for the shadow to be further suppressed. In addition, the distance h21 and the distance h22 may be set to the same degree, but by increasing the distance h21, there is a tendency for the mechanical strength of the metal mask to be further improved. From such a viewpoint, the distance h1, the distance h21, and the distance h22 are preferably configured to satisfy the relationship of h1>h21>h22.

[0126] In addition, in Figure 2C When the linear portion 41a has a relatively short first linear portion 41a1 and a relatively long second linear portion 41a2 as shown, the minimum distance h2 in the linear portion 41a is the distance h22. This is also the case when the linear portion 41a includes three or more linear portions 41a of different lengths, and the distance h of the multiple linear portions 41a with the shortest distance h is set as the minimum distance h2.

[0127] The formation of such a through hole 25 can also be adjusted by the etching conditions when forming the first recessed portion 30 and the second recessed portion 35 and the mask shape of the photoresist used.

[0128] The maximum distance h1 is preferably greater than 0.6 μm and less than 8.0 μm, greater than 0.8 μm and less than 6.0 μm, and greater than 1.0 μm and less than 4.0 μm. In addition, the maximum distance h1 is preferably greater than 0.6 μm, greater than 0.8 μm, greater than 1.0 μm, and greater than 1.2 μm. Furthermore, the maximum distance h1 is preferably less than 8.0 μm, less than 6.0 μm, less than 4.0 μm, less than 3.0 μm, and less than 2.0 μm. In addition, the range of the maximum distance h1 can also 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.

[0129] When the maximum distance h1 is 0.6 μm or more, the mechanical strength of the metal mask tends to be further improved. When the maximum distance h1 is 8.0 μm or less, shadows tend to be further suppressed.

[0130] The minimum distance h2 is preferably greater than 0.06 μm and less than 4.0 μm, greater than 0.08 μm and less than 3.0 μm, greater than 0.10 μm and less than 2.0 μm. In addition, the minimum distance h2 is preferably greater than 0.06 μm, greater than 0.08 μm, greater than 0.10 μm, greater than 0.25 μm, and greater than 0.50 μm. Furthermore, the minimum distance h2 is preferably less than 4.0 μm, less than 3.0 μm, less than 2.0 μm, less than 1.5 μm, and less than 1.0 μm. In addition, the range of the minimum distance h2 can also 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.

[0131] When the minimum distance h2 is 0.06 μm or more, the mechanical strength of the vapor deposition mask tends to be further improved. When the minimum distance h2 is 4.0 μm or less, shadows tend to be further suppressed.

[0132] 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. In addition, 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. Furthermore, 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. In addition, the range of the ratio (h1 / h2) may also be determined by a combination of any one of the candidate values ​​of the multiple lower limits and any one of the candidate values ​​of the multiple upper limits.

[0133] When the ratio (h1 / h2) is 1.1 or more, the shape accuracy of the linear portion tends to be further improved. When the ratio (h1 / h2) is 50 or less, shadows tend to be further suppressed.

[0134] The thickness H from the first surface 20a to the second surface 20b is preferably 50 μm or less, and may be 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less. By reducing the thickness H, the porous region 22 can be made thinner by etching or the like, and there is a tendency that the deposition material 98 can be suppressed from adhering to the second wall surface 36 of the second recess 35 during the deposition process.

[0135] The thickness H is preferably 5 μm or more, and may be 10 μm or more, or 15 μm or more. By increasing the thickness H, the strength of the metal mask 20 tends to be further improved. This tends to further suppress deformation and breakage of the porous region 22, for example.

[0136] The ratio (h1 / H) of the maximum distance h1 to the thickness H is preferably greater than 0.010 and less than 0.40, greater than 0.015 and less than 0.30, and greater than 0.020 and less than 0.20. In addition, the ratio (h1 / H) is preferably greater than 0.010, greater than 0.015, greater than 0.020, and greater than 0.025. Furthermore, the ratio (h1 / H) is preferably less than 0.40, less than 0.30, less than 0.20, and less than 0.15. In addition, the range of the ratio (h1 / H) can also 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.

[0137] When the ratio (h1 / H) is 0.010 or more, the mechanical strength of the metal mask tends to be further improved. When the ratio (h1 / H) is 0.40 or less, shadows tend to be further suppressed.

