Metal mask

Abstract

To provide a metal mask including a mask body with an excellent flatness by eliminating the generation of a distortion in the mask body attributed to an internal stress.SOLUTION: A metal mask according to the invention includes a mask body 2 made of a metal thin plate and including a pattern formation region 9 with many independent through holes 8 arranged, and a frame body 3 that has a mask opening 5 and supports the mask body 2 in a state where the pattern formation region 9 faces the mask opening 5. An easily expandable part 24 is arranged between the pattern formation region 9 and an inner peripheral surface 15 of the mask opening 5. The easily expandable part 24 is formed with a groove 51 caved in a thickness direction of the mask body 2.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a metal mask such as a vapor deposition mask used when forming a light-emitting layer of an organic EL element by a vapor deposition mask method, an arrangement mask used when mounting solder balls, or a printing mask used when forming a printing layer by a screen printing method. [Background technology]

[0002] In a metal mask consisting of a mask body and a frame that supports the mask body in a stretched state, improving the flatness of the mask body is useful for improving the positional accuracy of the light-emitting layer and the printing layer. The applicant previously proposed a technique for improving the flatness of the mask body in Patent Document 1, in which a vapor deposition mask consisting of a mask body with a large number of independent vapor deposition through-holes formed in the pattern formation area, a frame disposed on the outer periphery of the mask body, and an electrodeposited metal layer (metal layer) that inseparably bonds the mask body and the frame is provided with a stress relief portion on the upper surface of the frame, where the electrodeposited metal layer is divided. The mask body and the electrodeposited metal layer are formed by electroforming. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-280774 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the metal mask of Patent Document 1, the internal stress generated when the electrodeposited metal layer is formed by electroforming can be alleviated by the stress alleviation section, thereby preventing the mask body from waviness due to the internal stress of the electrodeposited metal layer and reducing the flatness of the mask body to some extent. However, because internal stress also occurs in the mask body formed by electroforming, it is difficult to completely alleviate the internal stress of the mask body with a configuration in which a stress alleviation section is provided on the upper surface of the frame, as in Patent Document 1. As a result, there is a risk that distortion will occur in the mask body due to expansion and contraction of the mask body, and the configuration of Patent Document 1 has limitations on improving the flatness of the mask body.

[0005] An object of the present invention is to provide a metal mask having a mask body with excellent flatness by suppressing distortion of the mask body due to internal stress. [Means for solving the problem]

[0006] The metal mask of the present invention comprises a mask body 2 made of a thin metal plate and having a pattern formation region 9 in which a large number of independent through holes 8 are arranged, and a frame 3 having a mask opening 5 and supporting the mask body 2 with the pattern formation region 9 facing the mask opening 5. An easily stretchable portion 24 is provided between the pattern formation region 9 and the inner peripheral surface 15 of the mask opening 5. The easy-to-stretch portion 24 is formed by a groove 51 recessed in the thickness direction of the mask body 2. It is characterized by the presence of

[0007] The mask body 2 is formed smaller than the mask opening 5, and includes an inner pattern forming region 9 and an outer peripheral region 10 surrounding the pattern forming region 9. The mask body 2 and the frame 3 are inseparably joined via a metal layer 4 that extends inward from the inner peripheral surface 15 of the mask opening 5 to the outer peripheral region 10. An easily stretchable portion 24 is provided between the outer peripheral region 1 of the mask body 2 and the frame 3. to 0 It is arranged in a circular pattern.

[0008] The mask body 2 and the metal layer 4 are joined together with the outer peripheral region 10 and the metal layer 4 overlapping on the front and back. The outer peripheral region 10 includes an outer peripheral portion 11 on the outer edge side overlapping with the metal layer 4, and an inner peripheral portion 12 between the outer peripheral portion 11 and the pattern formation region 9, and an easily stretchable portion 24 is provided in the inner peripheral portion 12.

