Manufacturing method of intermediate product of vapor deposition mask

Abstract

To provide a manufacturing method of an intermediate product of a vapor deposition mask, the intermediate product being capable of precisely detecting a contour of the vapor deposition mask.SOLUTION: A manufacturing method of an intermediate product includes: a processing step of processing a metal plate to form multiple vapor deposition mask parts 51 and a support part 56 on the metal plate; and a separation step of separating the vapor deposition mark part from the metal plate. The vapor deposition mask part includes: a pair of longer side faces 26 defining a contour of the vapor deposition mask part in a longitudinal direction of the vapor deposition mask part; and a pair of shorter side faces 27 defining a contour of the vapor deposition mask part in a width direction of the vapor deposition mask part. The longer side face includes: a first end part positioned on a first surface side; and a second end part positioned on a second face side and positioned inside the first end part, and has a first part recessed inside. A through hole includes: a first concave part formed in the first surface side; and a second concave part formed on the second surface side and connected to the first concave part in a hole connection part. The first end part of the first part in the longer side surface is positioned closer to the first surface side than the hole connection part.SELECTED DRAWING: Figure 22A

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a method for manufacturing an intermediate product such as an evaporation mask.

Background Art

[0002] In recent years, for display devices used in portable devices such as smartphones and tablet PCs, high definition, for example, a pixel density of 400 ppi or more, is required. Also, in portable devices, the demand for supporting ultra-high definition is increasing, and in this case, it is required that the pixel density of the display device is, for example, 800 ppi or more.

[0003] Among display devices, organic EL display devices have attracted attention due to their good responsiveness, low power consumption, and high contrast. As a method for forming pixels of an organic EL display device, a method is known in which an evaporation mask having through holes formed in a desired pattern is used to form pixels in a desired pattern. Specifically, first, an evaporation mask is brought into close contact with a substrate for an organic EL display device, and then, both the brought-into-close-contact evaporation mask and the substrate are put into an evaporation apparatus, and an evaporation process of evaporating an organic material onto the substrate is performed. As a result, pixels containing an organic material can be formed on the substrate in a pattern corresponding to the pattern of the through holes of the evaporation mask.

[0004] In the evaporation process, the evaporation mask is fixed to a frame having a predetermined rigidity, for example, as disclosed in Patent Document 1. For example, when the evaporation mask has a rectangular shape including a pair of long sides and a pair of short sides, the evaporation mask is fixed to the frame in a state of being pulled in the direction of the long sides. Thereby, it is possible to suppress the evaporation mask from being bent and improve the dimensional accuracy and positional accuracy of the pixels.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As a factor determining the positional accuracy of pixels formed on a substrate, the alignment accuracy of a vapor deposition mask with respect to the substrate or a frame can be mentioned. As a reference position of the vapor deposition mask during alignment, for example, the contour of the outer shape of the vapor deposition mask is used. The position of the contour of the vapor deposition mask is detected, for example, by photographing the vapor deposition mask using a camera or the like.

[0007] In the step of detecting the position of the contour of the vapor deposition mask based on an image photographed using a camera or the like, it is preferable that the boundary between the region of the vapor deposition mask and other regions is clearly shown in the image. However, if light scattering occurs in the portion defining the contour of the vapor deposition mask, the boundary between the region of the vapor deposition mask and other regions in the image will be blurred.

[0008] An embodiment of the present disclosure aims to provide a method for manufacturing an intermediate product of a vapor deposition mask that can effectively solve such problems.

Means for Solving the Problems

[0009] The first embodiment of the present disclosure is a method for manufacturing an intermediate product of a vapor deposition mask, including a processing step of processing a metal plate to form, on the metal plate, a plurality of vapor deposition mask portions each having a plurality of through-holes, and a support portion that surrounds the vapor deposition mask portions in a plan view and is partially connected to the vapor deposition mask portions, and a separation step of separating the vapor deposition mask portions from the metal plate. The vapor deposition mask portions include a first surface and a second surface on which the through-holes are formed, a pair of long side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask portion in the longitudinal direction of the vapor deposition mask portion, and a pair of short side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask portion in the width direction of the vapor deposition mask portion. The long side surface includes a first end portion located on the first surface side and a second end portion located on the second surface side and inside the first end portion, and has a first portion recessed inward. The through-hole includes a first recess formed on the first surface side and a second recess formed on the second surface side and connected to the first recess at a hole connection portion. The first end portion of the first portion of the long side surface is located on the first surface side of the hole connection portion. The intermediate product is such that the first end portion may coincide with a first connection portion where the first surface and the long side surface are connected and that is located on the same plane as the first surface. Alternatively, the first end portion may be a first connection portion where the first surface and the long side surface are connected and be located outside the first connection portion that is located on the same plane as the first surface.

[0010] The second embodiment of the present disclosure is a method for manufacturing an intermediate product of a vapor deposition mask, including a processing step of processing a metal plate to form, on the metal plate, a plurality of vapor deposition mask portions each having a plurality of through holes, and a support portion surrounding the vapor deposition mask portions in a plan view and being partially connected to the vapor deposition mask portions, and a separating step of separating the vapor deposition mask portions from the metal plate. The vapor deposition mask portions include a first surface and a second surface on which the through holes are formed, a pair of long side surfaces connected to the first surface and the second surface and defining a contour of the vapor deposition mask portions in a longitudinal direction thereof, and a pair of short side surfaces connected to the first surface and the second surface and defining a contour of the vapor deposition mask portions in a width direction thereof. The long side surfaces include a first end portion located on the first surface side and a second end portion located on the second surface side and inside the first end portion, and have a first portion recessed inward. The first end portion is a first connection portion where the first surface and the long side surface are connected, and coincides with the first connection portion located on the same plane as the first surface. It is an intermediate product.

[0011] In the method for manufacturing an intermediate product according to the embodiment of the present disclosure, the distance in the plane direction of the first surface between the first connection portion where the first surface and the long side surface are connected and which is located on the same plane as the first surface, and the first end portion of the first portion of the long side surface may be 3.5 μm or less.

[0012] In the method for manufacturing an intermediate product according to the first and second embodiments of the present disclosure, the first portion may be located inside a virtual plane or straight line passing through the first end portion and the second end portion.

[0013] In the method for manufacturing an intermediate product according to the first and second embodiments of the present disclosure, the thickness of the vapor deposition mask may be 50 μm or less.

[0014] In the method for manufacturing an intermediate product according to the first and second embodiments of the present disclosure, the second end portion is a second connection portion where the second surface and the long side surface are connected, and may coincide with the second connection portion located on the same plane as the second surface.

Advantages of the Invention

[0015] According to the embodiment of the present disclosure, the contour of the vapor deposition mask can be accurately detected.

Brief Description of the Drawings

[0016]

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Mode for Carrying Out the Invention

[0017] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, for the convenience of illustration and easy understanding, the scale, the aspect ratio of the vertical and horizontal dimensions, etc. are appropriately changed and exaggerated from those of the actual object.

[0018] FIGS. 1 to 25 are diagrams for explaining an embodiment of the present disclosure. In the following embodiments and their modifications, a method for manufacturing a vapor deposition mask used for patterning an organic material on a substrate in a desired pattern when manufacturing an organic EL display device will be described as an example. However, the present disclosure is not limited to such applications, and the embodiments of the present disclosure can be applied to vapor deposition masks used for various applications.

[0019] In this specification, the terms "plate", "sheet", and "film" are not distinguished from each other based only on the difference in name. For example, the "plate" is a concept including members that can be called sheets or films.

[0020] Further, the "plate surface (sheet surface, film surface)" refers to a surface that coincides with the planar direction of the target plate-like (sheet-like, film-like) member when the target plate-like member (sheet-like member, film-like member) is viewed as a whole and globally. Also, the normal direction used for a plate-like (sheet-like, film-like) member refers to the normal direction with respect to the plate surface (sheet surface, film surface) of the member.

[0021] Furthermore, terms used in this specification for specifying shapes, geometric conditions, physical properties, and their degrees, such as terms like "parallel", "orthogonal", "identical", "equivalent", etc., lengths, angles, and values of physical properties, etc., are not bound by a strict meaning, and will be interpreted to include a range where similar functions can be expected.

[0022] <Evaporation device> First, an evaporation device 90 for performing an evaporation process of evaporating an evaporation material onto an object will be described with reference to FIG. 1. As shown in FIG. 1, the evaporation device 90 includes an evaporation source (for example, crucible 94), a heater 96, and an evaporation mask device 10 inside thereof. Further, the evaporation device 90 further includes an exhaust means for making the inside of the evaporation device 90 a vacuum atmosphere. The crucible 94 accommodates an evaporation material 98 such as an organic light-emitting material. The heater 96 heats the crucible 94 to evaporate the evaporation material 98 under a vacuum atmosphere. The evaporation mask device 10 is arranged to face the crucible 94.

