Metal mask and manufacturing method thereof

Abstract

A metal mask has a porous region having a plurality of through-holes, and a peripheral region located around the porous region, the peripheral region having a stress dispersion region, the stress dispersion region having a plurality of recesses, the opening shape of the recesses in plan view having a minor axis of length R, the stress dispersion region has the recesses arranged at a pitch P in the short axis direction, and the ratio (R / P) of the length R to the pitch P is 0.90 or more.

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 providing a metal mask having uniform through holes in order to improve the uniformity of vapor deposition.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2019-508588 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, a technique for forming a half-etched portion in order to disperse stress applied during stretching is disclosed in Patent Document 1. One recessed portion of the half-etched portion described in Patent Document 1 is a relatively large recessed portion having a length that crosses a plurality of through holes.

[0008] However, as described in Patent Document 1, if a recess is formed relatively large, the depth of the recess is likely to be different even in the same recess. If the depth of the recess is different, it is difficult to disperse the stress evenly. If the stress is unevenly dispersed, wrinkles will be generated when the metal mask is set on the frame, or the accuracy of the setting position will be reduced. Here, "wrinkles" refer to the undulations in the width direction of the mask when the metal mask is mounted and welded to the frame by applying tension in the length direction of the metal mask. In addition, if a recess is formed relatively large, the risk of the recess penetrating to the back side during manufacturing increases, and the yield of the metal mask may also be reduced.

[0009] 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 which can disperse stress more uniformly, is less likely to wrinkle, and has excellent positional accuracy, and an effective method for manufacturing the metal mask.

[0010] Means for solving problems

[0011] A metal mask according to an embodiment of the present disclosure has a hole region and a surrounding region.

[0012] The perforated area has a plurality of through holes.

[0013] The surrounding area is located around the area with holes.

[0014] The above-mentioned surrounding area has a stress dispersion area,

[0015] The stress dispersion region has a plurality of recesses.

[0016] The opening shape of the above-mentioned recessed portion in plan view has a minor axis of length R,

[0017] The stress dispersion region has the recessed portions arranged at a pitch P in the short axis direction.

[0018] The ratio (R / P) of the length R to the pitch P is 0.90 or more.

[0019] The method for manufacturing the metal mask according to one embodiment of the present disclosure comprises:

[0020] 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

[0021] an etching step of forming the metal mask by etching the metal plate;

[0022] The metal mask has a hole area and a surrounding area.

[0023] The perforated area has a plurality of through holes.

[0024] The surrounding area is located around the area with holes.

[0025] The above-mentioned surrounding area has a stress dispersion area,

[0026] The stress dispersion region has a plurality of recesses.

[0027] The opening shape of the above-mentioned recessed portion in plan view has a minor axis of length R,

[0028] The stress dispersion region has the recessed portions arranged at a pitch P in the short axis direction.

[0029] The ratio (R / P) of the length R to the pitch P is 0.90 or more.

[0030] Effects of the Invention

[0031] At least one embodiment of the present disclosure provides a metal mask that can disperse stress more uniformly, is less likely to wrinkle, and has excellent positional accuracy, and an effective method for manufacturing the metal mask. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 1 is a top view showing a metal mask according to one embodiment of the present disclosure.

[0033] Figure 2A This is a plan view of the hole region as viewed from the second surface side.

[0034] Figure 2B It is along Figure 2A A cross-sectional view taken along line II' is shown.

[0035] Figure 2C It is along Figure 2A A cross-sectional view along line II-II' is shown.

[0036] Figure 2D It is along Figure 2A A cross-sectional view along line III-III' is shown.

[0037] Figure 2E Viewed from the second side Figure 2A A stereoscopic view of area S1 is shown.

[0038] Figure 3A This is a plan view of the stress dispersion region as viewed from the second surface side.

[0039] Figure 3B It is along Figure 3A A cross-sectional view along line IV-IV' is shown.

[0040] Figure 3C It is along Figure 3A A cross-sectional view along line V-V' is shown.

[0041] Figure 3D It is along Figure 3A The cross-sectional view along the line V-VI' is shown.

[0042] Figure 3E Viewed from the second side Figure 3A A stereoscopic view of area S2 is shown.

[0043] Figure 4A It is a plan view showing an example of arrangement of recessed portions in the stress dispersion region.

[0044] Figure 4B It is a plan view showing an example of arrangement of recessed portions in the stress dispersion region.

[0045] Figure 4C It is a plan view showing an example of arrangement of recessed portions in the stress dispersion region.

[0046] Figure 4D It is a plan view showing an example of arrangement of recessed portions in the stress dispersion region.

[0047] Figure 4E It is a plan view showing an example of arrangement of recessed portions in the stress dispersion region.

[0048] Figure 4F It is a plan view showing an example of arrangement of recessed portions in the stress dispersion region.

[0049] Figure 5A This is a schematic diagram for explaining an example of a method for manufacturing a metal mask.

[0050] Figure 5B This is a diagram showing an example of a process of forming a resist film on a metal plate.

[0051] Figure 5C This is a diagram showing an example of a process of patterning a resist film.

[0052] Figure 5D This is a diagram showing an example of the first surface etching step in the hole-containing region.

[0053] Figure 5E This is a diagram showing an example of the second surface etching step in the hole-containing region.

[0054] Fig. 5F This is a diagram showing an example of the second surface etching step in the stress dispersion region.

[0055] Figure 6 FIG. 1 is a diagram showing a metal mask device according to an embodiment of the present disclosure.

[0056] Figure 7 This is a cross-sectional view showing a vapor deposition device according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0057] Hereinafter, one embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that in the drawings attached to this specification, for the sake of convenience of illustration and understanding, the scale and aspect ratio may be appropriately changed and exaggerated relative to the actual object.

[0058] Unless otherwise specified in the present specification and / or the drawings, the following explanations shall be given.

[0059] The terms indicating a substance that is the basis of a certain structure may not be distinguished simply based on the difference in name. For example, the terms such as "substrate", "base material", "plate", "sheet" or "film" correspond to the above description.