[0009] A plurality of grooves 51 are formed alternately in the inward and outward directions on the upper and lower surfaces of the outer circumferential inner portion 12 . [Effects of the Invention]

[0010] In the metal mask of the present invention, an easily stretchable portion 24 is provided between the pattern formation region 9 of the mask body 2 and the inner circumferential surface 15 of the mask opening 5 formed in the frame 3. By providing the easily stretchable portion 24 between the pattern formation region 9 and the inner circumferential surface 15 of the mask opening 5 in this manner, the easily stretchable portion 24 expands and contracts, absorbing expansion and contraction of the mask body 2 due to internal stress generated during the formation of the mask body 2 (thin metal plate). This prevents distortion of the mask body 2 (metal mask 1) caused by expansion and contraction of the mask body 2. Furthermore, the easily stretchable portion 24 provided between the pattern formation region 9 and the inner circumferential surface 15 of the mask opening 5—in other words, the easily stretchable portion 24 provided outside the pattern formation region 9 (region excluding the pattern formation region 9)—prevents the expansion and contraction deformation of the easily stretchable portion 24 from affecting the pattern formation region 9, thereby preventing distortion in the pattern formation region 9 of the mask body 2, which requires higher flatness. As described above, according to the present invention, distortion in the mask body 2 can be suppressed, thereby providing a metal mask 1 having a mask body 2 with superior flatness. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a vertical cross-sectional side view showing a main part of a metal mask according to a first reference example. [Figure 2] FIG. 2 is a plan view showing the entire metal mask. [Figure 3] FIG. 2 is a partial vertical cross-sectional side view of the metal mask. [Figure 4] FIG. 2 is a partial plan view of a metal mask. [Figure 5]FIG. 2 is a perspective view of a mask body and a frame body. [Figure 6] FIG. 1 is an explanatory diagram showing the first stage of the manufacturing process of a metal mask. [Figure 7] FIG. 10 is an explanatory diagram showing the latter stage of the manufacturing process of the metal mask. [Figure 8] FIG. 10 is a vertical cross-sectional side view showing a main part of a metal mask according to a second reference example. [Figure 9] FIG. 11 is a partial plan view showing a stress relaxation portion of a metal mask according to a third reference example. [Figure 10] FIG. 10 is a partial plan view showing a stress relaxation portion of a metal mask according to a fourth reference example. [Figure 11] 1 is a partial plan view showing a stress relaxation portion of a metal mask according to a first embodiment of the present invention. FIG. [Figure 12] FIG. 10 is a vertical cross-sectional side view showing a main part of a metal mask according to a fifth reference example. [Figure 13] FIG. 2 is a perspective view of a mask body and a frame body. [Figure 14] FIG. 10 is a vertical cross-sectional side view showing a metal mask according to a sixth reference example. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1 to 7 show a first reference example in which a metal mask according to the present invention is applied to a deposition mask used in the manufacture of an organic EL display. In this reference example, the upper side of FIG. 1 is defined as the upper (front) surface of the deposition mask, and the lower side is defined as the lower (rear) surface of the deposition mask. Dimensions such as thickness and width in each figure are shown schematically and do not represent actual conditions. This also applies to FIGS. 8 to 14, which show other embodiments and reference examples. In FIG. 2, a deposition mask (metal mask) 1 includes a plurality of mask bodies 2 (four in this reference example) arranged in a matrix, a frame 3 arranged to surround each mask body 2 and support the mask bodies 2, and a metal layer 4 bonding the mask bodies 2 and 3 together in an inseparable manner.

[0013] 5, the frame 3 is made of a material with a low coefficient of linear thermal expansion, such as Invar, Super Invar, or ceramic, and is formed into a lattice frame shape with the same number of mask openings 5 ​​as the mask bodies 2. Each mask opening 5 is formed into a rectangular shape with rounded corners, and one mask body 2 is placed in each mask opening 5. The frame 3 also serves as a reinforcing member for the deposition mask 1, and supports the deposition mask 1 while reinforcing the mask bodies 2.

[0014] The mask body 2 is made of a thin metal plate formed by electroforming (plating) using an electrodeposited metal made of nickel, copper, nickel alloys such as nickel-cobalt, or iron alloys such as iron-nickel. As shown in Figures 2 and 5, the mask body 2 is formed in a rectangular shape slightly smaller than the mask opening 5 with rounded corners. The mask body 2 has a pattern formation region 9 inside which a vapor deposition pattern made up of numerous independent vapor deposition through-holes (through-holes) 8 is formed, and an outer periphery region 10 surrounding the pattern formation region 9 on all four sides. The outer periphery region 10 has an outer periphery outer portion 11 on the outer edge side to which the metal layer 4 is bonded, and an inner periphery portion 12 between the outer periphery outer portion 11 and the pattern formation region 9. The outer shape of the mask body 2 and the opening shape of the mask opening 5 are configured to be similar to each other.

