TW202430669A - Metal mask and manufacturing method thereof - Google Patents

Abstract

The metal mask of the present invention has a perforated area and a surrounding area, the perforated area has a plurality of through holes, the surrounding area is located around the perforated area, the surrounding area has a stress dispersion area, the stress dispersion area has a plurality of recesses, the opening shape of the recesses in a top view has a short axis of length R, the stress dispersion area has the recesses arranged at a pitch P in the direction of the short axis, and the ratio (R/P) of the length R to the pitch P is greater than 0.90.

Description

Metal mask and manufacturing method thereof

The present disclosure relates to a metal mask and a method for manufacturing the same.

The pixels of an organic EL display device are formed by attaching the material forming the pixels to a substrate by evaporation using a metal mask. Therefore, improving the performance of the metal mask is important for improving the image quality of the organic EL display device. For example, Patent Document 1 discloses that a metal mask having uniform through holes is provided for the purpose of improving the uniformity of evaporation. [Prior Technical Document] [Patent Document]

Patent document 1: Japanese Patent Publication No. 2019-508588

[The problem the invention is trying to solve]

In addition, Patent Document 1 discloses that a half-etched portion is formed in order to disperse the stress applied during stretching. One concave portion of the half-etched portion described in Patent Document 1 has a larger length that crosses a plurality of through holes.

However, as described in Patent Document 1, if a recess is formed to be larger, the depth of the recess is likely to be different even in the same recess. If the depth of the recess is different, it is difficult to disperse the stress uniformly. If the stress is not dispersed uniformly, wrinkles will be generated when the metal mask is set on the frame, or the accuracy of the setting position will be reduced. Here, "wrinkles" means the undulations generated in the width direction of the mask when a tensile force is applied in the length direction of the metal mask and the metal mask is tensioned and welded to the frame. In addition, if a recess is formed to be larger, the risk of the recess penetrating to the back side during manufacturing becomes higher, and the yield of the metal mask may also be reduced.

The present invention is completed in view of the above-mentioned problems, and its purpose is to provide a metal mask that can disperse stress more evenly, is less likely to produce wrinkles, and has excellent positioning accuracy, and a highly efficient manufacturing method thereof. [Technical means to solve the problem]

The metal mask of one embodiment of the present disclosure, has a perforated area and a surrounding area; and the perforated area has a plurality of through holes; the surrounding area is located around the perforated area; the surrounding area has a stress dispersion area; the stress dispersion area has a plurality of recesses; the opening shape of the recess in a top view has a short axis of length R; the stress dispersion area has the recesses arranged at a pitch P in the direction of the short axis; the ratio (R/P) of the length R to the pitch P is greater than 0.90.

The manufacturing method of the above-mentioned metal mask of one embodiment of the present disclosure includes: A step of preparing a metal plate, the metal plate having a first surface and a second surface located on the opposite side of the aforementioned first surface; and An etching step, which forms the aforementioned metal mask by etching the aforementioned metal plate; and The aforementioned metal mask has a hole area and a surrounding area; The aforementioned hole area has a plurality of through holes; The aforementioned surrounding area is located around the aforementioned hole area; The aforementioned surrounding area has a stress dispersion area; The aforementioned stress dispersion area has a plurality of recesses; The opening shape of the aforementioned recess in a top view has a short axis of length R; The aforementioned stress dispersion area has the aforementioned recesses arranged at a pitch P in the direction of the aforementioned short axis; The ratio of the aforementioned length R to the aforementioned pitch P (R/P) is greater than 0.90. [Effect of the invention]

In at least one embodiment of the present disclosure, a metal mask is provided that can disperse stress more evenly, is less likely to produce wrinkles, and has excellent position accuracy, and a highly efficient manufacturing method thereof.

In the following, the embodiments of the present disclosure are described with reference to the drawings. In addition, in the drawings attached to this specification, the scale and the ratio of the vertical and horizontal dimensions are sometimes appropriately changed or exaggerated for the convenience of illustration and easy understanding.

Unless otherwise specified in this specification and/or the drawings, the following explanations shall apply.

Terms that refer to a substance that forms the basis of a certain structure can be distinguished from each other not only by different names. For example, terms such as "substrate", "base material", "board", "sheet", or "film" are equivalent to the above description.

The terms and/or numerical values referring to shapes and/or geometric conditions need not be strictly defined and can be interpreted as including a range of degrees in which the same function can be expected. For example, "parallel" and/or "orthogonal" are equivalent to the above terms. Also, "length value" and/or "angle value" are equivalent to the above numerical values.

When a certain component is expressed as being "on", "under", "upper side", "lower side", "above", or "below" another component, it may include a state where the certain component is directly connected to the other component and a state where another component is included between the certain component and the other component. In other words, the state where another component is included between the certain component and the other component may be expressed as the certain component being indirectly connected to the other component. Furthermore, the expression "on", "upper side", or "above" may be converted into the expression "under", "lower side", or "below". In other words, the up and down directions may be reversed.

When the same part and/or parts having the same function are given the same symbol or similar symbol, repeated description may be omitted. Also, the dimensional ratios in the drawings may be different from the actual ratios. Also, part of the components of the implementation form may be omitted from the drawings.

One or more embodiments of the embodiment may be combined with one or more embodiments of the variation within the scope that no contradiction occurs. Also, one or more embodiments of the embodiment may be combined with each other within the scope that no contradiction occurs. Also, one or more embodiments of the variation may be combined with each other within the scope that no contradiction occurs.

When a plurality of steps are disclosed in a method such as a manufacturing method, other steps not disclosed may be performed between the disclosed steps. In addition, the order of the steps is not limited within the scope of no contradiction.

The numerical range expressed by the "～" and/or "-" sign includes the numerical values placed before and after the "～" and/or "-" sign. For example, the numerical range expressed as "34-38 mass %" is the same as the numerical range expressed as "34 mass % or more and 38 mass % or less".

Regarding the numerical values disclosed in this disclosure, a numerical range can be defined by combining any one of a plurality of upper limit candidate values with any one of a plurality of lower limit candidate values. In addition, even if not specifically mentioned, a numerical range can be defined by combining any two of a plurality of upper limit candidate values, and a numerical range can be defined by combining any two of a plurality of lower limit candidate values.

An embodiment of the present disclosure is described in the following paragraphs. An embodiment of the present disclosure is an example of the embodiment of the present disclosure. The present disclosure is not limited to the embodiment of the present disclosure.