[0060] The terms and / or numerical values ​​indicating shapes and / or geometric conditions need not be limited to strict meanings, and may be interpreted as including a range of degrees in which the same function can be expected. For example, "parallel" and / or "orthogonal" etc. correspond to the above terms. In addition, "value of length" and / or "value of angle" etc. correspond to the above numerical values.

[0061] When expressing that a certain structure is "above", "below", "upper side", "lower side", "above" or "below" another structure, the following modes may be included: a mode in which a certain structure is directly connected to the other structure; and a mode in which another structure is included between the certain structure and the other structure. In other words, the mode in which another structure is included between the certain structure and the other structure may also be expressed as that the certain structure is indirectly connected to the other structure. In addition, expressions such as "above", "upper side" or "above" can be interchanged with expressions such as "below", "lower side" or "below". In other words, the up and down directions may also be reversed.

[0062] 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.

[0063] In the range that no contradiction occurs, one or more modes of the embodiment and one or more modes of the modification examples may be combined. 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 modification examples may be combined with each other.

[0064] When a plurality of steps are disclosed in a method such as a manufacturing method, other steps 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.

[0065] Numerical ranges represented by the symbol “to” and / or “-” include the numerical values ​​before and after the symbol “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”.

[0066] Regarding the numerical values ​​described in this disclosure, the numerical range can be limited by combining any one of the multiple upper limit candidate values ​​with any one of the multiple lower limit candidate values. In addition, even if not specifically mentioned, the numerical range can be limited by combining any two of the multiple upper limit candidate values, and the numerical range can be limited by combining any two of the multiple lower limit candidate values.

[0067] 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 only one embodiment of the present disclosure.

[0068] 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 an organic material on a substrate in a desired pattern in the manufacture of an organic EL display device. The metal mask disclosed in the present invention can achieve patterning with high pixel density. In the organic EL display device that can be manufactured, in addition to displays such as smartphones or televisions, it also includes a device for displaying or projecting images and videos for expressing virtual reality (VR) and augmented reality (AR).

[0069] It should be noted that, in this specification and the drawings, unless otherwise specified, an example of a metal mask used in manufacturing an organic EL display device and a method for manufacturing the same will be described as one embodiment of the present invention.

[0070] A first aspect of the present disclosure is a metal mask having a hole region and a peripheral region.

[0071] The perforated area has a plurality of through holes.

[0072] The surrounding area is located around the area with holes.

[0073] The above-mentioned surrounding area has a stress dispersion area,

[0074] The stress dispersion region has a plurality of recesses.

[0075] The opening shape of the above-mentioned recessed portion in plan view has a minor axis of length R,

[0076] The stress dispersion region has the recessed portions arranged at a pitch P in the short axis direction.

[0077] The ratio (R / P) of the length R to the pitch P is 0.90 or more.

[0078] In a second aspect of the present disclosure, in the metal mask of the first aspect, the recessed portions are arranged in a staggered pattern or a grid pattern.

[0079] In a third aspect of the present disclosure, in the metal mask of the first aspect or the second aspect, wall surfaces of the adjacent concave portions merge with each other.

[0080] In a fourth aspect of the present disclosure, in any one of the metal masks of the first to third aspects,

[0081] The thickest part of the above-mentioned surrounding area has a height H0,

[0082] The thinnest portion of the stress dispersion region has a height H1,

[0083] The ratio (H1 / H0) of the height H1 to the height H0 is not less than 0.20 and not more than 0.90.

[0084] In a fifth aspect of the present disclosure, in any one of the metal masks of the first to fourth aspects,

[0085] The surrounding area has an edge,

[0086] The stress dispersion region is located between the edge and the perforated region.

[0087] In a sixth aspect of the present disclosure, in the metal mask of the fifth aspect,

[0088] The edge of the peripheral area has a pair of long sides and a pair of short sides,

[0089] The stress dispersion region is located between the edge serving as the long side and the hole region.

[0090] In a seventh aspect of the present disclosure, in any one of the metal masks of the first to sixth aspects,

[0091] having a plurality of the above-mentioned porous regions,

[0092] The stress dispersion region is located between the plurality of porous regions.

[0093] In an eighth aspect of the present disclosure, in any one of the metal masks of the first to seventh aspects,

[0094] The above surrounding area has a cutting line,

[0095] The cutting lines are rows of recesses or through holes.

[0096] The stress dispersion area is located between the cutting line and the hole area.

[0097] In a ninth aspect of the present disclosure, in any one of the metal masks of the first to eighth aspects,

[0098] The above surrounding area has a cutting line,

[0099] The cutting lines are rows of recesses or through holes.

[0100] The cutting line is located between the stress dispersion area and the hole area.

[0101] A tenth aspect of the present disclosure is a method for manufacturing a metal mask, the method comprising:

[0102] 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

[0103] an etching step of forming the metal mask by etching the metal plate;

[0104] The metal mask has a hole area and a surrounding area.

[0105] The perforated area has a plurality of through holes.

[0106] The surrounding area is located around the area with holes.

[0107] The above-mentioned surrounding area has a stress dispersion area,

[0108] The stress dispersion region has a plurality of recesses.

[0109] The opening shape of the above-mentioned recessed portion in plan view has a minor axis of length R,

[0110] The stress dispersion region has the recessed portions arranged at a pitch P in the short axis direction.

[0111] The ratio (R / P) of the length R to the pitch P is 0.90 or more.

[0112] 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. Furthermore, the peripheral region 23 includes a stress dispersion region 24 having a predetermined recessed portion.

[0113] 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 when viewed from above. It should be noted that, in the present disclosure, “viewed from above” means observing the metal mask 20 from a plane along the plate surface of the metal mask 20 .

[0114] In the metal mask 20 of the present disclosure, one porous region 22 can be configured to correspond to one organic EL display device. Figure 1 As shown, the metal mask 20 may include a plurality of perforated regions 22 arranged in a row at predetermined intervals along the length 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.