[0023] <Evaporation mask device> Hereinafter, the evaporation mask device 10 will be described. As shown in FIG. 1, the evaporation mask device 10 includes an evaporation mask 20 and a frame 15 that supports the evaporation mask 20. The frame 15 supports the evaporation mask 20 in a state where the evaporation mask 20 is pulled in its plane direction so that the evaporation mask 20 does not bend. As shown in FIG. 1, the evaporation mask device 10 is arranged in the evaporation device 90 so that the evaporation mask 20 faces a substrate, for example, an organic EL substrate 92, which is an object to which the evaporation material 98 is to be attached. In the following description, among the surfaces of the evaporation mask 20, the surface on the organic EL substrate 92 side is referred to as the first surface 20a, and the surface located on the opposite side of the first surface 20a is referred to as the second surface 20b, but the present invention is not limited thereto.

[0024] As shown in FIG. 1, the evaporation mask device 10 may include a magnet 93 disposed on the surface of the organic EL substrate 92 opposite to the evaporation mask 20. By providing the magnet 93, the evaporation mask 20 can be attracted toward the magnet 93 by magnetic force, and the evaporation mask 20 can be brought into close contact with the organic EL substrate 92. Thereby, it is possible to suppress the generation of shadows in the evaporation process, and to improve the dimensional accuracy and positional accuracy of the evaporation material 98 attached to the EL substrate 92.

[0025] FIG. 3 is a plan view showing the vapor deposition mask apparatus 10 as viewed from the first surface 20a side of the vapor deposition mask 20. As shown in FIG. 3, the vapor deposition mask apparatus 10 includes a plurality of vapor deposition masks 20. In the present embodiment, each vapor deposition mask 20 has a rectangular shape extending in the longitudinal direction D1. In the vapor deposition mask apparatus 10, the plurality of vapor deposition masks 20 are arranged in the width direction D2 intersecting the longitudinal direction D1 of the vapor deposition mask 20. Each vapor deposition mask 20 is fixed to the frame 15, for example, by welding, at both ends in the longitudinal direction D1 of the vapor deposition mask 20.

[0026] FIG. 4 is a perspective view showing the vapor deposition mask 20. The vapor deposition mask 20 includes a plate-like base material 21 made of metal and a plurality of through holes 25 penetrating the base material 21. The vapor deposition material 98 that has evaporated from the crucible 94 and reached the vapor deposition mask apparatus 10 adheres to the organic EL substrate 92 through the through holes 25 of the vapor deposition mask 20. Thereby, the vapor deposition material 98 can be formed into a film on the surface of the organic EL substrate 92 in a desired pattern corresponding to the positions of the through holes 25 of the vapor deposition mask 20.

[0027] FIG. 2 is a cross-sectional view showing the organic EL display device 100 manufactured using the vapor deposition apparatus 90 of FIG. 1. The organic EL display device 100 includes an organic EL substrate 92 and pixels including a vapor deposition material 98 provided in a pattern.

[0028] When color display using a plurality of colors is desired, vapor deposition apparatuses 90 each equipped with a vapor deposition mask 20 corresponding to each color are prepared, and the organic EL substrate 92 is sequentially loaded into each vapor deposition apparatus 90. Thereby, for example, an organic light-emitting material for red, an organic light-emitting material for green, and an organic light-emitting material for blue can be sequentially vapor-deposited on the organic EL substrate 92.

[0029] Incidentally, the vapor deposition process may be carried out inside a vapor deposition apparatus 90 that has a high-temperature atmosphere. In this case, during the vapor deposition process, the vapor deposition mask 20, the frame 15, and the organic EL substrate 92 held inside the vapor deposition apparatus 90 are also heated. At this time, the vapor deposition mask 20, the frame 15, and the organic EL substrate 92 will exhibit behavior of dimensional change based on their respective coefficients of thermal expansion. In this case, if the coefficients of thermal expansion of the vapor deposition mask 20 and the frame 15 are significantly different from that of the organic EL substrate 92, displacement will occur due to the difference in their dimensional changes. As a result, the dimensional accuracy and positional accuracy of the vapor deposition material adhering to the organic EL substrate 92 will decrease.

[0030] To solve such problems, it is preferable that the coefficients of thermal expansion of the vapor deposition mask 20 and the frame 15 are equal to that of the organic EL substrate 92. For example, when a glass substrate is used as the organic EL substrate 92, an iron alloy containing nickel can be used as the main material of the vapor deposition mask 20 and the frame 15. For example, an iron alloy containing 30 mass% or more and 54 mass% or less of nickel can be used as the material of the base material constituting the vapor deposition mask 20. Specific examples of the iron alloy containing nickel include an Invar material containing 34 mass% or more and 38 mass% or less of nickel, a Super Invar material containing cobalt in addition to 30 mass% or more and 34 mass% or less of nickel, and a low thermal expansion Fe-Ni based plating alloy containing 38 mass% or more and 54 mass% or less of nickel.

[0031] Note that when the temperatures of the vapor deposition mask 20, the frame 15, and the organic EL substrate 92 do not reach a high temperature during the vapor deposition process, there is no particular need to make the coefficients of thermal expansion of the vapor deposition mask 20 and the frame 15 equal to that of the organic EL substrate 92. In this case, a material other than the above-described iron alloy may be used as the material constituting the vapor deposition mask 20. For example, an iron alloy other than the above-described iron alloy containing nickel, such as an iron alloy containing chromium, may be used. As the iron alloy containing chromium, for example, an iron alloy so-called stainless steel can be used. Also, an alloy other than an iron alloy, such as nickel or a nickel-cobalt alloy, may be used.

[0032] (Evaporation mask) Next, the evaporation mask 20 will be described in detail. First, the outer shape of the evaporation mask 20 will be described. As shown in FIGS. 3 and 4, the evaporation mask 20 includes the above-described first surface 20a and second surface 20b in which through holes 25 are formed, and a pair of long side surfaces 26 and a pair of short side surfaces 27 connected to the first surface 20a and the second surface 20b. The pair of long side surfaces 26 extends in the longitudinal direction D1 of the evaporation mask 20. The pair of long side surfaces 26 defines the contour of the evaporation mask 20 in the longitudinal direction D1 when the evaporation mask 20 is viewed along the normal direction of the first surface 20a. The pair of short side surfaces 27 extends in the width direction D2 of the evaporation mask 20. The pair of short side surfaces 27 defines the contour of the evaporation mask 20 in the width direction D2 when the evaporation mask 20 is viewed along the normal direction of the first surface 20a. In the example shown in FIGS. 3 and 4, the width direction D2 is orthogonal to the longitudinal direction D1. In the following description, the portion where the first surface 20a and the long side surface 26 are connected is referred to as the first connection portion 20e, and the portion where the second surface 20b and the long side surface 26 are connected is also referred to as the second connection portion 20f. The first connection portion 20e is located on the same plane as the first surface 20a. The second connection portion 20f is located on the same plane as the second surface 20b.

[0033] Next, the configuration of the evaporation mask 20 related to the through holes 25 will be described. As shown in FIGS. 3 and 4, the evaporation mask 20 includes at least one effective region 22 in which through holes 25 are formed from the first surface 20a to the second surface 20b, and a peripheral region 23 surrounding the effective region 22. The effective region 22 is a region of the evaporation mask 20 that faces the display region of the organic EL substrate 92.

[0034] In the example shown in FIGS. 3 and 4, the evaporation mask 20 includes a plurality of effective regions 22 arranged at a predetermined interval along the longitudinal direction D1 of the evaporation mask 20. One effective region 22 corresponds to the display region of one organic EL display device 100. Therefore, multi-sided evaporation of the organic EL display device 100 is possible. That is, using a single evaporation mask 20, it is possible to form a pattern of the evaporation material 98 corresponding to a plurality of organic EL display devices 100 on a single organic EL substrate 92.

[0035] As shown in FIGS. 3 and 4, the effective region 22 has, for example, a substantially rectangular shape in plan view, and more precisely, a contour that is substantially rectangular in plan view. Although not shown, each effective region 22 can have contours of various shapes according to the shape of the display region of the organic EL substrate 92. For example, each effective region 22 may have a circular contour.

[0036] 〔Effective Region〕 Hereinafter, the cross-sectional shape of the effective region 22 will be described in detail. FIG. 5 is a plan view showing an enlarged view of the effective region 22 when viewed from the second surface 20b side of the evaporation mask 20. As shown in FIG. 5, in the illustrated example, the plurality of through holes 25 formed in each effective region 22 are arranged at a predetermined pitch along two directions orthogonal to each other in the effective region 22. An example of the through hole 25 will be described in more detail mainly with reference to FIGS. 6 to 8. FIGS. 6 to 8 are cross-sectional views along the VI-VI direction to VIII-VIII direction of the effective region 22 of FIG. 5, respectively.

[0037] As shown in FIGS. 6 to 8, the plurality of through holes 25 penetrate from the first surface 20a on one side along the normal direction N of the evaporation mask 20 to the second surface 20b on the other side along the normal direction N of the evaporation mask 20. In the illustrated example, as will be described in detail later, a first recess 30 is formed by etching on the first surface 20a of the evaporation mask 20, and a second recess 35 is formed on the second surface 20b of the evaporation mask 20. The first recess 30 is connected to the second recess 35, and thus the second recess 35 and the first recess 30 are formed to communicate with each other. The through hole 25 is constituted by the second recess 35 and the first recess 30 connected to the second recess 35.

