Metal mask

Abstract

The utility model provides a metal mask. 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 metal masks. Background Art

[0002] Pixels in organic EL displays are formed by depositing the pixel-forming material onto a substrate using a metal mask. Therefore, improving the performance of the metal mask is crucial for enhancing the image quality of organic EL displays. For example, Patent Document 1 discloses a technique in which the corners of a large opening are designed to protrude outward relative to the edge, with the goal of providing a metal mask capable of suppressing variations in the film thickness of the vapor-deposited pattern.

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

[0004] However, the metal mask described in Patent Document 1 has a polygonal shape with corners extending outward from the polygon. Therefore, it is expected that the deposition material entering the mask holes near the corners of the larger openings will easily reach the smaller openings. However, the metal mask described in Patent Document 1 has a complex opening shape, making it difficult to uniformly form multiple through-holes of complex shapes. Furthermore, there are concerns that the complex shape may affect mechanical strength. Utility Model Content

[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 same.

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

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

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

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

[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 includes:

[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 porous area has a plurality of through holes,

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

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

[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] At least one embodiment of the present disclosure can provide 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 same. 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 through-holes 25 of a metal mask 20 showing a pattern of a vapor-deposited layer.

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

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

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

[0030] Figure 3B It will 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 the through hole taken along the line BB' is shown.

[0033] Figure 3E This is a perspective view showing one embodiment of the perforated region as viewed 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 illustrating a metal mask device according to one embodiment of the present disclosure;

[0040] Figure 6 This is a cross-sectional view showing a vapor deposition device according to one embodiment of the present disclosure. DETAILED DESCRIPTION

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

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

[0043] The terms indicating the substance that forms the basis of a certain structure may not be distinguished simply by the difference in name. For example, the terms "substrate," "base material," "plate," "sheet," or "film" fall within the above description.

[0044] Terms and / or numerical values indicating shape and / or geometric conditions do not need to be strictly defined and can be interpreted as encompassing a range of degrees within which the same function can be expected. For example, "parallel" and / or "orthogonal" fall within the above-mentioned terms. Furthermore, "length values" and / or "angle values" fall within the above-mentioned numerical values.

[0045] When a structure is described as being "above," "below," "upper side," "lower side," "above," or "below" another structure, this also includes the situation where the structure is directly connected to the other structure, as well as the situation where another structure is included between the two structures. In other words, the situation where another structure is included between the two structures can also be described as the structure being indirectly connected to the other structure. Furthermore, expressions such as "above," "upper side," or "above" can be replaced with expressions such as "lower," "lower side," or "below." In other words, the up and down directions can be reversed.

[0046] When identical parts and / or parts having the same function are marked with the same or similar reference numerals, duplicate descriptions may be omitted. In addition, the dimensional ratios in the drawings may differ from the actual ratios. In addition, a portion of the structure of the embodiment may be omitted from the drawings.

[0047] To the extent that no contradiction arises, one or more aspects of the embodiment and one or more aspects of the modified example may be combined. Furthermore, to the extent that no contradiction arises, one or more aspects of the embodiment may be combined with each other. Furthermore, to the extent that no contradiction arises, one or more aspects 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 undisclosed steps may be performed between the disclosed steps. Furthermore, the order of the steps is not limited to the extent that no contradiction occurs.

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

[0050] For the numerical values described in this disclosure, a numerical range can 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 can be defined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of 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. Without particular limitation, for example, the metal mask of the present invention can be used as such a metal mask: it is used to pattern an organic material on a substrate in a desired pattern in the manufacture of an 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. Among the organic EL display devices that can be manufactured, in addition to displays such as smartphones or televisions, devices for displaying or projecting images and videos for expressing virtual reality (VR) and augmented reality (AR) are also included.

[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 manufacturing method thereof is 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 porous area has a plurality of through holes,

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

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

[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] The second aspect of the present disclosure is, in addition to 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 described above.

