Mask assembly

Abstract

A mask assembly is provided. The mask assembly may include a frame, a mask sheet, and an auxiliary rod. The mask sheet may include a sheet frame and a protrusion protruding from the sheet frame. The sheet frame may have inner surfaces defining an opening of the sheet frame, and the protrusion may protrude toward the opening from one of the inner surfaces of the sheet frame extending in the first direction in a second direction intersecting the first direction. The mask sheet may include a shank recess extending from the sheet frame to the protrusion in the second direction. The auxiliary rod can be arranged in the rod seat groove. A plurality of auxiliary rods may be provided, and the plurality of auxiliary rods may be arranged such that the plurality of auxiliary rods are spaced apart from each other in the first direction.

Description

[0001] This application claims priority to and all benefits derived therefrom of Korean Patent Application No. 10-2024-0090984, filed on July 10, 2024, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This disclosure relates to a mask assembly and a method of manufacturing the mask assembly, and more specifically, to a mask assembly having improved deposition accuracy and reliability, and a method of manufacturing the mask assembly. Background Technology

[0003] Displays can be manufactured using various processes, including deposition processes. In deposition processes used to manufacture displays, mask assemblies that are tightly attached to the substrate can be used.

[0004] A mask assembly can be used in the deposition process to form a pattern on a substrate, and the mask assembly includes an opening on the substrate that defines a deposition area.

[0005] Mask assemblies can be manufactured with small thicknesses to prevent shading, and therefore, there has been research on improving the deposition accuracy and reliability of mask assemblies. Summary of the Invention

[0006] This disclosure provides a mask assembly for deposition processes that improves deposition accuracy and reliability.

[0007] This disclosure also provides a method for manufacturing a mask assembly for deposition processes that has improved deposition accuracy and reliability.

[0008] A mask assembly according to embodiments of the present disclosure may include a frame, a mask sheet, and an auxiliary rod. The mask sheet may include a sheet frame coupled to the frame and a protrusion projecting from the sheet frame. The sheet frame may include an inner surface defining an opening in the sheet frame. The protrusion may project toward the opening from one of the inner surfaces of the sheet frame extending in the first direction in a second direction intersecting the first direction.

[0009] The mask sheet may be provided with a rod seat groove extending from the sheet frame to the protrusion in a second direction.

[0010] The auxiliary rod can be attached to the mask sheet and is set in the rod seat groove.

[0011] According to embodiments of this disclosure, the sheet frame and the groove can have an integral shape.

[0012] According to embodiments of this disclosure, multiple auxiliary rods may be provided, and the multiple auxiliary rods may be arranged such that the multiple auxiliary rods are spaced apart from each other in a first direction.

[0013] According to embodiments of this disclosure, the height of the auxiliary rod in the third direction may be less than or equal to the depth of the rod seat groove in the third direction, and the third direction intersects with the first direction and the second direction.

[0014] According to embodiments of this disclosure, in a third-party orientation, the thickness of the sheet frame and the thickness of the protrusion can be equal.

[0015] According to an embodiment of the present disclosure, in the second direction, the length of the rod seat groove may be less than the length from the end of the protrusion adjacent to the opening in the second direction to the outer surface of the end of the sheet frame facing the protrusion.

[0016] According to embodiments of this disclosure, in a plan view, the auxiliary rod may be stacked with the protrusion and the plate frame, and the length of the auxiliary rod in the second direction may be less than or equal to the length of the rod seat groove in the second direction.

[0017] According to an embodiment of the present disclosure, the end of the auxiliary rod facing the opening in the second direction may be spaced apart from the end of the protrusion in the second direction, and the other end of the auxiliary rod may be spaced apart from the outer surface of the end of the sheet frame opposite to the protrusion.

[0018] According to embodiments of the present disclosure, the mask sheet may include a first surface adjacent to the target substrate and a second surface opposite to the first surface, and a rod seat groove may be disposed on the first surface of the mask sheet.

[0019] According to embodiments of this disclosure, the sheet frame and auxiliary rod may include Invar alloy 36.

[0020] According to embodiments of this disclosure, the bottom surface of the auxiliary rod can be tilted at a predetermined angle relative to the bottom surface of the rod seat groove.

[0021] According to embodiments of this disclosure, the predetermined angle can be 5° or greater.

[0022] According to embodiments of this disclosure, the rod seat groove can be provided in multiple locations, and the auxiliary rod can have an H-beam shape extending in a second direction.

[0023] According to embodiments of this disclosure, the protrusion may include: a first region, which overlaps with the auxiliary rod in a plane perpendicular to a second direction and has a width equal to the width of the auxiliary rod in the first direction; and a second region, which does not overlap with the first region, wherein the second region has a width equal to the width of the first region in the plane and has an area equal to that of the first region.

[0024] The moment of inertia of the first region relative to the first direction can be greater than or equal to the moment of inertia of the second region relative to the first direction.

