CN117821896A

CN117821896A - Metal mask for vapor deposition and method for manufacturing metal mask for vapor deposition

Info

Publication number: CN117821896A
Application number: CN202311802064.9A
Authority: CN
Inventors: 田村纯香; 新纳干大; 藤户大生; 西辻清明; 西刚广; 三上菜穗子; 仓田真嗣; 武田宪太
Original assignee: Toppan Printing Co Ltd
Current assignee: Toppan Inc
Priority date: 2015-07-17
Filing date: 2016-07-15
Publication date: 2024-04-05
Also published as: CN106350768A; CN205974646U; JP6120038B1; TW201708576A; JP2017193775A; TWI665319B

Abstract

The present invention provides a metal mask for vapor deposition and a method for manufacturing the metal mask for vapor deposition, which can improve the structural accuracy of a pattern formed by vapor deposition and the operability of the metal mask for vapor deposition. The device is provided with: a mask portion (32) having a contact surface for contacting a deposition target and a non-contact surface opposite to the contact surface, the mask portion being formed in a sheet shape, the mask portion having a plurality of mask holes penetrating from a first opening located on the contact surface to a second opening located on the non-contact surface, respectively, the first opening having a smaller size than the second opening; and a mask frame (31) having higher rigidity than the mask portion and formed in a frame shape surrounding the plurality of mask holes. The mask portion (32) has a portion surrounding the plurality of mask holes in the non-contact surface, and is joined to the mask frame by a joint portion.

Description

Metal mask for vapor deposition and method for manufacturing metal mask for vapor deposition

The present application is a divisional application of application number 201610561108.7, which is entitled "method for manufacturing a metal mask for vapor deposition", and of which the application number is 2016, 7, 15.

Technical Field

The present invention relates to a metal mask for vapor deposition and a method for manufacturing the metal mask for vapor deposition.

Background

When vapor deposition is performed on a vapor deposition target such as a substrate by a vapor deposition material, a metal mask may be used. The metal mask for vapor deposition includes a contact surface and a non-contact surface. The contact surface is a surface that comes into contact with the deposition target. The non-contact surface is the surface opposite to the contact surface. The mask Kong Jubei penetrating from the non-contact surface to the contact surface is a non-contact side opening and a contact side opening. The non-contact side opening is an opening located on the non-contact surface and into which the vapor deposition material enters. The contact side opening is located on the contact surface and faces the vapor deposition object. The vapor deposition material that has entered from the non-contact side opening and passed through the contact side opening is deposited on the vapor deposition target. Thus, a pattern is formed according to the position and shape of the contact side opening (for example, refer to japanese patent application laid-open No. 2015-055007).

In order to improve the accuracy of the position on the pattern, the passage cross-sectional area of the mask hole of the vapor deposition metal mask monotonically decreases from the non-contact side opening toward the contact side opening. In recent years, in order to improve accuracy such as uniformity of film thickness of a pattern, it is also desired to reduce the distance between a non-contact side opening and a contact side opening, that is, the thickness of a metal mask for vapor deposition.

On the other hand, in the case of a metal mask for vapor deposition having a small thickness, sufficient mechanical resistance of the metal mask for vapor deposition cannot be obtained, and therefore, the operability of the metal mask for vapor deposition is remarkably low.

Disclosure of Invention

The purpose of the present invention is to provide a metal mask for vapor deposition and a method for manufacturing a metal mask for vapor deposition, which can improve both the structural accuracy such as the position and the film thickness of a pattern formed by vapor deposition and the operability of the metal mask for vapor deposition.

The metal mask for vapor deposition includes a mask portion having a contact surface for contacting a vapor deposition object and a non-contact surface opposite to the contact surface, the mask portion having a sheet shape, and the mask portion having a plurality of mask holes penetrating from first openings located on the contact surface to second openings located on the non-contact surface, respectively, the first openings having a smaller size than the second openings. The metal mask for vapor deposition further includes a mask frame having higher rigidity than the mask portion and formed in a frame shape surrounding the plurality of mask holes. The mask portion has a portion surrounding the plurality of mask holes in the non-contact surface, and is joined to the mask frame by a joint portion.

The method for manufacturing a metal mask for vapor deposition for solving the above problems comprises: a step of forming a mask portion having a contact surface for contacting a deposition target and a non-contact surface opposite to the contact surface, the mask portion being formed in a sheet shape, the mask portion having a plurality of mask holes penetrating from a first opening located on the contact surface to a second opening located on the non-contact surface, respectively, the first opening having a smaller size than the second opening; and

and a step of joining the mask portion to a mask frame, the mask frame having a higher rigidity than the mask portion and being formed in a frame shape surrounding the plurality of mask holes, the mask portion having a portion surrounding the plurality of mask holes in the non-contact surface, the mask portion being joined to the mask frame at the portion through a joint portion.

According to the above-described configurations, the vapor deposition material entering the mask hole from the second opening is deposited on the vapor deposition target through the first opening having a smaller size than the second opening. Therefore, the structural accuracy of the pattern formed by the vapor deposition material can be improved. The non-contact surface where the second opening is located is joined to a mask frame having higher rigidity than the mask portion. Therefore, the contact surface can be easily brought into contact with the deposition target, and the rigidity of the metal mask for deposition itself can be improved, and further, the operability of the metal mask for deposition can be improved.

The metal mask for vapor deposition may include a plurality of mask portions joined to a common mask frame.

In the method for manufacturing a metal mask for vapor deposition, the step of bonding the mask frame to the non-contact surface may be performed by bonding a plurality of mask portions to one mask frame.

According to the above configurations, the number of mask holes required for one mask frame can be divided into a plurality of mask portions. The metal mask for vapor deposition is superior to a structure in which one mask portion includes all mask holes required for one mask frame, in the following aspects. That is, even when a part of one mask portion is deformed, the size of a new mask portion to be replaced with the deformed mask portion can be suppressed to one of the plurality of mask portions. Further, the consumption of various materials required for repairing the vapor deposition metal mask can be suppressed.

In the vapor deposition metal mask, the mask portion may be a metal sheet, at least one of the contact surface and the non-contact surface may include a smooth surface, the smooth surface may be formed so that a reflectance of specular reflection of light incident on the smooth surface is 45.2% or more, and a thickness of the metal sheet may be 50 μm or less.

In the method for manufacturing a metal mask for vapor deposition, the mask portion may be a metal sheet, at least one of the contact surface and the non-contact surface may include a smooth surface, the smooth surface may have a reflectance of 45.2% or more of specular reflection of light incident on the smooth surface, and the metal sheet may have a thickness of 50 μm or less.

The effect of bonding with the mask frame is more remarkable as the mask portion has a smaller thickness. According to the above-described respective configurations, the above-described effects can be obtained for a thin mask portion having a thickness of 50 μm or less.

In the vapor deposition metal mask, the mask portion may be a metal sheet, at least one of the contact surface and the non-contact surface may include a smooth surface, the smooth surface may be formed so that a reflectance of specular reflection of light incident on the smooth surface is 53.0% or more, and a thickness of the metal sheet may be 40 μm or less.