[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 the metal mask according to 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 porous area has a plurality of through holes,

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

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

[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. 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 hole 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 also 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 hole regions 22. By using such a metal mask 20, a plurality of organic EL display devices can be vapor-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, nickel-containing iron alloy is preferred. By using nickel-containing iron alloy, 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 ). As a result, during the vapor deposition process, positional deviation caused by differences in the dimensions of the metal mask 20, the frame 15, and the substrate 92 can be suppressed. Therefore, a decrease in the dimensional accuracy or positional accuracy of the vapor deposition material 98 attached to the substrate 92 due to positional deviation can be suppressed.

[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 or more and 34% by mass or less of nickel; an Invar alloy material containing 34% by mass or more and 38% by mass or less of nickel; a low thermal expansion Fe-Ni plated alloy containing 48% by mass or more and 54% by mass or less of nickel; and an iron alloy containing 0% by mass or more and 54% by mass or less 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 and back surfaces.

[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 holes 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 is a surface having a smaller opening area of the through hole 25 in the hole region 22, and the second surface 20b is a surface having a larger range S3 of the through hole 25. Figure 3E As shown in FIG. 1 and FIG. 2 , in the second surface 20 b, when the second wall surfaces 36 of the second recesses 35 of adjacent through-holes 25 merge, the area S3 enclosed by the ridge line 33 surrounding one through-hole 25 can also be regarded as the opening of the through-hole 25. In this case, the area enclosed by the ridge line 33 becomes the opening area.

[0096] In addition, from the perspective of the vapor 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 vapor deposition device 90 (see Figure 6 ). In addition, the second surface 20b may be the surface of the metal mask 20 located on the side of the crucible 94 holding the vapor deposition material 98 when the metal mask device 10 is accommodated in the vapor deposition 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 , a top view showing an example of the shape, size, and position of the pattern of the vapor deposition layer attached to the substrate 92 is shown. Figure 2A In the figure, the rectangles with RGB characters are respectively the vapor-deposited layers of different colors of red R, green G, and blue B. When different types of vapor-deposited materials 98 are vapor-deposited according to pixels of RGB, etc., different metal masks 20 can also 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, when the pattern of the deposition material 98 is different depending on the type of the deposition material 98, the metal mask 20 having the through hole 25 pattern different depending on the type of the deposition material 98 can also be used. Figure 2A When the pattern of the deposition material 98 is the same regardless of the color, such as red R and blue B, the same metal mask 20 can be used. 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 for the composition 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 FIG. 1 are used as references to indicate the positions of other vapor-deposited layers formed by other metal masks. That is, the dotted line portion represents the first surface 20a of the metal plate where no through-holes are actually present.

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

[0102] Figure 2B The metal mask 20 having the through hole 25a through which the blue vapor deposition material 98 passes is shown. Figure 2B In the example shown, the through hole 25a has a substantially square connection portion 41 when viewed from above. 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 FIG. 4 , the connection portion 41 of the through hole 25 a 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 25 a 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 the 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 angular shapes, it also includes a shape with an arc having a specified curvature radius. The curvature radius of the corner 41b is preferably greater than 1 μm and less than 40 μm. The curvature radius of the corner 41b is preferably less than 40 μm, less than 30 μm, less than 20 μm, or less than 15 μm. In addition, the curvature radius of the corner 41b is preferably greater than 1 μm, greater than 3 μm, or greater than 5 μm.

[0104] In this disclosure, a "linear portion" is defined as the side of the polygon formed by the connecting portion 41, which connects adjacent corner portions 41b. Linear portion 41a includes not only straight lines but also lines with arcs having a radius of curvature greater than or equal to a specified value. The radius of curvature of linear portion 41a is preferably 100 μm or greater, 200 μm or greater, or 300 μm or greater. Furthermore, when linear portion 41a includes straight lines, the upper limit of the radius of curvature is not particularly limited and may be 10,000 μm or less.

