Mask frame assembly

Abstract

A mask frame assembly is provided. The mask frame assembly includes: a platform provided with a seat portion having a top surface; a frame located on the seat portion and having a bottom surface in contact with the top surface of the seat portion; and a mask located on the frame. At least one of the top surface of the seat portion and the bottom surface of the frame is an uneven surface.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0149513, filed on November 28, 2018, in the Korean Intellectual Property Office, entitled “Mask Frame Assembly and Method for Manufacturing Mask Frame Assembly,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure herein relates to a mask frame assembly and a method for manufacturing the mask frame assembly. Background Art

[0003] Typically, in an organic light-emitting display device, an organic layer and / or an electrode is formed by a vacuum deposition method. As the resolution of an organic light-emitting display device is improved, the openings in a mask used in a deposition process for manufacturing an organic light-emitting display device are reduced in size and spacing therebetween.

[0004] During the deposition process, the mask may thermally expand and / or deform due to its own weight. As a result, a shadowing effect may occur. Summary of the invention

[0005] An embodiment provides a mask frame assembly, the mask frame assembly comprising: a platform having a seat portion with a top surface; a frame located on the seat portion and having a bottom surface contacting the top surface of the seat portion; and a mask located on the frame. At least one of the top surface of the seat portion and the bottom surface of the frame is an uneven surface.

[0006] In an embodiment, the non-planar surface may be a laser textured surface.

[0007] In an embodiment, the non-planar surface may be a plasma nitrided surface.

[0008] In an embodiment, the mask frame assembly may further include a rod portion between the frame and the mask.

[0009] In an embodiment, the rod portion may include a first rod extending in a first direction.

[0010] In an embodiment, the thermal deformation force of the first rod may be less than or equal to the friction force between the seat portion and the frame.

[0011] In an embodiment, the rod portion may further include a second rod extending in a second direction intersecting the first direction.

[0012] In an embodiment, the thermal deformation force of the second rod may be less than or equal to the friction force between the seat portion and the frame.

[0013] In an embodiment, a bottom surface of the frame may be parallel to a bottom surface of the mask.

[0014] In an embodiment, a static friction coefficient between the seat portion and the bottom surface of the frame may be 1 or greater. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Features will become apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the accompanying drawings, in which:

[0016] Figure 1 shows a perspective view of a mask frame assembly according to an embodiment;

[0017] Figure 2 shows an exploded perspective view of a mask frame assembly according to an embodiment;

[0018] Figure 3 shows a cross-sectional view of a mask frame assembly according to an embodiment;

[0019] Figure 4 It shows that according to the embodiment Figure 3 An enlarged cross-sectional view of area AA';

[0020] Figure 5 A flow chart of a method of manufacturing a mask frame assembly according to an embodiment is shown;

[0021] Figure 6 The formation according to the embodiment is shown Figure 5 A perspective view of the steps of the uneven bottom surface;

[0022] Figure 7 illustrates a cross-sectional view of a process of depositing a deposition layer on a substrate by using a mask frame assembly according to an embodiment;

[0023] Figure 8 illustrates a cross-sectional view of a process of depositing a deposition layer on a substrate by using a mask frame assembly according to an embodiment;

[0024] Fig. 9 illustrates a cross-sectional view of a process of depositing a deposition layer on a substrate by using a mask frame assembly according to an embodiment;

[0025] Fig.10 shows an exploded perspective view of a mask frame assembly according to an embodiment; and

[0026] Fig.11 A cross-sectional view of an organic light emitting display device including a light emitting layer deposited by using a mask frame assembly according to an embodiment is illustrated. DETAILED DESCRIPTION

[0027] In this specification, it will also be understood that when a component (or region, layer, part) is referred to as being "on", "connected to" or "coupled to" another component, the one component may be directly disposed on / connected to / coupled to the other component, or an intervening third component may also be present.

[0028] The same reference numerals refer to the same elements throughout. In addition, in the drawings, the thickness, proportion and size of components are exaggerated for clear illustration.

[0029] The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0030] It will be understood that although terms such as "first" and "second" are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one component from other components. For example, an element referred to as a first element in one embodiment may be referred to as a second element in another embodiment without departing from the scope of the appended claims. Unless otherwise indicated, terms in the singular may include plural forms.