[0025] A method for manufacturing a mask assembly according to embodiments of the present disclosure may include the following steps: providing a mask sheet including a sheet frame and a protrusion, the sheet frame having an inner surface defining an opening of the sheet frame, the protrusion projecting toward the opening from an inner surface of the inner surface of the sheet frame extending in the first direction in a second direction intersecting a first direction; forming a rod seat groove on the mask sheet, the rod seat groove extending from the sheet frame to the protrusion in the second direction; and disposing an auxiliary rod within the rod seat groove.

[0026] According to embodiments of the present disclosure, the step of setting the auxiliary rod may include: aligning the central axis of the original rod extending in a second direction with the central axis of the rod seat groove extending in the second direction on the protrusion; stretching the original rod in the second direction; and welding the stretched original rod to the rod seat groove.

[0027] According to embodiments of this disclosure, the step of forming a rod holder groove may include forming a rod holder groove on a first surface of a mask sheet.

[0028] The step of welding the stretched original rod is performed from the second surface upward toward the first surface, and the second surface faces away from the first surface of the mask in which the rod seat groove is formed.

[0029] According to embodiments of the present disclosure, a method for manufacturing a mask assembly may further include the step of removing the portion of the stretched original rod that does not overlap with the rod seat groove in a plan view.

[0030] A mask assembly according to embodiments of the present disclosure may include a frame, a mask sheet attached to the frame, and an auxiliary rod attached to the mask sheet.

[0031] The mask may include a first flange, a second flange, a connecting portion, and a protrusion.

[0032] A first stop edge may extend in a first direction, and a second stop edge may extend in the first direction and may be spaced apart from the first stop edge in the first direction. A connecting portion may be connected to the first stop edge and the second stop edge. A protrusion may connect between the first stop edge and the second stop edge in the first direction, may protrude relative to the first stop edge and the second stop edge in a second direction intersecting the first direction, and may include a rod seat groove extending in the second direction. An auxiliary rod may be disposed within the rod seat groove.

[0033] According to embodiments of this disclosure, the first stop, the second stop, the connecting portion, and the protrusion may have an integral shape, and the thicknesses of the first stop, the second stop, the connecting portion, and the protrusion may be equal to each other.

[0034] According to embodiments of the present disclosure, an auxiliary rod included in the mask sheet can mitigate the deflection of the protrusion, thereby providing a mask assembly with improved deposition accuracy and reliability, as well as a method for manufacturing such a mask assembly. Attached Figure Description

[0035] These and / or other features will become apparent and more readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 This is an exploded perspective view of a mask assembly according to an embodiment of the present disclosure; Figure 2 This is a perspective view of a mask assembly according to an embodiment of the present disclosure; Figure 3 This is a cross-sectional view of a deposition apparatus according to an embodiment of the present disclosure; Figure 4 This is a plan view of a mask sheet according to an embodiment of the present disclosure; Figure 5 yes Figure 4 An enlarged view of region AA shown in the image; Figure 6 It is along Figure 4 A sectional view of a portion of the line A-A' and a portion of the sheet frame; Figure 7 This is a cross-sectional view of a protrusion according to an embodiment of the present disclosure; Figure 8 It is along Figure 5 A sectional view taken by line B-B'; Figure 9 This is a partial perspective view of the protrusions and sheet frame according to an embodiment of the present disclosure; Figure 10 It is along Figure 9 A sectional view taken by line C-C'; Figure 11 This is a partial cross-sectional view of the protrusions and sheet frame according to an embodiment of the present disclosure; Figure 12 This is a partial perspective view of a protrusion according to an embodiment of the present disclosure; Figure 13 It is along Figure 12 A sectional view taken by line D-D'; Figures 14A to 14F This is a perspective view illustrating a method of manufacturing a mask assembly according to an embodiment of the present disclosure; and Figures 15A to 15D This is a cross-sectional view illustrating how the auxiliary rod is configured according to an embodiment of the present disclosure. Detailed Implementation

[0036] Referring now to certain embodiments, examples of which are illustrated in the accompanying drawings, in which the same reference numerals consistently refer to the same elements. Embodiments may have various forms and arrangements, but this disclosure should in no way be construed as limited to the described embodiments. Rather, this disclosure should be construed as covering all forms, arrangements, equivalents, and alternatives that are covered by the technical concept and scope of this disclosure. Therefore, embodiments are described herein with reference to the accompanying drawings to explain the features of this disclosure.

[0037] When an element is described as being “set on”, “placed on”, “arranged on”, “connected to”, or “joined to” another element, the element should be interpreted as being directly set on, placed on, arranged on, connected to, or joined to the other element, but it is also possible that another element is present therein. In some respects, if an element is described as being “directly set on”, “placed on”, “arranged on”, “connected to”, or “joined to” another element, this should be interpreted as no other element being placed therein.