In the method for manufacturing a metal mask for vapor deposition, the mask portion may be a metal sheet, at least one of the contact surface and the non-contact surface may include a smooth surface, the smooth surface may have a reflectance of 53.0% or more of specular reflection of light incident on the smooth surface, and the metal sheet may have a thickness of 40 μm or less.

According to the above-described respective configurations, the above-described effects can be obtained for a thin mask portion having a thickness of 40 μm or less.

In the vapor deposition metal mask, the mask frame may have a plane in which the joint portion is located, and the plane may have a size extending outward of the mask portion.

According to the metal mask for vapor deposition, the plane joined to the non-contact surface extends outward of the mask portion. That is, the mask frame has a surface structure in which the non-contact surface of the mask portion having a sheet shape virtually expands. Therefore, in the range of the planar expansion of the mask frame, a space corresponding to the thickness of the mask portion is easily formed around the mask portion. As a result, physical interference between the vapor deposition object in contact with the contact surface and the mask frame can be suppressed.

Drawings

Fig. 1 is a plan view showing a planar structure of a mask device according to an embodiment.

Fig. 2 is a sectional view partially showing an example of a sectional structure of the mask portion.

Fig. 3 is a sectional view partially showing another example of a sectional structure of the mask portion.

Fig. 4 is a sectional view partially showing an example of a joint structure between an edge of a mask portion and a mask frame.

Fig. 5 is a sectional view partially showing another example of the joint structure between the edge of the mask portion and the mask frame.

Fig. 6 is a diagram showing an example of the relationship between the number of mask holes in the metal mask for vapor deposition and the number of mask holes in each mask portion, (a) is a plan view showing the planar structure of the metal mask for vapor deposition, and (b) is a cross-sectional view showing the cross-sectional structure of the metal mask for vapor deposition.

Fig. 7 is a diagram showing another example of the relationship between the number of mask holes in the metal mask for vapor deposition and the number of mask holes in the mask portion, (a) is a plan view showing the planar structure of the metal mask for vapor deposition, and (b) is a cross-sectional view showing the cross-sectional structure of the metal mask for vapor deposition.

Fig. 8 is a cross-sectional view showing a cross-sectional structure of an example of a metal mask base material for vapor deposition.

Fig. 9 is a cross-sectional view showing a cross-sectional structure of another example of the metal mask base material for vapor deposition.

Fig. 10 is a graph showing the relationship among the respective manufacturing methods, the surface roughness of the sheet target surface of the metal mask base material for vapor deposition, and the reflectance of the sheet target surface of the metal mask base material for vapor deposition.

Fig. 11 is a graph showing the reflectance of the sheet target surface of each metal mask base material for vapor deposition.

Fig. 12 is a diagram illustrating an example of a method for manufacturing a metal mask for vapor deposition according to one embodiment, and (a) to (h) are each a process diagram showing a flow of a process.

Fig. 13 is a diagram illustrating another example of a method for manufacturing a metal mask for vapor deposition according to one embodiment, and (a) to (e) are process charts each showing a flow of a process.

Fig. 14 is a diagram illustrating another example of a method for manufacturing a metal mask for vapor deposition according to one embodiment, and (a) to (f) are process charts each showing a flow of a process.

Description of symbols

The film includes a film of F … stress, S … vapor deposition target, V … space, EPS … electrode surface, H1 … back side opening, H2 … surface opening, PR … resist layer, RM … resist mask, SH … step height, T1, T32 … thickness, TM … intermediate transfer substrate, 10 … mask set, 20 … main frame, 21 … main frame aperture, 30 … vapor deposition metal mask, 31 … mask frame, 31E … frame inner side edge portion, 32A, 32B, 32C … mask portion, 32BN … joint portion, 32E … outer peripheral edge portion, 32H … mask aperture, 32K … substrate, 32LH … mask aperture, 32SH … mask aperture, 33A, 33B, 33C … mask frame aperture, 311 … frame back side, 312 … frame surface, 321 … back side, 322 mask surface, 323 … die.

Detailed Description

Referring to fig. 1 to 14, an embodiment of a metal mask for vapor deposition and a method for manufacturing the metal mask for vapor deposition will be described.

[ mask device ]

As shown in fig. 1, the mask device 10 includes a main frame 20 and a plurality of vapor deposition metal masks 30. The main frame 20 has a rectangular frame shape that supports a plurality of vapor deposition metal masks 30. The main frame 20 is attached to a vapor deposition device for vapor deposition. The main frame 20 has a plurality of main frame holes 21. The main frame holes 21 penetrate the main frame 20 over substantially the entire region where the vapor deposition metal masks 30 are located.

The vapor deposition metal mask 30 includes a mask frame 31 and a plurality of mask portions 32. The mask frame 31 has a short strip shape supporting the mask portion 32. The mask frame 31 is mounted to the main frame 20. The mask frame 31 has a plurality of mask frame holes 33. Each mask frame hole 33 penetrates the mask frame 31 over substantially the entire region where the corresponding mask portion 32 is located. The mask frame 31 has higher rigidity than the mask portion 32, and has a frame shape surrounding each mask frame hole 33. Each mask portion 32 is fixed to the frame inner edge portion of the mask frame 31, in which the corresponding mask frame hole 33 is formed, by welding or adhesion.

Next, an example of the cross-sectional structure of the mask portion 32 will be described with reference to fig. 2, and another example of the cross-sectional structure of the mask portion 32 will be described with reference to fig. 3.

As in the example shown in fig. 2, one example of the mask portion 32 is constituted by a mask sheet 323. The mask sheet 323 is any one of a single metal sheet, a multi-layered metal sheet, and a laminate of a metal sheet and a resin sheet. The material of the metal sheet constituting the mask sheet 323 is nickel or iron-nickel alloy. The material of the metal sheet constituting the mask sheet 323 is, for example, an iron-nickel alloy containing 30 mass% or more of nickel, and is invar (invar) which is composed mainly of an alloy of 36 mass% of nickel and 64 mass% of iron. In the case of an alloy of 36 mass% nickel and 64 mass% iron as the main component, the residual components include additives such as chromium, manganese, carbon, cobalt, and the like. In the case where the metal sheet constituting the mask sheet 323 is a invar alloy sheet, the coefficient of thermal expansion of the metal sheet is, for example, 1.2x10 ^-6 Degree of/(degree of C.). In the case of the mask sheet 323 having such a thermal expansion coefficient, the mask portion 32 is thermally insulatedThe degree of expansion matches the degree of thermal expansion of the glass substrate. Therefore, a glass substrate is preferably used as an example of the vapor deposition target.

The mask sheet 323 has a mask back surface 321 which is an example of a contact surface. The mask sheet 323 includes a mask surface 322 which is an example of a non-contact surface, and the mask surface 322 is a surface opposite to the mask back surface 321. The mask surface 322 is a surface for facing the vapor deposition source in the vapor deposition apparatus. The mask back surface 321 is a surface for contacting a deposition target such as a glass substrate in a deposition apparatus.