[0138] The ratio (h2 / H) of the minimum distance h2 to the thickness H is preferably greater than 0.001 and less than 0.20, greater than 0.002 and less than 0.10, and greater than 0.004 and less than 0.080. In addition, the ratio (h2 / H) is preferably greater than 0.001, greater than 0.002, greater than 0.003, and greater than 0.004. Furthermore, the ratio (h2 / H) is preferably less than 0.20, less than 0.10, less than 0.080, and less than 0.060. In addition, the range of the ratio (h2 / H) can also 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.

[0139] When the ratio (h2 / H) is 0.001 or more, the mechanical strength of the metal mask tends to be further improved. When the ratio (h2 / H) is 0.20 or less, shadows tend to be further suppressed.

[0140] Furthermore, the ratio (h21 / h22) of the distance h21 to the distance h22 when there are distances h21 and h22 is preferably greater than 1.00 and less than 10, greater than 1.03 and less than 8.0, greater than 1.05 and less than 6.0, greater than 1.07 and less than 4.0. In addition, the ratio (h21 / h22) is preferably greater than 1.00, greater than 1.05, greater than 1.1, greater than 1.2, and greater than 1.3. Furthermore, the ratio (h21 / h22) is preferably less than 10, less than 8.0, less than 6.0, less than 4.0, and less than 2.0. In addition, the range of the ratio (h21 / h22) can also 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.

[0141] like Figure 3A As shown, in the present disclosure, the edge of the first recess 30 is referred to as a ridgeline 33. The ridgeline 33 is a portion that divides adjacent through-holes 25. In other words, each through-hole 25 is surrounded by the ridgeline 33. Figure 3A In the embodiment, adjacent through holes 25 are separated by a certain distance or more, and unetched second surfaces 20b remain between adjacent second recesses 35. Figure 3A In the embodiment, the remaining portion of the second surface 20b becomes the ridgeline 33 that divides the adjacent through holes 25. In addition, in this case, the ridgeline 33 may also be the first surface 51a of the metal plate 51 remaining between the adjacent first recesses 30. In this case, the height of the ridgeline 33 may also be fixed.

[0142] in addition, Figure 3E Another example of a stereoscopic view of the perforated region 22 as viewed from the second surface 20b side is shown. Figure 3E In the embodiment, the distance between adjacent through holes 25 is relatively short. Therefore, the second wall surfaces 36 of adjacent second recesses 35 are merged by etching, and the ridge line 33 is formed by the merged second wall surfaces 36. Figure 3E In this embodiment, the second surface 51 b of the metal plate 51 constituting the metal mask 20 does not remain between the adjacent second recessed portions 35 .

[0143] like Figure 3E As shown, the height of the ridgeline 33 formed by the converging second wall surface 36 may not be fixed but may vary according to the distance from the center of the through hole 25. For example, the longer the distance from the center of the through hole 25 to the ridgeline 33, the higher the height of the ridgeline 33.

[0144] Such a through hole 25 can also be formed by etching the metal plate 51 in such a manner that the second surface 51b of the metal plate 51 does not remain between adjacent second recesses 35, as in the 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.

[0145] The surrounding region 23 is a region located around the perforated region 22. The surrounding region 23 may be located at a position surrounding the perforated region 22. The surrounding region 23 may be a region supporting the perforated region 22 by being located around the perforated region 22.

[0146] In addition, the surrounding area 23 may also be an area where the evaporation material 98 is not desired to pass through. From this point of view, the surrounding area 23 may also mainly have a non-porous surface without through holes. However, for various purposes, the surrounding area 23 may also have a non-porous surface, and a through hole that is not intended to allow the evaporation material to pass through may be partially provided in the portion other than the non-porous surface. In the present disclosure, a "non-porous surface" refers to a surface that does not have a through hole.

[0147] As described later, the metal mask 20 is fixed to the frame 15 to form the metal mask device 10. The peripheral region 23 may also have an end portion 23a fixed to the frame 15. Figure 1 As shown, when the metal mask 20 is in the shape of an elongated rod, the end portions 23a may be located at both ends in the elongated direction D2. In addition, the end portions 23a may have a U-shaped cutout or the like.

[0148] The end portion 23a may also be configured so that a portion of the metal mask 20 can be cut off after being fixed to the frame 15. Figure 1 As shown, the end portion 23a may be formed integrally with the other surrounding regions 23, or may be formed of a member different from the other surrounding regions. In this case, the end portion may also be joined to the other parts of the surrounding region by welding, for example.

[0149] Finally, a method for manufacturing a metal mask according to an embodiment of the present disclosure will be described.

