JP2024027394A - Mask frame, mask assembly and vapor deposition method for vapor deposition mask - Google Patents

Abstract

[Object] A mask frame for a vapor deposition mask used in a vertical vapor deposition method, in which the influence of misalignment on the vapor deposition mask is suppressed, and a mask assembly including the same. A vapor deposition method using the same is provided. A mask frame for a deposition mask includes a frame body configured to hold a deposition mask. A recess is provided in at least a portion of the frame body. A first rib extending in the width direction of the frame body parallel to the first surface on which the vapor deposition mask is held, and a second rib extending diagonally from the first rib are formed in the recess. There is. [Selection diagram] Figure 1

Description

Embodiments relate to a mask frame for a vapor deposition mask, a mask assembly including the same, and a vapor deposition method using the same.

In a vacuum deposition process, which is one of the manufacturing processes of organic EL (electro-luminescence) displays, a deposition mask is used when depositing a deposition substance such as an organic substance. Misalignment of the vapor deposition mask leads to misalignment of the film deposition position. Therefore, the deposition mask is usually used while being held by a mask frame. Here, depending on the process temperature, the mask frame and the deposition mask undergo thermal expansion, which may cause misalignment and size misalignment. Therefore, the mask frame is manufactured from a material with a low coefficient of thermal expansion. At the same time, as a measure to prevent deformation of the vapor deposition mask, a method is used in which the vapor deposition mask is stretched and fixed to the mask frame by welding. In this case, the mask frame is required to have rigidity that can withstand the tensile force when the vapor deposition mask is stretched. In order to obtain such rigidity, the mask frame is made wide and thick. Therefore, mask frames are typically heavy.

Japanese Patent Application Publication No. 2014-194062

In recent years, as glass substrates used in organic EL displays have become larger, a vertical vapor deposition method in which vapor deposition is performed by vertically arranging a vapor deposition mask has come to be used. In the vertical vapor deposition method, unlike the horizontal vapor deposition method, misalignment due to deflection of the vapor deposition mask due to its own weight is canceled out. On the other hand, misalignment in the vapor deposition mask may occur due to deformation of the mask frame due to the deflection of the mask frame holding the vapor deposition mask due to its own weight.

An embodiment is a mask frame for a vapor deposition mask used in a vertical vapor deposition method, in which the influence of misalignment on the vapor deposition mask is suppressed, and a mask assembly including the same. The present invention also provides a vapor deposition method using the same.

A mask frame for a deposition mask in one embodiment includes a frame body configured to hold a deposition mask. A recess is provided in at least a portion of the frame body. A first rib extending in the width direction of the frame body parallel to the first surface on which the vapor deposition mask is held, and a second rib extending diagonally from the first rib are formed in the recess. There is.

An embodiment is a mask frame for a vapor deposition mask used in particular in a vertical vapor deposition method, in which the influence of misalignment on the vapor deposition mask is suppressed, and a mask assembly including the same. In addition, a vapor deposition method using the same can be provided.

FIG. 1 is a diagram showing the configuration of a mask assembly in which a vapor deposition mask is held by a mask frame according to an embodiment. FIG. 2 is a sectional view taken along line II-II of the lower portion of the frame main body in FIG. 1(A). FIG. 3 is a schematic diagram showing a vapor deposition process using the mask assembly according to the embodiment. FIG. 4A is a schematic diagram showing the effect of the mask frame according to this embodiment. FIG. 4B is a schematic diagram showing the effect of the mask frame according to this embodiment. FIG. 5 is a cross-sectional view showing the configuration of the recessed portion of Modification Example 1. FIG. 6 is a plan view showing the structure of the mask assembly of Modification 2, viewed from the side opposite to the joint surface side. FIG. 7 is a cross-sectional view showing the configuration of a recessed portion of Modification 3. FIG. 8 is a plan view showing the first configuration of the mask assembly of Modification 4, viewed from the side opposite to the joint surface side. FIG. 9 is a side view showing a second configuration of the mask assembly of Modification 4. FIG. FIG. 10 is a front view of the mask frame of modification 5 seen from the joint surface side. FIG. 11 is a plan view showing the first configuration of the mask assembly of Modification 6, viewed from the joint surface side. FIG. 12 is a plan view showing the second configuration of the mask assembly of Modified Example 6, viewed from the joint surface side. FIG. 13 is a plan view showing the first configuration of the mask assembly of Modification Example 7, viewed from the joint surface side. FIG. 14 is a plan view showing the second configuration of the mask assembly of Modification Example 7, viewed from the joint surface side.