The thickness of the mask sheet 323, that is, the distance between the mask surface 322 and the mask back surface 321 is 1 μm or more and 100 μm or less, preferably 1 μm or more and 50 μm or less, and more preferably 2 μm or more and 40 μm or less. If the mask sheet 323 has a thickness of 40 μm or less, the depth of the mask hole 32H formed in the mask sheet 323 is 40 μm or less. Such a thinner mask sheet 323 is excellent in the following respects. That is, when the deposition target is observed from the particles (vapor deposition particles) of the vapor deposition material flying toward the mask sheet 323, the number of portions (portions to be blocked) that cannot be attached by the metal mask for vapor deposition 30 can be reduced as compared with the thicker mask sheet 323. In other words, the shadow effect can be suppressed.

Each mask portion 32 has a plurality of mask holes 32H penetrating the mask sheet 323. The hole side surface that defines the mask hole 32H is inclined with respect to the thickness direction of the mask sheet 323 in a cross-sectional view. The shape of the hole side surface defining the mask hole 32H may be linear in a cross-sectional view, may be a semicircular arc protruding toward the outside of the mask hole 32H, or may be a complex curved shape having a plurality of bending points.

Mask surface 322 includes a second or surface opening H2 for each mask aperture 32H. The mask back 321 includes a first opening, i.e., a back opening H1, of each mask hole 32H. The size of the front opening H2 is larger than the size of the rear opening H1 in plan view. Each of the mask holes 32H is a passage through which vapor deposition particles sublimated from the vapor deposition source pass. Vapor deposition particles sublimated from the vapor deposition source enter from the front surface opening H2 toward the rear surface opening H1. If the mask hole 32H has a front surface opening H2 larger than a rear surface opening H1, the shadow effect can be suppressed for vapor deposition particles entering from the front surface opening H2. The area of the mask hole 32H in the cross section parallel to the mask back surface 321 may be monotonously increased from the back surface opening H1 to the front surface opening H2 as the cross section moves from the back surface opening H1 to the front surface opening H2. In other words, the cross-sectional area of the mask hole 32H may be monotonously reduced from the front surface opening H2 toward the rear surface opening H1. In the case of such a mask hole 32H, the above-described shadow effect can be further suppressed.

In another example shown in fig. 3, each mask portion 32 has a plurality of mask holes 32H penetrating the mask sheet 323. In the example shown in fig. 3, the size of the front surface opening H2 is larger than the size of the rear surface opening H1 in plan view. Each mask aperture 32H is composed of a mask large aperture 32LH having a front surface opening H2 and a mask small aperture 32SH having a back surface opening H1. The mask large hole 32LH is a hole whose cross-sectional area monotonically decreases from the surface opening H2 toward the mask back surface 321. Mask apertures 32SH are apertures that monotonically decrease in cross-sectional area from back side opening H1 toward mask surface 322. The hole side surface of each mask hole 32H is divided, and has a portion where the mask large hole 32LH and the mask small hole 32SH are connected in a cross-sectional view. The portion where the mask large hole 32LH is connected to the mask small hole 32SH is located in the middle of the thickness direction of the mask sheet 323. The mask large hole 32LH and the portion connected to the mask small hole 32SH have shapes protruding toward the inside of the mask hole 32H. The distance between the most inward protruding portion of the hole side surface of the mask hole 32H and the mask back surface 321 is a step height SH. The cross-sectional structure described above with reference to fig. 2 is an example in which the step height SH is zero. From the viewpoint of suppressing the above-described shadow effect, it is preferable that the step height SH is zero. In order to obtain the mask portion 32 having the step height SH of zero, for example, the thickness of the mask sheet 323 is preferably 40 μm or less, so that the mask hole 32H is formed by wet etching from the mask surface 322 to the mask back surface 321, without requiring wet etching from the mask back surface 321.

[ engagement of mask portion ]

Next, an example of a cross-sectional structure of a joint structure between the mask portion 32 and the mask frame 31 will be described with reference to fig. 4. Other examples of the cross-sectional structure of the joint structure between the mask portion 32 and the mask frame 31 will be described with reference to fig. 5.

As in the example shown in fig. 4, a region where the mask hole 32H is not formed is continuous with the outer peripheral edge portion 32E of the mask sheet 323. On the mask surface 322 of the mask sheet 323, a portion included in the outer peripheral edge portion 32E of the mask sheet 323 is bonded to the mask frame 31. The mask frame 31 includes a frame inner edge portion 31E that defines each mask frame hole 33. The frame inner edge 31E includes a frame back 311 facing the mask sheet 323. The frame inner edge portion 31E has a frame surface 312 which is a surface opposite to the frame back surface 311. The thickness T31 of the frame inner edge 31E, that is, the distance between the frame back 311 and the frame surface 312 is thicker than the thickness T32 of the mask sheet 323, and thus the mask frame 31 has higher rigidity than the mask sheet 323. In particular, the mask frame 31 has higher rigidity than the mask sheet 323 in the case where the frame inner edge portion 31E hangs down due to its own weight and in the case where the frame inner edge portion 31E is displaced toward the center of the mask portion 32. The engagement portion 32BN with the mask surface 322 is located at the frame back 311 of the frame inner side edge portion 31E.

The joint 32BN is disposed continuously or intermittently over substantially the entire periphery of the frame inner edge 31E. The joint 32BN is a weld mark formed by welding the frame back surface 311 and the mask surface 322. The weld mark is a mixture of the material constituting the mask frame 31 and the material constituting the mask portion 32. Alternatively, the bonding portion 32BN is a bonding layer that bonds the frame back surface 311 and the mask surface 322. The bonding layer includes a material different from the material constituting the mask frame 31 and the material constituting the mask portion 32. In the mask frame 31, the frame back 311 of the frame inner edge portion 31E is joined to the mask surface 322 of the mask sheet 323. The mask surface 322 is joined to the mask frame 31, and therefore, the rigidity of the vapor deposition metal mask 30 itself can be improved as compared with a vapor deposition metal mask not provided with the mask frame 31.

The mask frame 31 applies a stress F to the mask sheet 323 such that each mask sheet 323 is pulled toward the outside of the mask sheet 323. In addition, with respect to the mask frame 31, a stress is applied by the main frame 20 such that the mask frame 31 is pulled toward the outside of the mask frame 31. The magnitude of this stress is the same as the stress F of the mask sheet 323. Therefore, in the vapor deposition metal mask 30 detached from the main frame 20, the stress due to the joint between the main frame 20 and the mask frame 31 is relieved, and the stress F applied to the mask blank 323 is also relaxed. The position of the joint 32BN on the frame back 311 is preferably a position where the stress F acts isotropically on the mask sheet 323. The position of the joint portion 32BN on the frame back surface 311 is appropriately selected based on the shape of the mask sheet 323 and the shape of the mask frame hole 33.

The thickness of the mask sheet 323 constituting the mask portion 32 is, for example, 1 μm or more and 50 μm or less. At least one of the mask surface 322 and the mask back surface 321 includes a smooth surface in a region surrounding the mask hole 32H. The smooth surface is, for example, set such that the reflectance of specular reflection of light incident on the smooth surface is 45.2% or more. Alternatively, the smooth surface has a three-dimensional surface roughness Sa of 0.11 μm or less and a three-dimensional surface roughness Sz of 3.17 μm or less, for example.