[0031] In addition, “below,” “below,” “above,” and “on” etc. are used to explain the relative relationship of components shown in the drawings. Terms may be relative concepts and may be described based on directions expressed in the drawings.

[0032] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. In addition, terms such as those defined in general dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art, and are not to be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0033] The meaning of “include” or “comprising” indicates the existence of properties, fixed numbers, steps, operations, elements, components or a combination thereof, but does not exclude other properties, fixed numbers, steps, operations, elements, components or a combination thereof.

[0034] Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings.

[0035] Figure 1 is a perspective view of a mask frame assembly according to an embodiment, Figure 2 is an exploded perspective view of a mask frame assembly according to an embodiment. Figure 1 and Figure 2The mask frame assembly MFA may include a mask MK, a rod SK, a frame FR and a platform ST.

[0036] The mask MK may be manufactured using a thin plate. The mask MK may be made of various materials (eg, stainless steel, Invar, nickel (Ni), cobalt (Co), a nickel alloy, a nickel-cobalt alloy, etc.).

[0037] The mask MK may be parallel to a plane defined by the first direction DR1 and the second direction DR2. For example, the mask MK may have various shapes, such as a rectangular shape parallel to the first direction DR1 and the second direction DR2. The vertical direction of the mask MK may correspond to the thickness direction of the mask MK (hereinafter, referred to as the third direction DR3).

[0038] Directions as indicated by the first direction DR1, the second direction DR2, and the third direction DR3 may be relative. Hereinafter, the first direction, the second direction, and the third direction may be directions indicated by the first direction DR1, the second direction DR2, and the third direction DR3, respectively, and designated by the same reference numerals. In addition, in the present specification, a surface defined by the first direction DR1 and the second direction DR2 may be defined as a plane, and “when viewed from the plane” may be defined as viewed in the third direction DR3.

[0039] The pattern holes PH may be defined in the mask MK. Each of the pattern holes PH may provide a passage through which a deposition material passes. The pattern holes PH may expose a substrate CB on which deposition is to be performed (see FIG. Figure 7 ) area. The pattern hole PH may have substantially the same shape as a deposition pattern to be formed on a plane, or may have various shapes according to the characteristics of a deposition process to be performed through the pattern hole PH. For example, in the pattern hole PH, the mask pattern may have a single opening, or may have a strip shape. The pattern hole PH may be provided in plurality. A plurality of pattern holes PH may be formed in an array arranged in the first direction DR1 and the second direction DR2.

[0040] The stem SK may be located on the lower portion of the mask MK. The stem SK may be located on the lower portion of the mask MK to additionally support the mask MK. The stem SK may overlap the mask MK on a plane. The stem SK may not overlap the pattern hole PH on a plane.

[0041] The rod portion SK may include a first rod SK1 and a second rod SK2. The first rod SK1 may extend in the first direction DR1. The first rod SK1 may be located on the lower portion of the second rod SK2. A portion of the first rod SK1 may overlap with a portion of the second rod SK2 on a plane (e.g., along a third direction DR3). The first rod SK1 and the second rod SK2 may have various shapes, such as a cuboid. The first rod SK1 may include a rod groove SK1-1. The rod groove SK1-1 may be coupled to the second rod SK2. The rod groove SK1-1 may be coupled to the second rod SK2 by welding. The rod groove SK1-1 may be provided in plurality, and the plurality of rod grooves SK1-1 may be spaced apart from each other in the first direction DR1. The number of the rod grooves SK1-1 may correspond to the number of the second rod SK2. The rod groove SK1-1 has a depth equal to the height of the second rod SK2. When the first rod SK1 and the second rod SK2 are coupled to each other, the top surface of the rod portion SK (e.g., the surface facing the mask MK) is flat.

[0042] The second rod SK2 may extend in the second direction DR2. Each of the first rod SK1 and the second rod SK2 may have various lengths, for example, the first rod SK1 may extend in the first direction DR1 longer, shorter, or equal to the second rod SK2 extending in the second direction DR2. Each of the first rod SK1 and the second rod SK2 may be provided in plural.