[0038] As shown in FIGS. 6 to 8, the opening area of each second recess 35 in the cross-section along the plate surface of the vapor deposition mask 20 at each position along the normal direction N of the vapor deposition mask 20 gradually decreases from the side of the second surface 20b of the vapor deposition mask 20 toward the side of the first surface 20a. Similarly, the opening area of each first recess 30 in the cross-section along the plate surface of the vapor deposition mask 20 at each position along the normal direction N of the vapor deposition mask 20 gradually decreases from the side of the first surface 20a of the vapor deposition mask 20 toward the side of the second surface 20b.

[0039] As shown in FIGS. 6 to 8, the wall surface 31 of the first recess 30 and the wall surface 36 of the second recess 35 are connected via a circumferential hole connection portion 41. The hole connection portion 41 is defined by the ridge line of the protruding portion where the wall surface 31 of the first recess 30 inclined with respect to the normal direction N of the vapor deposition mask 20 and the wall surface 36 of the second recess 35 inclined with respect to the normal direction N of the vapor deposition mask 20 merge. And the hole connection portion 41 defines a through portion 42 where the opening area of the through hole 25 is minimized in the plan view of the vapor deposition mask 20.

[0040] As shown in FIGS. 6 to 8, on the first surface 20a of the vapor deposition mask 20, two adjacent through holes 25 are spaced apart from each other along the plate surface of the vapor deposition mask 20. That is, when the base material 21 is etched from the first surface 20a side of the vapor deposition mask 20 to form the first recess 30 as in the manufacturing method described later, the first surface 20a remains between two adjacent first recesses 30.

[0041] Similarly, as shown in FIGS. 6 and 8, on the second surface 20b side of the vapor deposition mask 20, two adjacent second recesses 35 may be spaced apart from each other along the plate surface of the vapor deposition mask 20. That is, the second surface 20b of the vapor deposition mask 20 may remain between two adjacent second recesses 35. In the following description, the portion of the effective region 22 of the second surface 20b of the vapor deposition mask 20 that remains without being etched is also referred to as the top portion 43. By manufacturing the vapor deposition mask 20 such that such a top portion 43 remains, the vapor deposition mask 20 can be given sufficient strength. As a result, for example, it is possible to prevent the vapor deposition mask 20 from being damaged during transportation or the like. If the width β of the top portion 43 is too large, a shadow may occur in the vapor deposition process, which may reduce the utilization efficiency of the vapor deposition material 98. Therefore, it is preferable that the vapor deposition mask 20 is manufactured so that the width β of the top portion 43 does not become excessively large. For example, it is preferable that the width β of the top portion 43 is 2 μm or less. Note that the width β of the top portion 43 generally varies depending on the direction in which the vapor deposition mask 20 is cut. For example, the widths β of the top portion 43 shown in FIGS. 6 and 8 may be different from each other. In this case, the vapor deposition mask 20 may be configured such that the width β of the top portion 43 is 2 μm or less when the vapor deposition mask 20 is cut in any direction. Note that the shadow means a phenomenon in which a part of the vapor deposition material 98 that has reached the vapor deposition mask 20 from the vapor deposition source collides with the wall surface 31 of the first recess 30 or the wall surface 36 of the second recess 35 of the vapor deposition mask 20 and thus cannot reach the substrate such as the organic EL substrate 92, resulting in insufficient area and thickness of the layer of the vapor deposition material 98 on the substrate.

[0042] As shown in FIG. 7, etching may be performed such that two adjacent second recesses 35 are connected depending on the location. That is, there may be a location where the second surface 20b does not remain between two adjacent second recesses 35. Although not shown, etching may be performed such that two adjacent second recesses 35 are connected over the entire area of the second surface 20b.

[0043] When the vapor deposition mask device 10 is accommodated in the vapor deposition device 90 as shown in FIG. 1, the first surface 20a of the vapor deposition mask 20 faces the organic EL substrate 92, and the second surface 20b of the vapor deposition mask 20 is located on the side of the crucible 94 holding the vapor deposition material 98. Therefore, the vapor deposition material 98 adheres to the organic EL substrate 92 through the second recess 35 whose opening area gradually decreases. As shown by the arrow from the second surface 20b side to the first surface 20a in FIG. 6, the vapor deposition material 98 not only moves along the normal direction N of the organic EL substrate 92 from the crucible 94 toward the organic EL substrate 92, but may also move in a direction greatly inclined with respect to the normal direction N of the organic EL substrate 92. At this time, if the thickness of the vapor deposition mask 20 is large, most of the vapor deposition material 98 moving obliquely reaches and adheres to the wall surface 36 of the second recess 35 before reaching the organic EL substrate 92 through the through hole 25. Therefore, in order to improve the utilization efficiency of the vapor deposition material 98, it is preferable to reduce the thickness t of the vapor deposition mask 20, and thereby reduce the height of the wall surface 36 of the second recess 35 and the wall surface 31 of the first recess 30. That is, as the base material 21 for constituting the vapor deposition mask 20, it can be said that it is preferable to reduce the thickness t as much as possible within the range where the strength of the vapor deposition mask 20 can be ensured. Considering this point, in the present embodiment, preferably, the thickness t of the vapor deposition mask 20 is set to 50 μm or less, for example, 5 μm or more and 50 μm or less. The thickness t of the vapor deposition mask 20 may be 30 μm or less, 25 μm or less, 20 μm or less, 18 μm or less, 15 μm or less, or 13 μm or less. By reducing the thickness t of the vapor deposition mask 20, it is possible to suppress the vapor deposition material 98 from colliding with the wall surface 31 of the first recess 30 and the wall surface 36 of the second recess 35 in the vapor deposition process, so that it is possible to suppress the generation of shadows. Also, the thickness of the metal plate 64 may be 2 μm or more, 5 μm or more, 10 μm or more, or 15 μm or more. Note that the thickness t is the thickness of the peripheral region 23, that is, the thickness of the portion of the vapor deposition mask 20 where the first recess 30 and the second recess 35 are not formed. Therefore, it can also be said that the thickness t is the thickness of the base material 21.Also, it can be said that the thickness t is the thickness of the metal plate 64 that constitutes the base material 21 of the vapor deposition mask 20.

[0044] In FIG. 6, a straight line L1 passing through the hole connection part 41 which becomes the part having the minimum opening area of the through hole 25 and any other arbitrary position of the wall surface 36 of the second recessed part 35 forms a minimum angle with respect to the normal direction N of the vapor deposition mask 20, which is represented by the symbol θ1. In order to make the vapor deposition material 98 moving obliquely reach the organic EL substrate 92 as much as possible without reaching the wall surface 36, it is advantageous to increase the angle θ1. In increasing the angle θ1, in addition to reducing the thickness t of the vapor deposition mask 20, it is also effective to reduce the width β of the above-mentioned top part 43.

[0045] In FIG. 8, the symbol α represents the width of the portion (hereinafter also referred to as the rib portion) that remains without being etched in the effective region 22 of the first surface 20a of the vapor deposition mask 20. The width α of the rib portion and the dimension r2 of the through portion 42 are appropriately determined according to the dimensions of the organic EL display device and the number of display pixels. For example, the width α of the rib portion is 5 μm or more and 40 μm or less, and the dimension r2 of the through portion 42 is 10 μm or more and 60 μm or less.

[0046] Although not limited, the vapor deposition mask 20 according to the present embodiment is particularly effective when manufacturing an organic EL display device with a pixel density of 450 ppi or more. Hereinafter, with reference to FIG. 9, an example of the dimensions of the vapor deposition mask 20 required for manufacturing such an organic EL display device with a high pixel density will be described. FIG. 9 is a cross-sectional view showing an enlarged view of the through hole 25 of the vapor deposition mask 20 shown in FIG. 6 and the region in the vicinity thereof.

[0047] In FIG. 9, as parameters related to the shape of the through-hole 25, the distance in the direction along the normal direction N of the vapor deposition mask 20 from the first surface 20a of the vapor deposition mask 20 to the hole connection portion 41, that is, the height of the wall surface 31 of the first recess 30 is represented by the symbol r1. Further, the dimension of the first recess 30 at the portion where the first recess 30 is connected to the second recess 35, that is, the dimension of the through portion 42 is represented by the symbol r2. Also in FIG. 9, the angle formed by the straight line L2 connecting the hole connection portion 41 and the leading edge of the first recess 30 on the first surface 20a of the vapor deposition mask 20 with respect to the normal direction N of the base material 21 is represented by the symbol θ2.

[0048] When manufacturing an organic EL display device having a pixel density of 450 ppi or more, the dimension r2 of the through portion 42 is preferably set to 10 μm or more and 60 μm or less. Thereby, a vapor deposition mask 20 capable of manufacturing an organic EL display device having a high pixel density can be provided. Preferably, the height r1 of the wall surface 31 of the first recess 30 is set to 6 μm or less.