[0150] The method for manufacturing a metal mask according to an embodiment of the present disclosure includes a preparation step of preparing a metal plate 51 having a first surface 51 a and a second surface 51 b located opposite to the first surface 51 a , and an etching step of forming the metal mask 20 by etching the metal plate 51 .

[0151] In addition, a method of manufacturing the metal mask 20 by etching will be described below, but the metal mask 20 may be formed by etching, may be formed by laser processing, or may be formed by electroforming.

[0152] Main reference Figure 4A to Figure 4E A method for manufacturing the metal mask 20 according to one embodiment of the present disclosure will be described. Figure 4A 2 is a schematic diagram showing a manufacturing apparatus 70 for manufacturing a metal mask 20 using a metal plate 51 together with its processing sequence. Figure 4A , an example of continuously supplying the metal plate 51 from the resist film forming device 71 to the stripping device 74 is shown. However, the manufacturing method of the metal mask 20 disclosed in the present invention is not limited to this, and for example, the metal plate 51 may be wound up to form a wound body each time it passes through the processing of each device. In addition, when the metal plate 51 is supplied to each device, it may be supplied by unwinding the metal plate 51 from the wound body.

[0153] Hereinafter, each step of the method for manufacturing the metal mask 20 will be described in detail.

[0154] First, a metal plate 51 having a desired thickness is prepared (preparation step). The metal plate 51 may be in the form of a winding body 50 wound around a core 52. There are no particular limitations on the method for producing the metal plate 51 having a desired thickness, and examples thereof include rolling, plating film forming, and the like.

[0155] Next, using the resist film forming apparatus 71, resist films 53a and 53b are formed on the first surface 51a and the second surface 51b of the metal plate 51 ( Figure 4B Specifically, the resist films 53a and 53b may be formed by pasting a dry film resist on the first surface 51a and the second surface 51b. In addition, the resist films 53a and 53b may be formed by applying a coating liquid containing a photosensitive resist material on the first surface 51a and the second surface 51b and drying the coating liquid.

[0156] There is no particular limitation on the dry film resist or the coating liquid, and conventionally known materials can be used. In addition, the resist films 53a and 53b formed in this way can be negative resists or positive resists. Among them, negative resists are preferably used.

[0157] The thickness of the resist films 53a and 53b is preferably 15 μm or less, and may be 10 μm or less, 6 μm or less, or 4 μm or less. In addition, the thickness of the resist films 53a and 53b is preferably 1 μm or more, and may be 3 μm or more, 5 μm or more, or 7 μm or more. The range of the thickness of the resist films 53a and 53b may also be determined by a combination of any one of the candidate values ​​of the plurality of upper limits and any one of the candidate values ​​of the plurality of lower limits.

[0158] Next, the resist films 53a and 53b are exposed and developed using the exposure and development device 72. Figure 4CAs shown, a first resist pattern 53c can be formed on the first surface 51a, and a second resist pattern 53d can be formed on the second surface 51b. For example, when a negative resist film is used, a photomask that prevents light from penetrating the region to be removed in the resist film can be arranged on the resist film, and the resist film can be exposed through the photomask, and then the resist film can be developed.

[0159] Next, the metal plate 51 is etched using the first resist pattern 53c and the second resist pattern 53d as masks using the etching device 73 (etching step). The etching step may include a first surface etching step and a second surface etching step.

[0160] Figure 4D A schematic diagram showing an example of the first surface etching process in the porous region 22 is shown. In the first surface etching process, an etching liquid is used to etch the area of ​​the first surface 51a that is not covered by the first resist pattern 53c. At this time, the second surface 51b may also be covered with a resin or the like that is resistant to the etching liquid.

[0161] The etching liquid causes the first surface 51a not covered by the first resist pattern 53c to be eroded ( Figure 4D ). Thus, a plurality of first recesses 30 are formed on the first surface 51a. In addition, the etching of the metal plate 51 can be performed isotropically from the hole of the resist pattern toward various directions. Therefore, the cross-sectional areas of the first recesses 30 and the second recesses 35 at various positions along the thickness direction of the metal mask 20 are gradually reduced as they proceed in the thickness direction from the surface.

[0162] exist Figure 4E 2 shows a schematic diagram showing an example of the second surface etching process in the porous region 22. In the second surface etching process, an etching liquid is used to etch the area of ​​the second surface 51b that is not covered by the second resist pattern 53d. At this time, the film or the like covering the second surface 51b in the first surface etching process may be peeled off in advance. In addition, the first surface 51a may also be covered with a resin 54 or the like that is resistant to the etching liquid.