[0043] The frame FR may be located below the mask MK to support the mask MK, for example, between the mask MK and the platform ST. A portion of the mask MK may overlap with a portion of the frame FR in a plane (for example, along a third direction DR3). The opening HA1 may be defined in the frame FR and may correspond to the shape of the mask MK while having a smaller area in a plane than the mask MK. The opening HA1 may provide a channel through which the deposition material passes. The frame FR may have various shapes, for example, a rectangular ring shape. The frame FR may be made of various metals or metal alloys (for example, Invar alloy and stainless steel, etc.) having a low coefficient of thermal expansion.

[0044] The frame FR may include a first frame portion FR1 and a second frame portion FR2 as one body. The first frame portion FR1 may extend in the second direction DR2. The second frame portion FR2 may extend in the first direction DR1. The first frame portion FR1 and the second frame portion FR2 may have various lengths, for example, the second frame portion FR2 may extend in the first direction DR1 longer, shorter, or equal to the first frame portion FR1 extending in the second direction DR2.

[0045] The first coupling groove FR-1 may be defined in the first frame portion FR1. The first rod SK1 may be in the first coupling groove FR-1. The first coupling groove FR-1 and the first rod SK1 may be fixed to each other, for example, welded to each other. A portion of the first rod SK1 may overlap with a portion of the first frame portion FR1 on a plane. The first coupling groove FR-1 may be provided in plurality spaced apart from each other in the second direction DR2. The number of the first coupling grooves FR-1 may correspond to the number of the first rods SK1.

[0046] The second coupling groove FR-2 may be defined in the second frame portion FR2. The second rod SK2 may be in the second coupling groove FR-2. The second coupling groove FR-2 and the second rod SK2 may be fixed to each other, for example, welded to each other. A portion of the second rod SK2 may overlap with a portion of the second frame portion FR2 on a plane. The second coupling groove FR-2 may be provided in a plurality of spaces apart from each other in the first direction DR1. The number of the second coupling grooves FR-2 may correspond to the number of the second rods SK2.

[0047] The first coupling groove FR-1 may have a depth greater than that of the second coupling groove FR-2, so that the upper surface of the rod portion SK is flat. The platform ST may be located below the frame FR, for example, between the frame FR and the substrate CB to be processed. The seat portion AN may be disposed on the platform ST. The frame FR may be located on the seat portion AN, for example, directly contacting the seat portion AN.

[0048] Figure 3 is a cross-sectional view of a mask frame assembly according to an embodiment. The same reference numerals may be used for Figure 1 and Figure 2 The components are the same as the components of the present invention, and their detailed description will be omitted.

[0049] Reference Figure 3 , the bottom surface BT of the frame FR may directly contact the top surface of the seat portion AN. The bottom surface BT may be parallel to the bottom surface of the mask MK. The bottom surface BT may include an uneven structure PT (see Figure 4 ). The friction force between the bottom surface BT and the platform ST may be increased due to the uneven structure PT. The static friction coefficient between the bottom surface BT and the top surface of the seat portion AN may be 1 or greater, for example, the friction force is stronger than the normal force. The first force F1 may be the friction force generated between the bottom surface BT and the top surface of the seat portion AN. The second force F2 may be the thermal deformation force of the rod SK and the mask MK. The first force F1 may be greater than or equal to the second force F2.

[0050] According to an embodiment, the first force F1 can control the second force F2, for example, the first force F1 is strong enough to offset the second force F2. Therefore, deformation of the rod SK due to thermal expansion can be prevented. Therefore, deformation of the mask MK on the rod SK can also be prevented. Therefore, the shadow effect caused by the deformation of the mask MK can be prevented from occurring. Therefore, the mask frame assembly MFA can be improved in reliability.

[0051] Figure 4 According to the embodiment Figure 3 The same reference numerals may be used for the enlarged cross-sectional view of the area AA'. Figures 1 to 3 The components are the same as the components of the present invention, and their detailed description will be omitted.

[0052] Reference Figure 3 and Figure 4 , the bottom surface BT may include an uneven structure PT. Alternatively or additionally, the top surface of the seat portion AN may include an uneven structure. Each of the top surface and the bottom surface BT of the seat portion AN having an uneven structure may be referred to as an uneven surface. The friction force between the bottom surface BT and the top surface of the seat portion AN is increased due to the uneven structure PT. The uneven structure PT may be sufficiently uneven so that the first force F1 between the bottom surface BT and the top surface of the seat portion AN offsets or constrains the second force F2 to prevent deformation.