1. Embodiment A mask frame according to an embodiment will be described. The mask frame according to the embodiment is a frame for holding a vapor deposition mask used for forming a vapor deposition pattern on a substrate to be vapor-deposited in the manufacturing process of an organic EL panel. By being joined to the deposition mask, the deposition mask can be accurately positioned with respect to the substrate to be deposited.

The display methods of organic EL panels include two methods: a method in which organic EL layers of the three primary colors of red, blue, and green, each of which is deposited independently, emit light individually for colored display, and a method in which a white organic EL panel is deposited on one surface. A possible method is to display the white light emitted from the EL layer in color through a color filter. The mask frame according to the embodiment can be applied to the manufacturing process of organic EL panels of any of the display methods described above. On the other hand, the embodiment is preferably used in the manufacturing process of an organic EL panel in which red, blue, green, and other organic EL layers individually emit light to display colored images, which requires more accurate positioning.

1.1 Configuration First, the configuration of a mask frame according to an embodiment and a mask assembly including the same will be described. The mask assembly is a mask frame to which a deposition mask is attached.

1.1.2 Mask Assembly FIG. 1 is a diagram showing the configuration of a mask assembly in which a vapor deposition mask is held by a mask frame according to an embodiment. On the left side of FIG. 1 (FIG. 1A), a top view of the mask assembly is shown. The plan view of FIG. 1A is a plan view of the mask frame viewed from the side of the bonding surface between the vapor deposition mask and the mask frame. Further, a side view of the long side of the mask assembly is shown on the right side of FIG. 1 ((B) of FIG. 1).

The mask assembly 10 is constructed by joining a vapor deposition mask 30 to a mask frame 50 in a stretched state. Here, the vapor deposition mask 30 and the mask frame 50 are joined by, for example, welding. As will be described later, the mask assembly 10 is installed vertically, for example, with the long side direction parallel to the direction of gravity. Here, for the following explanation, the upper short side of the mask assembly 10 is the upper part of the mask assembly 10, the lower short side is the lower part of the mask assembly 10, and the long sides on both left and right sides are referred to as the upper part of the mask assembly 10. Defining the sides of the mask assembly 10, the vapor deposition mask 30 and the mask frame 50 are joined at, for example, the upper and lower parts.

Vapor deposition is performed toward the mask assembly 10 from the surface opposite to the bonding surface between the vapor deposition mask 30 and the mask frame 50, that is, from the direction of arrow V in FIG. 1(B). As described above, by joining the deposition mask 30 to the mask frame 50, the deposition mask 30 can be positioned during deposition.

The vapor deposition mask 30 and mask frame 50 that constitute the mask assembly 10 will be further described below.

1.1.2.1 Vapor Deposition Mask First, the configuration of the vapor deposition mask 30 will be explained. As shown in FIG. 1A, the vapor deposition mask 30 is bonded at a bonding spot 32 serving as a fixing portion so as to cover an internal region, which is an opening formed in the mask frame 50. The vapor deposition mask 30 has, for example, the same rectangular shape as the mask frame 50, and has a thickness of about 2 micrometers to 50 micrometers ([μm]). The size of the vapor deposition mask 30 may be determined as appropriate depending on, for example, the size of the substrate to be vapor deposited.

A plurality of openings 31 are formed in the evaporation mask 30, each of which provides a evaporation pattern to the substrate to be evaporated. The vapor deposition mask 30 may be a metal mask configured by forming an opening 31 in a metal layer. Alternatively, the vapor deposition mask 30 may be a hybrid mask configured by laminating a metal layer and a resin layer, and forming an opening 31 in the metal layer and the resin layer. The material used for the metal layer of the metal mask or hybrid mask is not particularly limited. The materials used for the metal layer may be materials such as stainless steel, iron-nickel alloys, and aluminum. In particular, a low-expansion Fe--Ni alloy, a so-called Invar alloy, which is an alloy mainly composed of iron and nickel, has a small coefficient of thermal expansion and is therefore less prone to misalignment due to thermal deformation, which may be more advantageous than other materials. In addition, there are no particular limitations on the material of the resin layer used in the hybrid mask, but for example, it is possible to form high-definition openings by laser processing, etc., and the material has a low thermal expansion coefficient to suppress positional displacement due to thermal deformation. A material having a moisture absorption rate and moisture absorption rate is desirable. For example, polyimide is used as a material for such a resin layer.