[0115] 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.

[0116] 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 and the thermal expansion coefficient of the substrate 92. As a result, during the evaporation process, the generation of positional deviation caused by the difference in dimensional changes of the metal mask 20, the frame 15, and the substrate 92 can be suppressed. Therefore, the reduction in dimensional accuracy and positional accuracy of the evaporation material 98 attached to the substrate 92 caused by the positional deviation can be suppressed.

[0117] The iron alloy containing nickel is not particularly limited, and examples thereof include a super Invar alloy material containing cobalt in addition to 30 mass % to 34 mass % of nickel, an Invar alloy material containing 34 mass % to 38 mass % of nickel, a low thermal expansion Fe-Ni plated alloy containing 48 mass % to 54 mass % of nickel, and other iron alloys containing 0 mass % to 54 mass % of nickel.

[0118] Next, the details of the hole region 22 will be described. First, before describing the hole region 22 in detail, 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 front and back surfaces.

[0119] In the present disclosure, the first surface 20a and the second surface 20b of the metal mask 20 are distinguished according to the diameter of the through hole 25 in the front and back surfaces of the hole area 22. Specifically, the first surface 20a refers to the surface with a small opening area of ​​the through hole 25 in the hole area 22, and the second surface 20b refers to the surface with a large opening area of ​​the through hole 25. Figure 2E As shown in FIG. 1 and FIG. 2 , 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.

[0120] In addition, from the perspective of the vapor deposition process, the first surface 20a may be a surface of the metal mask 20 facing the substrate 92 when the metal mask device 10 is accommodated in the vapor deposition device 90 (see Figure 7 ). In addition, Figure 7 As shown, 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 7 ).

[0121] Figure 2A FIG. 2 shows a top view of the perforated region 22 as viewed from the second surface 20b. Figure 2AAs shown, each perforated region 22 of the metal mask 20 has a plurality of through holes 25. The through holes 25 may also be formed in a desired pattern. 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.

[0122] 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 (about 0.5 inches to 32 inches) of mobile phones, digital cameras, etc., the pitch of the through holes 25 may also be about 20 μm to 254 μm in the width direction D1 and the length direction D2, respectively.

[0123] 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 vapor deposition process, the vapor deposition material 98 is attached to the substrate 92 through the through holes 25. That is, each through hole 25 defines a portion for the vapor deposition material to be attached to the substrate 92. The pattern of the through holes 25 in the perforated region 22 corresponds to the pattern for the vapor deposition material 98 to be attached.

[0124] When the pattern for attaching the vapor deposition material 98 differs depending on the type of the vapor deposition material 98, the metal mask 20 having different patterns of the through holes 25 may be used depending on the type of the vapor deposition material 98. Alternatively, when the pattern for attaching the vapor deposition material 98 is the same regardless of the type, the same metal mask 20 may be used. In this case, by relatively moving the metal mask 20 and the substrate 92, different types of vapor deposition materials 98 can be attached in the same pattern.

[0125] like Figure 2A As shown, the perforated region 22 may include a plurality of through holes 25 and a plurality of ridge lines 33. In addition, the ridge lines 33 may be located at positions that divide adjacent through holes 25.

[0126] Next, the through hole will be described in further detail using a cross-sectional view and a perspective view of the hole region. Figure 2B It is along Figure 2A A cross-sectional view taken along line II' is shown. Figure 2C It is along Figure 2A A cross-sectional view along line II-II' is shown. Figure 2B and Figure 2C The cross-sectional view shown is a cross-sectional view when the hole region 22 is cut in a direction crossing the through hole 25 and the ridge line 33 .

[0127] Figure 2D It is along Figure 2AA cross-sectional view along line III-III' is shown. Figure 2D The cross-sectional view shown is a cross-sectional view when the perforated region 22 is cut in a direction passing through the through hole 25 and the top 32. Here, the top 32 is a portion with a maximum height in the perforated region 22. Alternatively, the top 32 may be a portion with a maximum height in the ridge line 33.

[0128] like Figure 2B to Figure 2D As shown in the figure, the through hole 25 may be formed by connecting the first recess 30 on the first surface 20a side and the second recess 35 on the second surface 20b side. In this case, the area of ​​the first recess 30 when viewed from above may gradually decrease from the first surface 20a toward the second surface 20b. In addition, the area of ​​the second recess 35 when viewed from above may gradually decrease from the second surface 20b toward the first surface 20a. In addition, the first recess 30 may also be configured as a recess having a smaller diameter than the second recess 35.

[0129] In addition, if Figure 2B to Figure 2D As shown, the first wall surface 31 of the first recess 30 and the second wall surface 36 of the second recess 35 may also be connected via a circumferential connecting portion 41. The connecting portion 41 is an edge portion connecting the first recess 30 and the second recess 35. In the connecting portion 41, the expansion direction of the wall surface of the through hole 25 changes discontinuously. In one embodiment of the present disclosure, it may also be that in the connecting portion 41, the opening area of ​​the through hole 25 when viewed from above is the smallest. In addition, outside the connecting portion 41, the opening area of ​​the through hole 25 when viewed from above may also be the smallest.

[0130] Figure 2E The figure shows the state of the vehicle when viewed from the second surface 20b. Figure 2A The stereogram of the area S1 shown in FIG. Figure 2E As shown, the ridge lines 33 divide the adjacent through holes 25. Figure 2E As shown, on the second surface 20 b side of the perforated region 22 , each through hole 25 may be surrounded by a plurality of ridge lines 33 .

[0131] like Figure 2E As shown, the second wall surfaces 36 of the adjacent second recesses 35 may also merge. This can also be said to be a state in which the second surface 51b of the metal plate 51 constituting the metal mask 20 does not remain between the adjacent second recesses 35. In this case, the ridge line 33 is formed by the merged second wall surfaces 36. Figure 2E As shown, the height of the ridgeline 33 formed by the merged second wall surface 36 is not constant, 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 may be.