[0053] The uneven structure PT may be formed by a laser surface texturing process. The bottom surface BT may be a strengthened surface. The strengthening process may be a plasma nitriding process. The friction between the bottom surface BT and the top surface of the seat portion AN may be increased by the strengthening process.

[0054] If the frame FR is uneven, the mask MK may be deformed in shape. However, according to the embodiment, by providing the uneven bottom surface BT, no separate member is used to increase the friction between the frame FR and the platform ST. Therefore, the frame FR remains flat, and the mask MK on the frame FR remains flat. Therefore, the shadow effect due to the deformation of the mask MK can be prevented.

[0055] Figure 5 is a flowchart illustrating a method of manufacturing a mask frame assembly according to an embodiment. Figure 6 is a diagram showing a method according to an embodiment of the present invention. Figure 5 The same reference numerals may be used for the process of forming an uneven bottom surface in FIG. Figures 1 to 4 For components that are identical to the components of the present invention, their detailed description will be omitted.

[0056] Reference Figure 5 and Figure 6 , used to manufacture the mask frame assembly MFA (see Figure 2) may include a frame preparation process (S100), a bottom surface unevenness forming process (S200), a bottom surface strengthening treatment process (S300), and a process of placing the frame on a platform (S400).

[0057] The frame preparation process (S100) may include providing a frame FR (see Figure 2 ).

[0058] The bottom surface unevenness forming process (S200) may be performed on the bottom surface BT (see Figure 4 ) to form an uneven structure PT (see Figure 4 ) process. The bottom surface unevenness forming process (S200) may include a process of irradiating a laser beam LZ onto the bottom surface BT. The laser beam LZ (see Figure 6 ) An uneven structure PT is formed on the bottom surface BT. The uneven structure PT may be formed at various portions of the bottom surface BT (e.g., at one side extending in the second direction DR2) as long as the first force F1 between the bottom surface BT and the top surface of the seat portion AN is sufficient to offset or constrain the second force F2 to prevent deformation. Alternatively or additionally, an uneven structure may be formed on the top surface of the seat portion AN of the platform ST.

[0059] The laser beam LZ may have a pulse wavelength of about 50 μm or less. For example, the laser beam LZ may have a pulse wavelength of about 15 μm to about 25 μm. The laser beam LZ may be irradiated onto the bottom surface BT to form an uneven structure PT (see Figure 4 The uneven structure PT can enhance the bottom surface BT and the platform ST (see Figure 4 ) between them.

[0060] The bottom surface strengthening treatment process (S300) may include a plasma nitriding treatment. The plasma nitriding treatment may be performed to harden the bottom surface BT, thereby increasing friction.

[0061] The process of placing the frame on the platform (S400) may include placing the frame FR on the platform ST (see Figure 3 ). For example, the process of placing the frame on the platform (S400) may include placing the frame FR on the platform ST (see Figure 3 ) on the top surface of the seat portion AN so that the bottom surface BT directly contacts the top surface of the seat portion AN.

[0062] Figure 7 is a cross-sectional view showing a process of depositing a deposition layer on a substrate by using a mask frame assembly according to an embodiment. The same reference numerals may be used for Figures 1 to 6 The components are the same as the components of the present invention, and their detailed description will be omitted.

[0063] Reference Figure 7 , the deposition source EV may be located below the mask frame assembly MFA. The substrate CB may be located above the mask MK. The deposition source EV may spray a deposition material toward the mask frame assembly MFA. The deposition material passing through the mask MK may be deposited on one surface of the substrate CB. The deposition material may be an organic light-emitting layer of an organic light-emitting display device. As the number of depositions using the deposition source EV increases, heat energy may be generated at the rod portion SK (see Figure 2 ) and the mask MK, thermal deformation may occur. For example, the rod SK and the mask MK may expand. The second force F2 represents the thermal deformation force. The first force F1 represents the friction force between the frame FR and the platform ST, that is, the friction force between the bottom surface BT and the top surface of the seat part AN.

[0064] According to the embodiment, the second force F2 can be offset by the first force F1. Therefore, the rod SK (see Figure 2 ) and the expansion of the mask MK. As a result, the deformation of the mask MK can be prevented, and thus the shadow effect can be prevented. Therefore, the mask frame assembly MFA (see Figure 2 ).