[0049] Next, the above-described angle θ2 shown in FIG. 9 will be described. The angle θ2 corresponds to the maximum value of the inclination angle of the vapor deposition material 98 that flies while being inclined with respect to the normal direction N of the base material 21 and passes through the through portion 42 in the vicinity of the hole connection portion 41 and can reach the organic EL substrate 92. This is because the vapor deposition material 98 that flies through the hole connection portion 41 at an inclination angle larger than the angle θ2 adheres to the wall surface 31 of the first recess 30 before reaching the organic EL substrate 92. Therefore, by reducing the angle θ2, it is possible to suppress the vapor deposition material 98 that flies at a large inclination angle and passes through the through portion 42 from adhering to the organic EL substrate 92, and thereby suppress the vapor deposition material 98 from adhering to a portion outside the portion overlapping the through portion 42 of the organic EL substrate 92. That is, reducing the angle θ2 leads to suppression of variations in the area and thickness of the vapor deposition material 98 adhering to the organic EL substrate 92. From such a viewpoint, for example, the through hole 25 is formed such that the angle θ2 is 45 degrees or less. In FIG. 9, an example is shown in which the dimension of the first recess 30 on the first surface 20a, that is, the opening dimension of the through hole 25 on the first surface 20a, is larger than the dimension r2 of the first recess 30 at the hole connection portion 41. That is, an example in which the value of the angle θ2 is a positive value is shown. However, although not shown, the dimension r2 of the first recess 30 at the hole connection portion 41 may be larger than the dimension of the first recess 30 on the first surface 20a. That is, the value of the angle θ2 may be a negative value.

[0050] 〔Peripheral region〕 Next, the cross-sectional shape of the peripheral region 23 will be described in detail. FIG. 10 is a cross-sectional view when the vapor deposition mask 20 is cut along the X-X line in FIG. 4. As shown in FIG. 10, the long side surface 26 constituting the end portion of the peripheral region 23 has a first portion 261 that is a surface recessed inward. In the present embodiment, the first portion 261 is a curved surface that is curved so as to be recessed inward. The first portion 261 includes a first end portion 261a that defines the contour of the first portion 261 on the side of the first surface 20a and a second end portion 261b that defines the contour of the first portion 261 on the side of the second surface 20b when the long side surface 26 is viewed from the outside along the surface direction of the first surface 20a. When the term "inner side" is used with respect to the long side surface 26, "inner side" means the central side in the width direction D2 of the vapor deposition mask 20, as represented by the arrow A1 in FIGS. 10 and 22B described later. "Central side" means the side of the center line C passing through the midpoint of the vapor deposition mask 20 in the width direction D2, as shown in FIGS. 4 and 10. Further, "outer side" means the side away from the center line C of the vapor deposition mask 20 in the width direction D2 of the vapor deposition mask 20, as represented by the arrow A2 in FIGS. 10 and 22B described later. Further, "recessed inward" means that the first portion 261 is located inside a virtual straight line or plane connecting the first end portion 261a on the side of the first surface 20a and the second end portion 261b on the side of the second surface 20b of the first portion 261. Although not shown, the first portion 261 may include a flat surface. That is, the first portion 261 does not have to be composed only of a curved surface. Further, the first portion 261 may locally include an uneven surface such as a zigzag.

[0051] As shown in FIG. 10, the first end portion 261a of the first portion 261 is located outside the second end portion 261b. Such a first portion 261 is formed by etching the metal plate constituting the base material 21 from the side of the second surface 20b, as will be described later. The distance γ in the width direction D2 between the first end portion 261a and the second end portion 261b is, for example, 5 μm or more and 50 μm or less.

[0052] In the example shown in FIG. 10, the second end portion 261b of the first portion 261 coincides with a second connection portion 20f where the second surface 20b and the long side surface 26 are connected. In other words, the first portion 261 extends to the second surface 20b. Further, in the example shown in FIG. 10, the first end portion 261a of the first portion 261 coincides with a first connection portion 20e where the first surface 20a and the long side surface 26 are connected. In other words, the first portion 261 extends to the first surface 20a.

[0053] Next, the shape of the long side surface 26 in a plan view will be described. FIG. 11 is a plan view showing the long side surface 26 viewed from the first surface 20a side along the normal direction of the first surface 20a. FIG. 12 is a plan view showing the long side surface 26 viewed from the second surface 20b side along the normal direction of the second surface 20b.

[0054] As shown in FIG. 11, when the long side surface 26 is viewed from the first surface 20a side, the first portion 261 is not visible. In this case, the contour of the vapor deposition mask 20 in the longitudinal direction D1 is defined by a first connection portion 20e where the first surface 20a and the long side surface 26 are connected. In this case, the region in the vicinity of the first connection portion 20e is constituted by the flat first surface 20a. Therefore, the position of the contour of the vapor deposition mask 20 in the longitudinal direction D1 can be easily detected.

[0055] On the other hand, as is apparent from FIG. 12, when the long side surface 26 is viewed from the second surface 20b side, the first portion 261 is visible. In the first portion 261, light is scattered in various directions. Therefore, in the example shown in FIG. 12, the first portion 261 is visually recognized as a portion that appears darker than the second surface 20b or appears in the image. Further, the first portion 261 has a width corresponding to the distance γ in FIG. 10. For this reason, there is an ambiguity corresponding to the width of the first portion 261 at the position of the contour of the evaporation mask 20 when viewed from the second surface 20b side. Therefore, it is more difficult to detect the position of the contour of the evaporation mask 20 in the longitudinal direction D1 when viewed from the second surface 20b side than when viewed from the first surface 20a side. Therefore, in the step of aligning the evaporation mask 20 with the organic EL substrate 92 or the frame 15, by adjusting the position of the evaporation mask 20 based on the result of photographing the evaporation mask 20 from the first surface 20a side, the adjustment becomes easy and the alignment accuracy is improved.

[0056] Manufacturing method of vapor deposition mask Next, a method for manufacturing the evaporation mask 20 will be described.

[0057] (Preparation of metal plate) First, a metal plate 64 for manufacturing the evaporation mask is prepared. The metal plate 64 is prepared, for example, in the form of a roll obtained by winding a long metal plate. As the metal plate 64, for example, a metal plate composed of an iron alloy containing nickel is used. The thickness of the metal plate 64 is, for example, 5 μm or more and 50 μm or less. As a method for producing the metal plate 64 having a desired thickness, a rolling method, a plating film forming method, or the like can be adopted.

[0058] Next, a method for manufacturing the evaporation mask 20 using the metal plate 64 will be described mainly with reference to FIGS. 13 to 24. In the method for manufacturing the evaporation mask 20 described below, as shown in FIG. 13, the metal plate 64 is processed to form a plurality of evaporation mask portions including through holes 25 in the metal plate 64 (processing step), and then the evaporation mask portions are separated from the metal plate 64 (separation step), whereby a single-sheet evaporation mask 20 can be obtained.

[0059] (Processing Step) The step of processing the metal plate 64 includes a step of performing etching using photolithography technology on the long metal plate 64 to form the first recess 30 from the side of the first surface 64a of the metal plate 64, and a step of performing etching using photolithography technology on the metal plate 64 to form the second recess 35 from the side of the second surface 64b of the metal plate 64. Then, by the first recess 30 and the second recess 35 formed in the metal plate 64 communicating with each other, the through hole 25 is produced in the metal plate 64. In the example described below, the step of forming the first recess 30 is performed before the step of forming the second recess 35, and a step of sealing the produced first recess 30 is performed between the step of forming the first recess 30 and the step of forming the second recess 35. Hereinafter, the details of each step will be described.

[0060] FIG. 13 shows a manufacturing apparatus 60 for producing the vapor deposition mask 20. As shown in FIG. 13, first, a wound body 62 obtained by winding the metal plate 64 around the core 61 is prepared. Then, by rotating the core 61 and unwinding the wound body 62, the metal plate 64 extending in a strip shape as shown in FIG. 13 is supplied.

[0061] The supplied metal plate 64 is conveyed to a processing apparatus (etching means) 70 by the conveying roller 72. Each process shown in FIGS. 14 to 21 is performed by the processing apparatus 70. In the present embodiment, a plurality of vapor deposition masks 20 are assigned in the width direction of the metal plate 64. In other words, the metal plate 64 is processed so that a plurality of later-described vapor deposition mask portions separated from the metal plate 64 to become the vapor deposition masks 20 are arranged in the width direction of the metal plate 64. In this case, preferably, the plurality of vapor deposition masks 20 are assigned to the metal plate 64 so that the direction of the long side surface 26 of the vapor deposition mask portion, that is, the vapor deposition mask 20, coincides with the longitudinal direction of the long metal plate 64.

[0062] First, as shown in FIG. 14, resist films 65c and 65d containing a negative photosensitive resist material are formed on the first surface 64a and the second surface 64b of the metal plate 64. For example, a coating solution containing a negative photosensitive resist material is applied onto the first surface 64a and the second surface 64b of the metal plate 64, and then the coating solution is dried to form the resist films 65c and 65d.