[0015] The metal layer 4 is formed by electroforming (plating) using an electrodeposited metal made of nickel, copper, a nickel alloy such as nickel-cobalt, or an iron alloy such as iron-nickel, and includes a covering portion 16 that covers the upper edge of the frame 3 and the inner circumferential surface 15 of the mask opening 5, and an extending portion 17 that extends inward from the inner circumferential surface 15 of the mask opening 5 toward the center of the opening via the covering portion 16. The extending portion 17 is formed in a rectangular frame shape and includes a joining portion 18 at the tip of the extending portion to which the outer peripheral portion 11 is joined, and a support portion 19 between the joining portion 18 and the inner circumferential surface 15 of the mask opening 5. In this reference example, the metal layer 4 is divided at the upper surface of the frame 3, and the upper surface of the frame 3 is exposed to the outer surface of the deposition mask 1. By dividing the metal layer 4 on the top surface of the frame body 3, the metal layers 4 supporting each mask body 2 can be formed individually. This allows the internal stress generated in the metal layer 4 to be alleviated compared to a form in which the entire metal layer 4 is formed integrally, thereby suppressing expansion and contraction of the metal layer 4 after electroforming.

[0016] The mask body 2 and the metal layer 4 are joined together with the outer circumferential portion 11 and the joint portion 18 overlapping each other, and the overlapping portion of the two (the outer circumferential portion 11 and the joint portion 18) constitutes a joint region 20. The outer circumferential portion 11 and the joint portion 18 in the joint region 20 are formed in a flat plate shape, and the upper surface of the outer circumferential portion 11 and the lower surface of the joint portion 18 are in close contact with each other. The extension portion 17 also has a circumferential joint rib 21 that protrudes downward from the lower surface of the support portion 19, and the inner surface of the joint rib 21 and the peripheral end surface of the mask body 2 are in close contact with each other.

[0017] As described above, the mask body 2 and the metal layer 4 are formed by electroforming, and therefore, slight expansion and contraction of the mask body 2 and the metal layer 4 is unavoidable when the temperature drops after electroforming. To prevent deformation of the mask body 2 and the metal layer 4 due to this expansion and contraction, the deposition mask 1 is provided with an easily expandable portion 24 between the pattern formation region 9 and the inner circumferential surface 15 of the mask opening 5. In the deposition mask 1 of this reference example, the easily expandable portion 24 is formed in a circumferential shape on the outer circumferential inner portion 12 of the outer circumferential region 10.

[0018] As shown in FIG. 4 , the easily stretchable portion 24 is formed by a large number of regularly arranged independent through-holes 25. Each through-hole 25 is a hole that penetrates the mask body 2, which is formed in a diamond shape (rectangular shape) in a plan view, from top to bottom (front to back). By regularly arranging a group of through-holes 25, the outer peripheral inner portion 12 of the easily stretchable portion 24 is formed in a mesh-like shape. The outer edge of the through-holes 25 that form the easily stretchable portion 24 is arranged up to the boundary between the outer peripheral inner portion 12 and the outer peripheral outer portion 11, while the inner edge of the through-holes 25 that form the easily stretchable portion 24 is arranged with a gap between them and the pattern formation region 9. As a result, the easily stretchable portion 24 is formed in the outer peripheral inner portion 12 so as to be biased toward the outer peripheral outer portion 11 (metal layer 4) side. The mask body 2, which is formed in a mesh-like shape in the easily stretchable portion 24, has spring properties, and expansion and contraction of the mask body 2 and the metal layer 4 is absorbed by the mask body 2 between adjacent through-holes 25 elastically deforming, thereby eliminating deformation of the mask body 2. The pattern formation region 9 and the easy stretchable portion 24 are preferably configured to satisfy the relationship: (total opening area of ​​vapor deposition through-holes 8 formed in the pattern formation region 9)>(total opening area of ​​through-holes 25 forming the easy stretchable portion 24). Also, the pattern formation region 9 and the easy stretchable portion 24 are preferably configured to satisfy the relationship: (opening area of ​​each vapor deposition through-hole 8)>(opening area of ​​each through-hole 25).