[0105] Figure 2C The metal mask 20 having the through hole 25b through which the green vapor deposition material 98 passes is shown. Figure 2CIn the example shown, the through hole 25b has a substantially rectangular connecting portion 41 in a plan view. Figure 2C In FIG. 2 , 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 includes 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 such that the distance h21 from the first surface 20a to the first linear portion 41a1 in the thickness direction is greater than the 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. Furthermore, without limitation, the connecting portion 41 of the through hole 25b may also be a polygon such as a triangle, pentagon, hexagon, or octagon. When the connecting portion 41 of the through hole 25b has these polygons, the connecting portion 41 may include three or more linear portions 41a of different lengths. In this case, two linear portions 41a arbitrarily selected from the three or more linear portions 41a can be identified as the first linear portion 41a1 and the second linear portion 41a2 based on their lengths. Furthermore, the arbitrarily selected first linear portion 41a1 and 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 in the thickness direction from the first surface 20 a to the linear portion 41 a 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 roughly 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 deposition layer forming 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 FIG. 4 , the connection portion 41 of the through hole 25 c 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 25 c 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 is the same. Therefore, it is also possible to 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 deposited in the same pattern.

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

[0111] The above two directions may also coincide 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 region 22 is not particularly limited. For example, when the metal mask 20 is used to manufacture displays (approximately 0.5 inches to 32 inches) for mobile phones, digital cameras, etc., the pitch of the through holes 25 in the width direction D1 and the length direction D2 may be approximately 20 μm to 254 μm, 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 perspective view of the perforated region 22 as viewed from the second surface 20b is shown. Figure 3B Shows the Figure 3A The through hole 25 is shown in an enlarged perspective view. Figure 3C Shown Figure 3B The cross-sectional view of the through hole 25 taken along the AA' section is shown. Figure 3D Shown Figure 3B A cross-sectional view of the through hole 25 taken along the line BB' is shown.

[0114] like Figure 3A and Figure 3BAs shown, the through-hole 25 includes a first recess 30 formed on the first surface 20a, a second recess 35 formed on the second surface 20b, and a circumferential connecting portion 41 connecting the first and second recesses 30, 35. The through-hole 25 is formed by connecting the first recess 30 on the first surface 20a side with the second recess 35 on the second surface 20b side. Furthermore, the portion where the first and second recesses 30, 35 communicate is the connecting 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 connecting portion 41.

[0115] The area of the first recess 30, when viewed from above, may gradually decrease from the first surface 20a toward the second surface 20b. Furthermore, the area of the second recess 35, when viewed from above, may gradually decrease from the second surface 20b toward the first surface 20a. Furthermore, the first recess 30 may be configured to have a smaller diameter than the second recess 35.

[0116] Furthermore, the direction of expansion of the wall surface of the through-hole 25 changes discontinuously in the connecting portion 41. Typically, the opening area of the through-hole 25 is minimized in the connecting portion 41 when viewed from above. From the perspective of suppressing shadows, the distance h in the thickness direction N from the first surface 20a to the connecting portion 41 is preferably small.

[0117] Shadowing refers to a phenomenon in which a portion of the vapor deposition material 98 reaching 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 is prevented from reaching the substrate 92. As a result, the area or thickness of the vapor deposition material 98 layer on the substrate 92 becomes insufficient. In particular, the connection portion 41 is the portion where the opening area of the through-hole 25 is minimized 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, making shadowing less likely to occur. On the other hand, the further the connection portion 41 is from the substrate 92, the further away the vapor deposition material 98 is from the substrate, the further away it is from the substrate, and the more obstructed it is by the second wall surface 36. Consequently, the area or thickness of the vapor deposition material 98 layer reaching the substrate 92 tends to be insufficient, leading to a tendency for shadowing to occur.

[0118] Therefore, from the perspective of suppressing shadows, it is preferable to reduce the overall distance h. However, reducing the overall distance h reduces the mechanical strength of the metal mask, making it more likely to deform or break. Alternatively, increasing the size of the first recess 30 is an option to reduce the distance h, but such etching is difficult to perform precisely. Consequently, the shape of the through-holes may vary.