1.1.2.2 Mask Frame Next, the configuration of the mask frame 50 will be described. The mask frame 50 includes a frame body 51. The frame body 51 is, for example, a rectangular frame integrally molded. Here, the length of the frame body 51 in the direction parallel to each side is, for example, the dimension of the applied vapor deposition mask 30 + 50 to 500 millimeters ([mm]). Further, the length of the frame body 51 in the direction parallel to the joint surface and perpendicular to each side, that is, the width, may be, for example, the dimension of the applied vapor deposition mask 30 + 50 to 500 millimeters ([mm]). Furthermore, the length of the frame body 51 in the direction perpendicular to the joint surface, that is, the thickness, is, for example, 30 to 60 mm.

The frame main body 51 is joined to the vapor deposition mask 30, and thus mainly has the function of suppressing deformation of the thin film vapor deposition mask 30. Therefore, it is desirable that the frame body 51 be made of a material with a small coefficient of thermal expansion. For example, the material of the frame body 51 may be the aforementioned Invar alloy. Further, as the material of the frame body 51, a low expansion high Ni cast iron casting product, so-called Novinite or Niresist may be used.

The frame body 51 has a plurality of support holes 52. For example, two supporting holes 52 are provided in each of the upper and lower parts of the frame body 51 so as to be lined up along the short side direction. Mask assembly 10 is supported by a rod passing through support hole 52 during the deposition process.

As shown in FIG. 1B, the frame body 51 has a planar shape so that the internal region, which is an opening formed in the mask frame 50, expands from the bonding surface side to the surface opposite to the bonding surface. An inclined surface 53 is provided. The inclined surface 53 is provided to reduce deposition defects due to shadows. Shadow is a phenomenon that occurs when a high-definition pattern is formed by vapor deposition, and uniform vapor deposition is inhibited by blocking the vapor deposition material that enters the thick frame body 51 from an oblique direction. be. By forming the inclined surface 53 on the frame body 51, it is suppressed that the vapor deposition material incident on the frame body 51 from an oblique direction is blocked.

Here, in the embodiment, at least one recess 54 is formed on the joint surface side of the frame main body 51. The recess 54 is formed at least in the upper part of the frame body 51, and may be further formed in the side and lower parts. The number of recesses 54 formed on the top, bottom, and side surfaces may be determined as appropriate depending on the size of the frame body 51, for example. In FIG. 1A, eight recesses 54 are formed at the top, eight at the bottom, 16 at the right side, and 16 at the left side. By forming the recess 54 in the frame main body 51, the frame main body 51 is reduced in weight.

FIG. 2 is a cross-sectional view taken along the line II-II of the lower portion of the frame body 51 in FIG. 1A. As shown in FIG. 2, the recess 54 is, for example, a counterbore formed from the joint surface side of the frame body 51. Further, a portion of the recess 54 located on the back side of the inclined surface 53 is processed to have a planar inclined surface 54c parallel to the inclined surface 53. By processing the frame body 51 to have the inclined surface 54c, the thickness of the concave portion 54 of the frame body 51 is made uniform.

Furthermore, in the embodiment, as shown in FIG. 1A, the recess 54 is provided with a columnar rib 54a as a first rib and a bracing rib 54b as a second rib.

The pillar rib 54a is a rib formed, for example, in the center of the recess 54 so as to extend in the width direction of the frame main body 51. That is, the pillar ribs 54a are formed to extend from the top to the bottom of the frame body 51 on the short sides, that is, on the upper and lower sides of the frame body 51. Similarly, the pillar ribs 54a are formed to extend from the left to the right of the frame body 51 on the long sides of the frame body 51, that is, on the left and right sides.

The bracing rib 54b is a rib formed to extend diagonally from the columnar rib 54a toward the end of the recess 54, that is, to have a bracing structure. FIG. 1A shows an example in which two bracing ribs 54b are formed from a columnar rib 54a formed at the center of the recess 54.

The structure in which the columnar ribs 54a and the bracing ribs 54b are combined reduces deformation of the mask frame 50 due to deflection of the mask frame 50 under its own weight, which will be described later. This also suppresses misalignment of the vapor deposition mask 30 joined to the mask frame 50.