[0038] The same or identical reference numerals refer to the same or identical elements. Furthermore, in the drawings, the thickness, ratios, and dimensions of elements may not be precise proportions and may be exaggerated for the purpose of effectively explaining the advantages of the technical features associated with these elements. Therefore, this disclosure should not be limited to the thicknesses, ratios, dimensions, etc., shown in the drawings.

[0039] Terms such as “first” and “second” may be used when describing various elements, but the elements described above should not be limited to these terms. These terms may be used to distinguish one element from others. For example, without departing from the scope of the claims of this disclosure, a first element may be named a second element, and vice versa. Unless expressly used otherwise, any singular expression may include the meaning of the plural form. The term “and / or” should include a combination of or any one of the listed items.

[0040] Furthermore, relative terms such as "below," "under," "below," "down," "bottom," "above," "above," "upper," "top," etc., are used herein to describe the relationship between one element and another as shown in the accompanying drawings. It should be understood that, in addition to the orientations depicted in the drawings, relative terms are intended to encompass different orientations of the device. For example, if the device in one of the drawings is flipped, an element described as being "below" the other element will subsequently be oriented "above" the other element. Thus, the example term "below" can encompass both "below" and "upper" orientations depending on the specific orientation of the drawing. Similarly, if the device in one of the drawings is flipped, an element described as being "below" or "below" the other element will subsequently be oriented "above" the other element. Thus, the example terms "below" or "below" can encompass both "above" and "below."

[0041] Expressions such as “comprising” or “including” are intended to specify a feature, quantity, step, operation, element, component or combination thereof, and should not be construed as excluding any possibility of the presence or addition of one or more other features, quantities, steps, operations, elements, components or combinations thereof.

[0042] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Any term defined in a common dictionary shall be interpreted as having the same meaning in the context of the relevant field, and, unless expressly defined otherwise, shall not be interpreted as having an idealized or overly formal meaning.

[0043] In this specification, if any embodiment can be implemented differently, the specified process sequence may be performed differently than the described sequence. For example, two processes described as being performed sequentially may be performed simultaneously or in reverse order.

[0044] In the following, certain embodiments of the mask assembly according to the present disclosure will be described in detail with reference to the accompanying drawings. In describing embodiments of the present disclosure with reference to the accompanying drawings, any identical or corresponding elements will be given the same reference numerals and will not be described repeatedly.

[0045] Figure 1 This is an exploded perspective view of a mask assembly according to an embodiment of the present disclosure. Figure 2 This is a perspective view of a mask assembly according to an embodiment of the present disclosure. Figure 3 This is a cross-sectional view of a deposition apparatus according to an embodiment of the present disclosure.

[0046] Reference Figures 1 to 3The mask assembly MA may include a mask sheet MS, a frame FR, and an auxiliary rod AS. The mask assembly MA is an open mask used in the deposition process and may have a shape corresponding to the cell unit pattern of the target substrate. In embodiments of this disclosure, the mask assembly MA may additionally include an additional mask FM on the mask sheet MS corresponding to the pixel pattern. The additional mask FM may have a shape corresponding to the pixel unit pattern of the target substrate. However, the construction in this disclosed embodiment is not limited to this, and the mask sheet MS may directly face the target substrate for the deposition process.

[0047] The mask sheet MS may include a sheet frame SF, a protrusion PT, and a rod holder groove GR. The mask sheet MS may be provided with an opening OP that defines a unit-unit deposition area. The mask sheet MS may be mounted on a frame FR, and the frame FR may be mounted on a stage ST of the deposition apparatus ED to secure the mask assembly MA to the deposition apparatus ED.

[0048] The sheet frame SF can be disposed on and directly coupled to the frame FR. In an embodiment, the sheet frame SF may have a coupling groove (not shown) defined for coupling with the frame FR.

[0049] The sheet frame SF, together with the protrusion PT, defines an opening OP corresponding to a single unit region formed on the target deposition substrate, and may include Invar alloy 36. Furthermore, the sheet frame SF may be combined with the protrusion PT and, together with the protrusion PT, have a shape surrounding the opening OP.

[0050] The protrusion PT can extend from the inner surface of the sheet frame SF in the first direction DR1 and can protrude in the second direction DR2.

[0051] A rod holder recess GR can be provided within a mask sheet MS. For example, embodiments of this disclosure include forming a rod holder recess GR within a mask sheet MS. The rod holder recess GR can extend from the sheet frame SF to the protrusion PT in a second direction DR2. The rod holder recess GR can provide space configured to accommodate an auxiliary rod AS, which will be described later.

[0052] The frame FR can be integrated with the mask sheet MS and provides a frame for mounting the mask assembly MA onto the deposition apparatus ED. The mask sheet MS can be stretched in four directions to prevent sagging and then integrated with the frame FR. The four directions can be a first direction DR1, a direction opposite to the first direction DR1, a second direction DR2, and a direction opposite to the second direction DR2. The frame FR can be formed of a material with small deformation, such as a high-rigidity metal (e.g., a material with relatively high tolerance to deformation).