[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 in the shape and size of the through hole 25 becomes larger. Therefore, in the second-side 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. In this way, 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, if the linear portion 41a bends 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 apex of the bend 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 ZEISS ULTRA55 scanning electron microscope 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 the distance at which the distance h becomes the largest at the corner portion 41b. When there are multiple corner portions 41b, the maximum distance h at all the corner portions 41b is the maximum distance h1.

[0122] The minimum distance h2 is the distance at which the distance h is the smallest in the linear portion 41a. If there are multiple linear portions 41a, the minimum distance h among all the linear portions 41a is the minimum distance h2. For example, if there are distances h21 and h22 for each linear portion 41a of different lengths, the minimum of these distances 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 the corner portion does not need to be formed into a protruding shape, the shape uniformity of the through-hole is also excellent.

[0124] Furthermore, 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 can be the same, or h21 can be longer than h22, or shorter than h22. Preferably, h21 is longer than h22. Thus, the distance h22 of the longer portion of the linear portion 41a (the second linear portion 41a2) is shorter, thereby tending to further suppress shadows. Alternatively, the distances h21 and h22 can be set to be approximately the same, but increasing h21 tends to further improve the mechanical strength of the metal mask. From this viewpoint, the distance h1 , the distance h21 , and the distance h22 are preferably configured to satisfy the relationship h1 > h21 > h22 .

[0126] In addition, in Figure 2C As shown, when the linear portion 41a includes 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 h22. This also applies to the case where the linear portion 41a includes three or more linear portions 41a of different lengths. The minimum distance h2 is the shortest distance among the plurality of linear portions 41a.

[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 or equal to 0.6 μm and less than or equal to 8.0 μm, greater than or equal to 0.8 μm and less than or equal to 6.0 μm, or greater than or equal to 1.0 μm and less than or equal to 4.0 μm. Furthermore, the maximum distance h1 is preferably greater than or equal to 0.6 μm, greater than or equal to 0.8 μm, greater than or equal to 1.0 μm, or greater than or equal to 1.2 μm. Furthermore, the maximum distance h1 is preferably less than or equal to 8.0 μm, less than or equal to 6.0 μm, less than or equal to 4.0 μm, less than or equal to 3.0 μm, or less than or equal to 2.0 μm. Furthermore, the range of the maximum distance h1 may also be determined by a combination of any one of the multiple lower limit candidate values described above and any one of the multiple upper limit candidate values described above.

[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 or equal to 0.06 μm and less than or equal to 4.0 μm, greater than or equal to 0.08 μm and less than or equal to 3.0 μm, or greater than or equal to 0.10 μm and less than or equal to 2.0 μm. Furthermore, the minimum distance h2 is preferably greater than or equal to 0.06 μm, greater than or equal to 0.08 μm, greater than or equal to 0.10 μm, greater than or equal to 0.25 μm, or greater than or equal to 0.50 μm. Furthermore, the minimum distance h2 is preferably less than or equal to 4.0 μm, less than or equal to 3.0 μm, less than or equal to 2.0 μm, less than or equal to 1.5 μm, or less than or equal to 1.0 μm. Furthermore, the range of the minimum distance h2 may also be determined by a combination of any one of the multiple lower limit candidate values described above and any one of the multiple upper limit candidate values described above.

[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 greater and 50 or less, 1.2 or greater and 45 or less, or 1.5 or greater and 40 or less. Furthermore, the ratio (h1 / h2) is preferably 1.1 or greater, 1.2 or greater, 1.5 or greater, 1.8 or greater, 2.0 or greater, 3.0 or greater, or 4.0 or greater. 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. Furthermore, the range of the ratio (h1 / h2) may be determined by a combination of any one of the multiple candidate lower limit values described above and any one of the multiple candidate upper limit values described above.