[0163] The etching liquid causes the second surface 51b not covered by the second resist pattern 53d to be eroded ( Figure 4E ). Thus, the second recess 35 is formed on the second surface 51b. Furthermore, the first recess 30 and the second recess 35 are communicated with each other, thereby forming the through hole 25.

[0164] The etching liquid is not particularly limited as long as it is a conventionally known etching liquid, and examples thereof include an etching liquid containing a ferric chloride solution and hydrochloric acid.

[0165] In the second side etching process, if Figure 4EAs shown in the figure, etching may be performed until adjacent second recesses 35 are connected. At the portion where adjacent second recesses 35 are connected, adjacent second recesses 35 merge to form a ridge 33. In addition, the ridge 33 is separated from the second resist pattern 53d, and at the top of the ridge 33, erosion by etching also proceeds in the thickness direction of the metal plate 51. Thus, the second resist pattern 53d is peeled off from the metal plate 51. In addition, the second surface 51b may be partially left between adjacent second recesses 35.

[0166] Furthermore, the resin 54 or the like resistant to the resist pattern or the etching solution is peeled off from the metal plate 51 using the peeling device 74. Then, a separation step is performed in which the long metal plate 51 is cut using the separating device 75, thereby separating the metal mask 20 composed of a single metal plate from the metal plate 51. In this way, the metal mask 20 can be obtained.

[0167] The metal mask device 10 according to one embodiment of the present disclosure includes a frame 15 and the metal mask 20 provided on the frame 15. The metal mask 20 may be provided on the frame 15 so that the second surface 20b contacts the frame 15. Figure 5 2 shows a top view of the metal mask device 10 viewed from the first surface 20a side of the metal mask 20. Figure 6 A cross-sectional view showing a vapor deposition device is shown in FIG.

[0168] The metal mask device 10 of the present disclosure can also install multiple metal masks 20 ( Figure 5 In this case, the plurality of metal masks 20 may be arranged in the width direction D1 intersecting the length direction D2 of the metal mask 20. In addition, each metal mask 20 may be fixed to the frame 15 at both ends 23a of the metal mask 20 in the length direction D2.

[0169] The method of fixing to the frame 15 is not particularly limited, and examples thereof include welding and the like.

[0170] The metal mask device 10 may also include a component that is fixed to the frame 15 and partially overlaps with the metal mask 20 in the thickness direction of the metal mask 20. Examples of such a component are not particularly limited, and examples thereof include a component that extends in a direction intersecting the length direction of the metal mask 20 and supports the metal mask 20, and a component that overlaps with a gap between two adjacent metal masks.

[0171] Next, refer to Figure 6 A method of manufacturing an organic EL display device using the metal mask 20 of the present disclosure will be described. The organic EL display device may include a substrate 92 and a vapor deposition layer including a vapor deposition material 98 provided in a pattern in a stacked state.

[0172] The method for manufacturing the organic EL display device according to one embodiment of the present disclosure is not particularly limited, and includes, for example, a vapor deposition step of vapor-depositing the vapor deposition material 98 onto a substrate such as the substrate 92 using the metal mask 20 .

[0173] In the vapor deposition process, first, the metal mask device 10 is arranged so that the metal mask 20 and the substrate 92 face each other. Figure 6 As shown in FIG. 1 , the first surface 20a of the metal mask 20 may be opposed to the substrate 92. Here, the substrate 92 is a vapor deposition object such as a glass substrate.

[0174] like Figure 6 As shown, when the metal mask device 10 is housed in the evaporation 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 evaporation material 98 is the second surface 20b. In the evaporation device 90, the metal mask 20 is arranged on the surface of the substrate 92 on the crucible 94 side. Here, the metal mask 20 and the substrate 92 can also be closely attached by magnetic force.

[0175] In the evaporation device 90, a crucible 94 for storing the evaporation material 98 and a heater 96 for heating the crucible 94 may be arranged below the metal mask device 10. Here, as an example, the evaporation material 98 may also be an organic light-emitting material. The evaporation material 98 in the crucible 94 is vaporized or sublimated by the heating from the heater 96. The vaporized or sublimated evaporation material 98 is attached to the substrate 92 through the through hole 25 of the metal mask 20. Thus, the evaporation material 98 is formed on the surface of the substrate 92 in a desired pattern corresponding to the position of the through hole 25 of the metal mask 20. In addition, in the evaporation process, the interior of the evaporation device 90 may also be a vacuum atmosphere.