[0053] The auxiliary rod AS can be combined with the mask sheet MS and is set in the rod seat groove GR.

[0054] The mask sheet MS, frame FR, and auxiliary rod AS will be described in more detail later.

[0055] Reference Figure 3 The deposition apparatus ED according to the embodiments may include a chamber CB, a deposition source EP, a stage ST, a mask assembly MA, and a fixing member PP.

[0056] The chamber CB provides internal space for performing deposition processes. The internal space of the chamber CB can accommodate a deposition source EP, a stage ST, a mask assembly MA, an additional mask FM, and a fixing member PP. The chamber CB provides a sealed space, and its interior can be under vacuum. The chamber CB may be equipped with at least one door (not shown), and the chamber CB can be opened and closed through the door (not shown). The mask assembly MA, the additional mask FM, and the substrate SS can enter and exit through the door (not shown).

[0057] The chamber CB may include a bottom surface BP, a top surface (not shown) facing the bottom surface BP, and sidewalls (not shown). The bottom surface BP of the chamber CB may be parallel to a plane intersecting a first direction DR1 and a second direction DR2, and the normal direction of the bottom surface BP may be parallel to a third direction DR3.

[0058] The fixing member PP can be disposed on the top surface (not shown) of the chamber CB and can face the deposition source EP on the third-direction DR3. The fixing member PP can be configured to bring the substrate SS into close contact with the mask assembly MA. The fixing member PP can include a magnetic material for bringing the mask assembly MA and the substrate SS into close contact. For example, the magnetic material can be configured to generate a magnetic force to fix the mask assembly MA, and the substrate SS placed between the mask assembly MA and the fixing member PP can be in close contact with the mask assembly MA. However, this disclosure is not limited to the above configuration, and the fixing member PP can be a clamp or robotic arm configured to hold the mask assembly MA.

[0059] The substrate SS can be positioned between the mask assembly MA and the fixing member PP. The substrate SS can be a workpiece on which a deposited material is deposited. The substrate SS may include a supporting substrate and a synthetic resin layer disposed on the supporting substrate.

[0060] The deposition source EP can be disposed on the bottom surface BP of the chamber CB and can face the fixing member PP on the third direction DR3. The deposition source EP may include a storage space therein containing the deposited material EM and at least one nozzle NZ. The deposited material EM may include inorganic, metallic, or organic materials capable of sublimation or vaporization. For example, the deposited material EM may include an organic light-emitting material for forming a light-emitting pattern. The sublimated or vaporized deposited material EM can be ejected towards the substrate SS through the nozzle NZ. The deposited material EM can be patterned by passing through the opening OP of the mask assembly MA and depositing on the substrate SS.

[0061] The stage ST can be positioned between the deposition source EP and the fixing member PP. The stage ST can support the rear surface of the frame FR and can be positioned in the path of the deposition material EM supplied from the deposition source EP as it moves to the substrate SS. The stage ST may include stage holes. The deposition material EM can be supplied to the mask assembly MA through the stage holes. The stage ST may have a mating groove defined at a corner of the stage ST to support the stage ST and secure it to the mating member. The stage ST can be bolted to the mating member through the mating groove.

[0062] A mask assembly MA can be positioned between a stage ST and a substrate SS. The mask assembly MA may include a frame FR, a mask sheet MS, and an auxiliary rod AS. The mask assembly MA may have a pattern corresponding to the deposition area of ​​the substrate SS. In an embodiment, the mask assembly MA may further include an additional mask FM.

[0063] The frame FR can be disposed on the stage ST, i.e., positioned between the mask sheet MS and the stage ST. The frame FR can bond the mask sheet MS to it and can support the mask sheet MS. In an embodiment, the frame FR can bond an additional mask FM to the mask sheet MS.

[0064] The frame FR may include a top surface facing the mask MS, a rear surface facing away from the top surface and towards the stage ST, and a side surface connecting the top surface and the rear surface. The frame FR may be configured as a rectangular frame. Therefore, the frame FR may include frame holes stacked with the stage holes. The deposited material EM can be supplied to the mask MS through the frame holes.

[0065] The frame FR can have a predetermined stiffness. For example, the frame FR can include metals such as stainless steel (SUS), Invar alloy, nickel (Ni) and / or cobalt (Co).

[0066] A mask sheet (MS) can be placed between the substrate (SS) and the frame (FR). The mask sheet (MS) may include an opening (OP) defining a cell-unit deposition area. The deposited material (EM) can be supplied to the substrate (SS) through the opening (OP).

[0067] The mask sheet MS can be bonded to the frame FR. For example, the mask sheet MS can be bonded to the frame FR by a welding process. In this case, one end and the other end of the mask sheet MS can be placed on the frame FR, and a welding process is performed on said one end and said other end of the mask sheet MS to bond the mask sheet MS to the frame FR.

[0068] The auxiliary rod AS can be attached to the mask sheet MS and is positioned within the rod holder groove GR. The auxiliary rod AS will be described in more detail later.