[0132] Such a through hole 25 may be formed by etching the metal plate 51 so that the second surface 51 b of the metal plate 51 does not remain between the adjacent second recessed portions 35 , as in a manufacturing method described later.

[0133] In addition, although not shown, the second wall surfaces 36 of the adjacent second recesses 35 may not merge. This can also be said that the adjacent second recesses 35 are separated along the surface direction of the second surface 20b. In this case, the portion remaining as the second surface 20b between the adjacent second recesses 35 becomes the ridge line 33 that divides the adjacent through holes 25. In addition, 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 be constant.

[0134] Furthermore, although not shown, adjacent through holes 25 may be separated along the surface direction of the first surface 20a on the first surface 20a side of the perforated region 22. In other words, the first surface 51a of the metal plate 51 may remain between adjacent first recesses 30.

[0135] It should be noted that the first surface 51 a of the metal plate 51 may correspond to the first surface 20 a of the metal mask 20 , and it should be noted that the second surface 51 b of the metal plate 51 may correspond to the second surface 20 b of the metal mask 20 .

[0136] 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.

[0137] The surrounding area 23 has a predetermined stress dispersion area 24. Thus, even if tension is applied to the metal mask, the stress can be dispersed more evenly. Therefore, the metal mask is less likely to wrinkle. In addition, the accuracy of the setting position when the metal mask is set on the frame is further improved. It should be noted that the scene where tension is applied to the metal mask is not particularly limited, and examples thereof include when the metal mask is set on the frame, when the metal mask is transported, etc.

[0138] In addition, the surrounding area 23 may be an area that does not intentionally allow the vapor deposition material 98 to pass through. From this point of view, the surrounding area 23 may 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 partially have through holes other than the non-porous surface that are not intended to allow the vapor deposition material to pass through. In the present disclosure, "non-porous surface" refers to a surface that does not have through holes.

[0139] 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 a long 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.

[0140] The end portion 23a may also be configured so that a portion thereof can be cut off after the metal mask 20 is 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 be joined to the other parts of the surrounding region by welding, for example.

[0141] The thickest part of the surrounding area 23 has a height H0. The thickest part of the surrounding area 23 may be the height from the first surface 20a to the second surface 20b in the surrounding area 23. The height H0 may preferably be 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less. By reducing the height of the surrounding area, the porous area 22 can be made thinner by etching or the like, and there is a tendency to suppress the deposition material 98 from adhering to the second wall surface 36 of the second recess 35 during the deposition process.

[0142] The height H0 may be preferably 2.5 μm or more, 5 μm or more, 10 μm or more, or 15 μm or more. By increasing the height of the surrounding area, the strength of the metal mask 20 tends to be further improved. Thus, for example, deformation or fracture of the porous area 22 tends to be further suppressed.

[0143] The stress dispersion region 24 has a plurality of recessed portions 37. The recessed portions 37 included in the stress dispersion region 24 are also referred to as "third recessed portions 37". Figure 3A FIG. 1 shows a plan view of the stress dispersion region 24 viewed from the second surface 20 b side.

[0144] like Figure 3A As shown in FIG. 2 , the stress dispersion region 24 has third recesses 37 arranged at a pitch P in the minor axis direction. The third recesses 37 have a minor axis of length R. Figure 3A In the figure, the short axis direction is parallel to the D2 direction, but the present invention is not limited thereto. For example, the short axis direction may be parallel to the D1 direction, or the short axis direction may be not parallel to the D1 direction or the D2 direction but may be a direction intersecting these directions.

[0145] Figure 3B It is along Figure 3AHere, the IV-IV' line may be a line parallel to the short axis direction. Figure 3B As shown, the third wall surfaces 38 of the third recesses 37 may merge to form a ridgeline 39. The ridgeline 39 divides the adjacent third recesses 37. Here, the opening shape of the third recess 37 in a plan view may be a shape defined by the ridgeline 39.

[0146] Figure 3C It is along Figure 3A A cross-sectional view along line V-V' is shown. Figure 3B and Figure 3C The cross-sectional view shown is a cross-sectional view when the stress dispersion region 24 is cut in a direction crossing the third recessed portion 37 and the ridge line 39 . Figure 3D It is along Figure 3A A cross-sectional view along line VI-VI' is shown. Figure 3D The cross-sectional view shown is a cross-sectional view obtained by cutting the stress dispersion region 24 in a direction passing through the intersection of the third recess 37 and the ridge line 39 .

[0147] in addition, Figure 3E The figure shows the state of the vehicle when viewed from the second surface 20b. Figure 3A The stereogram of the area S2 shown in FIG. Figure 3E As shown in FIG. 1 , the ridge line 39 divides the adjacent third recesses 37. Figure 3E As shown, on the second surface 20 b side of the stress dispersion region 24 , each third recessed portion 37 may be surrounded by a plurality of ridge lines 39 .

[0148] It should be noted that in Figure 3B to Figure 3E , an example in which the third recess 37 is formed on the second surface 20b is shown. However, the present invention is not limited thereto, and the third recess 37 may be formed on the second surface 20b, may be formed on the first surface 20a, or may be formed on both. For example, by forming the third recess 37 on the second surface 20b side, the volume difference between the perforated area 22 and the surrounding area 23 on the second surface 20b side becomes smaller, the stress dispersion effect is further improved, and there is a tendency to further suppress the generation of wrinkles during installation. The area of ​​the third recess 37 when viewed from above may also gradually decrease from the second surface 20b toward the first surface 20a.

[0149] The third recesses 37 may also be formed in a desired pattern. For example, the third recesses 37 may be arranged in a grid pattern at predetermined intervals along two mutually intersecting directions (D1, D2). Figure 3A As shown in FIG. 1 , the adjacent third recesses 37 may also be adjacent to each other along the surface direction. In other words, the third wall surfaces 38 of the adjacent third recesses 37 may also merge. Figure 4AAs shown in FIG. 1 , the adjacent third recesses 37 may be separated along the surface direction. In other words, the third wall surfaces 38 of the adjacent third recesses 37 may not merge. Figure 4B As shown, in a predetermined direction, the adjacent third recesses 37 are adjacent to each other, and in other directions, the adjacent third recesses 37 may be separated.