[0176] When different types of deposition materials are to be deposited according to pixels such as RGB, different metal masks 20 may be used according to the colors of the deposition materials 98 and the deposition materials 98 may be formed into films on the surface of the substrate 92. For example, the deposition materials 98 for red, the deposition materials 98 for green, and the deposition materials 98 for blue may be sequentially deposited on the substrate 92. In addition, the metal mask 20 (metal mask device 10) and the substrate 92 may be relatively moved little by little along the arrangement direction of the through holes 25 (the aforementioned one direction), and the deposition materials 98 for red, the deposition materials 98 for green, and the deposition materials 98 for blue may be sequentially deposited.

[0177] In addition, the method for manufacturing an organic EL display device may include various steps in addition to the vapor deposition step of vapor-depositing the vapor deposition material 98 on a substrate such as a substrate 92 using a metal mask 20. For example, the method for manufacturing an organic EL display device may include a step of forming a first electrode on a substrate. The vapor deposition layer is formed on the first electrode. In addition, the method for manufacturing an organic EL display device may include a step of forming a second electrode on the vapor deposition layer. In addition, the method for manufacturing an organic EL display device may include a sealing step of sealing the first electrode, the vapor deposition layer, and the second electrode provided on the substrate 92.

[0178] The vapor deposition layer formed on the substrate 92 or the like using the metal mask 20 is not limited to the light-emitting layer formed by vapor deposition of the above-mentioned organic light-emitting material, but may also include other layers. For example, the vapor deposition layer may include a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. in order from the first electrode side. In this case, the vapor deposition process using the metal mask 20 corresponding to each layer may also be implemented separately.

[0179] In addition, various changes can be made to the above-mentioned embodiment. Below, the modified example is described with reference to the accompanying drawings as needed. In the following description and the accompanying drawings used in the following description, for the parts that can be constructed in the same way as the above-mentioned embodiment, the same reference numerals as those used for the corresponding parts in the above-mentioned embodiment are used, and repeated descriptions are omitted. In addition, in the case where it is obvious that the effects obtained in the above-mentioned embodiment can also be obtained in the modified example, its description is sometimes omitted.

[0180] [Example]

[0181] Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples. The present invention is not limited to the following Examples at all.

[0182] (Example)

[0183] By the above-mentioned method for manufacturing a metal mask, a metal mask having a through hole consisting of a first recess and a second recess and a third recess on a metal plate is manufactured. At this time, the maximum distance h1 at the corner and the minimum distance h2 at the linear portion have a prescribed relationship. In addition, the metal plate as the raw material of the metal mask is an Invar alloy material. Example A shows a method in which the through hole is roughly square when viewed from above, and Example B shows a method in which the through hole is roughly rectangular when viewed from above.

[0184] (Comparative Example)

[0185] A metal mask was obtained in the same manner as in Example except that the maximum distance h1 at the corner and the minimum distance h2 at the linear portion had the prescribed relationship described 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.

[0186] (Shape evaluation of connection portion)

[0187] In the linear portion of the connection, the straightness was evaluated as OK if it was within ±2 μm, and NG if it was beyond ±2 μm. The straightness was measured by photographing the connection using a scanning electron microscope (ULTRA55 manufactured by ZEISS).

[0188] Specifically, the “straightness” is measured by photographing the shape of the connecting portion 41 when viewed from above using a scanning electron microscope, and taking the distance (μm) between the straight line connecting the two ends of the linear portion 41a and the apex of the peak of the curve of the linear portion 41a as the straightness. The straight line connecting the two ends of the linear portion 41a is set to “0μm” when it coincides with the linear portion 41a, the linear portion 41a is set to “+” when it curves toward the outside of the through hole 25, and the linear portion 41a is set to “-” when it curves toward the inside of the through hole 25.

[0189] (Shadow Evaluation)

[0190] Next, a vapor deposition process was performed to form a vapor deposition layer by attaching the vapor deposition material to the substrate using a metal mask. As the vapor deposition material, tris(8-hydroxyquinoline)aluminum, which is an organic light-emitting material, was used. As the substrate, a glass substrate was used. The conditions of the vapor deposition process were set so that the thickness of the vapor deposition layer would be 40 nm.