[0019] Each through-hole 25 of the easily stretchable portion 24 is filled with a filler 26. The filler 26 is made of a material having a lower elastic modulus than the portion forming the easily stretchable portion 24, i.e., the material constituting the mask body 2, and is made of a resin material having a sufficiently lower elastic modulus than the mask body 2 made of nickel. The top and bottom surfaces of the filler 26 filling each through-hole 25 and the mask body 2 are flush with each other. Note that, because the filler 26 is made of a material having a lower elastic modulus than the mask body 2, it does not hinder the easily stretchable portion 24 from absorbing the stretch of the mask body 2 and the metal layer 4.

[0020] An example of a manufacturing method of the vapor deposition mask 1 according to this reference example is shown in FIGS. 6 and 7. First, as shown in FIG. 6(a), a negative photoresist layer 31 is formed on the surface of an electroforming matrix 30 made of, for example, stainless steel or brass, which has conductivity. Next, a pattern film 32 made of a glass mask is adhered to the photoresist layer 31. This results in a patterning precursor 33. The pattern film 32 has formed therein light-transmitting holes corresponding to the vapor deposition through-holes 8 of the mask body 2, the through-holes 25 constituting the easily stretchable portions 24, and the joining ribs 21.

[0021] Next, the interior of the furnace of the ultraviolet irradiation device, which is equipped with ultraviolet lamps 35, is preheated to the furnace temperature during the exposure operation. Once preheating is complete, the resulting patterning pre-stage 33 is placed in the furnace of the ultraviolet irradiation device, and after the patterning pre-stage 33 has been acclimatized to the furnace temperature, it is irradiated with ultraviolet light from the ultraviolet lamps 35, thereby exposing the photoresist layer 31 through the pattern film 32. After the exposed patterning pre-stage 33 is removed, the pattern film 32 is removed from the photoresist layer 31, and the photoresist layer 31 is developed (unexposed portions are dissolved and removed), thereby forming a primary pattern resist 36 on the electroforming matrix 30, as shown in FIG. 6(b). The primary pattern resist 36 is composed of resist bodies 37 that correspond to each light-transmitting hole in the pattern film 32.

[0022] Next, the electroforming mold 30 on which the primary pattern resist 36 has been formed is placed in an electroforming tank prepared under specified conditions, and the surface of the electroforming mold 30 that is not covered by the resist body 37 is subjected to electroforming processing to form a primary electroforming layer 38 within the height range of the resist body 37, as shown in FIG. 6(c). The primary electroforming layer 38 constitutes a plurality of mask bodies 2 that constitute the completed vapor deposition mask 1, and a frame support 39 that is removed before completion. After the primary electroforming layer 38 is formed, the primary pattern resist 36 is dissolved and removed, as shown in FIG. 6(d). This reveals the mask bodies 2 and frame support 39 with the vapor deposition through-holes 8 and through-holes 25 formed therein. Note that the frame support 39 may be omitted.

[0023] In the next step, the frame 3 is bonded to the mask body 2 of the primary electroforming layer 38 with the metal layer 4. Specifically, as shown in FIG. 7( a), a negative photoresist layer 42 is first formed on the entire surface of the primary electroforming layer 38, and a pattern film 43 is then adhered thereon. This pattern film 43 has rectangular light-transmitting holes with rounded corners that correspond to the pattern formation region 9 and the inner peripheral portion 12 of the mask body 2.

[0024] Next, ultraviolet light is irradiated from an ultraviolet lamp 44 to expose the photoresist layer 42 through the pattern film 43. After exposure, the pattern film 43 is removed from the photoresist layer 42, and the photoresist layer 42 is developed (unexposed portions are dissolved and removed), thereby forming a secondary pattern resist 45 shown in FIG. 7(b). The secondary pattern resist 45 is composed of a resist body 46 that covers the pattern formation region 9 and the surface of the outer circumferential inner portion 12 of the mask body 2. Because the vapor deposition through holes 8 and through holes 25 in the pattern formation region 9 are covered with the secondary pattern resist 45, electroforming liquid will not penetrate into the vapor deposition through holes 8 and through holes 25 during the subsequent electroforming process.