[0150] In addition, the third recesses 37 may also be arranged in a staggered manner at a predetermined pitch along two directions intersecting each other. Figure 4C As shown in FIG. 1 , the adjacent third recesses 37 may also be adjacent to each other along the surface direction. In other words, the third wall surfaces 38 of the adjacent third recesses 37 may also merge. Figure 4D As shown in FIG. 1 , the adjacent third recesses 37 may be separated along the surface direction. In other words, the third wall surfaces 38 of the adjacent third recesses 37 may not merge. Figure 4E As shown, in a predetermined direction, the adjacent third recesses 37 are adjacent to each other, and in other directions, the adjacent third recesses 37 may be separated.

[0151] The two directions may coincide with the length direction D2 or the width direction D1 of the metal mask 20. The pitch of the third recesses 37 in the stress dispersion region 24 is not particularly limited, and may be about 20 μm to 254 μm in the width direction D1 and the length direction D2, respectively.

[0152] In addition, the third recessed portions 37 may be arranged in any pattern other than the above. In this case, the wall surfaces of the adjacent third recessed portions 37 may or may not merge.

[0153] When the third recess 37 is viewed from above, the opening shape may have various shapes such as a circle, an ellipse, a quadrilateral, etc. Figure 4F As shown, the oval third recesses 37 may be arranged in a staggered pattern. Alternatively, they may be arranged in a stripe pattern with long quadrilaterals.

[0154] The opening shape of the third recess 37 when viewed from above has a minor axis of length R. Figure 4A and Figure 4D As shown in FIG. 1 , when the adjacent third recesses 37 are separated along the surface direction, the length R of the minor axis can also be determined according to the opening shape of the third recesses 37 in the second surface 20 b. Figure 3A , Figure 3E Likewise, when the adjacent third recesses 37 are adjacent to each other in the surface direction, the length R of the minor axis may be determined based on the range S4 closed by the ridgeline 39 surrounding one third recess 37 .

[0155] The minor axis in the opening shape refers to the shortest line segment among the line segments that pass through the centroid point of the opening shape and divide the opening shape into two parts.

[0156] More specifically, if the opening shape is a rectangle, the direction and length R of the short axis are consistent with the direction and length of its short side (refer to Figure 4A to Figure 4E ). If the opening shape is a square, the direction and length R of the short axis are consistent with the direction and length of any side. If the opening shape is a rhombus, the direction and length R of the short axis are consistent with the direction and length of the shorter diagonal. If the opening shape is an ellipse, the direction and length R of the short axis are consistent with the direction and length of the short diameter (refer to Figure 4F ). If the opening shape is circular, the direction and length R of the minor axis are consistent with the direction and length of its diameter.

[0157] In addition, in this embodiment, the pitch P refers to the interval between the third recesses 37 arranged in the short axis direction. The pitch P may also be the interval between the center points of the third recesses 37 arranged in the short axis direction. Figure 4A to Figure 4B When the third recesses 37 are arranged in a grid pattern, the interval between the third recesses 37 adjacent to each other in the short axis direction is the pitch P. Figure 4C to Figure 4F In the embodiment, the third concave portions 37 adjacent to each other in the minor axis direction are offset in the D1 direction and arranged in a staggered manner. Figure 4C to Figure 4F As shown in FIG. 1 , the interval between the third recessed portions 37 adjacent to each other in the short-axis direction is a pitch P. As shown in FIG.

[0158] The minor axis length R may preferably be 250 μm or less, 225 μm or less, 200 μm or less, 175 μm or less, 150 μm or less, 125 μm or less, 100 μm or less, 75 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. In addition, the minor axis length R may preferably be 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, or 100 μm or more.

[0159] The stress dispersion region 24 has third recesses 37 arranged at a pitch P in the minor axis direction. The pitch P may preferably be 300 μm or less, 250 μm or less, 225 μm or less, 200 μm or less, 175 μm or less, 150 μm or less, 125 μm or less, 100 μm or less, 75 μm or less, or 50 μm or less. In addition, the pitch P may preferably be 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, or 100 μm or more.

[0160] In addition, the ratio (R / P) of the length R to the pitch P is 0.90 or more, preferably 0.92 or more, 0.94 or more, 0.96 or more, or 0.98 or more. The ratio (R / P) is preferably 1.00 or less, 0.99 or less, or 0.98 or less.

[0161] It should be noted that if Figure 3A As shown, when the third wall surfaces 38 of the adjacent third recesses 37 merge, the pitch P of the third recesses 37 arranged in the minor axis direction is equal to the minor axis length R. Therefore, the ratio (R / P) at this time is 1.00.

[0162] By making the minor axis length R1 and the ratio (R / P) greater than the above lower limit, the third recess 37 is formed larger and closer in the stress dispersion region 24. Therefore, the stress can be dispersed more evenly through the stress dispersion region 24. Thus, even when tension is applied to the metal mask, wrinkles are not easily generated, and the accuracy of the setting position can be improved. In addition, by making the minor axis length R1 and the ratio (R / P) less than the above upper limit, there is a tendency that the strength of the metal mask is further improved.

[0163] In addition, by making the pitch P less than the above upper limit, the adjacent third recesses 37 are formed closer in the stress dispersion region 24. Therefore, the stress can be dispersed more evenly by the stress dispersion region 24. Thus, even when tension is applied to the metal mask, wrinkles are not easily generated, and the installation position accuracy can be improved. In addition, by making the pitch P more than the above lower limit, there is a tendency that the strength of the metal mask is further improved.

[0164] It should be noted that the ranges of the minor axis length R, the pitch P, and the ratio (R / P) may also be determined by a combination of any one of the plurality of candidate values ​​for the lower limit and any one of the plurality of candidate values ​​for the upper limit.