The metal sheet constituting the mask sheet 323 is manufactured by any one of the following methods: (a) precipitation of metal material based on electrolysis; (B) rolling and grinding of the metal material; (C) precipitation and grinding of the metal material based on electrolysis; (D) Rolling of only the metal material. The effect of the bonding of the mask frame 31 and the mask portion 32 is more remarkable as the thickness of the mask portion 32 is thinner. According to the mask portion 32 exemplified above, the above-described effects can be obtained for the thin mask portion 32 having a thickness of 50 μm or less.

Further, in the metal sheet, the thinner the thickness of the metal sheet is, the higher the reflectance of the surface of the metal sheet tends to be. In addition, in the metal sheet, the three-dimensional surface roughness Sa and the three-dimensional surface roughness Sz of the surface of the metal sheet tend to be smaller as the thickness of the metal sheet is thinner. In addition, when the wet etching for forming the mask holes 32H is performed from the surface of the mask sheet 323, the adhesion to the resist mask formed on the surface can be improved by including the smooth surface on the surface of the mask sheet 323.

The thickness of the mask sheet 323 constituting the mask portion 32 is, for example, 2 μm or more and 40 μm or less. In this configuration, at least one of the mask surface 322 and the mask back surface 321 includes a smooth surface in a region surrounding the mask hole 32H. The smooth surface is, for example, set so that the reflectance of specular reflection of light incident on the smooth surface is 53.0% or more. Alternatively, the smooth surface has a three-dimensional surface roughness Sa of 0.019 μm or less and a three-dimensional surface roughness Sz of 0.308 μm or less, for example. According to the mask portion 32 illustrated here, particularly excellent effects can be obtained for an extremely thin mask portion 32 having a thickness of 40 μm or less. In addition, in the case where wet etching for forming the mask holes 32H is performed from the surface of the mask sheet 323, the size of the minimum resolution of the resist mask formed on the surface can be reduced by including the above-described smooth surface on the surface of the mask sheet 323.

The reflectance R is calculated from the following equation (1) by measuring the specular reflection light when the light emitted from the halogen lamp is incident on the target surface. Light emitted from the halogen lamp was directed to 14mm of the object surface at an incidence angle of 45 ° ± 0.2 ° with respect to the normal direction of the object surface ² Is incident on the area of the substrate. The area of the element receiving the reflected light was 11.4mm ² 。

Reflectance r= [ amount of specular reflected light/amount of incident light ] ×100 … (1)

Further, the three-dimensional surface roughness Sa and Sz are values measured by a method according to ISO 25178. The three-dimensional surface roughness Sa is an arithmetic average height in a defined area having a prescribed area. The three-dimensional surface roughness Sz is the maximum height in a defined area having a prescribed area.

The frame back 311 is a plane in which the joint 32BN is located. The frame back 311 extends from the outer peripheral edge portion 32E of the mask surface 322 toward the outside of the mask sheet 323. In other words, the frame inner edge portion 31E has a surface configuration in which the mask surface 322 virtually expands to the outside of the mask surface 322. The frame inner edge portion 31E extends from the outer peripheral edge portion 32E of the mask surface 322 toward the outside of the mask sheet 323. In the range where the frame back 311 extends, a space V corresponding to the thickness of the mask sheet 323 is easily formed around the mask sheet 323. As a result, the physical interference between the vapor deposition object S and the mask frame 31 can be suppressed around the mask sheet 323.

In the example shown in fig. 5, a region where the mask hole 32H is not formed is also continuous with the outer peripheral edge portion 32E of the mask sheet 323. The outer peripheral edge portion 32E of the mask surface 322 is joined to the frame back surface 311 provided in the mask frame 31 by joining based on the joining portion 32 BN. The mask frame 31 applies a stress F to the mask sheet 323 such that each mask sheet 323 is pulled toward the outside of the mask sheet 323. The mask frame 31 forms a space V corresponding to the thickness of the mask sheet 323 in a range where the frame back 311 extends.

[ number of mask portions ]

Next, an example of the relationship between the number of mask holes 32H provided in the vapor deposition metal mask 30 and the number of mask holes 32H provided in each mask portion 32 will be described with reference to fig. 6. Further, another example of the relationship between the number of mask holes 32H provided in the vapor deposition metal mask 30 and the number of mask holes 32H provided in the mask portion 32 will be described with reference to fig. 7.

As shown in the example of fig. 6 (a), the mask frame 31 has, for example, 3 mask frame holes 33 as a plurality of mask frame holes 33. As shown in the example of fig. 6 (b), each of the vapor deposition metal masks 30 includes one mask portion 32 in each of the mask frame holes 33. That is, the frame inner edge portion 31E defining the mask frame hole 33A is joined to one mask portion 32A. The other frame inner edge portion 31E, which defines the mask frame hole 33B, is joined to the other mask portion 32B. The remaining one frame inner edge portion 31E that defines the mask frame hole 33C is joined to the remaining one mask portion 32C.

The metal mask for vapor deposition 30 can be repeatedly used for a plurality of vapor deposition objects. Therefore, the plurality of mask holes 32H provided in the vapor deposition metal mask 30 are required to have high precision in the positions of the mask holes 32H, the structures of the mask holes 32H, and the like. As shown in fig. 6, the configuration in which the number of mask holes 32H required for one mask frame 31 is borne by 3 mask portions 32 is more excellent than the configuration in which the number of mask holes 32H required for one mask frame 31 is borne by one mask portion 32. For example, when a part of one mask portion 32 is deformed, the size of a new mask portion 32 to be replaced with the deformed mask portion 32 can be reduced. Further, the consumption of various materials required for manufacturing and repairing the vapor deposition metal mask 30 can be suppressed. Further, the inspection concerning the structure of the mask hole 32H is preferably performed in a state where the mask frame 31 and the mask portion 32 are bonded. From this point of view, the joint portion 32BN is preferably configured to be capable of replacing the deformed mask portion 32 with a new mask portion 32. Further, the smaller the thickness of the mask sheet 323 constituting the mask portion 32, the smaller the size of the mask hole 32H, and the easier the yield of the mask portion 32 is reduced. Therefore, the mask frame holes 33 each have a structure including one mask portion 32, and are preferably used for the metal mask for vapor deposition 30 which is required to have high definition.

As shown in the example of fig. 7 (a), the mask frame 31 has, for example, 3 mask frame holes 33 as a plurality of mask frame holes 33. As shown in the example of fig. 7 (b), the vapor deposition metal mask 30 includes one mask portion 32 shared by a plurality of mask frame holes 33. That is, the frame inner edge portion 31E that defines the mask frame hole 33A, the frame inner edge portion 31E that defines the mask frame hole 33B, and the frame inner edge portion 31E that defines the mask frame hole 33C are joined to the common mask portion 32.

In addition, if the number of mask holes 32H required for one mask frame 31 is constituted by one mask portion 32, the number of mask portions 32 to be joined to the mask frame 31 can be made one. Therefore, the load required for joining the mask frame 31 and the mask portion 32 can be reduced. Further, the thicker the thickness of the mask sheet 323 constituting the mask portion 32 is, the larger the size of the mask hole 32H is, and the easier the yield of the mask portion 32 is to be improved. Therefore, the configuration having the mask portion 32 shared by the mask frame holes 33 is preferable for the vapor deposition metal mask 30 requiring low resolution.