[0025] Next, as shown in FIG. 7( c), the frame 3 is placed at a predetermined position on the upper surface of the frame support portion 39 of the primary electroforming layer 38. In plan view, the frame support portion 39 is formed to be slightly larger than the frame 3. An adhesive layer 48 is pre-layered on the underside of the frame 3 supported by the frame support portion 39 via a release layer 47. This adhesive layer 48 fixes the frame 3 to the frame support portion 39 so that it cannot move. In addition, a coating layer 49 is laminated on the upper surface of the frame 3, and the coating layer 49 prevents a metal layer 4 from being formed on the upper surface of the frame 3. In this reference example, the release layer 47 is formed of nickel (metal material), and the adhesive layer 48 is formed of an unexposed photoresist layer (resin layer). In addition, the coating layer 49 is formed of an exposed photoresist layer (resin layer).

[0026] Next, the electroforming matrix 30 with the frame 3 placed on the primary electroforming layer 38 is placed in an electroforming tank prepared under specified conditions. The electroforming matrix 30, the primary electroforming layer 38, and the frame 3, which are not covered by the resist layer 46 or the coating layer 49, are electroformed to form a continuous secondary electroformed layer, i.e., a metal layer 4, extending from the surface of the frame 3 to the mask body 2, as shown in FIG. 7(d). The metal layer 4 on the surface of the primary electroformed layer 38 is formed within the height of the secondary pattern resist 45. After electroforming, the primary electroformed layer 38 and the metal layer 4 are peeled off from the electroforming matrix 30. The frame support portion 39 of the primary electroformed layer 38, along with the adhesive layer 48 and the peel layer 47, is then peeled off from the frame 3 and the metal layer 4. The secondary pattern resist 45 and the coating layer 49 are then removed, yielding the deposition mask 1 shown in FIG. 7(e). Finally, the through holes 25 of the easily stretchable portions 24 are filled with a filler 26 made of resin, thereby obtaining the finished vapor deposition mask 1.

[0027] In the above manufacturing process, prior to forming the photoresist layer 42 on the primary electroformed layer 38, an adhesion plating layer for increasing the bonding strength (adhesion) of the metal layer 4 to the mask body 2 can be formed on the primary electroformed layer 38 corresponding to the outer peripheral portion 11. The secondary pattern resist 45 can be removed before peeling off the primary electroformed layer 38 and the metal layer 4, or before peeling off the frame support portion 39, the adhesive layer 48, and the peeling layer 47.

[0028] As described above, in the deposition mask 1 of this reference example, the easily stretchable portion 24 is provided in the outer circumferential inner portion 12 between the pattern formation region 9 and the inner circumferential surface 15 of the mask opening 5. Therefore, the easily stretchable portion 24 expands and contracts to absorb expansion and contraction of the mask body 2 due to internal stress during electroforming, thereby suppressing distortion of the mask body 2 (deposition mask 1) due to expansion and contraction of the mask body 2. Furthermore, the easily stretchable portion 24 provided in the outer circumferential inner portion 12 outside the pattern formation region 9 can prevent the expansion and contraction deformation of the easily stretchable portion 24 from affecting the pattern formation region 9, thereby suppressing distortion of the mask body 2 in the pattern formation region 9, where greater flatness is required. As described above, according to this reference example, distortion of the mask body 2 can be suppressed, and therefore a deposition mask 1 including a mask body 2 with excellent flatness can be obtained.

[0029] In the deposition mask 1 in which the mask body 2 and the frame 3 are inseparably joined via the metal layer 4, the easily stretchable portion 24 is provided on the outer circumferential inner portion 12 of the mask body 2, so that the easily stretchable portion 24 can absorb expansion and contraction of the mask body 2 and the metal layer 4 due to internal stress during electroforming, thereby preventing distortion of the mask body 2 due to expansion and contraction of the mask body 2 and the metal layer 4. Furthermore, since the easily stretchable portion 24 is provided in a circumferential shape, the easily stretchable portion 24 can absorb expansion and contraction of the entire periphery of the mask body 2 in a plan view, thereby further preventing distortion of the mask body 2.