[0065] Figure 8 is a cross-sectional view showing a process of depositing a deposition layer on a substrate by using a mask frame assembly according to an embodiment. The same reference numerals may be used for Figures 1 to 7 The components are the same as the components of the present invention, and their detailed description will be omitted.

[0066] Reference Figure 8 The magnet MG may be located above the substrate CB so that the substrate CB is between the magnet MG and the mask MK. The magnet MG may prevent the mask MK from falling downward due to its own weight. The mask MK may be made of, for example, nickel and a nickel alloy, and may have a thin film having magnetism thereon.

[0067] Fig. 9 2 is a cross-sectional view showing a process of depositing a deposition layer on a substrate by using a mask frame assembly according to an embodiment. Fig. 9 , the spacer SC may be located between the mask MK and the substrate CB. The spacer SC may constantly maintain the distance between the mask MK and the substrate CB. The spacer SC may have various shapes, for example, a columnar shape.

[0068] Fig.10 is an exploded perspective view of a mask frame assembly according to an embodiment. The same reference numerals may be used for Figures 1 to 9 The components are the same as the components of the present invention, and their detailed description will be omitted.

[0069] Reference Fig.10, the mask frame assembly MFA' may include a mask MK, a rod SK', a frame FR', and a platform ST. The rod SK' may be located on a lower portion of the mask MK. The rod SK' may be located on a lower portion of the mask MK to additionally support the mask MK. The rod SK' may overlap with the mask MK on a plane. The rod SK' may not overlap with the pattern hole PH on a plane. As discussed above, the bottom surface of the frame FR' facing the platform ST may be an uneven surface.

[0070] The rod portion SK' may include a first rod SK1' and a second rod SK2'. The first rod SK1' may extend in a first direction DR1. The second rod SK2' may extend in a second direction DR2. The first rod SK1' and the second rod SK2' may have various shapes, for example, a cuboid. The first rod SK1' may be located on a lower portion of the second rod SK2'. A portion of the first rod SK1' may overlap a portion of the second rod SK2' on a plane.

[0071] Each of the first rod SK1' and the second rod SK2' may have various lengths. For example, the first rod SK1' may extend in the first direction DR1 longer, shorter, or equal to the second rod SK2' extending in the second direction DR2. Each of the first rod SK1' and the second rod SK2' may be provided in plural. The thickness of the first rod SK1' in the third direction DR3 and the thickness of the second rod SK2' in the third direction DR3 may be smaller than each of the thickness of the frame FR' in the third direction DR3 and the thickness of the mask MK in the third direction DR3.

[0072] The frame FR' may be located below the mask MK. The frame FR' may support the mask MK. A portion of the mask MK may overlap with a portion of the frame FR' in a plane. An opening HA1 may be defined in the frame FR'. The opening HA1 may provide a passage through which the deposition material passes. The frame FR' may have various shapes, for example, a rectangular ring shape. The frame FR' may be made of various metals or metal alloys having a low thermal expansion coefficient (for example, Invar alloy and stainless steel, etc.).

[0073] The frame FR' may include a first frame portion FR1' and a second frame portion FR2'. The first frame portion FR1' may extend in the second direction DR2. The second frame portion FR2' may extend in the first direction DR1. The second frame portion FR2' may extend in the first direction DR1 longer, shorter, or equal to the first frame portion FR1' in the second direction DR2.

[0074] The first frame portion FR1' may provide a flat top surface. The second frame portion FR2' may provide a flat top surface. The rod portion SK' may be located on the top surface of the frame FR', for example, the first rod SK1' may extend longer than the second frame portion FR2' in the first direction DR1, and the second rod SK2' may extend longer than the first frame portion FR1' in the second direction DR2. The frame FR' and the mask MK may be separated from each other by the sum of the thickness of the first rod SK1' and the thickness of the second rod SK2' in the third direction DR3.

[0075] Fig.11 is a cross-sectional view of an organic light emitting display device including a light emitting layer deposited by using a mask frame assembly according to an embodiment. Fig.11 The base layer BL may be a silicon substrate, a plastic substrate, a glass substrate, an insulating film, a stacked structure including a plurality of insulating layers, etc. The thin film transistor TR may include a control electrode CNE, an input electrode IE, an output electrode OE, and a semiconductor pattern SP.