[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 also 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, which can suppress the tendency of the vapor deposition material 98 to adhere to the second wall surface 36 of the second recess 35 during the vapor deposition process.

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

[0136] 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. Furthermore, the ratio (h1 / H) is preferably 0.010 or more, 0.015 or more, 0.020 or more, or 0.025 or more. Furthermore, the ratio (h1 / H) is preferably 0.40 or less, 0.30 or less, 0.20 or less, or 0.15 or less. Furthermore, the range of the ratio (h1 / H) can also be determined by a combination of any one of the multiple lower limit candidate values and any one of the 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, shadowing tends to be further suppressed.

[0138] The ratio of the minimum distance h2 to the thickness H (h2 / H) is preferably 0.001 or more and 0.20 or less, 0.002 or more and 0.10 or less, or 0.004 or more and 0.080 or less. Furthermore, the ratio (h2 / H) is preferably 0.001 or more, 0.002 or more, 0.003 or more, or 0.004 or more. Furthermore, the ratio (h2 / H) is preferably 0.20 or less, 0.10 or less, 0.080 or less, or 0.060 or less. Furthermore, the range of the ratio (h2 / H) can also be determined by a combination of any one of the multiple lower limit candidate values and any one of the 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. In addition, when the ratio (h2 / H) is 0.20 or less, shadows tend to be further suppressed.

[0140] Furthermore, when distance h21 and distance h22 exist, the ratio of distance h21 to distance h22 (h21 / 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, or 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, or 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, or 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 this disclosure, the edge of the first recess 30 is referred to as a ridge line 33. The ridge line 33 is a portion that divides adjacent through-holes 25. In other words, each through-hole 25 is surrounded by the ridge line 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 ridge line 33 that divides the adjacent through-holes 25. In this case, the ridge line 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 ridge line 33 may also be fixed.

[0142] in addition, Figure 3E Another example of a perspective view of the perforated region 22 as viewed from the second surface 20b is shown. Figure 3E In the embodiment, the distance between adjacent through holes 25 is relatively short. Therefore, the second wall surfaces 36 of the 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 the embodiment, the second surface 51 b of the metal plate 51 constituting the metal mask 20 does not remain between the adjacent second recesses 35 .

[0143] like Figure 3E As shown, the height of the ridge line 33 formed by the converging second wall surfaces 36 may not be constant but may vary depending on the distance from the center of the through hole 25. For example, the height of the ridge line 33 may be higher as the distance from the center of the through hole 25 to the ridge line 33 increases.

[0144] Such through holes 25 can also 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 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 peripheral region 23 is a region located around the perforated region 22. The peripheral region 23 may be located at a position surrounding the perforated region 22. The peripheral region 23 may be a region supporting the perforated region 22 by being located around the perforated region 22.

[0146] Furthermore, the surrounding area 23 may also be an area where the deposition material 98 is not desired to pass through. From this perspective, the surrounding area 23 may primarily comprise a non-porous surface without through-holes. However, for various purposes, the surrounding area 23 may comprise a non-porous surface and partially comprise through-holes not intended for the deposition material to pass through in portions other than the non-porous surface. In this disclosure, a "non-porous surface" refers to a surface without through-holes.

[0147] As will be 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 longitudinal 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 component different from the other surrounding regions. In this case, the end portion may 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, the following describes a method of manufacturing the metal mask 20 by etching, but the metal mask 20 may be formed by etching, by laser processing, or by electroforming.

[0152] Main reference Figures 4A to 4E A method for manufacturing the metal mask 20 according to one embodiment of the present disclosure will be described. Figure 4A 1 is a schematic diagram showing a manufacturing apparatus 70 for manufacturing a metal mask 20 using a metal plate 51 and its processing sequence. Figure 4A , an example of continuously feeding the metal plate 51 from the resist film forming apparatus 71 to the stripping apparatus 74 is shown. However, the method for manufacturing the metal mask 20 of the present disclosure is not limited to this. For example, the metal plate 51 may be wound into a roll each time it passes through each apparatus. Alternatively, the metal plate 51 may be unwound from a roll when being fed to each apparatus.