[0063] Next, exposure masks 68a and 68b that prevent light from passing through the regions of the resist films 65c and 65d to be removed are prepared, and the exposure masks 68a and 68b are respectively placed on the resist films 65c and 65d as shown in FIG. 15. As the exposure masks 68a and 68b, for example, glass dry plates that prevent light from passing through the regions of the resist films 65c and 65d to be removed are used. Then, the exposure masks 68a and 68b are sufficiently adhered to the resist films 65c and 65d by vacuum adhesion. Note that a positive photosensitive resist material may be used as the photosensitive resist material. In this case, an exposure mask that allows light to pass through the regions of the resist film to be removed is used as the exposure mask.

[0064] Thereafter, the resist films 65c and 65d are exposed through the exposure masks 68a and 68b (exposure step). Further, the resist films 65c and 65d are developed to form an image on the exposed resist films 65c and 65d (development step). As described above, as shown in FIG. 16, a first resist pattern 65a can be formed on the first surface 64a of the metal plate 64, and a second resist pattern 65b can be formed on the second surface 64b of the metal plate 64. The development step may include a resist heat treatment step for increasing the hardness of the resist films 65c and 65d or for more firmly adhering the resist films 65c and 65d to the metal plate 64. The resist heat treatment step can be performed, for example, at a temperature of room temperature or higher and 400°C or lower. In FIG. 16 and FIGS. 17 to 21 described later, the manufacturing process of the effective region 22 is shown on the right side, and the manufacturing process of the peripheral region 23 is shown on the left side.

[0065] As shown in FIG. 16, the first resist pattern 65a provided in the effective region 22 has a hole 66a located in a portion of the first surface 64a where the first recess 30 is to be formed later. On the other hand, the first resist pattern 65a provided in the peripheral region 23 covers a portion of the first surface 64a that will later become the long side surface 26. Further, the second resist pattern 65b has a hole 66b located in a portion of the second surface 64b of the effective region 22 where the second recess 35 is to be formed later, and also has an opening 66d located in a portion of the second surface 64b of the peripheral region 23 that will later become the long side surface 26. The dimension M2 of the opening 66d is larger than the dimension M1 of the hole 66b. The dimension M2 of the opening 66d is, for example, 50 μm or more.

[0066] Next, as shown in FIG. 17, a first surface etching step is performed in which a region of the first surface 64a of the metal plate 64 that is not covered by the first resist pattern 65a is etched using a first etching solution. For example, the first etching solution is sprayed from a nozzle disposed on the side facing the first surface 64a of the conveyed metal plate 64 through the first resist pattern 65a toward the first surface 64a of the metal plate 64. As a result, as shown in FIG. 17, erosion by the first etching solution proceeds in the region of the first surface 64a of the metal plate 64 corresponding to the hole 66a. Thereby, a large number of first recesses 30 are formed in the first surface 64a of the metal plate 64. As the first etching solution, for example, one containing ferric chloride solution and hydrochloric acid is used. As described above, the first resist pattern 65a provided in the peripheral region 23 covers a portion of the first surface 64a that will later become the long side surface 26. Therefore, the first recesses 30 are not formed in the portion of the first surface 64a that will later become the long side surface 26.

[0067] Thereafter, as shown in FIG. 18, the first recesses 30 are covered with a resin 69 having resistance to the second etching solution used in the subsequent second surface etching step. That is, the first recesses 30 are sealed with the resin 69 having resistance to the second etching solution. In the example shown in FIG. 18, the film of the resin 69 is formed so as to cover not only the formed first recesses 30 but also the first surface 64a (first resist pattern 65a).

[0068] Next, as shown in FIG. 19, an etching process for forming a second recess 35 in the second surface 64b is performed by etching a region of the second surface 64b of the metal plate 64 corresponding to the holes 66b and the openings 66d. FIG. 20 is a view showing a state in which the second surface etching process has further progressed. As shown in FIG. 20, in the region of the metal plate 64 corresponding to the effective region 22, the second surface etching process is performed until the first recess 30 and the second recess 35 communicate with each other, thereby forming the through hole 25. On the other hand, in the region of the metal plate 64 corresponding to the peripheral region 23, the second surface etching process is performed until the second recess 35 reaches the first surface 64a. As described above, the dimension M2 of the opening 66d of the second resist pattern 65b located in the peripheral region 23 is larger than the dimension M1 of the hole 66b of the second resist pattern 65b located in the effective region 22. Therefore, as shown in FIG. 20, etching in the thickness direction of the metal plate 64 can proceed faster in the peripheral region 23 than in the effective region 22. As the second etching solution, similar to the above-described first etching solution, for example, a solution containing ferric chloride solution and hydrochloric acid is used.

[0069] Note that the erosion by the second etching solution progresses in the portion of the metal plate 64 that is in contact with the second etching solution. Therefore, the erosion does not proceed only in the normal direction N (thickness direction) of the metal plate 64, but also proceeds in the direction along the plate surface of the metal plate 64. Here, preferably, in the region of the metal plate 64 corresponding to the effective region 22, the second surface etching process is terminated before the two second recesses 35 formed at positions facing two adjacent holes 66a of the second resist pattern 65b merge on the back side of the second resist pattern 65b located between the two holes 66a. As a result, as shown in FIG. 20, the above-described top portion 43 can be left on the second surface 64b of the metal plate 64.

[0070] Thereafter, as shown in FIG. 21, the resin 69 is removed from the metal plate 64. The resin 69 can be removed, for example, by using an alkaline stripping solution. When an alkaline stripping solution is used, as shown in FIG. 21, the resist patterns 65a and 65b are also removed simultaneously with the resin 69. Note that after removing the resin 69, the resist patterns 65a and 65b may be removed separately from the resin 69 by using a stripping solution different from the stripping solution for stripping the resin 69.

[0071] As shown in FIG. 21, in the region of the metal plate 64 corresponding to the peripheral region 23, when the second recess 35 reaches the first surface 64a, a long side surface 26 separated from other portions of the metal plate 64 in the width direction D2 can be formed. The long side surface 26 includes a first portion 261 based on the second recess 35 formed in the second surface 64b of the metal plate 64 corresponding to the opening 66d of the second resist pattern 65b. In this case, the first end portion 261a of the first portion 261 coincides with the first connection portion 20e where the long side surface 26 and the first surface 64a (the first surface 20a) are connected.

[0072] FIG. 22A is a plan view showing an intermediate product 50 obtained by processing the vapor deposition mask 20 as described above to form the through holes 25. The intermediate product 50 includes a plurality of vapor deposition mask portions 51 and a support portion 56. The transport direction of the metal plate 64 in the manufacturing process of the vapor deposition mask 20 coincides with the longitudinal direction D1.

[0073] The vapor deposition mask portion 51 is a portion of the metal plate 64 that becomes the vapor deposition mask 20 by being separated. As shown in FIG. 22A, the plurality of vapor deposition mask portions 51 are arranged side by side in the width direction D2.

[0074] The support portion 56 is a portion that surrounds the plurality of vapor deposition mask portions 51 in a plan view and is partially connected to the vapor deposition mask portions 51. In the example shown in FIG. 22A, the support portion 56 is a portion of the metal plate 64 other than the vapor deposition mask portions 51. As shown in FIG. 22A, the vapor deposition mask portions 51 are connected to the support portion 56 via connection points 54 on the short side surface 27.

[0075] Figure 22B is a view showing an enlarged area surrounded by a dotted line with reference numeral XXIIB in the intermediate product 50 of Figure 22A. At the above-described connection portion 54, the short side surface 27 of the vapor deposition mask portion 51 protrudes toward the support portion 56 and includes a plurality of convex portions 53a connected to the support portion 56. For example, between the short side surface 27 and the support portion 56 of the intermediate product 50, a plurality of second through-holes 55b penetrating the metal plate 64 are arranged along the direction in which the short side surface 27 extends. The dimension K of the second through-hole 55b in the width direction D2 is, for example, 30 μm or more and, for example, 100 μm or less. The convex portion 53a is located between two adjacent second through-holes 55b in the direction in which the short side surface 27 extends. On the other hand, the long side surface 26 of the vapor deposition mask portion 51 is not connected to the support portion 56. In other words, between the long side surface 26 of the vapor deposition mask portion 51 and the support portion 56 of the intermediate product 50, a first through-hole 55a penetrating the metal plate 64 extends along the direction in which the long side surface 26 extends. The dimension S of the first through-hole 55a in the width direction D2 is, for example, 0.1 mm or more and, for example, 5 mm or less.

[0076] As described above, the first through-hole 55a constituting the long side surface 26 is formed by performing the second surface etching process until the second recess 35 reaches the first surface 64a. In this case, the first end portion 261a of the above-described first portion 261 included in the long side surface 26 formed by the second surface etching process is positioned on the first surface 64a of the metal plate 64. That is, the first end portion 261a of the first portion 261 comes to coincide with the first connection portion 20e where the first surface 20a of the vapor deposition mask 20 and the long side surface 26 are connected.