[0076] The control electrode CNE may be located on the base layer BL. The control electrode CNE may include a conductive material, such as a metal material. The metal material may include, for example, molybdenum, silver, titanium, copper, aluminum, and alloys thereof.

[0077] The first insulating layer L1 may be located on the base layer BL to cover the control electrode CNE. That is, the control electrode CNE may be between the first insulating layer L1 and the base layer BL.

[0078] The semiconductor pattern SP may be located on the first insulating layer L1. In a cross section, the semiconductor pattern SP may be spaced apart from the control electrode CNE with the first insulating layer L1 located therebetween.

[0079] The semiconductor pattern SP may include a semiconductor material, for example, at least one of amorphous silicon, polycrystalline silicon, single crystal silicon, an oxide semiconductor, a compound semiconductor, etc. The input electrode IE and the output electrode OE may be located on the semiconductor pattern SP.

[0080] The second insulating layer L2 may be located on the first insulating layer L1 to cover the semiconductor pattern SP, the input electrode IE, and the output electrode OE. That is, the semiconductor pattern SP, the input electrode IE, and the output electrode OE may be located between the first insulating layer L1 and the second insulating layer L2.

[0081] The third insulating layer L3 may be located on the second insulating layer L2. For example, each of the first insulating layer L1 and the second insulating layer L2 may include an inorganic material, and the third insulating layer L3 may include an organic material. The third insulating layer L3 may provide a planarized surface.

[0082] The light emitting element ED may be an organic light emitting diode and may include a pixel electrode PE, a first auxiliary layer HC (or a hole control layer), a light emitting layer EML, a second auxiliary layer EC (or an electron control layer), and a common electrode CE.

[0083] The pixel electrode PE may be located on the third insulating layer L3. A through hole is defined in each of the second insulating layer L2 and the third insulating layer L3. A portion of the output electrode OE may be exposed through the through hole. The pixel electrode PE may be electrically connected to the exposed output electrode OE. For example, the pixel electrode PE may be an anode layer.

[0084] The fourth insulating layer L4 may be located on the third insulating layer L3. The fourth insulating layer L4 may cover a portion of the pixel electrode PE and expose other portions of the pixel electrode PE. The fourth insulating layer L4 may be a pixel defining layer. The pixel light emitting area PXA may be defined to correspond to the pixel electrode PE exposed by the fourth insulating layer L4. The opening POP defining the pixel light emitting area PXA may be defined in the fourth insulating layer L4. The opening POP may be defined by removing a portion of the fourth insulating layer L4. In this specification, a portion of the indicator line of the reference numeral of the opening POP is marked as representing the side surface of the structure defining the opening POP.

[0085] The common electrode CE is located on the pixel electrode PE. The common electrode CE may include, for example, a cathode electrode. The common electrode CE may be made of a material having a low work function to facilitate electron injection.

[0086] The pixel electrode PE and the common electrode CE may be provided as a single layer or a multilayer. Each of the pixel electrode PE and the common electrode CE may include a conductive material. The conductive material may be a metal, an alloy, a conductive compound, and a mixture thereof. For example, each of the pixel electrode PE and the common electrode CE may include indium zinc oxide (IZO), indium tin oxide (ITO), indium gallium oxide (IGO), indium gallium zinc oxide (IGZO), and mixtures / complexes thereof, molybdenum, silver, titanium, copper, aluminum, and alloys thereof.

[0087] The light emitting layer EML may be located between the pixel electrode PE and the common electrode CE. The light emitting layer EML may have a single layer structure formed of a single material, a single layer structure formed of materials different from each other, or a multilayer structure including a plurality of layers formed of materials different from each other.

[0088] The light emitting layer EML may include an organic material. The organic material is not particularly limited as long as the organic material is commonly used. For example, the light emitting layer EML may be made of at least one of materials emitting light having red, green, and blue colors, and may include a fluorescent material or a phosphorescent material. The light emitting layer EML may be formed by using a reference Figures 7 to 9 A mask frame assembly is described while depositing layers.