[0030] According to the easily stretchable portion 24 formed by the many independent through-holes 25 penetrating the mask body 2 from front to back, the portion of the outer circumferential inner portion 12 (mask body 2) where the easily stretchable portion 24 is provided can be configured in a mesh (network) shape to have springiness, and this springiness can reliably absorb the expansion and contraction of the mask body 2 and the metal layer 4. Another advantage is that by changing the diameter and number of the through-holes 25 that form the easily stretchable portion 24, the easily stretchable portion 24 can be made to exhibit various springiness.

[0031] Since the easily stretchable portion 24 is provided in the outer peripheral inner portion 12, the easily stretchable portion 24 can be provided by a simple manufacturing method that simply involves forming a through hole 25 in the outer peripheral inner portion 12 at the same time as electroforming the mask body 2.

[0032] Since the easily stretchable portion 24 is biased toward the metal layer 4, it is possible to more effectively prevent the expansion and contraction deformation of the easily stretchable portion 24 from affecting the pattern formation region 9, thereby further improving the flatness of the mask body 2 in the pattern formation region 9.

[0033] The inside of the through-hole 25 is filled with a filler 26 made of a material having a lower elastic modulus than the material constituting the portion forming the easily stretchable portion 24, so that the vapor deposition material in the vapor deposition mask method can be prevented from passing through the vapor deposition mask 1 via the through-hole 25, and therefore the vapor deposition material can be prevented from being deposited in unnecessary portions.

[0034] For these reasons, the deposition mask according to this reference example can contribute to Goal 9 (Industry, innovation and infrastructure: Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation) and Goal 12 (Responsible consumption and production: Ensure sustainable consumption and production patterns) of the Sustainable Development Goals (SDGs) advocated by the United Nations.

[0035] (No. 2 Reference examples ) FIG. 8 shows the first metal mask according to the present invention. 2 Reference examples This indicates Reference example The present embodiment differs from the first embodiment in that the stretchable portion 24 is formed on the metal layer 4, but is otherwise the same as the first embodiment. Therefore, the same components, structures, and members are denoted by the same reference numerals and will not be described again. and As shown in FIG. 8, the easily expandable portion 24 formed by a large number of independent through holes 25 is formed in a circumferential shape on the support portion 19 of the metal layer 4. Reference example In this case, the expansion and contraction of the mask body 2 and the metal layer 4 is absorbed by the elastic deformation of the metal layer 4 between the adjacent through-holes 25, and the deformation of the mask body 2 is thereby eliminated.

[0036] Book Reference example The manufacturing method of the vapor deposition mask 1 according to this embodiment differs from that of the first reference example in the pattern films 32 and 43 used when exposing the photoresist layers 31 and 42. The pattern film 32 has light-transmitting holes formed therein that correspond to the vapor deposition through-holes 8 and the joining ribs 21 of the mask body 2, and a primary electroformed layer 38 formed by electroforming is composed of the mask body 2 with the vapor deposition through-holes 8 formed therein and a frame support portion 39. The pattern film 43 has light-transmitting holes formed therein that correspond to the pattern formation region 9, the outer circumferential inner portion 12, and the through-holes 25 of the mask body 2, and a metal layer 4 formed by electroforming has the through-holes 25 in the support portion 19.

[0037] As described above, even when the easily stretchable portion 24 is provided in the support portion 19, the easily stretchable portion 24 can be provided by a simple manufacturing method in which the through hole 25 is formed at the same time as the metal layer 4 is electroformed.

[0038] (No. 3 Reference examples 9 shows the first metal mask according to the present invention. 3 Reference examples This indicates Reference example The through-hole 25 forming the easily expandable portion 24 Variant As shown in FIG. 9, each through hole 25 is formed in a regular hexagonal shape (polygonal shape) in a plan view, and by regularly arranging the through holes 25, the outer circumferential inner portion 12 of the easily expandable portion 24 is formed in a honeycomb structure.