Here, the method for forming the recessed portion 54 including the pillar ribs 54a and the bracing ribs 54b may be appropriately selected depending on the material used for the frame body 51. For example, when the material used for the frame body 51 is an invar alloy, the recess 54 including the column ribs 54a and the brace ribs 54b may be formed by cutting. Further, for example, when the material used for the frame body 51 is novinite or nyresist, the recessed portion 54 including the column ribs 54a and the bracing ribs 54b may be formed by casting. Forming the recess 54 by casting is cheaper than forming the recess 54 by cutting.

1.2 Operation Next, the operation using the mask assembly according to the embodiment will be described.

1.2.1 Vapor Deposition Process A vapor deposition process using the mask assembly according to the embodiment will be described. FIG. 3 is a schematic diagram showing a vapor deposition process using the mask assembly according to the embodiment. FIG. 3 shows a state in which the mask assembly 10 (the vapor deposition mask 30 and the mask frame 50) is installed in the vapor deposition chamber. Although not shown in FIG. 3, a substrate to be deposited is placed so as to face the deposition mask 30.

As shown in FIG. 3, a vapor deposition source 70 is provided within the vapor deposition chamber. The vapor deposition source 70 has a function of emitting vapor 71 of the vapor deposition material by heating and vaporizing the vapor deposition material contained therein. The evaporation source 70, the mask frame 50, the evaporation mask 30, and the substrate to be evaporated are arranged in this order along the direction in which the vapor 71 of the evaporation substance is emitted from the evaporation source 70.

The mask assembly 10 is configured such that the opening 31 of the evaporation mask 30 is aligned in the direction of the strongest emission range of the vapor 71 of the evaporation material from the evaporation source 70 (for example, along the central axis of a nozzle (not shown) provided in the evaporation source 70). It is installed so that it can be perpendicular to the Specifically, the thickness direction of the mask assembly 10 may coincide with the emission direction of the vapor 71 of the deposition material. As a result, the deposition material that has passed through the opening 31 is deposited on the substrate to be deposited.

As described above, the mask frame 50 is vertically supported using the four support holes 52. In this case, gravity acts along a direction parallel to the long side of the frame body 51 (-Q direction in FIG. 3).

The evaporation source 70 emits vapor 71 of the evaporation substance toward the substrate to be evaporated while moving in parallel along, for example, the direction of the arrow A in FIG. 3 (that is, the ±Q direction in FIG. 3). As a result, even if the size of the deposition target substrate is large, the deposition material can be deposited on the entire surface of the deposition target substrate without moving the deposition target substrate and the mask assembly 10. Here, the recess is formed on the side of the joint surface between the vapor deposition mask 30 and the mask frame 50 in the frame body. Therefore, the deposited substance does not enter the recess.

1.3 Effects of the Present Embodiment According to the present embodiment, the recess 54 is formed in at least a portion of the frame main body 51 of the mask frame 50. By forming the recess 54, the weight of the frame body 51 is reduced. By reducing the weight of the frame body 51, deflection of the frame body 51 due to its own weight is suppressed. Furthermore, according to this embodiment, the columnar rib 54a and the bracing rib 54b are formed in the recess 54. Due to the structure in which the columnar ribs 54a and the bracing ribs 54b are combined, deflection of the frame body 51 due to its own weight is further suppressed. In addition, due to the structure in which the columnar ribs 54a and the bracing ribs 54b are combined, not only the deflection due to the frame body 51's own weight but also the tension from the vapor deposition mask 30 due to the vapor deposition mask 30 being stretched and joined to the mask frame 50 Deflection of the frame body 51 due to stress is also suppressed. By suppressing deformation of the frame body 51, misalignment of the vapor deposition mask 30 is also suppressed. Therefore, the precision of vapor deposition is improved.

FIGS. 4A and 4B are schematic diagrams showing the effects of the mask frame according to this embodiment, and schematically show the magnitude of deflection that occurs in the mask frame during vapor deposition processing. Here, FIG. 4A schematically shows, as a comparative example, the size that occurs in a mask frame in which a recess including a columnar rib and a bracing rib is not formed. On the other hand, FIG. 4B schematically shows the size of a mask frame in which a recess is formed. Here, the arrow G shown in FIGS. 4A and 4B indicates the direction of gravity.