The metal mask disclosed herein can be used for various purposes. Although not particularly limited, for example, the metal mask of the present invention can be used as a metal mask for patterning an organic material on a substrate in a desired pattern in the manufacture of an organic EL display device. The metal mask disclosed herein can achieve high pixel density patterning. In addition to displays such as smartphones and televisions, the organic EL display devices that can be manufactured also include devices for displaying or projecting images and images for expressing virtual reality (VR) or augmented reality (AR).

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

The metal mask of the first embodiment of the present disclosure, has a perforated area and a surrounding area; and the perforated area has a plurality of through holes; the surrounding area is located around the perforated area; the surrounding area has a stress dispersion area; the stress dispersion area has a plurality of recesses; the opening shape of the recess in a top view has a short axis of length R; the stress dispersion area has the recesses arranged at a pitch P in the direction of the short axis; the ratio (R/P) of the length R to the pitch P is greater than 0.90.

The second aspect of the present disclosure is the metal mask of the first aspect described above, wherein the recesses are arranged in a staggered or grid pattern.

The third aspect of the present disclosure is the metal mask of the first aspect or the second aspect, wherein the wall surfaces of the adjacent aforementioned recesses meet.

The fourth aspect of the present disclosure is a metal mask as in any of the first to third aspects described above, wherein the thickest portion of the aforementioned surrounding area has a height H0; and the thinnest portion of the aforementioned stress dispersion area has a height H1; the ratio of the aforementioned height H1 to the aforementioned height H0 (H1/H0) is greater than 0.20 and less than 0.90.

The fifth aspect of the present disclosure is a metal mask as in any of the first to fourth aspects described above, wherein the surrounding area has an edge; and the stress dispersion area is located between the edge and the porous area.

The sixth aspect of the present disclosure is a metal mask as in the fifth aspect described above, wherein the aforementioned edge of the surrounding area has a pair of long sides and a pair of short sides; and the aforementioned stress dispersion area is located between the aforementioned edge of the aforementioned long side and the aforementioned perforated area.

The seventh aspect of the present disclosure is a metal mask as in any of the above-mentioned aspects 1 to 6, which has a plurality of the aforementioned porous regions; and the aforementioned stress dispersion region is located between the plurality of the aforementioned porous regions.

The eighth aspect of the present disclosure is a metal mask as in any of the first to seventh aspects, wherein the surrounding area has a cutting line; and the cutting line is a row of recesses or through holes; and the stress dispersion area is located between the cutting line and the hole area.

The ninth aspect of the present disclosure is a metal mask as in any of the first to eighth aspects described above, wherein the aforementioned surrounding area has a cutting line; and the aforementioned cutting line is a row of recesses or through holes; and the aforementioned cutting line is located between the aforementioned stress dispersion area and the aforementioned hole area.

The manufacturing method of the metal mask of the 10th aspect of the present disclosure includes the following steps: A step of preparing a metal plate, the metal plate having a first surface and a second surface located on the opposite side of the first surface; and An etching step, which forms the metal mask by etching the metal plate; and The metal mask has a hole area and a surrounding area; The hole area has a plurality of through holes; The surrounding area is located around the hole area; The surrounding area has a stress dispersion area; The stress dispersion area has a plurality of recesses; The opening shape of the recess in a top view has a short axis of length R; The stress dispersion area has the aforementioned recesses arranged at a pitch P in the direction of the short axis; The ratio of the aforementioned length R to the aforementioned pitch P (R/P) is greater than 0.90.

The metal mask 20 disclosed in the present invention has a perforated region 22 and a peripheral region 23. The perforated region 22 is a region formed with a plurality of through holes 25. Moreover, the peripheral region 23 is a region located around the perforated region 22. Furthermore, the peripheral region 23 has a stress dispersing region 24 having a predetermined concave portion.

FIG1 shows a top view of the second surface 20b side of the metal mask 20 of one embodiment of the present disclosure. As shown in FIG1, the metal mask 20 may have a substantially rectangular outline in a top view. In addition, in the present disclosure, "top view" means observing the metal mask 20 from a surface along the plate surface of the metal mask 20.

In the metal mask 20 of the present disclosure, one perforated region 22 can be configured to correspond to one organic EL display device. For example, as shown in FIG1 , the metal mask 20 can have a plurality of perforated regions 22 arranged in a row with a predetermined interval along the long side direction D2. In FIG1 , the surrounding region 23 is located around each perforated region 22. By using such a metal mask 20, a plurality of organic EL display devices can be evaporated on the substrate 92.

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

Among them, an iron alloy containing nickel is preferred. By using an iron alloy containing nickel, the thermal expansion coefficient of the metal mask 20 can be set to a value equivalent to the thermal expansion coefficient of the frame 15 and the thermal expansion coefficient of the substrate 92. In this way, the generation of positional deviation caused by the difference in dimensional changes of the metal mask 20, the frame 15 and the substrate 92 during the evaporation process can be suppressed. Therefore, the reduction in dimensional accuracy and positional accuracy of the evaporation material 98 attached to the substrate 92 caused by the positional deviation can be suppressed.

The iron alloy containing nickel is not particularly limited, and examples thereof include: iron alloys containing 0% to 54% by mass, such as super indium steel containing cobalt in addition to 30% to 34% by mass of nickel, indium steel containing 34% to 38% by mass of nickel, and low thermal expansion Fe-Ni based plated alloy containing 48% to 54% by mass of nickel.

Next, the details of the hole area 22 are described. First, before the details of the hole area 22, the surfaces of the metal mask 20 disclosed in the present invention are described. The metal mask 20 disclosed in the present invention has a first surface 20a and a second surface 20b as the front and back surfaces.

In the present disclosure, the first surface 20a and the second surface 20b of the metal mask 20 are distinguished by the diameter of the through hole 25 in the front and back surfaces of the hole area 22. Specifically, the first surface 20a means the surface with a small opening area of the through hole 25 in the hole area 22, and the second surface 20b means the surface with a large opening area of the through hole 25. In addition, as shown in FIG. 2E and the like, in the case where the second wall surfaces 36 of the second recessed portions 35 of the adjacent through holes 25 in the second surface 20b meet, the range S3 closed by the ridge 33 surrounding one through hole 25 can be regarded as the opening of the through hole 25. In this case, the range closed by the ridge 33 is the opening area.

Furthermore, from the perspective of the evaporation step, the first surface 20a may be the surface of the metal mask 20 opposite to the substrate 92 when the metal mask device 10 is accommodated in the evaporation device 90 (see FIG. 7 ). Furthermore, the second surface 20b may be the surface of the metal mask 20 located on the crucible 94 side holding the evaporation material 98 when the metal mask device 10 is accommodated in the evaporation device 90 as shown in FIG. 7 (see FIG. 7 ).