[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 wound 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 and plating film forming methods.

[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 attaching a dry film resist to the first surface 51a and the second surface 51b. Alternatively, the resist films 53a and 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.

[0156] There are no particular limitations on the dry film resist or coating liquid, and any conventionally known material can be used. Furthermore, the resist films 53a and 53b thus formed can be either negative-type resists or positive-type resists. Among these, negative-type resists are preferably used.

[0157] The thickness of the resist films 53a and 53b is preferably 15 μm or less, but may also be 10 μm or less, 6 μm or less, or 4 μm or less. Furthermore, the thickness of the resist films 53a and 53b is preferably 1 μm or more, but may also 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 aforementioned multiple upper limit candidate values and any one of the aforementioned multiple lower limit candidate values.

[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 area to be removed in the resist film can be placed on the resist film, and the resist film can be exposed through the photomask, and then 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 perforated region 22 is shown. In the first surface etching process, the area of the first surface 51a not covered by the first resist pattern 53c is etched using an etching solution. At this time, the second surface 51b may also be covered with a resin or the like that is resistant to the etching solution.

[0161] The etching liquid causes the first surface 51a not covered by the first resist pattern 53c to be corroded ( Figure 4D ). Thus, a plurality of first recesses 30 are formed on the first surface 51a. Furthermore, the etching of the metal plate 51 can be performed isotropically in all directions from the holes in the resist pattern. 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 progress in the thickness direction from the surface.

[0162] exist Figure 4E is 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. Alternatively, the first surface 51a may 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 corroded ( Figure 4E ). Thus, the second recess 35 is formed on the second surface 51b. Furthermore, the first recess 30 and the second recess 35 communicate 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 etching liquids containing a ferric chloride solution and hydrochloric acid.

[0165] In the second side etching process, Figure 4EAs shown, etching may be continued until adjacent second recesses 35 are connected. At the location where adjacent second recesses 35 are connected, the adjacent second recesses 35 merge to form a ridge line 33. Furthermore, the ridge line 33 is separated from the second resist pattern 53d, and etching also progresses in the thickness direction of the metal plate 51 at the top of the ridge line 33. As a result, the second resist pattern 53d is peeled off from the metal plate 51. Furthermore, the second surface 51b may partially remain between adjacent second recesses 35.

[0166] Furthermore, the resin 54 or the like resistant to the resist pattern or etching solution is peeled off from the metal plate 51 using the peeling device 74. Next, 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 manner, 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 apparatus 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 end portions 23a in the length direction D2 of the metal mask 20.

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

[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 include a component that extends in a direction intersecting the longitudinal direction of the metal mask 20 and supports the metal mask 20, and a component that overlaps with the gap between two adjacent metal masks.

[0171] Next, refer to Figure 6 A method for 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 containing 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 that holds the evaporation material 98 is the second surface 20b. In the evaporation device 90, the metal mask 20 is placed on the crucible 94 side of the substrate 92. Here, the metal mask 20 and the substrate 92 can also be tightly adhered by magnetic force.

[0175] In the evaporation device 90, below the metal mask device 10, there may be arranged: a crucible 94 for storing the evaporation material 98; and a heater 96 for heating the crucible 94. 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 heat from the heater 96. The vaporized or sublimated evaporation material 98 adheres to the substrate 92 through the through-holes 25 of the metal mask 20. As a result, the evaporation 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. In addition, during the evaporation process, the interior of the evaporation device 90 may 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 material 98 for red, the deposition material 98 for green, and the deposition material 98 for blue may be sequentially deposited on the substrate 92. Alternatively, 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 material 98 for red, the deposition material 98 for green, and the deposition material 98 for blue may be sequentially deposited.