[0089] The first auxiliary layer HC is located between the pixel electrode PE and the light emitting layer EML. The first auxiliary layer HC may be a region through which holes injected from the pixel electrode PE pass to reach the light emitting layer EML.

[0090] The first auxiliary layer HC may include at least one of a hole injection layer, a hole transport layer, and a single layer having both hole injection and hole transport functions. The first auxiliary layer HC may be made of at least one of a hole injection material and a hole transport material.

[0091] The second auxiliary layer EC is located between the light emitting layer EML and the common electrode CE. The second auxiliary layer EC may be a region through which electrons injected from the common electrode CE pass to reach the light emitting layer EML.

[0092] The second auxiliary layer EC may include at least one of an electron injection layer, an electron transport layer, and a single layer having both electron injection and electron transport functions. The second auxiliary layer EC may include at least one of an electron transport material and an electron injection material.

[0093] The thin film encapsulation layer TFE may be located on the common electrode CE. The thin film encapsulation layer TFE may directly cover the common electrode CE. In an embodiment, a cover layer covering the common electrode CE may be further located between the thin film encapsulation layer TFE and the common electrode CE. In this case, the thin film encapsulation layer TFE may directly cover the cover layer. In an embodiment, the thin film encapsulation layer TFE may be omitted.

[0094] The thin film encapsulation layer TFE may include a first inorganic layer TE1, an organic layer TE2, and a second inorganic layer TE3 stacked in sequence. The organic layer TE2 may be located between the first inorganic layer TE1 and the second inorganic layer TE3. The first inorganic layer TE1 and the second inorganic layer TE3 may be formed by depositing inorganic materials, and the organic layer TE2 may be formed by depositing, printing, or coating an organic material.

[0095] The first inorganic layer TE1 and the second inorganic layer TE3 can protect the light emitting element ED from moisture and oxygen, and the organic layer TE2 can protect the light emitting element ED from impurities such as dust particles. The first inorganic layer TE1 and the second inorganic layer TE3 may include at least one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, aluminum oxide, etc. For example, the organic layer TE2 may include an acrylic organic layer.

[0096] Although in Fig.11 In the embodiment, the thin film encapsulation layer TFE includes two inorganic layers and one organic layer, but the thin film encapsulation layer TFE may include three inorganic layers and two organic layers, etc. In this case, the inorganic layers and the organic layers may be alternately stacked.

[0097] As a summary and review, an uneven structure can be provided between the frame and the platform, for example, the bottom surface of the frame and / or the top surface of the platform can be an uneven surface. The friction between the frame and the platform can be increased due to the unevenness. Even if the mask and the rod portion supported by the frame are thermally expanded during the deposition process, the mask can be prevented from being deformed by the friction between the frame and the platform. Therefore, the shadow effect caused by the deformation of the mask can be prevented from occurring. Therefore, the mask frame assembly can be improved in reliability.

[0098] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and interpreted in a general and descriptive sense only and not for purposes of limitation. In some cases, it will be apparent to one of ordinary skill in the art that, from the time of filing this application, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise specifically noted. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the claims.

Claims

1. A mask frame assembly, comprising: a platform including a seat portion having a top surface; a frame located on the seat portion and having a bottom surface in contact with the top surface of the seat portion, at least one of the top surface of the seat portion and the bottom surface of the frame being an uneven surface, wherein the frame includes a first coupling groove and a second coupling groove; a mask located on the frame; and a rod portion, located between the frame and the mask, and comprising a first rod extending in a first direction and fixed to the first coupling groove and a second rod extending in a second direction intersecting the first direction and fixed to the second coupling groove, The uneven surface is a laser textured surface and a plasma nitrided surface, so that the friction force between the seat portion and the frame is greater than or equal to the thermal deformation force of the rod portion and the mask.

2. The mask frame assembly according to claim 1, wherein: The thermal deformation force of the first rod is less than or equal to the friction force between the seat portion and the frame.

3. The mask frame assembly according to claim 1, wherein: The thermal deformation force of the second rod is less than or equal to the friction force between the seat portion and the frame.

4. The mask frame assembly according to claim 1, wherein: The uneven surface is parallel to a bottom surface of the mask.

5. The mask frame assembly according to claim 1, wherein: A static friction coefficient between the seat portion and the bottom surface is 1 or more.

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