[0069] In one embodiment, an additional mask FM may be placed between the mask sheet MS and the substrate SS. The additional mask FM may include pixel openings defining pixel unit deposition areas. The additional mask FM may be attached to the frame FR together with the mask sheet MS on the mask sheet MS.

[0070] Figure 4 This is a plan view of a mask sheet according to an embodiment of the present disclosure. Figure 5 yes Figure 4 The image shows an enlarged view of region AA.

[0071] Reference Figure 4 and Figure 5 The mask sheet MS may include a sheet frame SF and a protrusion PT.

[0072] The mask sheet MS may have openings OP. The openings OP may include a first opening OP1, a second opening OP2, and a third opening OP3. The openings OP may be areas defined by a sheet frame SF and a protrusion PT. The openings OP may have a shape surrounded by the sheet frame SF and the protrusion PT.

[0073] In the embodiments, the shape of the opening OP can be set differently. The opening OP is not limited to shapes such as triangles, squares, ellipses and circles, but can have a shape corresponding to the deposition area of ​​the target substrate.

[0074] The sheet frame SF can form the periphery of the mask sheet MS. In some aspects, the sheet frame SF can distinguish the opening OP. The sheet frame SF may include a protrusion PT extending thereon and defining the inner surface of the opening OP.

[0075] In an embodiment, the sheet frame SF may include elements attached to the frame FR (see...). Figure 2 The connecting parts (not shown). For example, a connecting part (not shown) with a protruding shape can be arranged on the periphery of the sheet frame SF, and the frame FR can include a structure corresponding to the protruding shape, so that the sheet frame SF and the frame FR can be stably connected to each other.

[0076] In the following text, since all the protrusions PT are identical or substantially identical to each other, and all the openings OP are also identical or substantially identical to each other, the first protrusion PT1 and the first opening OP1 will be described primarily, without redundant description of the other protrusions and openings. As used herein, the term "substantially" means approximately or actually. The term "substantially identical" means approximately or actually the same. The term "substantially the same" means approximately or actually the same.

[0077] The sheet frame SF may include an inner surface 100. The inner surface 100 may include a first inner surface 101, a second inner surface 102, a third inner surface 103, and a fourth inner surface 104. The first inner surface 101 and the second inner surface 102 may extend in a first direction DR1, and the third inner surface 103 and the fourth inner surface 104 may each be connected between the first inner surface 101 and the second inner surface 102, and may extend in a second direction DR2.

[0078] A first protrusion PT1 may extend from a first inner surface 101 of the sheet frame SF in a first direction DR1 and may protrude toward a first opening OP1 in a second direction DR2. In conjunction with the inner surface 100 of the sheet frame SF, the first protrusion PT1 may form the first opening OP1. In this embodiment, the first protrusion PT1 is shown and described as an example extending from the first inner surface 101.

[0079] In this embodiment, the first protrusion PT1 and the inner surface 100 of the sheet frame SF may together have a shape surrounding the first opening OP1. However, this embodiment is not limited to this configuration and shape. For example, the protrusion may extend from a third inner surface 103 or a fourth inner surface 104 of the inner surface 100 of the sheet frame SF in the second direction DR2, and protrude toward the first opening OP1 in the first direction DR1. That is, the protrusion may extend from one side of the inner surface 100 of the sheet frame SF surrounding the first opening OP1 and protrude toward the first opening OP1.

[0080] Despite Figure 4 The diagram shows a mask sheet MS including a first protrusion PT1 to a third protrusion PT3 and having a first opening OP1 to a third opening OP3, but embodiments of this disclosure are not limited to the illustrated configuration. In embodiments, for example, the mask sheet MS may include at least one protrusion and at least one opening.

[0081] The rod seat groove GR can be disposed within the first protrusion PT1 and the plate frame SF. The rod seat groove GR can extend from the plate frame SF to the first protrusion PT1 in the second direction DR2. The rod seat groove GR can provide space in which the auxiliary rod AS, which will be described later, is disposed.

[0082] Reference Figure 2 andFigure 4 The mask sheet MS may include a second surface F2 adjacent to the frame FR and a first surface F1 facing the second surface F2 (i.e., adjacent to the substrate SS). In an embodiment, a rod holder groove GR may be provided on the first surface F1 of the mask sheet MS.

[0083] Although Figure 4 The diagram shows multiple rod seat grooves GR, but embodiments of this disclosure are not limited to the shown configuration, and at least one rod seat groove GR may be provided.

[0084] In this embodiment, the rod seat groove GR can be configured in various shapes. For example, the rod seat groove GR can have an X or Y shape on a plane. Furthermore, multiple rod seat grooves GR can have different lengths in the second direction DR2.