[0177] Furthermore, 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 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. The vapor-deposited layer is formed on the first electrode. The method for manufacturing an organic EL display device may also include a step of forming a second electrode on the vapor-deposited layer. The method for manufacturing an organic EL display device may also include a sealing step of sealing the first electrode, the vapor-deposited layer, and the second electrode provided on the substrate 92.

[0178] The vapor-deposited layer formed on a substrate such as substrate 92 using the metal mask 20 is not limited to the light-emitting layer formed by vapor-depositing the above-mentioned organic light-emitting material, but may also include other layers. For example, the vapor-deposited 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, etc. In this case, the vapor deposition process using the metal mask 20 corresponding to each layer may be performed separately.

[0179] In addition, various modifications can be made to the above-described embodiment. Below, modifications will be described with reference to the accompanying drawings as needed. In the following description and the accompanying drawings used therein, parts that can be configured similarly to the above-described embodiment are denoted by the same reference numerals as those used for the corresponding parts in the above-described embodiment, and duplicate descriptions are omitted. In addition, if it is clear that the effects obtained in the above-described embodiment can also be obtained in a modification, the description thereof may be 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 in any way by the following examples.

[0182] (Example)

[0183] The above-described metal mask manufacturing method produces a metal mask having through-holes formed by a first recess and a second recess, and a third recess, on a metal plate. In this case, the maximum distance h1 at the corners and the minimum distance h2 at the linear portion have a predetermined relationship. Furthermore, the metal plate serving as the raw material for the metal mask is made of Invar alloy. Example A shows a method in which the through-holes are approximately square in plan view, while Example B shows a method in which the through-holes are approximately rectangular in plan view.

[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 portion and the minimum distance h2 at the linear portion had the prescribed relationship described in Table 1. Comparative Example A shows an embodiment in which the through-holes are substantially square in plan view, and Comparative Example B shows an embodiment in which the through-holes are substantially rectangular in plan view.

[0186] (Shape Evaluation of Connecting Portions)

[0187] In the linear portion of the connection, straightness within ±2 μm was rated as OK, and exceeding ±2 μm was rated as NG. Note that straightness was measured by photographing the connection using a scanning electron microscope (ZEISS ULTRA55).

[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 measuring the distance (μm) between the straight line connecting the two ends of the linear portion 41a and the apex of the curvature of the linear portion 41a. The straightness is measured by setting the straight line connecting the two ends of the linear portion 41a and the linear portion 41a to "0 μm," the curvature of the linear portion 41a to "+" when the linear portion 41a curves toward the outside of the through-hole 25, and the curvature of the linear portion 41a to "-" when the linear portion 41a curves toward the inside of the through-hole 25.

[0189] (Shadow Evaluation)

[0190] Next, a deposition process was performed using a metal mask to deposit the deposition material onto the substrate, forming a deposition layer. Tris(8-hydroxyquinoline)aluminum, an organic light-emitting material, was used as the deposition material. A glass substrate was used as the substrate. The deposition process conditions were set to achieve a deposition layer thickness of 40 nm.

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

[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. A case where the area ratio V was 0.70 or greater among all the 30 deposited layers on the substrate was evaluated as "OK", and a case where at least one of the layers had an area ratio V less than 0.70 was evaluated as "NG".

[0194] [Table 1]

[0195]

[0196] [Table 2]

[0197]

[0198] ※The distance h22 is used 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 manufacture of an organic EL display device, etc.

[0201] Description of labels

[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 sheet;

[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: second resist pattern;

[0233] 54…resin;

[0234] 70… manufacturing equipment;

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

[0236] 72…exposure and development 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 materials.

Claims

1. A metal mask, characterized in that: The metal mask has a hole area and a surrounding area, The porous area has a plurality of through holes, The surrounding area is located around the perforated area, The through hole has: a first recess formed on the first surface; a second recess formed on the second surface; and a circumferential connecting portion connecting the first recess and the second recess. 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, wherein 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, wherein 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, wherein 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, wherein 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, wherein 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, wherein 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.

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