FIG. 2A shows a top view of the hole area 22 viewed from the second surface 20b. As shown in FIG. 2A, each hole area 22 of the metal mask 20 has a plurality of through holes 25. The through holes 25 can be formed in a desired pattern. For example, the through holes 25 can be arranged in a grid shape at a predetermined pitch along two mutually intersecting directions. In addition, the through holes 25 can be arranged in a staggered shape at a predetermined pitch along two mutually intersecting directions.

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

The through hole 25 can penetrate from the first surface 20a to the second surface 20b of the metal mask 20 in the thickness direction N. In the evaporation step, the evaporation material 98 is attached to the substrate 92 through the through hole 25. That is, each through hole 25 defines a location for the evaporation material to be attached on the substrate 92. The pattern of the through hole 25 in the hole area 22 corresponds to the pattern for the evaporation material 98 to be attached.

In the case where the pattern of the deposited material 98 is different depending on the type of the deposited material 98, the metal mask 20 having different patterns of the through holes 25 can be used according to the type of the deposited material 98. In addition, in the case where the pattern of the deposited material 98 is the same regardless of the type, the same metal mask 20 can be used. In this case, by moving the metal mask 20 and the substrate 92 relative to each other, different types of deposited materials 98 can be attached with the same pattern.

As shown in FIG2A , the apertured region 22 may include a plurality of through holes 25 and a plurality of ridges 33. The ridges 33 may be arranged in a manner to partition adjacent through holes 25.

Next, the through hole is further described in detail by means of the cross-sectional view and the stereoscopic view of the hole area. FIG. 2B is a cross-sectional view along the I-I' line shown in FIG. 2A. FIG. 2C is a cross-sectional view along the II-II' line shown in FIG. 2A. The cross-sectional views shown in FIG. 2B and FIG. 2C are cross-sectional views of the hole area 22 cut in the direction transverse to the through hole 25 and the ridge 33.

FIG2D is a cross-sectional view along the line III-III' shown in FIG2A. The cross-sectional view shown in FIG2D is a cross-sectional view of the case where the perforated area 22 is cut in the direction passing through the through hole 25 and the top 32. Here, the top 32 is a portion with a very large height in the perforated area 22. Alternatively, the top 32 may be a portion with a very large height in the ridge 33.

As shown in FIG. 2B to FIG. 2D , the through hole 25 may be a first recess 30 on the first surface 20a side and a second recess 35 on the second surface 20b side connected. At this time, the area of the first recess 30 in a top view may gradually decrease from the first surface 20a to the second surface 20b. In addition, the area of the second recess 35 in a top view may gradually decrease from the second surface 20b to the first surface 20a. In addition, the first recess 30 may be configured as a recess with a smaller diameter than the second recess 35.

Furthermore, as shown in FIG. 2B to FIG. 2D , the first wall surface 31 of the first recess 30 and the second wall surface 36 of the second recess 35 can be connected via a circumferential connecting portion 41. The connecting portion 41 is a ridge connecting the first recess 30 and the second recess 35. In the connecting portion 41, the direction in which the wall surface of the through hole 25 expands changes discontinuously. In one embodiment of the present disclosure, in the connecting portion 41, the opening area of the through hole 25 in a top view can be minimized. Furthermore, in addition to the connecting portion 41, the opening area of the through hole 25 in a top view can also be minimized.

FIG2E shows a three-dimensional view of the region S1 shown in FIG2A viewed from the second surface 20b. As shown in FIG2E, ridges 33 divide adjacent through holes 25. For example, as shown in FIG2E, on the second surface 20b side of the perforated region 22, each through hole 25 may be surrounded by a plurality of ridges 33.

As shown in FIG2E , the second walls 36 of the adjacent second recesses 35 may meet. This can also be referred to as a state where the second surface 51 b of the metal plate 51 constituting the metal mask 20 is not left between the adjacent second recesses 35. In this case, the ridge 33 is formed by the met second walls 36. As shown in FIG2E , the height of the ridge 33 formed by the met second walls 36 is not constant, but may vary according to the distance from the center of the through hole 25. For example, the longer the distance from the center of the through hole 25 to the ridge 33, the higher the height of the ridge 33.

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

Furthermore, although not shown, the second wall surfaces 36 of the adjacent second recesses 35 may not meet. This can also be said that the adjacent second recesses 35 are separated along the direction of the second surface 20b. In this case, the portion remaining as the second surface 20b between the adjacent second recesses 35 is the ridge 33 that demarcates the adjacent through hole 25. Furthermore, in this case, the ridge 33 may be the first surface 51a of the metal plate 51 remaining between the adjacent first recesses 30. In this case, the height of the ridge 33 may be constant.

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

In addition, the first surface 51 a of the metal plate 51 may correspond to the first surface 20 a of the metal mask 20 , and in addition, the second surface 51 b of the metal plate 51 may correspond to the second surface 20 b of the metal mask 20 .

The surrounding area 23 is an area located around the hole area 22. The surrounding area 23 may be arranged in a manner of surrounding the hole area 22. The surrounding area 23 may be an area that supports the hole area 22 by being located around the hole area 22.

The surrounding area 23 has a predetermined stress dispersion area 24. Thus, even if tension is applied to the metal mask, the stress can be dispersed more uniformly. Therefore, wrinkles are less likely to be generated on the metal mask. In addition, the accuracy of the setting position when the metal mask is set on the frame is further improved. In addition, the scene where tension is applied to the metal mask is not particularly limited, but for example, when the metal mask is set on the frame and when the metal mask is transported, etc. are cited.

Furthermore, the surrounding area 23 may be an area not intended for the evaporation material 98 to pass through. Based on this viewpoint, the surrounding area 23 may mainly have a non-porous surface without through holes. However, although the surrounding area 23 has a non-porous surface for various purposes, a through hole not intended for the evaporation material to pass through may be partially formed in a portion other than the non-porous surface. In the present disclosure, "non-porous surface" means a surface without through holes.

As described later, the metal mask 20 is fixed to the frame 15 to form the metal mask device 10. The peripheral area 23 may have an end 23a fixed to the frame 15. As shown in FIG1 , when the metal mask 20 is in the shape of a long bar, the end 23a may be located at both ends of the long side direction D2. In addition, the end 23a may have a U-shaped notch or the like.

The end portion 23a may be configured so that a portion thereof can be cut off after the metal mask 20 is fixed to the frame 15. Furthermore, the end portion 23a may be integrally configured with the other surrounding regions 23 as shown in FIG1 , or may be configured by a member different from the other surrounding regions. In this case, the end portion may be joined to the other portions of the surrounding region by, for example, welding.