[0085] In an embodiment, the mask assembly MA may include a frame FR, a mask sheet MS, and an auxiliary rod AS coupled to the mask sheet MS. The mask sheet MS may include a first stop RB1, a second stop RB2, a connecting portion, and a protrusion PT having a rod seat groove GR arranged in a first direction DR1. The first stop RB1 may extend in the first direction DR1, and the second stop RB2 may be spaced apart from the first stop RB1 in the first direction DR1 and may also extend in the first direction DR1. The first stop RB1 and the second stop RB2 may be connected by the connecting portion. The protrusion PT may be connected to the first stop RB1 and the second stop RB2 and may protrude in the second direction DR2 relative to the first stop RB1 and the second stop RB2. The auxiliary rod AS may be disposed within the rod seat groove GR.

[0086] In this embodiment, the sheet frame SF and the protrusion PT can have an integral shape. For example, the sheet frame SF and the protrusion PT can be formed integrally.

[0087] In this embodiment, the first stop RB1, the second stop RB2, the connecting portion, and the protrusion PT may have an integral shape. For example, the first stop RB1, the second stop RB2, the connecting portion, and the protrusion PT may be integrally formed. The first stop RB1, the second stop RB2, the connecting portion, and the protrusion PT may have the same thickness. For example, the respective thicknesses of the first stop RB1, the second stop RB2, the connecting portion, and the protrusion PT may be equal to each other.

[0088] Reference Figure 5In an embodiment, in the second direction DR2, the length GRD of the rod holder groove GR can be less than the length PFD from the end PT-E of the first protrusion PT1 adjacent to the first opening OP1 in the second direction DR2 to the outer surface SF-E of the end PT-E of the sheet frame SF facing the first protrusion PT1. That is, the length GRD of the rod holder groove GR in the second direction DR2 can be smaller than the sum of the width FD of the sheet frame SF in the second direction DR2 and the width PD of the first protrusion PT1 in the second direction DR2. In some aspects, the rod holder groove GR can be configured to be spaced apart from the end PT-E of the first protrusion PT1 and the outer surface SF-E of the sheet frame SF by a predetermined distance SD. Therefore, in the plane, the rod holder groove GR may not contact the inner surface 100 of the mask sheet MS, and during the deposition process, on the substrate SS (see Figure 3 No gaps are formed between the pattern of the mask sheet MS which is in close contact with the substrate SS, thus enabling stable deposition on the substrate SS.

[0089] Reference Figure 4 and Figure 5 The auxiliary rods AS can be respectively set in the rod holder grooves GR. The auxiliary rods AS can be respectively coupled to the rod holder grooves GR, which each have a space for accommodating the auxiliary rods AS. The auxiliary rods AS can be coupled to the rod holder grooves GR provided in the mask sheet MS to reduce the sagging of the protrusion PT.

[0090] In this embodiment, the auxiliary rod AS can be stacked with the first protrusion PT1 and the sheet frame SF in a plan view. That is, the auxiliary rod AS can extend from the sheet frame SF to the first protrusion PT1 in the second direction DR2.

[0091] In this embodiment, the length ASD of the auxiliary rod AS can be less than or equal to the length GRD of the rod seat groove GR. Therefore, the auxiliary rod AS can be placed in the rod seat groove GR.

[0092] In an embodiment, the end AS-E1 of the auxiliary rod AS facing the first opening OP1 in the second direction DR2 may be spaced apart from the end PT-E of the first protrusion PT1, and the other end AS-E2 of the auxiliary rod AS may be spaced apart from the outer surface SF-E of the sheet frame SF.

[0093] In an embodiment, the auxiliary rod AS may include Invar alloy 36.

[0094] Figure 6 It is along Figure 4 A sectional view of a portion of the line A-A' and a portion of the sheet frame. Figure 7 This is a cross-sectional view of a protrusion according to an embodiment of the present disclosure. Figure 8 It is along Figure 5The sectional view taken by line B-B'.

[0095] Reference Figure 6 In this embodiment, the height PH of the first protrusion PT1 on the third-direction DR3 can be equal to the height FH of the sheet frame SF on the third-direction DR3. That is, the mask sheet MS can have a uniform thickness overall. Therefore, when performing the deposition process, the top surface of the mask sheet MS can be uniformly attached to the substrate SS (see...). Figure 3 ).

[0096] Reference Figure 7 and Figure 8 In this embodiment, the height SH of the auxiliary rod AS in the third direction DR3 can be smaller than, or equal to, the depth GH of the rod holder groove GR in the third direction DR3. Therefore, the auxiliary rod AS disposed in the rod holder groove GR does not need to protrude from the top surface of the mask MS. In a comparative example, when the top surface of the auxiliary rod protrudes above the top surface of the mask, in a deposition process performed under vacuum, cracks may occur in the substrate due to the close contact between the auxiliary rod and the substrate.

[0097] Figure 9 This is a partial perspective view of the protrusions and sheet frame according to an embodiment of the present disclosure. Figure 10 It is along Figure 9 A sectional view taken by line C-C'.

[0098] Reference Figure 9 and Figure 10 According to embodiments of the present disclosure, a protrusion PT may have a first region A1 and a second region A2 defined therein.