[ method for producing vapor deposition Metal mask ]

Next, examples of a method for manufacturing a metal mask for vapor deposition will be described. Fig. 8 and 9 show an example of a metal mask base material for vapor deposition used in a manufacturing method using wet etching. Fig. 10 shows characteristics of the sheet target surface of the metal sheet 32S provided in the metal mask base for vapor deposition. Fig. 11 shows the reflectivity of the sheet object surface of the metal sheet 32S. A part of the sheet target surface includes a smooth surface of the mask sheet 323. The sheet object surface has the same surface characteristics as the smooth surface throughout the entire sheet object surface.

An example of a method of forming a mask hole by wet etching will be described with reference to fig. 12. Further, an example of a method of forming a mask hole by electrolysis will be described with reference to fig. 13. Other examples of the method of forming the mask hole by electrolysis will be described with reference to fig. 14.

The method for manufacturing the metal mask for vapor deposition 30 illustrated in fig. 2 is different from the method for manufacturing the metal mask for vapor deposition 30 illustrated in fig. 3 in the manner of etching the metal mask for vapor deposition 32K, which is the substrate of the mask blank 323, but the steps are almost the same. Hereinafter, a method for manufacturing the metal mask for vapor deposition 30 described in fig. 2 will be mainly described, and a repetitive description of the method for manufacturing the metal mask for vapor deposition 30 described in fig. 3 will be omitted.

The metal sheet 32S includes a mask surface 322 and a mask back surface 321.

In the method of forming a resist mask on the mask surface 322 and forming the mask sheet 323 by etching from the mask surface 322, the mask surface 322 is a sheet target surface. In the method of forming the mask sheet 323 by etching from the mask surface 322 and etching from the mask back surface 321 by forming the respective resist masks on the mask surface 322 and the mask back surface 321, the mask surface 322 and the mask back surface 321 are the sheet target surfaces. The sheet target surface is a surface on which a resist mask is formed during the formation of the vapor deposition metal mask.

The material constituting the metal sheet 32S is nickel or an iron-nickel alloy, for example, an iron-nickel alloy containing 30 mass% or more of nickel, and is invar iron-nickel alloy containing an alloy of 36 mass% of nickel and 64 mass% of iron as a main component.In the case where the metal sheet 32S is a invar alloy sheet, the thermal expansion coefficient of the metal sheet 32S is, for example, 1.2X10 ^-6 Degree of/(degree of C.). In the case of the metal sheet 32S having such a thermal expansion coefficient, the degree of thermal expansion of the mask portion 32 manufactured by using the metal sheet 32S is matched with the degree of thermal expansion of the glass substrate, and therefore, a glass substrate is suitably used as an example of the vapor deposition target.

The thickness T1 of the metal sheet 32S is, for example, 1 μm or more and 100 μm or less, preferably 1 μm or more and 50 μm or less, and more preferably 2 μm or more and 40 μm or less. If the thickness T1 of the metal sheet 32S is 40 μm or less, the depth of the hole formed in the metal sheet 32S can be made 40 μm or less. The metal sheet 32S having the thickness T1 is excellent in the following point in the metal mask for vapor deposition manufactured by using the metal sheet 32S. That is, when the film formation object is observed from the vapor deposition particles flying toward the metal mask for vapor deposition, the portion that is undesirably blocked by the metal mask for vapor deposition can be reduced. In other words, the shadow effect can be suppressed.

The surface characteristics of the sheet target surface of the metal sheet 32S preferably satisfy at least one of the following [ condition 1] and [ condition 2 ].

[ condition 1] three-dimensional surface roughness Sa ].

[ condition 2] the reflectance R of the object surface is 53.0% or less and 97.0% or less.

The three-dimensional surface roughness Sa and Sz are values measured by a method according to ISO 25178. The reflectance R is calculated from the following equation (2) by measuring the specular reflection light when the light emitted from the halogen lamp is incident on the target surface. Light emitted from the halogen lamp was directed to 14mm of the object surface at an incidence angle of 45 ° ± 0.2 ° with respect to the normal direction of the object surface ² Is incident on the area of the substrate. The area of the element receiving the reflected light was 11.4mm ² 。

Reflectance r= [ amount of specular reflected light/amount of incident light ] ×100 … (2)

If the surface characteristics of at least one of [ condition 1] and [ condition 2] are satisfied, scattering of light irradiated to the target surface due to the target surface can be suppressed. When light is irradiated to the resist layer located on the resist target surface, it is possible to suppress scattering of a part of the light by the target surface, and the scattered light irradiates a region other than the exposure target region in the resist layer. As a result, it is possible to suppress the occurrence of a difference between the structure of the resist mask formed by exposure and development and the structure of the designed resist mask, and to suppress the occurrence of a difference between the structure of the mask hole 32H formed by the wet etching method and the structure of the designed mask hole 32H.

As shown in fig. 9, the metal mask base material for vapor deposition may further include a resin body PB on at least one of the mask back surface 321 and the mask surface 322, in addition to the metal sheet 32S. That is, the metal mask base material for vapor deposition can be embodied as a laminate of the metal sheet 32S and the resin body PB. The material constituting the resin body PB located on the mask surface 322 is resist. The material constituting the resin body PB located on the mask back surface 321 is, for example, resist or polyimide.

In the case where the material constituting the resin body PB is a resist, the resin body PB is a resist layer. The resist layer as the resin body PB is formed into a sheet shape and then attached to the mask surface 322. Alternatively, a resist layer as the resin body PB is formed by applying a coating liquid for forming the resist layer to the mask surface 322.

In the case where the material constituting the resin body PB is polyimide, the resin body PB is closely adhered to the mask back surface 321. Since the polyimide has a coefficient of thermal expansion and its temperature dependency that are the same as those of the nickel-iron-nickel alloy, the warpage of the metal sheet 32S is suppressed by the expansion and contraction of the resin body PB due to the temperature change of the resin body PB.

The thickness T2 of the resin body PB is, for example, 5 μm or more and 50 μm or less. From the viewpoint of improving the mechanical strength of the laminate of the resin body PB and the metal sheet 32S, the thickness T2 of the resin body PB is preferably 5 μm or more. In addition, in the process of forming the mask portion 32, the resin body PB may be removed from the metal sheet 32S by dipping into an alkaline solution or the like. The thickness of the resin body PB is preferably 50 μm or less from the viewpoint of suppressing the time required for such removal from becoming excessively long.

The method for producing the metal sheet uses any one of the following methods: (A) electrolysis; (B) rolling and grinding; (C) electrolysis and grinding; (D) Rolling only.

In addition, when forming the rolling base material for producing the metal sheet 32S, oxygen mixed into the material for forming the rolling base material is generally removed. In removing oxygen mixed into the material, for example, a deoxidizer such as granular aluminum or magnesium is mixed into the material for forming the base material. As a result, aluminum and magnesium are contained in the base material as metal oxides such as aluminum oxide and magnesium oxide. Most of the metal oxide is removed from the base material before the base material is rolled. On the other hand, a part of the metal oxide remains in the base material to be rolled. In this regard, according to the manufacturing method using electrolysis, the metal oxide can be suppressed from being mixed into the metal sheet 32S.