[0191] Next, the deposited layer on the substrate was observed using an optical microscope DMRXHXDC300F manufactured by LEICA and a scanning white interference microscope Bird Scan manufactured by Hitachi High-Tech Technologies. The area ratio V of the deposited layer was calculated based on the observation results. The area ratio V of the deposited layer is the ratio (V2 / V1) of the effective area V2 of the deposited layer to the area V1 of the through hole.

[0192] The effective area V2 is the area of ​​the region of the vapor deposition 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 vapor deposition layer having a thickness of 38 nm or more.

[0193] For each of the 30 deposited layers on the substrate, the area ratio V was calculated. Among all of the 30 deposited layers on the substrate, if the area ratio V was 0.70 or more, it was evaluated as "OK", and if at least one of the deposited layers had an area ratio V less than 0.70, it was evaluated as "NG".

[0194] [Table 1]

[0195]

[0196] [Table 2]

[0197]

[0198] ※The distance h22 is adopted as the minimum distance h2.

[0199] Industrial Applicability

[0200] The metal mask of the present invention has industrial applicability as a metal mask used in the production of an organic EL display device, etc.

[0201] Description of symbols

[0202] 10…Metal mask device;

[0203] 15…frame;

[0204] 20…metal mask;

[0205] 20a...Side 1;

[0206] 20b…side 2;

[0207] 22…perforated area;

[0208] 23…surrounding areas;

[0209] 23a…end;

[0210] 25…through hole;

[0211] 25a ... through hole;

[0212] 25b ... through hole;

[0213] 25c ... through hole;

[0214] 30…1st recess;

[0215] 31...1st wall;

[0216] 33… Ridgeline;

[0217] 35…2nd recess;

[0218] 36…2nd wall;

[0219] 41…connecting part;

[0220] 41a…parietal part;

[0221] 41a…first linear part;

[0222] 41a…second linear part;

[0223] 41b…corner;

[0224] 50…winding body;

[0225] 51…Metal plate;

[0226] 51a…Page 1;

[0227] 51b…side 2;

[0228] 52…core;

[0229] 53a ... resist film;

[0230] 53b ... resist film;

[0231] 53c ... a first resist pattern;

[0232] 53d ... a second resist pattern;

[0233] 54…resin;

[0234] 70… manufacturing device;

[0235] 71 ... resist film forming apparatus;

[0236] 72…exposure and developing device;

[0237] 73… Etching device;

[0238] 74 ... stripping device;

[0239] 75…Separation device;

[0240] 90…Evaporation device;

[0241] 92...Substrate;

[0242] 94… Crucible;

[0243] 96…heater;

[0244] 98…evaporation material.

Claims

1. A metal mask, characterized in that: The metal mask has a hole area and a surrounding area, The perforated area has a plurality of through holes, The surrounding area is located around the perforated area, The through hole has: a first recessed portion formed on the first surface; a second recessed portion formed on the second surface; and a circumferential connecting portion connecting the first recessed portion and the second recessed portion. The connecting portion includes a plurality of corner portions and a plurality of linear portions located between adjacent corner portions. The distance h from the first surface to the connecting portion in the thickness direction varies depending on the position. A maximum distance h1 from the first surface to the connecting portion in the thickness direction at the corner portion is longer than a minimum distance h2 from the first surface to the connecting portion in the thickness direction at the linear portion.

2. The metal mask according to claim 1, characterized in that: 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 from the first surface to the first linear portion in the thickness direction is longer than a distance h22 from the first surface to the second linear portion in the thickness direction.

3. The metal mask according to claim 1, characterized in that: The maximum distance h1 is greater than or equal to 0.6 μm and less than or equal to 8.0 μm.

4. The metal mask according to claim 1, characterized in that: The minimum distance h2 is greater than or equal to 0.06 μm and less than or equal to 4.0 μm.

5. The metal mask according to claim 1, characterized in that: A ratio of the maximum distance h1 to the minimum distance h2, that is, h1 / h2, is greater than or equal to 1.1 and less than or equal to 50.

6. The metal mask according to claim 1, characterized in that: A ratio of the maximum distance h1 to the thickness H from the first surface to the second surface, that is, h1 / H, is greater than or equal to 0.010 and less than or equal to 0.

40.

7. The metal mask according to claim 1, characterized in that: A ratio of the minimum distance h2 to the thickness H from the first surface to the second surface, that is, h2 / H, is greater than or equal to 0.001 and less than or equal to 0.

20.

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

Images