[0099] The first region A1 can be stacked with the auxiliary rod AS on a plane perpendicular to the second direction DR2, and has a width equal to the width SCD of the auxiliary rod AS in the first direction DR1. The first region A1 can be stacked with the auxiliary rod AS on the aforementioned plane.

[0100] The second region A2 may not overlap with the first region A1 on the aforementioned plane, but may have the same width and area as the first region A1. On this plane, the first region A1 may be a region overlapping with the auxiliary rod AS, and the second region A2 may be a region between adjacent auxiliary rods AS with the same area as the first region A1.

[0101] In the comparative example, the mask assembly may not include auxiliary rods, and the mask sheet may include protrusions. Even if the mask sheet is subjected to tension in all four directions and attached to the frame, these forces may not be applied to the protrusions, or may apply relatively small tensions, causing the protrusions to sag. If the protrusions sag, a gap may form between the substrate and the mask assembly, causing the deposited material to clump together as icicle-like formations during the deposition process. In some aspects, as the protrusions sag, the sheet frame attached to the protrusions may be subjected to torque, resulting in twisting.

[0102] In embodiments of the present invention, the moment of inertia (or second moment of area) of the first region A1 relative to the first direction DR1 can be greater than or equal to the moment of inertia of the second region A2 relative to the first direction DR1. In other words, by integrating the auxiliary rod AS into the rod seat groove GR, the sag of the protrusion PT can be reduced, thereby improving deposition accuracy during deposition. Furthermore, with the reduction of the sag of the protrusion PT, the deformation of the sheet frame SF is smaller, which can improve the reliability of the mask assembly MA.

[0103] Figure 11 This is a partial cross-sectional view of the protrusions and sheet frame according to an embodiment of the present disclosure.

[0104] Reference Figure 11 In one embodiment, the bottom surface of the auxiliary rod AS-A may be inclined at a predetermined angle θ relative to the bottom surface of the rod seat groove GR. In some embodiments, the predetermined angle θ may be 5° or greater. Therefore, the moment of inertia of the first region A1 can be increased, and the sagging of the protrusion PT can be reduced.

[0105] Figure 12 This is a partial perspective view of a protrusion according to an embodiment of the present disclosure. Figure 13 It is along Figure 12 A sectional view taken along line D-D'. (Refer to...) Figure 12 and Figure 13 In one embodiment, the auxiliary rod AS-H may have an H-beam shape extending in the second direction DR2. Because the auxiliary rod AS-H has an H-beam shape, the rod seat groove GR-H may be shaped such that the rod seat groove GR-H can accommodate the auxiliary rod AS-H.

[0106] The H-beam shape can be designed to maximize the moment of inertia of the section about the extension central axis, providing excellent bending stiffness. The H-beam shape of the auxiliary rod AS-H can mitigate the sagging of the protrusion PT-H.

[0107] In the following text, reference will be made to Figures 14A to 15C A method for manufacturing a mask assembly according to embodiments of the present disclosure is described. (Refer to...) Figures 1 to 13Any element described will be identified with the same reference numerals and will not be described again.

[0108] In the description of the methods herein, operations may be performed in a different order than those shown and / or described, or in a different order or at different times. Certain operations may also be excluded from the method, one or more operations may be repeated, or additional operations may be added. Based on the example aspects described herein, the descriptions of elements "can be set," "can be formed," "can be aligned," etc., include methods, processes, and techniques for setting, forming, positioning, and modifying elements. Figures 14A to 14F This is a perspective view illustrating a method of manufacturing a mask assembly according to an embodiment of the present disclosure. Figures 15A to 15D This is a cross-sectional view illustrating how the auxiliary rod is set according to an embodiment of the present disclosure, and is along... Figure 14E A sectional view taken by line D-D'.

[0109] Reference Figures 14A to 14F A method for manufacturing a mask assembly MA may include: preparing a mask sheet; forming openings, protrusions, and rod holder grooves within the mask sheet; mounting the mask sheet onto a frame; and setting auxiliary rods in the rod holder grooves.

[0110] Reference Figures 14A to 14B In the step of preparing the mask sheet, the method may include preparing a raw mask sheet MS1. In the step of forming an opening, a protrusion, and a rod holder groove within the mask sheet, the method may include etching the prepared raw mask sheet MS1 to form the opening OP, the protrusion PT, and the rod holder groove GR.

[0111] The opening OP can be formed such that the opening OP is surrounded by the protrusion PT and the sheet frame SF connected to the protrusion PT.

[0112] The protrusion PT can be formed such that the protrusion PT protrudes toward the opening OP in the second direction DR2, and has a rod seat groove GR included therein.

[0113] Reference Figures 14B to 14D In the step of mounting the mask onto the frame, the method may include stretching the etched mask MS2 in both directions of the first direction DR1 (e.g., positive first direction DR1 and negative first direction DR1) and in both directions of the second direction DR2 (e.g., positive second direction DR2 and negative second direction DR2), and then mounting the stretched mask MS3 onto the frame FR. Figure 14D The frame FR and the stretched mask MS3 mounted on the frame FR are shown.