(A) Electrolysis

In the case where electrolysis is used as a method for producing the metal sheet 32S, the metal sheet 32S is formed on the surface of the electrode used for electrolysis. Then, the metal sheet 32S is separated from the surface of the electrode. Thus, a metal sheet 32S having a mask surface 322 which is a sheet target surface and a mask back surface 321 which is a surface that has been in contact with the surface of the electrode before is manufactured. When the surface of the electrode has the same surface characteristics as the sheet target surface, both the mask surface 322 and the mask back surface 321 of the metal sheet 32S have the surface characteristics corresponding to the sheet target surface. When the surface of the electrode has a surface roughness larger than the sheet target surface and a reflectivity lower than the sheet target surface, the mask surface 322 of the metal sheet 32S has a surface characteristic corresponding to the sheet target surface. In addition, in the configuration in which both the mask surface 322 and the mask back surface 321 have surface characteristics corresponding to the sheet target surface, when the resist layer is formed on the sheet target surface, the load required for distinguishing the mask surface 322 from the mask back surface 321 can be reduced. In addition, the separated metal sheet 32S may be subjected to an annealing treatment after being separated.

Electrolytic baths for electrolysis, e.g.Comprises an iron ion donor, a nickel ion donor and a pH buffer. The electrolytic bath used for electrolysis may contain a stress-relieving agent and Fe ³⁺ Ion masking agents, complexing agents such as malic acid and citric acid, and the like, and is adjusted to a weakly acidic solution having a pH suitable for electrolysis. Examples of the iron ion donor include ferrous sulfate heptahydrate, ferrous chloride, and iron sulfamate. Examples of the nickel ion donor include nickel (II) sulfate, nickel (II) chloride, nickel sulfamate, and nickel bromide. The pH buffer is, for example, boric acid, malonic acid. Malonic acid also as Fe ³⁺ The ion masking agent acts. The stress relieving agent is, for example, sodium saccharin. The electrolytic bath used for electrolysis is, for example, an aqueous solution containing the above-mentioned additives, and the pH is adjusted to, for example, 2 to 3 by a pH adjuster such as 5% sulfuric acid or nickel carbonate.

The electrolysis conditions used for the electrolysis are conditions in which the surface characteristics of the sheet target surface, the composition ratio of nickel in the metal sheet 32S, and the like are adjusted according to the temperature of the electrolytic bath, the current density, and the electrolysis time. Anodes under electrolysis conditions using the above-described electrolytic bath are, for example, pure iron and nickel. The cathode under electrolysis conditions is, for example, a stainless steel plate such as SUS 304. The temperature of the electrolytic bath is, for example, 40 ℃ to 60 ℃. The current density is, for example, 1A/dm ² Above 4A/dm ² The following is given.

(B) Grinding

The sheet metal 32S before polishing may be produced by electrolysis or rolling. In the method of manufacturing the metal sheet 32S before polishing by rolling, first, a metal base material is rolled, and then the rolled base material is annealed. At this time, the level difference of the surface of the metal piece 32S before polishing is smaller than that of the surface of the base material. The step on the back surface of the metal piece 32S before polishing is smaller than the step on the back surface of the base material. Then, chemical or electric polishing is performed on the surface of the metal sheet 32S before polishing. Thus, the metal sheet 32S having the polishing surface, i.e., the sheet target surface, is manufactured.

The polishing liquid used in the chemical polishing is, for example, a chemical polishing liquid for an iron-based alloy containing hydrogen peroxide as a main component. The electrolytic solution used in the electric polishing is a perchloric acid-based electrolytic polishing solution or a sulfuric acid-based electrolytic polishing solution. The metal piece 32S before polishing can be embodied as a thin piece obtained by wet etching with an acidic etching solution, for example, by rolling a metal piece.

An example of the three-dimensional surface roughness Sa, the three-dimensional surface roughness Sz, the reflectance R, and the processing accuracy of the resist mask of the metal sheet 32S will be described with reference to fig. 10 and 11. Fig. 10 shows the three-dimensional surface roughness Sa, the three-dimensional surface roughness Sz, and the reflectance R at each level from test example 1 to test example 9. Fig. 11 shows the reflectances of test example 1, test example 2, test example 3, and test example 9, which are representative examples among the levels of test example 1 to test example 9.

As shown in fig. 10, test example 1, test example 2, test example 3, test example 6, and test example 7 were each a metal sheet 32S having a thickness of 20 μm produced by the electrolysis of (a) described above. Test example 4 and test example 5 were each a metal piece 32S having a thickness of 20 μm, which was produced by grinding a metal piece 32S produced by rolling (B). The metal sheet 32S produced by (a) electrolysis has a surface that contacts the electrode. At this time, the three-dimensional surface roughness Sa of the SUS-made electrode was 0.018 μm, and the three-dimensional surface roughness Sz was 0.170 μm. Test example 8 and test example 9 are each a metal piece 32S manufactured by rolling, and are metal pieces 32S to which no polishing is applied. The thickness of each of test example 8 and test example 9 was 10 μm thicker than the thickness of each of test example 4 and test example 5, which is the polishing amount of test example 4 and test example 5.

Test example 1, test example 2, test example 3, test example 6 and test example 7 were each carried out by using an electrolytic bath adjusted to pH2.3 with an aqueous solution to which the following additives were added, and the current density was set at 1 (A/dm ² ) Above 4 (A/dm) ² ) The following ranges were modified. The composition ratios of iron and nickel in each of test example 1, test example 2, test example 3, test example 6, and test example 7 were different from each other.

(electrolyte for test example)

Test example 4 and test example 5 were each obtained by subjecting a metal piece 32S before polishing, which was obtained by rolling, to chemical polishing using a hydrogen peroxide-based chemical polishing liquid.

Test examples 8 and 9 are metal pieces 32S obtained by rolling in test examples 4 and 5, respectively, and are levels at which chemical polishing is not performed.

In each of the levels from test example 1 to test example 7, it was confirmed that the three-dimensional surface roughness Sa of the sheet object surface was 0.019 μm or less and the three-dimensional surface roughness Sz of the sheet object surface was 0.308 μm or less. In contrast, at each level of test example 8 and test example 9, the three-dimensional surface roughness Sa of the sheet object surface was approximately 0.04 μm. This can confirm that: in the metal sheet 32S manufactured by the above-described (a) electrolysis, (B) rolling and polishing, the three-dimensional surface roughness Sa is greatly reduced as the metal sheet 32S having a small thickness is obtained. In each of the levels of test example 8 and test example 9, the three-dimensional surface roughness Sz of the sheet target surface was 0.35 μm or more. This can confirm that: in the metal sheet 32S manufactured by the above-described (a) electrolysis, (B) rolling and polishing, as the metal sheet 32S having a small thickness is obtained, the three-dimensional surface roughness Sz is reduced.

As shown in fig. 10 and 11, it can be confirmed that, at each level from test example 1 to test example 3: the reflectance R is 53.0% to 97.0%. On the other hand, in each level of test example 8 and test example 9, it was confirmed that: the reflectance R is smaller than 53.0% and has a half-value width larger than other test examples. This can confirm that: in the case of the metal sheet 32S produced by the electrolysis (a), rolling (B), and polishing, a large reflectance R of 53.0% or more can be obtained.