[0077] Similar to the first through-hole 55a constituting the long side surface 26, the second through-hole 55b constituting the short side surface 27 can also be formed by performing the second surface etching process until the second recess 35 reaches the first surface 64a.

[0078] The fact that the first through-hole portion 55a and the second through-hole portion 55b are formed by performing the second surface etching process until the second recessed portion 35 reaches the first surface 64a means that the first through-hole portion 55a and the second through-hole portion 55b do not include the first recessed portion 30 connected to the second recessed portion 35. Hereinafter, the advantages of the first through-hole portion 55a and the second through-hole portion 55b not including the first recessed portion 30 will be described.

[0079] After the first surface etching process, the metal plate 64 is conveyed to the location where the second surface etching process is performed. At this time, if the first recessed portion 30 is formed in the portion of the metal plate 64 where the long side surface 26 or the short side surface 27 will be formed later in the first surface etching process, the metal plate 64 may be bent starting from the first recessed portion 30 during conveyance. Since the first recessed portion 30 formed in the portion where the long side surface 26 is formed has the same dimensions as the vapor deposition mask 20 in the longitudinal direction D1, it is particularly likely to be a starting point for bending.

[0080] On the other hand, in the present embodiment, the first through-hole portion 55a or the second through-hole portion 55b does not include the first recessed portion 30. Therefore, in the first surface etching process, the first recessed portion 30 is not formed in the portion of the metal plate 64 where the long side surface 26 or the short side surface 27 will be formed later. As a result, it is possible to suppress the occurrence of conveyance defects such as bending in the metal plate 64 when the metal plate 64 is conveyed to the location where the second surface etching process is performed after the first surface etching process.

[0081] Also, the fact that the first recessed portion 30 is not formed means that the step of coating the first recessed portion 30 with the resin 69 is also unnecessary. If the first recessed portion 30 is formed in the portion where the long side surface 26 is formed, its dimensions are larger than those of the first recessed portion 30 constituting the through-hole 25, so the cost and labor required for coating with the resin 69 are also large. On the other hand, according to the present embodiment, since the first through-hole portion 55a or the second through-hole portion 55b does not include the first recessed portion 30, the cost and labor required for coating with the resin 69 can be reduced.

[0082] (Separation process) Subsequently, a separation step of separating the vapor deposition mask portion 51 from the support portion 56 in the above intermediate product 50 is carried out. First, as shown in FIG. 13, the intermediate product 50 obtained by processing the metal plate 64 is transported to a separation device 73 for carrying out the separation step. For example, it is transported to the separation device 73 by transport rollers 72, 72 that rotate while holding the intermediate product 50. By the way, when the long side surface 26 of the vapor deposition mask portion 51 is not connected to the support portion 56 in the intermediate product 50, the vapor deposition mask portion 51 is likely to shake or bend during transportation. Considering this point, a suppressing means for suppressing the shaking and bending of the vapor deposition mask portion 51 may be provided in the intermediate product 50, the transport roller 72, or the transport path. For example, the suppressing means includes a pair of films provided on the first surface side and the second surface side of the intermediate product 50. By transporting the intermediate product 50 to the separation device 73 with the intermediate product 50 sandwiched between a pair of films, it is possible to suppress the vapor deposition mask portion 51 from shaking or bending.

[0083] FIG. 23 is a diagram showing the separation step of separating the vapor deposition mask portion 51 from the support portion 56. As described above, the long side surface 26 of the vapor deposition mask portion 51 and the support portion 56 are not connected. For this reason, by breaking the connection portion 54 between the vapor deposition mask portion 51 and the support portion 56 on the short side surface 27, the vapor deposition mask portion 51 can be separated from the support portion 56 to obtain the vapor deposition mask 20. FIG. 24 is a plan view showing an enlarged view of the vapor deposition mask 20 obtained from the intermediate product 50.

[0084] The separation step includes, for example, a breaking step of breaking the connection portion 54 connected to the support portion 56 in the short side surface 27 of the vapor deposition mask portion 51. In this case, as shown in FIG. 24, at the portion of the vapor deposition mask 20 where the connection portion 54 is broken, for example, the tip of the convex portion 27a of the short side surface 27 becomes the broken surface 27b. The broken surface 27b is a surface where there is burr due to the force received from the support portion 56 during breaking. On the other hand, there is no broken surface on the long side surface 26.

[0085] In FIG. 24, reference numeral ε represents the shortest distance in the plane direction of the base material 21 from the first connection portion 20e where the long side surface 26 and the first surface 20a are connected to the through hole 25. The distance ε is smaller than the shortest distance in the plane direction of the base material 21 from the connection portion where the short side surface 27 and the first surface 20a are connected to the through hole 25. For this reason, when a deformation such as a wavy shape appears on the long side surface 26, the dimensional accuracy and the positional accuracy of the vapor deposition material 98 attached to the organic EL substrate 92 through the through hole 25 located in the vicinity of the long side surface 26 will deteriorate. Here, in the present embodiment, the long side surface 26 is not connected to the support portion 56. For this reason, during the separation process of separating the vapor deposition mask portion 51 from the support portion 56, since the long side surface 26 does not receive the force from the support portion 56, it is possible to suppress the appearance of a deformation such as a wavy shape on the long side surface 26. As a result, the vapor deposition material 98 can be attached to the organic EL substrate 92 with high dimensional accuracy and positional accuracy.

[0086] Manufacturing method of vapor deposition mask apparatus Next, a method for manufacturing the vapor deposition mask device 10 by combining the vapor deposition mask 20 and the frame 15 will be described. First, the frame 15 is prepared. Subsequently, as shown in FIG. 25, the second surface 20b of the vapor deposition mask 20 is fixed to the frame 15 by welding or the like. For example, first, with the frame 15 and the vapor deposition mask 20 overlapped, the vapor deposition mask 20 is photographed from the first surface 20a side using a camera or the like. At this time, a tension may be applied to the vapor deposition mask 20. Subsequently, based on the image obtained by the photographing, the position of the vapor deposition mask 20 with respect to the frame 15 is detected. For example, the position of the contour of the vapor deposition mask 20 in the longitudinal direction D1 is detected. Subsequently, the position of the vapor deposition mask 20 is adjusted so that the position of the vapor deposition mask 20 with respect to the frame 15 becomes a predetermined position.

[0087] Here, according to the present embodiment, as described above, when the long side surface 26 is viewed from the first surface 20a side, the first portion 261 is not visible. Also, since the first portion 261 extends to the first surface 20a, that is, since the first end portion 261a of the first portion 261 coincides with the first connection portion 20e, when the long side surface 26 is viewed from the first surface 20a side, the surface of the long side surface 26 other than the first portion 261 is also not visible. For this reason, the contour of the vapor deposition mask 20 in the longitudinal direction D1 is clearly defined by the first connection portion 20e between the first surface 20a and the long side surface 26. Therefore, the position of the contour of the vapor deposition mask 20 in the longitudinal direction D1 can be easily detected. As a result, the position of the contour of the vapor deposition mask 20 in the longitudinal direction D1 can be adjusted more accurately with respect to the frame 15.

[0088] Vapor deposition method Next, a vapor deposition method for vapor-depositing a vapor deposition material 98 onto a substrate such as an organic EL substrate 92 using the vapor deposition mask 20 will be described. First, the vapor deposition mask apparatus 10 is arranged so that the vapor deposition mask 20 faces the organic EL substrate 92. Also, the vapor deposition mask 20 is brought into close contact with the organic EL substrate 92 using a magnet 93. In this state, by evaporating the vapor deposition material 98 and causing it to fly onto the organic EL substrate 92 through the vapor deposition mask 20, the vapor deposition material 98 can be attached to the organic EL substrate 92 in a pattern corresponding to the through holes 25 of the vapor deposition mask 20. Here, in the present embodiment, as described above, the position of the contour of the vapor deposition mask 20 in the longitudinal direction D1 can be easily detected. For this reason, the position of the contour of the vapor deposition mask 20 in the longitudinal direction D1 can be adjusted more accurately with respect to the organic EL substrate 92. As a result, the vapor deposition material 98 can be attached to the organic EL substrate 92 with high positional accuracy.

[0089] It should be noted that various modifications can be made to the above-described embodiments. Hereinafter, modifications will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, for parts that can be configured in the same manner as in the above-described embodiments, the same reference numerals as those used for the corresponding parts in the above-described embodiments will be used, and duplicate descriptions will be omitted. Also, when it is clear that the operational effects obtained in the above-described embodiments can also be obtained in the modifications, the description thereof may be omitted.

[0090] (Modification example of the long side surface) In FIG. 20 of the above-described embodiment, an example was shown in which the second recess 35 formed on the second surface 64b of the metal plate 64 reaches the first surface 64a to form the long side surface 26 separated from the portions of the other metal plates 64. In this modification example, an example of forming the long side surface 26 separated from the portions of the other metal plates 64 by communicating the first recess 30 formed on the first surface 64a of the metal plate 64 and the second recess 35 formed on the second surface 64b will be described.