[0114] Reference Figure 14E and Figure 14FIn the step of setting the auxiliary rod in the rod holder groove, the method may include: aligning the original rod AS1; stretching the original rod AS1; and stretching the original rod AS2 (see...). Figure 15B It is welded into the groove GR of the rod seat.

[0115] Reference Figure 14E and Figure 15A In the step of aligning the original rod AS1, the method may include aligning the central axis of the original rod AS1 extending in the second direction DR2 and the central axis of the rod seat groove GR extending in the second direction DR2 with each other in the second direction DR2 (and / or the first direction DR1) on the protrusion PT.

[0116] Reference Figures 15A to 15C In the step of stretching the original rod AS1, the method may include stretching the original rod AS1 in both directions of the second direction DR2. Then, the method may include using a pressing clamp JG to push the stretched original rod AS2 into the rod seat groove GR, so that the original rod AS2 is tightly seated in the rod seat groove GR. Figure 15C The original rod AS3 is shown to be tightly seated within the rod seat groove GR.

[0117] In embodiments of this disclosure, the method for welding the stretched original rod AS2 into the rod holder groove GR may include performing the welding from the bottom side of the mask sheet MS. That is, for example, the method may include welding the stretched original rod AS2 to the bottom side of the mask sheet MS. Therefore, slag (not shown) may form within the rod holder groove GR during the welding process.

[0118] Reference Figures 15C to 15D The method of manufacturing a mask assembly according to an embodiment may further include removing portions of the stretched original rod AS3 that do not overlap with the rod seat groove GR in a plane, thereby forming an auxiliary rod AS. The terms "in a plane" and "in a planar view" may be used interchangeably herein.

[0119] The method of manufacturing a mask assembly according to embodiments of the present disclosure can mitigate the sagging of the protrusion PT by incorporating a stretched auxiliary rod AS into a rod seat groove GR.

[0120] While certain embodiments of this disclosure have been described herein, it will be understood by any person skilled in the art to which this disclosure pertains that various modifications and arrangements of this disclosure may be made without departing from the concept and scope of this disclosure as defined in the appended claims. Furthermore, it should be understood that the disclosed embodiments are not intended to limit this disclosure, and each concept within the appended claims and their equivalents is to be construed as being included within the scope of this disclosure.

Claims

1. A mask assembly, the mask assembly comprising: frame; A mask sheet includes a sheet frame and a protrusion, wherein the sheet frame is coupled to the frame, and the protrusion protrudes from the sheet frame; and An auxiliary rod is attached to the mask sheet. in: The sheet frame includes an inner surface that defines an opening in the sheet frame. The protrusion extends toward the opening from one of the inner surfaces of the sheet frame that extends in the first direction, in a second direction intersecting the first direction. The mask sheet includes a rod seat groove extending from the sheet frame to the protrusion in the second direction, and The auxiliary rod is disposed within the groove of the rod seat.

2. The mask assembly according to claim 1, wherein, The frame and the protrusion have an integral shape.

3. The mask assembly according to claim 1, wherein: The auxiliary rods are configured in multiple ways, and The plurality of auxiliary rods are arranged such that they are spaced apart from each other in the first direction.

4. The mask assembly according to claim 1, wherein, The height of the auxiliary rod in the third direction is less than or equal to the depth of the rod seat groove in the third direction, and the third direction intersects with the first direction and the second direction.

5. The mask assembly according to claim 1, wherein, In a third direction intersecting the first and second directions, the thickness of the sheet frame and the thickness of the protrusion are equal.

6. The mask assembly according to claim 1, wherein, In the second direction, the length of the rod seat groove is less than the length from the end of the protrusion adjacent to the opening in the second direction to the outer surface of the sheet frame facing the end of the protrusion.

7. The mask assembly according to claim 1, wherein: The auxiliary rod overlaps with the protrusion and the sheet frame on a plane, and The length of the auxiliary rod in the second direction is less than or equal to the length of the rod seat groove in the second direction.

8. The mask assembly according to claim 1, wherein: The mask includes a first surface and a second surface, the first surface being adjacent to the target substrate, and the second surface facing away from the first surface. The rod holder groove is disposed on the first surface of the mask sheet.

9. The mask assembly according to claim 1, wherein, The frame and the auxiliary rod comprise Invar 36 alloy.

10. The mask assembly according to claim 1, wherein, The protrusion includes: A first region, overlapping the auxiliary rod on a plane perpendicular to the second direction, and having a width equal to the width of the auxiliary rod in the first direction; and The second region, which does not overlap with the first region, has a width on the plane equal to the width of the first region and an area equal to that of the first region; and Wherein, the moment of inertia of the first region relative to the first direction is greater than or equal to the moment of inertia of the second region relative to the first direction.

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