The thickest portion of the surrounding area 23 has a height H0. The thickest portion of the surrounding area 23 may be the height from the first surface 20a to the second surface 20b in the surrounding area 23. The height H0 may preferably be 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less. By reducing the height of the surrounding area, the porous area 22 may be made thinner by etching or the like, and it is expected that the evaporation material 98 may be suppressed from adhering to the second wall surface 36 of the second recess 35 in the evaporation step.

The height H0 is preferably 2.5 μm or more, 5 μm or more, 10 μm or more, or 15 μm or more. By increasing the height of the surrounding area, the strength of the metal mask 20 is expected to be further improved. This, for example, can further suppress deformation or fracture of the porous area 22.

The stress dispersion region 24 has a plurality of recesses 37. The recesses 37 of the stress dispersion region 24 are also referred to as "third recesses 37." FIG. 3A shows a top view of the stress dispersion region 24 viewed from the second surface 20b side.

As shown in FIG3A , the stress dispersion region 24 has third recesses 37 arranged at a pitch P in the minor axis direction. The third recesses 37 have a minor axis of length R. FIG3A shows that the minor axis direction is parallel to the D2 direction, but the present invention is not limited thereto. For example, the minor axis direction may be parallel to the D1 direction, or the minor axis direction may be a direction that is not parallel to the D1 direction and the D2 direction but intersects these directions.

FIG. 3B is a cross-sectional view along the IV-IV' line shown in FIG. 3A. Here, the IV-IV' line may be a line parallel to the minor axis direction. As shown in FIG. 3B, the third wall surface 38 of the third recess 37 may meet to form a ridge 39. The ridge 39 divides the adjacent third recess 37. Here, the opening shape of the third recess 37 in a top view may be the shape drawn by the ridge 39.

FIG3C is a cross-sectional view along the V-V' line shown in FIG3A. The cross-sectional views shown in FIG3B and FIG3C are cross-sectional views of the case where the stress dispersion region 24 is cut in the direction that crosses the third recess 37 and the ridge 39. FIG3D is a cross-sectional view along the VI-VI' line shown in FIG3A. The cross-sectional view shown in FIG3D is a cross-sectional view of the case where the stress dispersion region 24 is cut in the direction that passes through the intersection of the third recess 37 and the ridge 39.

3E shows a three-dimensional view of the region S2 shown in FIG3A viewed from the second surface 20b side. As shown in FIG3E , ridges 39 divide adjacent third recesses 37. For example, as shown in FIG3E , each third recess 37 on the second surface 20b side of the stress dispersion region 24 may be surrounded by a plurality of ridges 39.

In addition, in FIG. 3B to FIG. 3E, an example in which the third recess 37 is formed on the second surface 20b is shown. However, the present invention is not limited thereto, and the third recess 37 may be formed on the second surface 20b, may be formed on the first surface 20a, or may be formed on both. For example, by forming the third recess 37 on the second surface 20b side, the volume difference between the hole area 22 and the surrounding area 23 on the second surface 20b side becomes smaller, and the stress dispersion effect is further improved, and it is expected that the generation of wrinkles during tension can be further suppressed. The area of the third recess 37 in a top view may gradually decrease from the second surface 20b to the first surface 20a.

The third recess 37 may be formed in a desired pattern. For example, the third recess 37 may be arranged in a grid shape at a predetermined pitch along two directions (D1, D2) that intersect each other. For example, as shown in FIG. 3A, the adjacent third recesses 37 may be adjacent along the surface direction. In other words, the third walls 38 of the adjacent third recesses 37 may meet. Furthermore, as shown in FIG. 4A, the adjacent third recesses 37 may be separated along the surface direction. In other words, the third walls 38 of the adjacent third recesses 37 may not meet. Furthermore, as shown in FIG. 4B, the adjacent third recesses 37 may be adjacent in a predetermined direction, and the adjacent third recesses 37 may be separated in other directions.

Furthermore, the third recesses 37 are arranged in a staggered state at a predetermined pitch along two directions intersecting each other. For example, as shown in FIG. 4C , the adjacent third recesses 37 may be adjacent along the surface direction. In other words, the third walls 38 of the adjacent third recesses 37 may meet. Furthermore, as shown in FIG. 4D , the adjacent third recesses 37 may be separated along the surface direction. In other words, the third walls 38 of the adjacent third recesses 37 may not meet. Furthermore, as shown in FIG. 4E , the adjacent third recesses 37 may be adjacent in a predetermined direction, and the adjacent third recesses 37 may be separated in other directions.

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

In addition, the third recesses 37 may be arranged in any pattern other than the above. In addition, at this time, the wall surfaces of the adjacent third recesses 37 may or may not meet.

When the third recesses 37 are viewed from above, the opening shape may be circular, elliptical, quadrilateral, etc. For example, as shown in FIG. 4F , the third recesses 37 of elliptical shape are arranged in a staggered shape. Alternatively, the third recesses 37 of elongated quadrilateral shape may be arranged in a strip shape.

The opening shape of the third recess 37 in a plan view has a short axis of length R. As shown in FIG. 4A and FIG. 4D , when the adjacent third recesses 37 are separated in the surface direction, the length R of the short axis can be specified based on the opening shape of the third recess 37 in the second surface 20b. Also, as shown in FIG. 3A , FIG. 3E , etc., when the adjacent third recesses 37 are separated in the surface direction, the length R of the short axis can be specified based on the range S4 closed by the ridge 39 surrounding one third recess 37.

The minor axis of an opening shape refers to the shortest line segment among the line segments passing through the center of gravity of the opening shape and dividing the opening shape into two.

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

Furthermore, in the present embodiment, the pitch P is the interval between the third recesses 37 arranged in the minor axis direction. The pitch P is the interval between the center points of the third recesses 37 arranged in the minor axis direction. For example, when the third recesses 37 are arranged in a grid pattern as shown in FIGS. 4A to 4B, the interval between the third recesses 37 adjacent to each other in the minor axis direction is the pitch P. Furthermore, in FIGS. 4C to 4F, the third recesses 37 adjacent to each other in the minor axis direction are offset in the D1 direction and arranged in a misaligned state. Even if there is such a positional offset, the interval between the third recesses 37 adjacent to each other in the minor axis direction is the pitch P as shown in FIGS. 4C to 4F.