[0091] FIG. 26 is a cross-sectional view showing the long side surface 26 of the vapor deposition mask 20 in this modification example. The long side surface 26 includes a first portion 261 and a second portion 262 that is connected to the first end portion 261a of the first portion 261 and reaches the first surface 20a. The second portion 262 is a part of the first recess 30 formed by etching the first surface 64a of the metal plate 64 in the first surface etching step, and is recessed inward. According to this modification example, by forming the first recess 30 in the portion of the first surface 64a of the metal plate 64 that becomes the long side surface 26, even when the metal plate 64 has a large thickness, for example, a thickness of 20 μm or more or 30 μm or more, the long side surface 26 can be formed by etching. Although not shown, the short side surface 27 may similarly include a second portion constituted by the first recess 30 and a first portion constituted by the second recess 35.

[0092] When the long side surface 26 or the short side surface 27 includes the second portion on the first surface 64a side, preferably, in the first surface etching step, the dimension in the width direction D2 of the first recess 30 formed in the portion that becomes the long side surface 26 or the short side surface 27 of the first surface 64a of the metal plate 64 is smaller than the dimension in the width direction D2 of the first recess 30 formed in the portion that becomes the through hole 25 of the first surface 64a of the metal plate 64. Thereby, when transporting the metal plate 64 to the place where the second surface etching step is performed after the first surface etching step, it is possible to suppress the first recess 30 corresponding to the long side surface 26 or the short side surface 27 from becoming the starting point of the bending of the metal plate 64.

[0093] As shown in FIG. 26, the first end portion 261a of the first portion 261 is located outside the first connection portion 20e where the first surface 20a of the vapor deposition mask 20 and the second portion 262 of the long side surface 26 are connected. For this reason, when the vapor deposition mask 20 is viewed from the first surface 20a side, the second portion 262 is visible, but the first portion 261 is not visible. In the second portion 262, light is scattered in various directions. For this reason, in the example shown in FIG. 26, the second portion 262 is visually recognized as a portion that looks blacker than the first surface 20a or appears in the image. Therefore, it is preferable that the width of the second portion 262 that is visually recognized when viewed from the first surface 20a side is small. Thereby, it becomes possible to accurately detect the contour of the vapor deposition mask 20 in the longitudinal direction D1 when viewed from the first surface 20a side, that is, the contour of the long side surface 26.

[0094] In FIG. 26, the symbol δ represents the distance in the plane direction of the first surface 20a between the first end portion 261a and the first connection portion 20e. The distance δ corresponds to the width of the second portion 262 that is visually recognized when viewed from the first surface 20a side. The distance δ is, for example, 3.5 μm or less, and more preferably 1.0 μm or less.

[0095] In FIG. 26, reference numeral r3 represents the distance in the normal direction of the vapor deposition mask 20 from the first surface 20a to the first end portion 261a. The distance r3 is, for example, 2 μm or more and 5 μm or less. As a result, the area of the second portion 262 becomes smaller, and light scattering caused by the second portion 262 is suppressed. Therefore, the contour of the vapor deposition mask 20 in the longitudinal direction D1, that is, the contour of the long side surface 26, when viewed from the first surface 20a side of the second portion 262 can be detected more accurately. Further, preferably, the distance r3 is smaller than the height r1 of the wall surface 31 of the first recess 30 constituting the through hole 25. In other words, the first end portion 261a of the long side surface 26 is located closer to the first surface 20a side than the hole connection portion 41 of the through hole 25.

[0096] (Modification example of the short side surface) In the above-described embodiment, an example is shown in which, on the long side surface 26 of the vapor deposition mask 20, the first connection portion 20e where the first surface 20a and the long side surface 26 are connected coincides with the first end portion 261a of the first portion 261, or the distance between the two is 3.5 μm or less. This makes it possible to easily detect the contour of the vapor deposition mask 20 extending in the longitudinal direction D1 when viewed from the first surface 20a. Such a technical idea may be applied to the short side surface 27 in addition to or instead of the long side surface 26. That is, although not shown, the connection portion where the first surface 20a and the short side surface 27 are connected and the end portion on the first surface 20a side of the surface recessed inward on the short side surface 27 may coincide with each other, or the distance between the two may be 3.5 μm or less. As a result, the contour of the vapor deposition mask 20 extending in the width direction D2, that is, the contour of the short side surface 27, when viewed from the first surface 20a can be easily detected.

[0097] In addition, in the above-described embodiment, an example was shown in which the vapor deposition mask portion 51 was separated from the support portion 56 by breaking the connection portion 54 between the vapor deposition mask portion 51 and the support portion 56 on the short side surface 27 of the intermediate product 50. However, the example of separating the vapor deposition mask portion 51 from the support portion 56 on the short side surface 27 is not particularly limited. For example, by using a processing device such as a laser processing device to cut the portion that becomes the short side surface 27 of the intermediate product 50, the vapor deposition mask portion 51 may be separated from the support portion 56. In this case, the plurality of second through-holes 55b described above may not be formed in the portion of the metal plate 64 that becomes the short side surface 27. Alternatively, a groove having a depth that does not penetrate the metal plate 64 may be formed on the first surface 64a or the second surface 64b of the portion of the metal plate 64 that becomes the short side surface 27. In this case, by irradiating the metal plate 64 with laser light along the groove, it is possible to reduce burrs generated due to laser processing or reduce the amount of chips generated during laser processing.

[0098] (Other embodiments) Another first embodiment of the present disclosure is a vapor deposition mask in which a plurality of through holes are formed, including a first surface and a second surface on which the through holes are formed, a pair of long side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask in the longitudinal direction of the vapor deposition mask, and a pair of short side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask in the width direction of the vapor deposition mask. The long side surface includes a first end portion located on the first surface side and a second end portion located on the second surface side and inside the first end portion, and has a first portion recessed inward. The through hole includes a first recess formed on the first surface side and a second recess formed on the second surface side and connected to the first recess at a hole connection portion. The first end portion of the first portion of the long side surface is located on the first surface side of the hole connection portion. The first end portion may coincide with a first connection portion where the first surface and the long side surface are connected and is located on the same plane as the first surface. Alternatively, the first end portion may be a first connection portion where the first surface and the long side surface are connected and is located outside the first connection portion located on the same plane as the first surface.

[0099] Another second embodiment of the present disclosure is a vapor deposition mask in which a plurality of through holes are formed, including a first surface and a second surface on which the through holes are formed, a pair of long side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask in the longitudinal direction of the vapor deposition mask, and a pair of short side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask in the width direction of the vapor deposition mask. The long side surface includes a first end portion located on the first surface side and a second end portion located on the second surface side and inside the first end portion, and has a first portion recessed inward. The first end portion is a first connection portion where the first surface and the long side surface are connected and coincides with the first connection portion located on the same plane as the first surface.

[0100] In the vapor deposition mask according to other embodiments of the present disclosure, a first connection portion where the first surface and the long side surface are connected, the first connection portion being located on the same plane as the first surface, and the distance in the surface direction of the first surface between the first end portion of the first portion of the long side surface may be 3.5 μm or less.

[0101] In the vapor deposition mask according to other first and second embodiments of the present disclosure, the first portion may be located inside a virtual plane or straight line passing through the first end portion and the second end portion.

[0102] In the vapor deposition mask according to other first and second embodiments of the present disclosure, the thickness of the vapor deposition mask may be 50 μm or less.

[0103] In the vapor deposition mask according to other first and second embodiments of the present disclosure, the second end portion may coincide with a second connection portion where the second surface and the long side surface are connected, the second connection portion being located on the same plane as the second surface.

[0104] Another third embodiment of the present disclosure is a method for manufacturing a vapor deposition mask in which a plurality of through holes are formed, the method comprising: preparing a metal plate including a first surface and a second surface located on the opposite side of the first surface; processing the metal plate to form the first surface and the second surface having the through holes, a pair of long side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask in the longitudinal direction of the vapor deposition mask, and a pair of short side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask in the width direction of the vapor deposition mask; and obtaining the vapor deposition mask, wherein the long side surface includes a first end portion located on the first surface side and a second end portion located on the second surface side and inside the first end portion, and has a first portion recessed inward, the through hole includes a first recess formed on the first surface side and a second recess formed on the second surface side and connected to the first recess at a hole connection portion, and the first end portion of the first portion of the long side surface is located on the first surface side of the hole connection portion. The processing step includes a second surface etching step of etching the metal plate from the second surface side to form the first portion of the long side surface, and the second surface etching step may be performed such that the first end portion of the first portion coincides with a first connection portion where the first surface and the long side surface are connected and which is located on the same plane as the first surface. Alternatively, the processing step includes a second surface etching step of etching the metal plate from the second surface side to form the first portion of the long side surface, and the processing step may further include a first surface etching step of etching the metal plate from the first surface side to form a surface located between the first end portion of the first portion of the long side surface and the first surface of the metal plate.