Can confirm that: the minimum resolution of the resist mask formed on the surface of each of the test pieces 1 to 7 was set to be in a range of 4 μm to 5 μm when circular holes were formed in the resist layer by exposure to ultraviolet light. On the other hand, the minimum resolution size of the resist mask formed by the same method on the surface of each of the test pieces 8 and 9 was 7 μm or more when circular holes were formed in the resist layer by exposure to ultraviolet light.

As in the examples shown in fig. 12 (a) to (h), in one example of the method for producing a metal mask for vapor deposition, first, a metal mask substrate 32K for vapor deposition, which is a substrate for a mask sheet 323, is prepared (see fig. 12 (a)). The vapor deposition metal mask blank 32K preferably includes a support SP for supporting the metal sheet 32S in addition to the metal sheet 32S processed into the mask sheet 323. Next, a resist layer PR is formed on the mask surface 322 of the vapor deposition metal mask base material 32K (see fig. 12 b), and the resist layer PR is exposed and developed. Thus, a resist mask RM is formed on the mask surface 322 (see fig. 12 (c)). Next, a wet etching from the mask surface 322 using the resist mask RM is performed to form mask holes 32H in the vapor deposition metal mask base 32K (see fig. 12 d). At this time, a front surface opening H2 is formed in the mask surface 322 from which wet etching from the mask surface 322 to the mask back surface 321 is started, and a back surface opening H1 smaller than the front surface opening H2 is formed in the mask back surface 321 which is etched more slowly than the front surface opening H2. Next, the resist mask RM is removed from the mask surface 322, whereby the mask portion 32 is manufactured (see fig. 12 (e)). Finally, the outer peripheral edge portion 32E of the mask surface 322 is joined to the frame inner edge portion 31E of the mask frame 31, and the support SP is released from the mask portion 32, thereby manufacturing the metal mask for vapor deposition 30 (see fig. 12 (f) to (h)).

In the method for manufacturing the metal mask for vapor deposition 30 described in fig. 3, the above-described steps are performed on the surface of the metal mask substrate for vapor deposition 32K corresponding to the mask back surface 321, with respect to the metal mask substrate for vapor deposition 32K having no support SP. Thereby, mask apertures 32SH are formed. Next, a resist or the like for protecting the mask apertures 32SH is filled in the mask apertures 32SH. Next, the mask portion 32 is manufactured by performing the above-described steps on the surface of the metal mask base 32K for vapor deposition corresponding to the mask surface 322.

For example, in the case where the mask sheet 323 is made of a metal sheet made of an iron-nickel alloy, electrolysis or rolling is used in the step of preparing the metal mask base material 32K for vapor deposition. Polishing, annealing, and the like are suitably used as the post-treatment of the metal mask base material 32K for vapor deposition.

In the case of using the support SP, for example, the support SP is bonded to the metal sheet 32S formed on the electrode surface. Next, as a laminate of the metal sheet 32S and the support SP, the metal mask base 32K for vapor deposition is separated from the electrode surface.

In the case of using rolling, the base material for producing the metal sheet 32S is rolled, and then the metal sheet 32S produced by rolling is annealed, whereby the metal mask base material 32K for vapor deposition is obtained. At this time, in the case of using the support body SP, the support body SP is joined to the metal sheet 32S manufactured by rolling.

The metal sheet 32S obtained by electrolysis and the metal sheet 32S obtained by rolling may be made thinner by wet etching using an acidic etching solution or may be made thinner by chemical mechanical polishing.

In the example shown in fig. 12 (f), resistance welding is used as a method of joining the outer peripheral edge portion 32E of the mask surface 322 and the frame inner edge portion 31E of the mask frame 31. At this time, a plurality of through holes SPH are formed in the insulating support SP. Each through hole SPH is formed in a portion of the support body SP that faces a portion serving as the joint portion 32BN. Then, in a state where a stress is applied to the mask portion 32 toward the outside of the mask portion 32, intermittent joint portions 32BN are formed by energization through the through holes SPH. Thereby, the outer peripheral edge portion 32E and the frame inner edge portion 31E are welded.

In the example shown in fig. 12 (g), laser welding is used as a method of joining the outer peripheral edge portion 32E of the mask surface 322 and the frame inner edge portion 31E of the mask frame 31. At this time, the laser light L is irradiated to the portion to be the joint portion 32BN through the support SP using the support SP having light transmittance. Then, intermittent joint portions 32BN are formed by intermittently irradiating laser light L, or continuous joint portions 32BN are formed by continuously irradiating laser light L. Thereby, the outer peripheral edge portion 32E and the frame inner edge portion 31E are welded. In addition, in the case where the mask portion 32 is supported by the support body SP in a state where stress directed to the outside of the mask portion 32 is applied to the mask portion 32, the application of stress to the mask portion 32 can be omitted during the welding.

In the example shown in fig. 12 (h), ultrasonic welding is used as a method of joining the outer peripheral edge portion 32E of the mask surface 322 and the frame inner edge portion 31E of the mask frame 31. At this time, the outer peripheral edge portion 32E and the frame inner edge portion 31E are clamped by a clamp CP or the like, and ultrasonic waves are applied to a portion to be the joint portion 32 BN. The member to which the ultrasonic wave is directly applied may be the mask frame 31 or the mask portion 32. In addition, in the case of using ultrasonic welding, pressing marks by the jig CP are formed in the mask frame 31 and the support body SP.

As in the examples shown in fig. 13 (a) to (e), in another example of the method for producing a metal mask for vapor deposition, first, a resist layer PR is formed on the electrode surface EPs, which is the surface of the electrode EP used for electrolysis (see fig. 13 (a)). Next, the resist layer PR is exposed and developed, whereby a resist mask RM (see fig. 13 (b)) which is an example of a pattern is formed on the electrode surface EPS. The resist mask RM has an inverted truncated cone shape with a top portion located on the electrode surface EPS in a cross section orthogonal to the electrode surface EPS, and has a shape in which the larger the distance from the electrode surface EPS is, the larger the area of the cross section parallel to the electrode surface EPS is. Next, electrolysis using the electrode surface EPS having the resist mask RM is performed. As a result, the metal sheet 32S is formed as the mask portion 32 so as to extend to the region other than the resist mask RM in the electrode surface EPS (see fig. 12 (c)).

At this time, since the metal sheet 32S is deposited outside the space occupied by the resist mask RM, a hole having a shape that follows the shape of the resist mask RM is formed in the metal sheet 32S. Then, the mask hole 32H of the mask portion 32 is self-matingly formed. That is, the surface in contact with the electrode surface EPS functions as the mask back surface 321 having the back surface opening H1. Further, the outermost surface having an opening larger than the back surface opening H1, i.e., the surface opening H2, functions as the mask surface 322.