The minor axis length R is preferably 250 μm or less, 225 μm or less, 200 μm or less, 175 μm or less, 150 μm or less, 125 μm or less, 100 μm or less, 75 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. Furthermore, the minor axis length R is preferably 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, or 100 μm or more.

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

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

3A , when the third wall surfaces 38 of the adjacent third recesses 37 meet, the pitch P of the third recesses 37 arranged in the minor axis direction is equal to the minor axis length R. Therefore, the ratio (R/P) in this case is 1.00.

By setting the minor axis length R1 and the ratio (R/P) to be greater than the above lower limit, the third recess 37 can be formed larger and closer in the stress dispersion area 24. Therefore, the stress can be more uniformly dispersed by the stress dispersion area 24. Thus, even when tension is applied to the metal mask, wrinkles are less likely to occur, and the accuracy of the installation position can be improved. In addition, by setting the minor axis length R1 and the ratio (R/P) to be less than the above upper limit, the strength of the metal mask can be expected to be further improved.

Furthermore, by setting the pitch P to be below the above upper limit, the adjacent third recesses 3 are formed closer together in the stress dispersion region 24. Therefore, the stress can be dispersed more uniformly by the stress dispersion region 24. Thus, even when tension is applied to the metal mask, wrinkles are less likely to occur, and the accuracy of the installation position can be improved. Furthermore, by setting the pitch P to be above the above lower limit, the strength of the metal mask is expected to be further improved.

In addition, the ranges of the minor axis length R, the pitch P, and the ratio (R/P) can be determined by combining any one of the above-mentioned plurality of lower limit candidate values with any one of the above-mentioned plurality of upper limit candidate values.

The thinnest portion of the stress dispersion area 24 has a height H1. The thinnest portion of the stress dispersion area 24 may be a portion of the bottom of the third recess 37 in the stress dispersion area 24. For example, when the third recess 37 is formed on the second surface 20b, the height H1 may be a height from the first surface 20a to the bottom of the third recess 37. Furthermore, when the third recess 37 is formed on the first surface 20a, the height H1 may be a height from the second surface 20b to the bottom of the third recess 37. In addition, the bottom of the third recess 37 may be a portion of the stress dispersion area 24 having a very small height.

The height H1 is preferably 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less. The height H1 is preferably 2.5 μm or more, 5 μm or more, or 10 μm or more.

Furthermore, the ratio of the height H1 to the height H0 (H1/H0) is preferably 0.20 or more, 0.25 or more, 0.30 or more, 0.35 or more, 0.40 or more, or 0.45 or more. Furthermore, the ratio of H1 (H1/H0) is preferably 0.80 or less, 0.75 or less, 0.70 or less, 0.65 or less, 0.60 or less, or 0.55 or less.

By setting the height H1 and the ratio (H1/H0) within the above range, the stress dispersion performance is improved and its uniform dispersion is expected to be further improved.

In addition, the ranges of the height H1 and the ratio (H1/H0) can be determined by combining any one of the above-mentioned plurality of candidate values for the lower limit and any one of the above-mentioned plurality of candidate values for the upper limit.

The stress dispersion region 24 can be formed at any position of the surrounding region 23. Hereinafter, an example of the position of the stress dispersion region 24 in the surrounding region 23 will be described with reference to Fig. 1. In Fig. 1, stress dispersion regions 24a to 24d are shown according to the position.

The stress dispersion region 24 may be located between the edge 23b of the surrounding region 23 and the porous region 22. In FIG. 1 , the edge 23b of the surrounding region 23 has a pair of long sides 23c and a pair of short sides 23d. In this case, the stress dispersion region 24a may be located between the long sides 23c and the porous region 22. Furthermore, the stress dispersion region 24c and 24d may be located between the short sides 23d and the porous region 22. Furthermore, the stress dispersion region 24a may be located around the porous region 22, and the stress dispersion region 24a may be arranged in a manner of surrounding the porous region 22.

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

In the width direction D1, the width L3 of the stress dispersion regions 24c and 24d and the width L4 of the hole region 22 can be set to be substantially the same. The ratio (L3/L4) of the width L3 to the width L4 is preferably 0.80 or more, 0.90 or more, or 1.00 or more. Furthermore, the ratio (L3/L4) is preferably 1.20 or less, 1.10 or less, or 1.00 or less.

In the width direction D1, the width L3 of the stress dispersion regions 24c and 24d and the width L0 of the surrounding region 23 can be set to be substantially the same. The ratio (L3/L0) of the width L3 to the width L0 is preferably 0.70 or more, 0.80 or more, or 0.90 or more. Furthermore, the ratio (L3/L0) is preferably 0.95 or less, 0.90 or less, or 0.85 or less.

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

In the width direction D1, the width L5 of the stress dispersion region 24b and the width L4 of the hole region 22 can be set to be substantially the same. The ratio (L5/L4) of the width L5 to the width L4 is preferably 0.80 or more, 0.90 or more, or 1.00 or more. Furthermore, the ratio (L5/L4) is preferably 1.20 or less, 1.10 or less, or 1.00 or less.

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

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

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

The stress dispersion area 24 may be rectangular, or may be substantially fan-shaped, polygonal, circular, or elliptical. The porous area 22 and the stress dispersion area 24 may both be rectangular. In this case, one side of the stress dispersion area 24 may be substantially parallel to one side of the porous area 22.

The manufacturing method of the metal mask of one embodiment of the present disclosure includes: a preparation step, which prepares a metal plate 51, wherein the metal plate 51 has a first surface 51a and a second surface 51b located on the opposite side of the first surface 51a; and an etching step, which forms the above-mentioned metal mask 20 by etching the metal plate 51.

In addition, the following describes a method of manufacturing the metal mask 20 by etching, but the metal mask 20 may be formed by etching, may be formed by laser processing, or may be formed by electrocasting.

The manufacturing method of the metal mask 20 of one embodiment of the present disclosure is mainly explained with reference to Figures 5A to 5F. Figure 5A is a schematic diagram showing a manufacturing device 70 that uses a metal plate 51 to manufacture the metal mask 20 along its processing sequence. Figure 5A shows an example of continuously supplying the metal plate 51 from the anti-etching film forming device 71 to the stripping device 74. However, the manufacturing method of the metal mask 20 of the present disclosure is not limited to this. For example, the metal plate 51 can be rolled up and set to a coil state each time it is processed by each device. In addition, when the metal plate 51 is supplied to each device, the metal plate 51 can be unwound from the coil and supplied.

The following describes in detail the steps of the method for manufacturing the metal mask 20.