[0105] Another fourth embodiment of the present disclosure is a method for manufacturing a vapor deposition mask having a plurality of through holes, the method comprising: preparing a metal plate including a first surface and a second surface located on the opposite side of the first surface; processing the metal plate to form the first surface and the second surface having the through holes, a pair of long side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask in the longitudinal direction of the vapor deposition mask, and a pair of short side surfaces connected to the first surface and the second surface and defining the contour of the vapor deposition mask in the width direction of the vapor deposition mask, to obtain the vapor deposition mask; wherein the long side surface includes a first end portion located on the first surface side and a second end portion located on the second surface side and inside the first end portion, and has a first portion recessed inward; the processing step includes a second surface etching step of etching the metal plate from the second surface side to form the first portion of the long side surface; and the second surface etching step is performed such that the first end portion of the first portion coincides with a first connection portion where the first surface and the long side surface are connected and which is located on the same plane as the first surface.

[0106] In the method for manufacturing a vapor deposition mask according to the other third and fourth embodiments of the present disclosure, the distance in the plane direction of the first surface between a first connection portion where the first surface and the long side surface are connected and which is located on the same plane as the first surface and the first end portion of the first portion of the long side surface may be 3.5 μm or less.

Example

[0107] Next, the embodiments of the present disclosure will be described more specifically with reference to examples. However, the embodiments of the present disclosure are not limited to the descriptions of the following examples as long as the gist thereof is not exceeded.

[0108] (Example 1) First, a metal plate 64 having a thickness of 25 μm was prepared. Next, the above-described processing steps were performed to form a plurality of through-holes 25 formed by the first recess 30 and the second recess 35 in the metal plate 64. Further, a second recess 35 reaching the first surface 64a was formed in a portion of the second surface 64b of the metal plate 64 corresponding to the long side surface 26. Fig. 27 shows the observation result of the cross-section of the long side surface 26. Also, Fig. 28A shows the result of observing the vapor deposition mask 20 having the long side surface 26 shown in Fig. 27 from the first surface 20a side, and Fig. 28B shows the result of observing it from the second surface 20b side.

[0109] As shown in Fig. 28B, when the vapor deposition mask 20 is observed from the second surface 20b side, the first portion 261 is visible. On the other hand, when the vapor deposition mask 20 is observed from the first surface 20a side, the first portion 261 is not visible. Therefore, the position of the contour of the vapor deposition mask 20 in the longitudinal direction D1 can be easily detected.

[0110] (Example 2) First, a metal plate 64 having a thickness of 30 μm was prepared. Next, the above-described processing steps were performed to form a plurality of through-holes 25 formed by the first recess 30 and the second recess 35 in the metal plate 64. Further, a first recess 30 was formed in a portion of the first surface 64a of the metal plate 64 corresponding to the long side surface 26, and a second recess 35 communicating with the first recess 30 was formed in a portion of the second surface 64b of the metal plate 64 corresponding to the long side surface 26. Fig. 29A shows the observation result of the cross-section of the long side surface 26. The long side surface 26 includes a first portion 261 that is part of the second recess 35 and a second portion 262 that is part of the first recess 30.

[0111] Fig. 29B is a cross-sectional view showing an enlarged view of the second portion 262 of the long side surface 26 in Fig. 29A. The distance δ between the first end portion 261a and the first connection portion 20e was 0.7 μm.

[0112] When observing the vapor deposition mask 20 having the long side surface 26 shown in FIGS. 29A and 29B from the second surface 20b side, the first portion 261 is visible. On the other hand, when observing the same vapor deposition mask 20 from the first surface 20a side, the first portion 261 is not visible, and instead, the second portion 262 is visible. The distance δ between the first end portion 261a and the first connection portion 20e is 0.7 μm. Therefore, the width of the second portion 262 visible when observing the vapor deposition mask 20 from the first surface 20a side is also 0.7 μm. For this reason, even when observing the vapor deposition mask 20 from the first surface 20a side using a camera in a state where the field of view size of the camera in the width direction D2 is enlarged to about 3.5 μm, both the first end portion 261a and the first connection portion 20e can be confirmed. Therefore, the contour of the vapor deposition mask 20 can be easily detected.

[0113] (Example 3) A vapor deposition mask 20 was produced in the same manner as in the case of Example 1 described above, except that a metal plate 64 having a thickness of 15 μm was used. FIG. 30 shows the observation result of the cross section of the long side surface 26. As shown in FIG. 27, also in this example, similar to the case of Example 1, the first portion 261 formed of a curved surface curved inwardly extends from the second surface 20b to the first surface 20a. In this case, since the first end portion 261a of the first portion 261 coincides with the first connection portion 20e, when the vapor deposition mask 20 is viewed from the first surface 20a side, the first portion 261 is not visible. Therefore, the position of the contour of the vapor deposition mask 20 in the longitudinal direction D1 when the vapor deposition mask 20 is viewed along the normal direction of the first surface 20a can be easily detected.

Explanation of reference numerals

[0114] 10 Vapor deposition mask device 15 Frame 20 Vapor deposition mask 20a First surface 20b Second surface 21 Substrate 22 Effective region 23 Peripheral region 25 Through hole 26 Long side surface 261 First portion Part 2, 262 27 Short side 30 First recess 31 Wall surface 35 Second recess 36 Wall surface 41 Hole connection part 43 Top part 50 Intermediate product 51 Evaporation mask part 54 Connection point 55 Gap 56 Support part 64 Metal plate 65a First resist pattern 65b Second resist pattern 65c First resist film 65d Second resist film 70 Processing device 72 Conveyor roller 73 Separation device 90 Evaporation device 92 Organic EL substrate 98 Evaporation material

Claims

1. A method for manufacturing an intermediate product of an evaporation mask, comprising: a processing step of processing a metal plate to form, on the metal plate, a plurality of evaporation mask portions each having a plurality of through holes, and a support portion that surrounds the evaporation mask portions in a plan view and is partially connected to the evaporation mask portions; a separation step of separating the evaporation mask portions from the metal plate; wherein the evaporation mask portions include: a first surface and a second surface on which the through holes are formed; a pair of long side surfaces that are connected to the first surface and the second surface and define the contour of the evaporation mask portion in the longitudinal direction of the evaporation mask portion; a pair of short side surfaces that are connected to the first surface and the second surface and define the contour of the evaporation mask portion in the width direction of the evaporation mask portion; the long side surfaces include a first end portion located on the first surface side, a second end portion located on the second surface side and inside the first end portion, and have a first portion recessed inward; the through holes include a first recess formed on the first surface side and a second recess formed on the second surface side and connected to the first recess at a hole connection portion; a method for manufacturing an intermediate product, wherein the first end portion of the first portion of the long side surface is located on the first surface side of the hole connection portion.

2. The method for manufacturing an intermediate product according to claim 1, wherein the first end portion is a first connection portion where the first surface and the long side surface are connected, and coincides with a first connection portion located on the same plane as the first surface.

3. The method for manufacturing an intermediate product according to claim 1, wherein the first end portion is a first connection portion where the first surface and the long side surface are connected, and is located outside the first connection portion located on the same plane as the first surface.

4. A method for manufacturing an intermediate product of an evaporation mask, comprising: a processing step of processing a metal plate to form, on the metal plate, a plurality of evaporation mask portions each having a plurality of through holes, and a support portion that surrounds the evaporation mask portions in a plan view and is partially connected to the evaporation mask portions; a separation step of separating the evaporation mask portions from the metal plate; wherein the evaporation mask portions include: a first surface and a second surface on which the through holes are formed; a pair of long side surfaces that are connected to the first surface and the second surface and define the contour of the evaporation mask portion in the longitudinal direction of the evaporation mask portion; A pair of short side surfaces that are connected to the first surface and the second surface and define the contour of the vapor deposition mask portion in the width direction of the vapor deposition mask portion. The long side surface includes a first end portion located on the first surface side, a second end portion located on the second surface side and inside the first end portion, and a first portion recessed inward, and a second portion connected to the first end portion of the first portion and reaching the first surface. A manufacturing method of an intermediate product, which is a first connection portion where the first surface is connected to the second portion of the long side surface, and the distance in the plane direction of the first surface between the first connection portion located on the same plane as the first surface and the first end portion of the first portion of the long side surface is 3.5 μm or less.

5. The long side surface has the first portion and a second portion that is connected to the first end portion of the first portion and reaches the first surface. A manufacturing method of an intermediate product according to claim 1 or 3, which is a first connection portion where the first surface is connected to the second portion of the long side surface, and the distance in the plane direction of the first surface between the first connection portion located on the same plane as the first surface and the first end portion of the first portion of the long side surface is 3.5 μm or less.

6. The manufacturing method of an intermediate product according to any one of claims 1 to 4, wherein the first portion is located inside a virtual plane or straight line passing through the first end portion and the second end portion.

7. The manufacturing method of an intermediate product according to any one of claims 1 to 4, wherein the thickness of the vapor deposition mask portion is 50 μm or less.

8. The manufacturing method of an intermediate product according to any one of claims 1 to 4, wherein the second end portion coincides with a second connection portion where the second surface is connected to the long side surface and is located on the same plane as the second surface.

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