[0165] The thinnest portion of the stress dispersion region 24 has a height H1. The thinnest portion of the stress dispersion region 24 may be a portion of the bottom of the third recess 37 in the stress dispersion region 24. For example, when the third recess 37 is formed on the second surface 20b, the height H1 may be the height from the first surface 20a to the bottom of the third recess 37. In addition, when the third recess 37 is formed on the first surface 20a, the height H1 may be the height from the second surface 20b to the bottom of the third recess 37. It should be noted that the bottom of the third recess 37 may also be a portion of the stress dispersion region 24 with an extremely small height.

[0166] The height H1 may be preferably 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. The height H1 may be preferably 2.5 μm or more, 5 μm or more, or 10 μm or more.

[0167] In addition, the ratio of the height H1 to the height H0 (H1 / H0) may preferably be 0.20 or more, 0.25 or more, 0.30 or more, 0.35 or more, 0.40 or more, or 0.45 or more. In addition, the ratio of H1 (H1 / H0) may preferably be 0.80 or less, 0.75 or less, 0.70 or less, 0.65 or less, 0.60 or less, or 0.55 or less.

[0168] By setting the height H1 and the ratio (H1 / H0) within the above ranges, the stress dispersion performance is improved and the uniform dispersion thereof tends to be further improved.

[0169] It should be noted that the ranges of the height H1 and the ratio (H1 / H0) may also be determined by a combination of any one of the plurality of candidate values ​​for the lower limit and any one of the plurality of candidate values ​​for the upper limit.

[0170] The stress dispersion region 24 may be formed at any position of the peripheral region 23. Figure 1 , an example of the position of the stress dispersion region 24 in the surrounding region 23 is described. Figure 1 24 a to 24 d are shown according to their positions.

[0171] The stress dispersion region 24 may be located between the edge 23 b of the peripheral region 23 and the apertured region 22 . Figure 1In the embodiment, the edge 23b of the surrounding area 23 has a pair of long sides 23c and a pair of short sides 23d. In this case, the stress dispersion area 24a may be located between the long side 23c and the hole area 22. In addition, the stress dispersion areas 24c and 24d may be located between the short side 23d and the hole area 22. In addition, the stress dispersion area 24a may be located around the hole area 22, and the stress dispersion area 24a may be located at a position surrounding the hole area 22.

[0172] In the longitudinal direction D2, the width L1 of the stress dispersion region 24a and the width L2 of the perforated region 22 may be substantially the same. The ratio (L1 / L2) of the width L1 to the width L2 may preferably be 0.80 or more, 0.90 or more, or 1.00 or more. In addition, the ratio (L1 / L2) may preferably be 2.00 or less, 1.50 or less, 1.20 or less, 1.10 or less, or 1.00 or less.

[0173] In the width direction D1, the width L3 of the stress dispersion regions 24c and 24d and the width L4 of the perforated region 22 may be substantially the same. The ratio (L3 / L4) of the width L3 to the width L4 may preferably be 0.80 or more, 0.90 or more, or 1.00 or more. In addition, the ratio (L3 / L4) may preferably be 1.20 or less, 1.10 or less, or 1.00 or less.

[0174] In the width direction D1, the width L3 of the stress dispersion regions 24c and 24d may be substantially the same as the width L0 of the surrounding region 23. The ratio (L3 / L0) of the width L3 to the width L0 may preferably be 0.70 or more, 0.80 or more, or 0.90 or more. In addition, the ratio (L3 / L0) may preferably be 0.95 or less, 0.90 or less, or 0.85 or less.

[0175] When there are a plurality of apertured regions 22 , the stress dispersion region 24 b may be located between the plurality of apertured regions 22 .

[0176] In the width direction D1, the width L5 of the stress dispersion region 24b and the width L4 of the perforated region 22 may be substantially the same. The ratio (L5 / L4) of the width L5 to the width L4 may preferably be 0.80 or more, 0.90 or more, or 1.00 or more. In addition, the ratio (L5 / L4) may preferably be 1.20 or less, 1.10 or less, or 1.00 or less.

[0177] In the width direction D1, the width L5 of the stress dispersion region 24b and the width L0 of the surrounding region 23 may be substantially the same. The ratio (L5 / L0) of the width L5 to the width L0 may preferably be 0.70 or more, 0.80 or more, or 0.90 or more. In addition, the ratio (L5 / L0) may preferably be 0.95 or less, 0.90 or less, or 0.85 or less.

[0178] The peripheral region 23 may have a cutting line 26. The cutting line 26 is a cutting line when the peripheral region 23 is cut. The cutting line 26 may be, for example, a row of through holes or recesses formed by half etching arranged at predetermined intervals. The peripheral region 23 may also be cut along the cutting line 26. For example, after the metal mask 20 is welded to the frame 15, the peripheral region 23 may be cut along the cutting line 26 located outside the welded portion.

[0179] The stress dispersion region 24c may be located between the cut line 26 and the hole region 22. In addition, the stress dispersion region 24d may be located between the cut line 26 and the short side 23d. In other words, the cut line 26 may be located between the stress dispersion region 24d and the hole region 22.

[0180] The stress dispersion region 24 may be rectangular, or may be approximately fan-shaped, polygonal, circular or elliptical. The perforated region 22 and the stress dispersion region 24 may both have a rectangular shape. At this time, one side of the stress dispersion region 24 may also be located at a position substantially parallel to one side of the perforated region 22.

[0181] 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 .

[0182] It should be noted that, below, a method of manufacturing the metal mask 20 by etching will be described, but the metal mask 20 may be formed by etching, may be formed by laser processing, or may be formed by electroforming.

[0183] Main reference Figure 5A to Figure 5F , a method for manufacturing the metal mask 20 according to one embodiment of the present disclosure is described. Figure 5A 1 is a schematic diagram showing a manufacturing apparatus 70 for manufacturing the metal mask 20 using the metal plate 51 and its processing sequence. Figure 5A, 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, the metal plate 51 may be unwound from the wound body for supply.