First, a metal plate 51 having a desired thickness is prepared (preparation step). The metal plate 51 may be in the form of a roll 50 wound around a core 52. There is no particular limitation on the method for producing the metal plate 51 having a desired thickness, and examples thereof include a rolling method, a coating method, and the like.

Next, an anti-etching film forming device 71 is used to form anti-etching films 53a and 53b on the first surface 51a and the second surface 51b of the metal plate 51 (FIG. 5B). Specifically, the anti-etching films 53a and 53b can be formed by attaching a dry film anti-etching agent to the first surface 51a and the second surface 51b. Alternatively, the anti-etching films 53a and 53b can be formed by applying a coating liquid containing a photosensitive anti-etching agent material to the first surface 51a and the second surface 51b and drying it.

There is no particular limitation on the dry film resist and the coating liquid, but any known ones can be used. The resist films 53a and 53b formed in this way can be either negative type resist or positive type resist. It is preferred to use a negative type resist.

The thickness of the anti-corrosion films 53a and 53b may be 15 μm or less, 10 μm or less, 6 μm or less, or 4 μm or less. Furthermore, the thickness of the anti-corrosion films 53a and 53b may be 1 μm or more, 3 μm or more, 5 μm or more, or 7 μm or more. The range of the thickness of the anti-corrosion films 53a and 53b may be determined by combining any one of the plurality of upper limit candidate values and any one of the plurality of lower limit candidate values.

Next, the anti-etching films 53a and 53b are exposed and developed using the exposure and development device 72. Thus, as shown in FIG. 5C , a first anti-etching agent pattern 53c can be formed on the first surface 51a, and a second anti-etching agent pattern 53d can be formed on the second surface 51b. For example, when a negative anti-etching film is used, a photomask that prevents light from passing through the region to be removed in the anti-etching film can be placed on the anti-etching film, and the anti-etching film can be exposed through the photomask, and then the anti-etching film can be developed.

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

FIG5D is a schematic diagram showing an example of the first surface etching step in the hole region 22. In the first surface etching step, an etching liquid is used to etch the area of the first surface 51a that is not covered by the first resist pattern 53c. At this time, the second surface 51b may be covered with a resin or the like that is resistant to the etching liquid.

The etching is continued in the first surface 51a not covered by the first resist pattern 53c by the etching liquid (FIG. 5D). Thus, a plurality of first recesses 30 are formed on the first surface 51a. In addition, the etching of the metal plate 51 can be performed isotropically from the hole of the resist pattern to various directions. Therefore, the cross-sectional area of the first recess 30 and the second recess 35 at each position along the thickness direction of the metal mask 20 is a shape that gradually decreases as it goes deeper along the thickness direction from the surface.

FIG. 5E shows a schematic diagram of an example of the second surface etching step in the hole region 22. In the second surface etching step, an etching liquid is used to etch the area of the second surface 51b that is not covered by the second resist pattern 53d. At this time, the film or the like that covered the second surface 51b in the first surface etching step may be peeled off in advance. In addition, the first surface 51a may be covered with a resin 54 or the like that has resistance to the etching liquid.

The etching liquid is used to continuously etch the second surface 51b not covered by the second resist pattern 53d (FIG. 5E). Thus, the second recess 35 is formed on the second surface 51b. Furthermore, the first recess 30 and the second recess 35 are connected to each other, thereby forming a through hole 25.

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

In the second surface etching step, as shown in FIG. 5E , etching may be continued until adjacent second recesses 35 are connected. At the portion where adjacent second recesses 35 are connected, the adjacent second recesses 35 meet to form a ridge 33. Furthermore, the ridge 33 is separated from the second resist pattern 53d, and at the top of the ridge 33, etching caused by etching also continues along the thickness direction of the metal plate 51. Thus, the second resist pattern 53d is peeled off from the metal plate 51. In addition, the second surface 51b may partially remain between the adjacent second recesses 35.

FIG5F is a schematic diagram showing an example of the second surface etching step in the stress dispersion region 24. The second recess 35 of the hole region 22 and the third recess 37 of the stress dispersion region 24 can be formed by the same second surface etching step. In the second surface etching step, as shown in FIG5F, etching can be continued until the adjacent third recesses 37 are connected. At the portion where the adjacent third recesses 37 are connected, the adjacent third recesses 37 meet to form an ridge 39.

Furthermore, the resin 54 or the like resistant to the resist pattern or the etching liquid is stripped from the metal plate 51 using the stripping device 74. Furthermore, the metal mask 20 made of a single metal plate is separated from the metal plate 51 by cutting the long metal plate 51 using the stripping device 75. In this way, the metal mask 20 can be obtained.

The metal mask device 10 of one embodiment of the present disclosure comprises: a frame 15, and the metal mask 20 disposed on the frame 15. The metal mask 20 is disposed on the frame 15 so that the second surface 20b of the metal mask 20 is in contact with the frame 15. FIG6 shows a top view of the metal mask device 10 viewed from the first surface 20a of the metal mask 20. FIG7 shows a cross-sectional view of the evaporation device.

The metal shield device 10 of the present disclosure can install a plurality of metal shields 20 on one frame ( FIG. 6 ). In this case, the plurality of metal shields 20 can be arranged along a width direction D1 intersecting with the long side direction D2 of the metal shield 20. In addition, each metal shield 20 can be fixed to the frame 15 at both ends 23a of the long side direction D2 of the metal shield 20.

In addition, a metal shield 20 as shown in FIG. 1C may be installed on a frame 15. At this time, the metal shield 20 may be fixed to the frame 15 at the end 23a of the peripheral region 23.

The method of fixing to the frame 15 is not particularly limited, and may include, for example, welding.

The metal mask device 10 may include a member fixed to the frame 15 and partially overlapping the metal mask 20 in the thickness direction of the metal mask 20. Examples of such a member include, but are not limited to, a member extending in a direction intersecting the long side direction of the metal mask 20 and supporting the metal mask 20, and a member overlapping the gap between two adjacent metal masks.

Next, a method for manufacturing an organic EL display device using the metal mask 20 of the present disclosure will be described with reference to Fig. 7. The organic EL display device may include a substrate 92 and a vapor deposition layer including a vapor deposition material 98 arranged in a pattern in a stacked state.

The manufacturing method of the organic EL display device of one embodiment of the present disclosure is not particularly limited, and for example, includes a evaporation step of using a metal mask 20 to evaporate the evaporation material 98 onto a substrate such as a substrate 92 .

In the evaporation step, first, the metal mask device 10 is arranged in such a manner that the metal mask 20 faces the substrate 92. At this time, as shown in Fig. 7, the first surface 20a of the metal mask 20 faces the substrate 92. Here, the substrate 92 is an evaporation object such as a glass substrate.