As shown by a comparison between FIGS. 4A and 4B, the convex deflection at the short side of the frame body and the convex deflection at the long side are greater in the case where the recess is formed than in the case where the recess is not formed. Any concave deflection is reduced. In addition, in stress simulation by the applicant using the finite element method, the maximum amount of deformation of the frame body when a recess is formed is reduced by about 55% compared to the maximum amount of deformation of the frame main body when a recess is not formed. It has been confirmed that

In recent years, deposition target substrates used in organic EL displays have become larger. Along with this, there is a tendency for vapor deposition masks and mask frames to become larger. Due to the increase in the size of the vapor deposition mask, in the conventional horizontal vapor deposition method in which the mask assembly is placed horizontally to perform vapor deposition, misalignment occurs due to the deflection of the vapor deposition mask due to its own weight. Therefore, in recent years, a vertical evaporation method has been used to manufacture large-sized organic EL displays, in which a mask assembly is arranged vertically to perform evaporation. In the vertical vapor deposition method, the influence of the deflection of the vapor deposition mask due to its own weight is canceled. On the other hand, in the vertical evaporation method, deformation due to the deflection of the mask frame under its own weight affects misalignment. In this embodiment, by increasing the number of recesses or the like, even if the mask frame is enlarged, excessive increase in weight of the mask frame is suppressed. Therefore, the technique of this embodiment is particularly effective when depositing a large substrate to be deposited, such as G8.5 Half or more, by the vertical deposition method.

2. Modifications Various modifications of the embodiment will be described below.

2.1 Modification 1
In the embodiment described above, as shown in FIG. 1A, the recess 54 is formed on the side of the joint surface of the frame body 51, that is, on the side opposite to the side facing the vapor deposition source 70 during the vapor deposition process. Ru. Therefore, the vapor deposition substance does not enter the recess 54 during the vapor deposition process. On the other hand, as shown in FIG. 5, the recess 54 may be formed on the opposite side to the bonding surface, that is, on the side facing the vapor deposition source 70 during the vapor deposition process. In this case, since there is a possibility that the vapor deposition substance may enter the recess 54 during the vapor deposition process, the recess 54 may be closed by the antifouling plate 54d. The antifouling plate 54d may be made of the same material as the frame body 51.

2.2 Modification 2
In the embodiment, the frame body 51 is provided with a recess 54 having a structure in which a columnar rib 54a and a bracing rib 54b are combined so that deformation of the frame body 51 is suppressed. In order to further suppress deformation of the frame body 51, a reinforcing member 55 may be provided on the frame body 51 as shown in FIG. FIG. 6 is a plan view showing the structure of the mask assembly of Modification 2, viewed from the side opposite to the joint surface. As shown in FIG. 6, the reinforcing member 55 is attached to the frame body 51 so as to cross the internal region of the frame body 51, for example along the direction of gravity. The reinforcing member 55 may be formed of the same material as the frame body 51. Further, in FIG. 6, the reinforcing member 55 is shown separately from the frame main body 51. The reinforcing member 55 may be formed integrally with the frame body 51.

2.3 Modification 3
In the embodiment, as shown in FIG. 2, the portion of the recess 54 located on the back surface of the inclined surface 53 is processed to have a planar inclined surface 54c parallel to the inclined surface 53. There is. On the other hand, the inclined surface 54c does not necessarily have to be parallel to the inclined surface 53. For example, as shown in FIG. 7, the inclined surface 54c may be a curved inclined surface having a shape that follows the inclined surface 53. That is, the shape of the recess 54 is not limited to a specific shape. In the third modification, the degree of freedom in designing the recess 54 increases.

2.4 Modification 4
In the embodiment, as shown in FIG. 1A, the upper, lower, and side structures of the frame main body 51 are the same. However, the structures of the upper part, lower part, and side surfaces of the frame main body 51 do not necessarily have to be the same.

FIG. 8 is a plan view showing the first configuration of the mask assembly of Modified Example 4, viewed from the side opposite to the joint surface. In FIG. 8, the lower part of the mask assembly 10 is fixedly installed on a predetermined reference plane B. In FIG. In this case, the lower part of the frame body 51 is less likely to be deformed due to deflection due to its own weight. In such a state, the width of the lower part of the frame body 51 can be made shorter than the width of the upper part. The width of the upper part and the width of the lower part of the frame main body 51 may be set depending on the amount of deformation caused by deflection due to their own weight.