[0184] Hereinafter, each step of the method for manufacturing the metal mask 20 will be described in detail.

[0185] 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 and plating film forming methods.

[0186] 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 5B 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 to the first surface 51a and the second surface 51b and drying the coating liquid.

[0187] There is no particular limitation on the dry film resist or coating liquid, and any conventionally known dry film resist or coating liquid can be used. In addition, the resist films 53a and 53b formed in this way can be either negative resists or positive resists. Among them, negative resists are preferably used.

[0188] The thickness of the resist films 53a and 53b may be 15 μm or less, 10 μm or less, 6 μm or less, or 4 μm or less. In addition, the thickness of the resist films 53a and 53b may be 1 μm or more, 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 upper limit and any one of the candidate values ​​of the lower limit.

[0189] Next, the resist films 53a and 53b are exposed and developed using the exposure / development device 72. Figure 5CAs 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 arranged on the resist film, and the resist film can be exposed through the photomask and then developed.

[0190] 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.

[0191] Figure 5D 2 shows a schematic diagram showing an example of the first surface etching process in the porous region 22. 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.

[0192] The etching liquid causes the first surface 51a not covered by the first resist pattern 53c to be eroded ( Figure 5D ). Thus, a plurality of first recesses 30 are formed on the first surface 51a. It should be noted that the etching of the metal plate 51 can be performed isotropically from the holes 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 become a shape that gradually decreases as it moves from the surface to the thickness direction.

[0193] Figure 5E 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.

[0194] The etching liquid causes the second surface 51b not covered by the second resist pattern 53d to be eroded ( Figure 5E ). 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.

[0195] 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.

[0196] In the second side etching process, if Figure 5EAs 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 erosion caused by etching also proceeds in the thickness direction of the metal plate 51 at the top of the ridge 33. Thus, the second resist pattern 53d is peeled off from the metal plate 51. It should be noted that the second surface 51b may be partially left between adjacent second recesses 35.

[0197] Fig. 5F FIG. 2 is a schematic diagram showing an example of the second surface etching process in the stress dispersion region 24. The second concave portion 35 of the hole region 22 and the third concave portion 37 of the stress dispersion region 24 can also be formed by the same second surface etching process. Fig. 5F As shown, etching may be performed until adjacent third recesses 37 are connected. At the portion where adjacent third recesses 37 are connected, the adjacent third recesses 37 merge to form a ridgeline 39.

[0198] Furthermore, the resist pattern or the resin 54 resistant to the etching solution is peeled off from the metal plate 51 using the peeling device 74. Then, the following separation step is performed: the long metal plate 51 is cut using the separation 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.

[0199] 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 6 2 shows a top view of the metal mask device 10 viewed from the first surface 20a side of the metal mask 20. Figure 7 A cross-sectional view showing a vapor deposition device is shown in FIG.

[0200] In the metal mask device 10 of the present disclosure, a plurality of metal masks 20 ( Figure 6 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.

[0201] In addition, it is also possible to install a frame 15 Figure 1 A metal mask 20 as shown in C. At this time, the metal mask 20 may be fixed to the frame 15 at the end 23 a of the peripheral region 23 .

[0202] The method for fixing the frame 15 is not particularly limited, and welding or the like may be mentioned, for example.

[0203] 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, for example, a component that extends in a direction intersecting the length direction of the metal mask 20 and supports the metal mask 20, a component that overlaps with a gap between two adjacent metal masks, and the like.

[0204] Next, refer to Figure 7 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.

[0205] 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 on a substrate such as the substrate 92 using the metal mask 20 .

[0206] 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 7 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.

[0207] like Figure 7 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.

[0208] 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. It should be noted that in the evaporation process, the interior of the evaporation device 90 may also be a vacuum atmosphere.

[0209] When it is desired to evaporate different types of evaporation materials according to pixels such as RGB, different metal masks 20 may be used according to the colors of the evaporation materials 98 to form a film of the evaporation materials 98 on the surface of the substrate 92. For example, the evaporation materials 98 for red, the evaporation materials 98 for green, and the evaporation materials 98 for blue may be sequentially evaporated 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 evaporation materials 98 for red, the evaporation materials 98 for green, and the evaporation materials 98 for blue may be sequentially evaporated.

[0210] In addition, in the method for manufacturing an organic EL display device, in addition to the vapor deposition step of vapor-depositing the vapor deposition material 98 on a substrate such as a substrate 92 using the metal mask 20, various steps may be included. For example, the method for manufacturing an organic EL display device may also 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 also 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 also include a sealing step of sealing the first electrode, the vapor deposition layer, and the second electrode provided on the substrate 92.

[0211] 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, and 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.

[0212] It should be noted that various changes can be made to the above-mentioned embodiment. Hereinafter, the modified example will be 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 manner 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, the description thereof is sometimes omitted.

[0213] (Variation Example)

[0214] As a first modification, the metal mask 20 may have two or more rows of multiple hole regions 22. In other words, the multiple hole regions 22 may be arranged in a lattice. In this case, the stress dispersion region 24 may be located between the edge 23b of the peripheral region 23 and the hole region 22. In addition, the stress dispersion region 24 may be located between the multiple hole regions 22.

[0215] When the metal mask 20 has two or more rows of the plurality of hole regions 22, one metal mask 20 may be mounted on one frame 15. In this case, the end 23a may be located at the periphery of the metal mask 20. When the end 23a has a cut line 26, the stress dispersion region 24c may be located between the cut line 26 and the hole region 22. In addition, the stress dispersion region 24d may be located between the cut line 26 and the short side 23d.

[0216] As a third variation, one perforated region 22 may also be configured to correspond to a plurality of organic EL display devices. For example, the perforated region 22 may include a first perforated region and a second perforated region. In this example, one first perforated region may correspond to one organic EL display device. In addition, the second perforated region may also be located at a position that divides the adjacent first perforated region.