As shown in FIG. 7 , when the metal mask device 10 is housed in the evaporation device 90, the surface of the metal mask 20 facing the substrate 92 is the first surface 20a, and the surface of the metal mask 20 located on the crucible 94 side holding the evaporation material 98 is the second surface 20b. In the evaporation device 90, the metal mask 20 is arranged on the crucible 94 side of the substrate 92. Here, the metal mask 20 and the substrate 92 can be closely attached by magnetic force.

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

In the case where different types of deposition materials are to be deposited according to pixels such as RGB, different metal masks 20 can be used according to the colors of the deposition materials 98 to form the deposition materials 98 on the surface of the substrate 92. For example, the deposition materials 98 for red, the deposition materials 98 for green, and the deposition materials 98 for blue can be sequentially deposited on the substrate 92. In addition, the metal mask 20 (metal mask device 10) and the substrate 92 can be relatively moved point by point along the arrangement direction of the through holes 25 (one of the aforementioned directions) to sequentially deposit the deposition materials 98 for red, the deposition materials 98 for green, and the deposition materials 98 for blue.

Furthermore, the manufacturing method of the organic EL display device may include various steps in addition to the evaporation step of evaporating the evaporation material 98 on the substrate such as the substrate 92 using the metal mask 20. For example, the manufacturing method of the organic EL display device may include the step of forming the first electrode on the substrate. The evaporation layer is formed on the first electrode. Furthermore, the manufacturing method of the organic EL display device may include the step of forming the second electrode on the evaporation layer. Furthermore, the manufacturing method of the organic EL display device may include the step of sealing the first electrode, the evaporation layer, and the second electrode provided on the substrate 92.

The evaporated layer formed on the substrate 92 or the like using the metal mask 20 is not limited to the luminescent layer formed by evaporating the above-mentioned organic luminescent material, and may include other layers. For example, the evaporated layer may include a hole injection layer, a hole transport layer, a luminescent layer, an electron transport layer, an electron injection layer, etc. in order from the first electrode side. In this case, the evaporation step using the corresponding metal mask 20 may be implemented on each layer separately.

In addition, various changes can be made to the above-mentioned implementation form. Below, as needed, the variation examples are explained while referring to the drawings. In the following description and the drawings used in the following description, the same symbols as the symbols used for the corresponding parts in the above-mentioned implementation form are used for the parts that can be constructed in the same way as the above-mentioned implementation form, and repeated descriptions are omitted. In addition, in the case where the effects obtained in the above-mentioned implementation form are obviously also obtained in the variation examples, the description is also omitted.

(Variation) As a first variation, the metal mask 20 may have a plurality of rows of a plurality of porous regions 22. In other words, the plurality of porous regions 22 may be arranged in a grid pattern. In this case, the stress dispersion region 24 may be located between the edge 23b of the surrounding region 23 and the porous region 22. Furthermore, the stress dispersion region 24 may be located between the plurality of porous regions 22.

When the metal mask 20 has a plurality of rows of a plurality of perforated areas 22, one metal mask 20 may be mounted on one frame 15. In this case, the end 23a may be located at the periphery of the metal mask 20. When the end 23a has a cutting line 26, the stress dispersion area 24c may be located between the cutting line 26 and the perforated area 22. Furthermore, the stress dispersion area 24d may be located between the cutting line 26 and the short side 23d.

As a third variation, one perforated region 22 may also be configured to correspond to a plurality of organic EL display devices. For example, the perforated region 22 may include a first perforated region and a second perforated region. In this example, one first perforated region may be configured to correspond to one organic EL display device. In addition, the second perforated region may be configured to divide the adjacent first perforated region.

The density of through holes in the first porous region is different from that in the second porous region. More specifically, the density of through holes in the first porous region may be higher than the density of through holes in the second porous region. Here, the density of through holes means the total area of through holes per unit area. In addition, the area of a through hole means the area of the smallest opening of the through hole in a top view. Here, the smallest opening of the through hole in a top view may be the opening surrounded by the connecting portion 41.

As a third variation, the first recess 30, the second recess 35, and the third recess 37 can be formed by irradiating laser light using a laser irradiator instead of etching. Example

The present invention is described in more detail below using examples and comparative examples. The present invention is not limited to the following examples in any way.

(Example) Using the above-mentioned method for manufacturing a metal mask, a metal mask having a through hole formed by a first recess and a second recess and a third recess is manufactured. At this time, the minor axis length R of the third recess and the pitch P arranged in the minor axis direction have a prescribed relationship. In addition, the metal plate used as the raw material of the metal mask is indium steel.

(Comparative Example) Except that the minor axis length R of the third recess and the pitch P arranged in the minor axis direction have the prescribed relationship described in Table 1, a metal mask is obtained in the same manner as in the embodiment.

(Evaluation) When a metal mask is tension-welded to a frame by applying a tensile force in the length direction, the fluctuations in the width direction of the mask are measured as the fluctuations after tension welding. Specifically, the fluctuations were obtained by three-dimensional measurement using μ-M1000 manufactured by Shinto Ultra Precision Co., Ltd. The fluctuations obtained were evaluated for the generation of wrinkles according to the following evaluation criteria. ◎・・・The fluctuation after tension welding is 100 μm or less. ○・・・The fluctuation after tension welding exceeds 100 μm and is 200 μm or less. ×・・・The fluctuation after tension welding exceeds 200 μm.

In addition, the so-called fluctuation momentum being less than 100 μm means that the metal mask has good adhesion to the substrate, and there is almost no floating of the metal mask. The so-called fluctuation momentum being more than 100 μm and less than 200 μm means that the metal mask is closely attached to the substrate by magnetic force, and thus there is no blurring. The so-called fluctuation momentum being more than 200 μm means that blurring occurs due to poor adhesion between the metal mask and the substrate.

In addition, the above-mentioned "prescribed steps" refer to a series of steps including manufacturing a metal mask, manufacturing a metal mask device by tensioning and melting the manufactured metal mask on a frame, using the obtained metal mask device for evaporation, and cleaning the metal mask device until it is reused for evaporation.

[Table 1] H0 H1 R Pitch P R/P H1/H0 Wrinkles Embodiment 1 10 3 30 30 1.00 0.30 ◎ 2 15 7 30 33 0.91 0.47 ◎ 3 20 18.5 30 33 0.91 0.93 ○ 4 25 12 30 33 0.91 0.48 ◎ 5 30 5 44 44 1.00 0.17 ◎ 6 30 28 25 25 1.00 0.93 ○ 7 40 38 27 27 1.00 0.95 ○ Comparison Example 1 20 20 70 80 0.88 1.00 × 2 20 18.5 30 45 0.67 0.93 × 3 25 twenty three 15 twenty two 0.68 0.92 × 4 40 38 80 95 0.84 0.95 × [Industrial Availability]

The metal mask of the present invention is applicable in the industry as a metal mask used in the manufacture of an organic EL display device.