Moreover, when the lower part of the frame body 51 is fixedly installed on the reference plane B, the lower part of the frame body 51 does not need to be provided with a recess. Further, if the tensile force when stretching the vapor deposition mask 30 is considered to be small, the recessed portion on the side surface of the frame body 51 may also be omitted.

FIG. 9 is a side view showing a second configuration of the mask assembly of Modification 4. FIG. Also in FIG. 9, the lower part of the mask assembly 10 is fixedly installed on a predetermined reference plane B. In the first configuration, an example is shown in which the upper and lower widths of the frame body 51 are made different. In addition to having different widths, the upper and lower parts of the frame body 51 may have different thicknesses, as shown in FIG. Furthermore, the thickness of the side surface of the frame body 51 may also be different from the thickness of the upper portion and the thickness of the lower portion. The thickness of the upper part, the thickness of the lower part, and the thickness of the side surfaces of the frame main body 51 may be set depending on the amount of deformation caused by deflection due to their own weight.

As in Modified Example 4, by varying the width and/or thickness depending on the amount of deformation that may occur in each portion of the frame body 51, deformation can be suppressed while suppressing an increase in weight of the frame body 51.

2.5 Modification 5
In the embodiments described above, the recesses are formed in the mask frame without gaps. However, the recess does not necessarily have to be formed without any gaps. FIG. 10 is a front view of the mask frame of modification 5 seen from the joint surface side. As shown in FIG. 10, the frame body 51 of the mask frame 50 may have a portion 56 in which the recess 54 is not formed. The position of the portion 56 where the recess 54 is not formed may be appropriately set depending on the amount of deformation that may occur in each portion of the frame body 51.

The portion 56 where the recess 54 is not formed has a higher weight than the portion where the recess 54 is formed. On the other hand, the strength of the portion 56 where the recess 54 is not formed is higher than the strength of the recess 54. As shown in FIG. 10, by providing a portion in which the recess 54 is formed and a portion 56 in which the recess 54 is not formed, a balance between weight reduction and strength of the frame body 51 can be achieved.

2.6 Modification 6
In the embodiment described above, only one vapor deposition mask 30 is joined to the mask frame 50. Some vapor deposition masks are divided into multiple submasks. The technique of the embodiment can be applied even if the deposition mask is divided into a plurality of submasks.

FIG. 11 is a plan view showing the first configuration of the mask assembly of Modified Example 6 viewed from the joint surface side. As shown in FIG. 11, in Modification 6, the deposition mask 30 is composed of a plurality of sub-masks 30a. Each of the sub-masks 30a has an opening 31 and forms a deposition mask. In the first configuration, the sub-masks 30a are joined to the mask frame 50 at the joining spots 32 so that each sub-mask 30a has a long side in a direction parallel to the direction of gravity.

Here, when the vapor deposition mask 30 is constituted by a plurality of sub-masks 30a, it is desirable that the pillar ribs 54a are formed corresponding to the bonding spots 32 of the respective sub-masks 30a. This is because the tensile force that the mask frame 50 receives from each sub-mask 30a becomes larger at the joining spot 32 of each sub-mask 30a. By forming the columnar ribs 54a corresponding to the respective bonding spots 32 of the sub-masks 30a, the mask frame 50 can efficiently increase its resistance to the tensile force from the respective sub-masks 30a.

FIG. 12 is a plan view showing the second configuration of the mask assembly of Modified Example 6, viewed from the joint surface side. As shown in FIG. 12, in Modification 6, the deposition mask 30 is composed of a plurality of sub-masks 30a. Each of the sub-masks 30a has an opening 31 and forms a deposition mask. In the second configuration, the sub-masks 30a are joined to the mask frame 50 at the joining spots 32 so that each sub-mask 30a has a long side in a direction perpendicular to the direction of gravity.

Here, in the second configuration, it is desirable that the columnar ribs 54a be formed corresponding to the boundaries 30b of each sub-mask 30a. This is because the tensile force that the mask frame 50 receives from each sub-mask 30a becomes larger at the boundary 30b of each sub-mask 30a. In other words, at the boundary 30b of the sub-mask 30a, the material is continuous in the long side direction of the sub-mask 30a to the opposite side of the frame body, so that a tensile force is easily applied thereto. By forming the pillar ribs 54a to correspond to the boundaries 30b of the sub-masks 30a, the mask frame 50 can efficiently increase its resistance to the tensile force from each sub-mask 30a.