Next, only the resist mask RM is removed from the electrode surface EPS, whereby mask holes 32H are formed so as to be hollow from the back surface opening H1 to the front surface opening H2 (see fig. 13 (d)). Finally, the frame back surface 311 of the frame inner side edge portion 31E is joined at the outer peripheral edge portion 32E of the mask surface 322 having the surface opening H2, and then, a stress for peeling the mask portion 32 from the electrode surface EPS is applied to the mask frame 31. Alternatively, the mask portion 32 bonded to the support or the like is peeled off from the electrode surface EPS, and the frame back surface 311 of the frame inner edge portion 31E is bonded to the outer peripheral edge portion 32E of the mask surface 322. Thus, the metal mask for vapor deposition 30 is manufactured in a state where the mask frame 31 is bonded to the mask portion 32 (see fig. 12 e).

As in the examples shown in fig. 14 (a) to (f), in another example of the method for producing a metal mask for vapor deposition, first, a resist layer PR is formed on an electrode surface EPS used for electrolysis (see fig. 14 (a)). Next, the resist layer PR is exposed and developed, whereby a resist mask RM (see fig. 14 (b)) which is an example of a pattern is formed on the electrode surface EPS. The resist mask RM has a truncated cone shape with a bottom portion located on the electrode surface EPS in a cross section orthogonal to the electrode surface EPS, and has a shape in which the area of a cross section parallel to the electrode surface EPS is smaller as the distance from the electrode surface EPS is larger. Next, electrolysis using the electrode surface EPS having the resist mask RM is performed, and the metal sheet 32S is formed as a mask portion 32 so as to extend to a region other than the resist mask RM in the electrode surface EPS (see fig. 14 (c)).

Here, since the metal sheet 32S is deposited outside the space occupied by the resist mask RM, a hole having a shape that follows the shape of the resist mask RM is formed in the metal sheet 32S. Then, the mask hole 32H of the mask portion 32 is self-matingly formed. That is, the surface in contact with the electrode surface EPS functions as a mask surface 322 having a surface opening H2, and the outermost surface having an opening smaller than the surface opening H2, that is, a back surface opening H1, functions as a mask back surface 321.

Next, only the resist mask RM is removed from the electrode surface EPS, whereby mask holes 32H are formed so as to be hollow from the back surface opening H1 to the front surface opening H2 (see fig. 14 (d)). Then, the intermediate transfer substrate TM is bonded on the mask back surface 321 having the back surface opening H1, and then a stress for peeling the mask portion 32 from the electrode surface EPS is applied to the intermediate transfer substrate TM. Thus, in a state where the mask portion 32 is bonded to the intermediate transfer substrate TM, the mask surface 322 is peeled off from the electrode surface EPS (see fig. 14 (e)). Finally, the frame back surface 311 of the frame inner side edge portion 31E is joined to the outer peripheral edge portion 32E of the mask surface 322 having the surface opening H2, and then the intermediate transfer substrate TM is peeled off from the mask portion 32. Thus, the metal mask 30 for vapor deposition in a state where the mask portion 32 is bonded to the mask frame 31 is manufactured (see fig. 14 (f)).

According to the above embodiment, the following effects can be obtained.

(1) The vapor deposition material entering the mask holes 32H from the front surface openings H2 is deposited on the vapor deposition target through the rear surface openings H1 smaller in size than the front surface openings H2. Therefore, the structural accuracy of the pattern formed by the vapor deposition material can be improved.

(2) Since the mask surface 322 and the mask frame 31 are joined, contact between the mask back surface 321 and the deposition target can be facilitated, and the rigidity of the metal mask for deposition 30 itself can be improved.

(3) The number of mask holes 32H required for one mask frame 31 is divided into, for example, 3 mask portions 32. Therefore, even when a part of one mask portion 32 is deformed, the size of a new mask portion 32 to be replaced with the deformed mask portion 32 can be reduced.

(4) In the case where the cross-sectional area of the mask hole 32H monotonously decreases from the front surface opening H2 to the rear surface opening H1, the shadow effect can be suppressed more favorably with respect to the vapor deposition particles entering from the front surface opening H2.

(5) Since the mask hole 32H having a shape following the shape of the resist mask RM is formed by electrolysis, the load of etching the metal sheet for forming the mask hole 32H is reduced.

Claims

1. A metal mask for vapor deposition, comprising:

a mask portion having a contact surface for contacting a deposition target and a non-contact surface opposite to the contact surface, the mask portion being formed in a sheet shape, the mask portion having a plurality of mask holes penetrating from a first opening located on the contact surface to a second opening located on the non-contact surface, respectively, the first opening having a smaller size than the second opening;

A mask frame having higher rigidity than the mask portion and formed in a frame shape surrounding the plurality of mask holes; and

a main frame for supporting the mask frame,

the mask portion has a portion surrounding the plurality of mask holes in the non-contact surface, and is joined to the mask frame by a joint portion,

the mask frame is formed in a short strip shape having a long side direction and a short side direction orthogonal to the long side direction, a plurality of mask portions are bonded to the long side direction of the mask frame, only one mask portion is bonded to the short side direction of the mask frame,

a main frame hole of the main frame, wherein a plurality of mask portions are exposed together with a part of the short strip-shaped mask frame,

the mask portion is a metal sheet,

at least one of the contact surface and the non-contact surface includes a smooth surface, the smooth surface is configured to have a reflectance of 45.2% or more of specular reflection of light incident on the smooth surface,

the thickness of the metal sheet is 50 μm or less,

the mask frame applies stress to the mask portion to pull the mask portion outward,

The position of the joint portion is a position at which the stress isotropically acts on the mask portion.

2. The metal mask for vapor deposition according to claim 1, wherein,

a plurality of mask portions coupled to a common mask frame.

3. The metal mask for vapor deposition according to claim 1 or 2, wherein,

the reflectance of the specular reflection of the light incident on the smooth surface is 53.0% or more,

the thickness of the metal sheet is 40 μm or less.

4. The metal mask for vapor deposition according to claim 1 or 2, wherein,

the mask frame has a plane on which the joint portion is located,

the plane has a size extending outward of the mask portion.

5. A method for manufacturing a metal mask for vapor deposition, comprising:

a step of forming a mask portion having a contact surface for contacting a deposition target and a non-contact surface opposite to the contact surface, the mask portion being formed in a sheet shape, the mask portion having a plurality of mask holes penetrating from a first opening located on the contact surface to a second opening located on the non-contact surface, respectively, the first opening having a smaller size than the second opening;

A step of joining the mask portion to a mask frame, the mask frame having higher rigidity than the mask portion and being formed in a frame shape surrounding the plurality of mask holes, the mask portion having a portion surrounding the plurality of mask holes in the non-contact surface, the mask portion being joined to the mask frame at the portion, the mask portion being joined to the mask frame by a joint portion; and

a step of supporting the mask frame by a main frame,

the mask portion is a metal sheet,

In the step of forming the mask portion, the thickness of the metal sheet is set to 50 μm or less,

when the mask portion is bonded to the mask frame by the bonding portion,

the mask frame applies a stress to the mask portion to pull the mask portion outward, and the position of the joint portion is a position at which the stress acts isotropically on the mask portion.

6. The method for producing a metal mask for vapor deposition according to claim 5, wherein,

the step of bonding the mask frame to the non-contact surface is to bond a plurality of mask portions to one mask frame.

7. The method for producing a metal mask for vapor deposition according to claim 5 or 6, wherein,

the thickness of the metal sheet is set to 40 μm or less.