10: Metal shielding device 15: Frame 20: Metal shielding 20a: 1st surface 20b: 2nd surface 22: Perforated area 23: Peripheral area 23a: End 23b: Edge 23c: Long side 23d: Short side 24,24a,24b,24c,24d: Stress dispersion area 25: Through hole 26: Cutting line 30: 1st recess 31: 1st wall 32: Top 33: Ridge 35: 2nd recess 36: 2nd wall 37: 3rd recess/recess 38: 3rd wall 39: Ridge 41: Connecting part 50: Winding body 51: Metal plate 51a: 1st surface 51b: 2nd surface 52: Core 53a, 53b: Anti-etching film 53c: 1st anti-etching agent pattern 53d: 2nd anti-etching agent pattern 54: Resin 70: Manufacturing device 71: Anti-etching film forming device 72: Exposure and development device 73: Etching device 74: Stripping device 75: Separation device 90: Evaporation device 92: Substrate 94: Crucible 96: Heater 98: Evaporation material D1: Width direction D2: Long side direction H0, H1: Height I-I’, II-II’, III-III’, IV-IV’, V-V’, VI-VI’: Line L0, L1, L2, L3, L4, L5: Width N: Thickness direction P: Pitch R: Length S1, S2: Area S3, S4: Range

FIG. 1 is a top view of a metal mask showing an embodiment of the present disclosure. FIG. 2A is a top view of a hole region observed from the second surface side. FIG. 2B is a cross-sectional view along the I-I’ line shown in FIG. 2A. FIG. 2C is a cross-sectional view along the II-II’ line shown in FIG. 2A. FIG. 2D is a cross-sectional view along the III-III’ line shown in FIG. 2A. FIG. 2E is a three-dimensional view of the region S1 shown in FIG. 2A observed from the second surface side. FIG. 3A is a top view of a stress dispersion region observed from the second surface side. FIG. 3B is a cross-sectional view along the IV-IV’ line shown in FIG. 3A. FIG. 3C is a cross-sectional view along the V-V’ line shown in FIG. 3A. FIG. 3D is a cross-sectional view along the VI-VI’ line shown in FIG. 3A. FIG. 3E is a three-dimensional view of the region S2 shown in FIG. 3A observed from the second surface side. FIG. 4A is a top view showing an example of arrangement of recesses in the stress dispersion region. FIG. 4B is a top view showing an example of arrangement of recesses in the stress dispersion region. FIG. 4C is a top view showing an example of arrangement of recesses in the stress dispersion region. FIG. 4D is a top view showing an example of arrangement of recesses in the stress dispersion region. FIG. 4E is a top view showing an example of arrangement of recesses in the stress dispersion region. FIG. 4F is a top view showing an example of arrangement of recesses in the stress dispersion region. FIG. 5A is a schematic diagram for explaining an example of a method for manufacturing a metal mask. FIG. 5B is a diagram showing an example of a step of forming an anti-corrosion film on a metal plate. FIG. 5C is a diagram showing an example of a step of patterning an anti-etching film. FIG. 5D is a diagram showing an example of a step of etching the first surface in a porous region. FIG. 5E is a diagram showing an example of a step of etching the second surface in a porous region. FIG. 5F is a diagram showing an example of a step of etching the second surface in a stress dispersion region. FIG. 6 is a diagram showing a metal mask device in an embodiment of the present disclosure. FIG. 7 is a cross-sectional view of an evaporation device in an embodiment of the present disclosure.

20: Metal mask

20b: Page 2

22: Perforated area

23:Surrounding area

23a: End

23b: Fate

23c: Long side

23d: short side

24a, 24b, 24c, 24d: stress dispersion area

26: Cutting line

D1: Width direction

D2: Long side direction

L0,L1,L2,L3,L4,L5:Width

Claims (10)

A metal mask having a perforated area and a surrounding area; and the perforated area has a plurality of through holes; the surrounding area is located around the perforated area; the surrounding area has a stress dispersion area; the stress dispersion area has a plurality of recesses; the opening shape of the recess in a top view has a short axis of length R; the stress dispersion area has the recesses arranged at a pitch P in the direction of the short axis; the ratio (R/P) of the length R to the pitch P is greater than 0.90. A metal mask as claimed in claim 1, wherein the aforementioned recesses are arranged in a staggered or grid pattern. A metal mask as claimed in claim 1, wherein the walls of adjacent aforementioned recesses converge. The metal mask of claim 1, wherein the thickest part of the aforementioned surrounding area has a height H0; and the thinnest part of the aforementioned stress dispersion area has a height H1; the ratio of the aforementioned height H1 to the aforementioned height H0 (H1/H0) is greater than 0.20 and less than 0.90. A metal mask as claimed in claim 1, wherein the surrounding area has an edge; and the stress dispersion area is located between the edge and the porous area. A metal mask as claimed in claim 5, wherein the aforementioned edge of the surrounding area has a pair of long sides and a pair of short sides; and the aforementioned stress dispersion area is located between the aforementioned edge of the aforementioned long side and the aforementioned perforated area. The metal mask of claim 1 has a plurality of the aforementioned porous regions; and the aforementioned stress dispersion region is located between the plurality of the aforementioned porous regions. A metal mask as claimed in claim 1, wherein the surrounding area has a cutting line; and the cutting line is a row of recesses or through holes; and the stress dispersion area is located between the cutting line and the hole area. A metal mask as claimed in claim 1, wherein the surrounding area has a cutting line; and the cutting line is a row of recesses or through holes; and the cutting line is located between the stress dispersion area and the hole area. A method for manufacturing a metal mask, comprising: a step of preparing a metal plate, the metal plate having a first surface and a second surface located on the opposite side of the first surface; and an etching step, in which the metal mask is formed by etching the metal plate; and the metal mask has a hole area and a surrounding area; the hole area has a plurality of through holes; the surrounding area is located around the hole area; the surrounding area has a stress dispersion area; the stress dispersion area has a plurality of recesses; the opening shape of the recess in a top view has a short axis of length R; the stress dispersion area has the recesses arranged at a pitch P in the direction of the short axis; the ratio (R/P) of the length R to the pitch P is greater than 0.90.