[0039] (No. 4 Reference examples ) FIG. 10 shows the first metal mask according to the present invention. 4 Reference examples This indicates Reference example Further, another through-hole 25 forming the easily expandable portion 24 Shape 10, each through hole 25 is formed in a perfect circular shape (circular shape) in a plan view, and by regularly arranging the through holes 25, the outer circumferential inner part 12 of the easily expandable part 24 is formed in a punched metal shape. Note that the through holes 25 can also be formed in an elliptical shape.

[0040] (No. 1 embodiment11 shows the first metal mask according to the present invention. 1 embodiment This indicates Embodiment The easy-to-stretch portion 24 is formed by a circumferential groove 51 recessed in the thickness direction of the mask body 2 instead of the through-hole 25. As shown in FIG. 11, the groove 51 is formed on the upper and lower surfaces of the mask body 2. Embodiment In the mask 2, four grooves 51 are alternately formed on the upper and lower surfaces of the outer circumferential inner portion 12. The mask body 2 in the groove 51 portions (the mask body 2 forming the bottoms of the grooves 51) is more flexible than other portions, and the expansion and contraction of the mask body 2 and the metal layer 4 is absorbed by the mask body 2 in the groove 51 portions being flexed and deformed, thereby eliminating deformation of the mask body 2. The number of grooves formed in the outer circumferential inner portion 12 (mask body 2) as the easily stretchable portion 24 can be more or less than four, and more grooves 51 can be provided in the easily stretchable portion 24 so that the easily stretchable portion 24 is formed in a bellows shape. Also, instead of the grooves 51, a number of independent bottomed holes (recesses) can be formed.

[0041] In addition to the above, the mask body 2 can also be formed by etching or laser processing a thin plate made of a metal material such as the materials mentioned in the above embodiments or Invar. During etching or laser processing, internal stress is generated in the mask body 2, so even in a mask body 2 formed by this type of method, the expansion and contraction of the mask body 2 can be absorbed by the easy-to-stretch portion 24, thereby preventing distortion in the pattern formation region 9.

[0042] Each of the above Reference example In the example, the through-holes 25 (easily stretchable portions 24) were formed simultaneously when the mask body 2 or the metal layer 4 was formed, but the through-holes 25 (easily stretchable portions 24) can also be formed after the mask body 2 or the metal layer 4 is formed, or by etching or laser on the thin metal plate. In this case, the easily stretchable portions 24 can be easily provided in the desired region, and the spring properties can also be increased by additionally machining the through-holes 25 into the existing easily stretchable portions 24. The easily stretchable portions 24 can be provided in the bonding region 20, and in this case the through-holes 25 are also formed by etching or laser so as to penetrate the mask body 2 and the metal layer 4.

[0043] The form, shape and forming area of ​​the easily stretchable portion 24 are as follows: Reference examples However, the present invention is not limited to this. For example, the easy-to-stretch portions 24 can be provided intermittently in the outer circumferential region 10 and / or the metal layer 4 along each side of the pattern formation region 9. Furthermore, the easy-to-stretch portions 24 may be provided in some places and not provided in other places (intermittently) in the outer circumferential region 10 and / or the metal layer 4 along each side of the pattern formation region 9. Furthermore, when locations or regions where internal stress will concentrate can be predicted by simulation using an analysis device, measures can be taken such as proactively providing the easy-to-stretch portions 24 in those locations or regions or increasing the spring properties of those locations or regions.

[0044] Furthermore, the filler 26 may be made of a material having a lower elastic modulus than the material constituting the mask body 2, and may be made of a metal or ceramic material. Furthermore, it is preferable that the filler 26 be made of a material having a coefficient of linear thermal expansion that is equal to or lower than that of the material constituting the mask body 2. Furthermore, the filler 26 may be omitted. In this case, it is preferable that the diameter of the through-holes 25 is made sufficiently small to prevent the vapor deposition material from passing through the through-holes 25.

[0045] Although the mask body 2 and the metal layer 4 are joined by forming the outer peripheral portion 11 and the joint portion 18 into a flat plate shape, the mask body 2 and the metal layer 4 can be joined by opening a large number of independent connecting holes in the outer peripheral portion 11 of the mask body 2 and inserting the joint portion 18 into the connecting holes. In this case, the two (mask body 2, metal layer 4) can be joined more firmly. The metal layer 4 may have a configuration in which the covering portion 16 covers the upper surface of the frame body 3.