In this manner, in Modification 6, even when the vapor deposition mask 30 is composed of a plurality of sub-masks 30a, a mask frame that is unlikely to be deformed due to the tensile force from each sub-mask can be provided.

2.7 Modification 7
In the embodiment described above, the columnar rib 54a and the bracing rib 54b are formed in the recess 54. The configuration of the ribs formed in the recess 54 may be changed as appropriate.

FIG. 13 is a plan view showing the first configuration of the mask assembly of Modification Example 7, viewed from the joint surface side. In the first configuration, the recess 54 is formed with a beam rib 54e as a third rib in addition to the pillar rib 54a and the brace rib 54b. The beam rib 54e is a rib formed to be orthogonal to the column rib 54a. By forming the beam ribs 54e, the mask frame 50 can obtain stronger resistance against the tensile force from the vapor deposition mask 30. In FIG. 13, beam ribs 54e are formed only in the upper part of the frame body 51. The beam ribs 54e may be formed on the bottom and side surfaces of the frame body 51.

FIG. 14 is a plan view showing the second configuration of the mask assembly of Modification Example 7, viewed from the joint surface side. In the second configuration, in addition to the columnar rib 54a and the bracing rib 54b, a bracing rib 54f as a fourth rib intersecting the bracing rib 54b is formed in the recess 54. Formation of the bracing ribs 54f also allows the mask frame 50 to obtain stronger resistance to the tensile force from the vapor deposition mask 30. In FIG. 14, the bracing ribs 54f are formed only in the upper part of the frame body 51. The bracing ribs 54f may be formed on the bottom and side surfaces of the frame body 51.

As shown in Modification 7, the structure of the rib formed in the recess 54 can be modified in various ways. In other words, the rib structure has a high degree of freedom.

3. Other Modifications In the embodiments and modifications described above, it is assumed that the frame body 51 is integrally molded. However, the frame body 51 may be formed by combining a plurality of frame materials. For example, the frame body 51 may be formed by combining an upper frame material that constitutes the upper part of the frame body 51, a lower frame material that constitutes the lower part, and a side frame material that constitutes the side surface. In this case, the recesses containing the rib structure may be formed individually for each frame member.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention at the implementation stage. Moreover, each embodiment may be implemented in combination as appropriate, and in that case, a combined effect can be obtained. Furthermore, the embodiments described above include various inventions, and various inventions can be extracted by combinations selected from the plurality of constituent features disclosed. For example, if a problem can be solved and an effect can be obtained even if some constituent features are deleted from all the constituent features shown in the embodiment, the configuration from which these constituent features are deleted can be extracted as an invention.

DESCRIPTION OF SYMBOLS 10... Mask assembly, 30... Vapor deposition mask, 30a... Submask, 31... Opening, 32... Welding spot, 50... Mask frame, 51... Frame body, 52... Supporting hole, 53... Inclined surface, 54... Recess, 54a... Column rib, 54b... Bracing rib, 54d... Antifouling plate, 54e... Beam rib, 54f... Bracing rib, 55... Reinforcing member, 70... Vapor deposition source, 71... Steam.

Claims (9)

comprising a frame body configured to hold a deposition mask;
A recess is provided in at least a portion of the frame main body,
The recess includes a first rib extending in the width direction of the frame body parallel to the first surface on which the vapor deposition mask is held, and a second rib extending diagonally from the first rib. is formed,
Mask frame for vapor deposition masks. The recess is formed on the first surface side of the frame main body.
The mask frame according to claim 1. The recess is formed on a second surface of the frame body opposite to the first surface.
The mask frame according to claim 1. The frame body has a rectangular shape,
A first side of the frame body and a second side parallel to the first side have different lengths in the width direction,
The mask frame according to claim 1. The frame body has a rectangular shape,
A first side of the frame body and a second side parallel to the first side have different thicknesses,
The mask frame according to claim 1. The frame body is configured to hold a plurality of sub-masks,
the first rib is formed corresponding to a boundary between the plurality of sub-masks;
The mask frame according to claim 1. The frame body is formed of a low expansion Fe-Ni alloy or a low expansion high Ni cast iron,
The mask frame according to claim 1. The mask frame according to any one of claims 1 to 7,
a vapor deposition mask fixed to the mask frame and having an opening corresponding to a vapor deposition pattern;
Equipped with
mask assembly. forming the vapor deposition pattern on a substrate to be vapor-deposited using the mask assembly according to claim 8;
Vapor deposition method.