[0217] The density of the through holes in the first perforated area and the second perforated area may also be different. More specifically, the density of the through holes in the first perforated area may be higher than the density of the through holes in the second perforated area. Here, the density of the through holes refers to the total area of ​​the through holes per unit area. In addition, the area of ​​a through hole refers to the area of ​​the through hole that is the smallest opening when viewed from above. Here, the opening of the through hole that is the smallest when viewed from above may also be the opening surrounded by the connecting portion 41.

[0218] As a third modification, instead of etching, the first recessed portion 30 , the second recessed portion 35 , and the third recessed portion 37 may be formed by irradiating with laser light using a laser irradiator.

[0219] Example

[0220] 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.

[0221] (Example)

[0222] By the above-mentioned method for manufacturing a metal mask, a metal mask having a through hole composed of a first recess and a second recess and a third recess in a metal plate is manufactured. At this time, the minor axis length R of the third recess and the pitch P arranged in the minor axis direction are made to have a predetermined relationship. In addition, the metal plate as a raw material of the metal mask is an Invar alloy material.

[0223] (Comparative Example)

[0224] A metal mask was obtained in the same manner as in Example except that the minor axis length R of the third recessed portions and the pitch P arranged in the minor axis direction had the prescribed relationship shown in Table 1.

[0225] (evaluate)

[0226] When the metal mask is welded to the frame by applying a tensile force in the length direction of the metal mask, the undulations generated in the width direction of the mask are measured as the wave amount after the welding. Specifically, the metal mask is welded to the frame and three-dimensionally measured using μ-M1000 manufactured by SINTO S-PRECISION, LTD. to obtain the wave amount. Based on the obtained wave amount, the generation of wrinkles is evaluated according to the following evaluation criteria.

[0227] ◎…The fluctuation after erection welding is less than 100μm.

[0228] 〇…The fluctuation amount after the bridge welding exceeds 100 μm and is 200 μm or less.

[0229] ×…The fluctuation amount after erection welding exceeds 200μm.

[0230] It should be noted that the above-mentioned fluctuation amount of less than 100μm means that the metal mask has good adhesion to the substrate and there is almost no metal mask floating. The above-mentioned fluctuation amount of more than 100μm and less than 200μm means that the metal mask is tightly bonded to the substrate through magnetic force without blurring. The fluctuation amount of more than 200μm means that blurring occurs due to poor adhesion between the metal mask and the substrate.

[0231] It should be noted that the above-mentioned "prescribed process" refers to a series of processes of manufacturing a metal mask, mounting and welding the manufactured metal mask on a frame to manufacture a metal mask device, using the obtained metal mask device for vapor deposition, and cleaning the metal mask device and using it again for vapor deposition.

[0232] [Table 1]

[0233]

[0234] Industrial Applicability

[0235] 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.

[0236] Description of Reference Numerals

[0237] 10 ... metal mask device, 15 ... frame, 20 ... metal mask, 20a ... first surface, 20b ... second surface, 22 ... holed region, 23 ... peripheral region, 23a ... end, 23b ... edge, 23c ... long side, 23d ... short side, 24 ... stress dispersion region, 24a ... stress dispersion region, 24b ... stress dispersion region, 24c ... stress dispersion region, 24d ... stress dispersion region, 25 ... through hole, 26 ... cutting line, 30 ... first concave portion, 31 ... first wall surface, 32 ... top portion, 33 ... ridge line, 35 ... second concave portion, 36 ... second wall surface, 37 ...third recess, 38...third wall surface, 39...ridgeline, 41...connecting portion, 50...wound body, 51...metal plate, 51a...first surface, 51b...second surface, 52...core, 53a...resist film, 53b...resist film, 53c...first resist pattern, 53d...second resist pattern, 54...resin, 70...manufacturing device, 71...resist film forming device, 72...exposure / developing device, 73...etching device, 74...peeling device, 75...separating device, 90...evaporation device, 92...substrate, 94...crucible, 96...heater, 98...evaporation material

Claims

1. A metal mask having 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 surrounding area has a stress dispersion area, The stress dispersion region has a plurality of recesses, The opening shape of the recessed portion in a plan view has a minor axis of length R, The stress dispersion region has the recessed portions arranged at a pitch P in the short axis direction, A ratio R / P of the length R to the pitch P is greater than or equal to 0.

90.

2. The metal mask according to claim 1, wherein: The recesses are arranged in a staggered or lattice shape.

3. The metal mask according to claim 1, wherein: The wall surfaces of the adjacent recessed portions merge with each other.

4. The metal mask according to claim 1, wherein: The thickest part of the surrounding area has a height H0, The thinnest portion of the stress dispersion region has a height H1, A ratio H1 / H0 of the height H1 to the height H0 is greater than or equal to 0.20 and less than or equal to 0.

90.

5. The metal mask according to claim 1, wherein: The surrounding area has an edge, The stress dispersion region is located between the edge and the apertured region.

6. The metal mask according to claim 5, wherein: The edge of the peripheral area has a pair of long sides and a pair of short sides, The stress dispersion region is located between the edge, which is the long side, and the perforated region.

7. The metal mask according to claim 1, comprising a plurality of the porous regions. The stress dispersion region is located between the plurality of apertured regions.

8. The metal mask according to claim 1, wherein: The surrounding area has a cutting line, The cutting lines are rows of recesses or through holes, The stress dispersion area is located between the cutting line and the hole area.

9. The metal mask according to claim 1, wherein: The surrounding area has a cutting line, The cutting lines are rows of recesses or through holes, The cutting line is located between the stress dispersion area and the hole area.

10. A method for manufacturing a metal mask, comprising: 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 surrounding area has a stress dispersion area, The stress dispersion region has a plurality of recesses, The opening shape of the recessed portion in a plan view has a minor axis of length R, The stress dispersion region has the recessed portions arranged at a pitch P in the short axis direction, A ratio R / P of the length R to the pitch P is greater than or equal to 0.90.

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