[0046] (No. 5 Reference Example) FIGS. 12 and 13 show the first metal mask according to the present invention. 5A reference example will be described. As shown in Fig. 13, the deposition mask 1 of this reference example is made of a thin metal plate and is composed of a mask body 2 in which pattern formation regions 9 are arranged in a matrix, and a frame 3 that supports the mask body 2 in which mask openings 5 ​​are formed so as to surround the pattern formation regions 9. Four pattern formation regions 9 are provided in the mask body 2, and a lattice-frame-shaped outer peripheral region 10 is provided so as to surround all four peripheries of the pattern formation regions 9. The outer peripheral region 10 has an outer peripheral inner portion 12 that surrounds the outside of the pattern formation regions 9, and an outer peripheral outer portion 11 that surrounds the outer peripheral inner portion 12, and the outer peripheral outer portion 11 is formed in a lattice-frame shape.

[0047] The outer shape of the mask body 2 is formed to be the same as the outer shape of the frame 3, and the frame 3 is inseparably joined to the outer peripheral part 11 of the mask body 2 with an adhesive, with the outer edges of both (mask body 2, frame 3) coinciding. A large number of independent through-holes 25 are formed circumferentially in the inner peripheral part 12 between the pattern formation region 9 and the inner peripheral surface 15 of the mask opening 5, and an easily stretchable part 24 is provided.

[0048] (No. 6 Reference Example) FIG. 14 shows the first metal mask according to the present invention. 6 A reference example will be described. In this reference example, the outer shape of the mask body 2 is formed slightly smaller than the outer shape of the frame body 3. 5 As described above, the outer shape of the mask body 2 does not need to match the outer shape of the frame body 3, and conversely, the outer shape of the mask body 2 can be formed slightly larger than the outer shape of the frame body 3.

[0049] As described above, even in a deposition mask in which the mask body 2 and the frame body 3 are inseparably bonded together with an adhesive, the stretchable portion 24 can expand and contract to absorb the expansion and contraction of the mask body 2 caused by internal stress during electroforming, thereby preventing distortion of the mask body 2. [Explanation of symbols]

[0050] 1 Metal mask (evaporation mask) 2 Mask body 3 Frame 4 metal layer 5 Mask opening 8 Through hole (evaporation through hole) 9 Pattern formation area 10 Outer area 11 outer periphery 12 Inner outer periphery 15 Inner surface of mask opening 24 Easily expandable part 51 Groove

Claims

1. a mask body (2) made of a thin metal plate and having a pattern forming region (9) in which a large number of independent through holes (8) are arranged; a frame (3) having a mask opening (5) and supporting the mask body (2) with a pattern forming region (9) facing the mask opening (5); Equipped with An easily stretchable portion (24) is provided between the pattern forming region (9) and the inner peripheral surface (15) of the mask opening (5), A metal mask characterized in that the easily stretchable portion (24) is formed by a groove (51) recessed in the thickness direction of the mask body (2).

2. The mask body (2) is formed smaller than the mask opening (5) and includes an inner pattern forming region (9) and an outer peripheral region (10) surrounding the pattern forming region (9); The mask body (2) and the frame body (3) are inseparably joined via a metal layer (4) extending inward from the inner peripheral surface (15) of the mask opening (5) to the outer peripheral region (10), 2. The metal mask according to claim 1, wherein the easily stretchable portion (24) is provided in a circumferential shape in the outer peripheral region (10) of the mask body (2).

3. The mask body (2) and the metal layer (4) are bonded together with the outer peripheral region (10) and the metal layer (4) overlapping on the front and back, The peripheral region (10) includes an outer peripheral portion (11) on the outer edge side overlapping the metal layer (4), and an inner peripheral portion (12) between the outer peripheral portion (11) and the pattern forming region (9), 3. The metal mask according to claim 2, wherein the easily stretchable portion (24) is provided on the inner peripheral portion (12).

4. A metal mask as described in claim 3, in which multiple grooves (51) are formed alternately in the inward and outward directions on the upper and lower surfaces of the outer circumferential inner portion (12).

Images