Mask assembly

Abstract

The mask assembly includes a mask frame including an open region and a mask sheet. The mask sheet includes: a first metal layer disposed on a mask frame and including a first opening; a second metal layer disposed on the first metal layer and including a plurality of second openings overlapping the first openings in a plan view; a third metal layer disposed on the second metal layer and including a plurality of third openings overlapping the first openings in a plan view; and a fourth metal layer disposed on the third metal layer and including a plurality of fourth openings overlapping the first openings in a plan view.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0028753 filed on March 3, 2023 in the Korean Intellectual Property Office (KIPO), the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments relate to a mask assembly capable of achieving precise deposition of a pattern and preventing a shadow phenomenon, and a method of manufacturing a display device. Background Art

[0004] Display devices provide users with visual information such as images or videos. With the development of various electronic devices such as computers and large televisions, various types of display devices applicable thereto have been developed. Recently, electronic devices based on mobility are widely used, and not only small electronic devices such as mobile phones, but also tablet personal computers (PCs) are widely used as mobile electronic devices.

[0005] The display device includes a display area and a non-display area, and a plurality of light emitting elements are arranged in the display area. The display device can provide an image by light emitted by the light emitting elements. The light emitting elements are formed by deposition of deposition materials, and in this regard, an apparatus for manufacturing a display device including a mask assembly can be used.

[0006] The above-mentioned background technology is technical information possessed by the applicant in order to derive the present disclosure or obtained in the process of deriving the present disclosure, and cannot be said to be known technology disclosed to the public before submitting the present disclosure. Utility Model Content

[0007] Embodiments include a mask assembly capable of achieving precise deposition of a pattern and preventing a shadow phenomenon and a method of manufacturing a display device.

[0008] However, the objects to be solved by the present disclosure are not limited thereto.

[0009] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosed embodiments.

[0010] According to an embodiment, the mask assembly may include a mask frame including an opening area and a mask sheet. The mask sheet may include: a first metal layer arranged on the mask frame and including a first opening; a second metal layer arranged on the first metal layer and including a plurality of second openings overlapping the first opening in a plan view; a third metal layer arranged on the second metal layer and including a plurality of third openings overlapping the first opening in a plan view; and a fourth metal layer arranged on the third metal layer and including a plurality of fourth openings overlapping the first opening in a plan view.

[0011] In an implementation, the first opening may be formed corresponding to the cell region of the mask sheet, and the first metal layer may be arranged along a periphery of the cell region.

[0012] In an implementation, the first metal layer and the third metal layer may include the same material.

[0013] In an implementation, the first metal layer and the second metal layer may include different materials, and the first metal layer and the fourth metal layer may include different materials.

[0014] In an embodiment, the first metal layer may include Invar.

[0015] In an implementation, the second metal layer may include tantalum nitride (TaN).

[0016] In an embodiment, the thermal expansion coefficient of the second metal layer may be about 3.0*10 -6 / K to about 4.0*10 -6 / K range.

[0017] In an implementation, the fourth metal layer may include titanium nitride (TiN).

[0018] In an implementation, a thickness of the first metal layer may be greater than a thickness of the third metal layer.

[0019] In an implementation, a thickness of the third metal layer may be greater than a thickness of the second metal layer and a thickness of the fourth metal layer.

[0020] In an implementation, the thickness of the first metal layer may be in a range of about 10 μm to about 15 μm.

[0021] In an implementation, the thickness of the third metal layer may be in a range of about 0.3 μm to about 0.7 μm.

[0022] In an implementation, a thickness of each of the second metal layer and the fourth metal layer may be in a range of about 0.05 μm to about 0.15 μm.

[0023] In an embodiment, one of the plurality of second openings, a corresponding one of the plurality of third openings, and a corresponding one of the plurality of fourth openings may be arranged to overlap each other in a plan view.

[0024] In an embodiment, in a plan view, a corresponding one of the plurality of fourth openings may be smaller than a corresponding one of the plurality of third openings, and a corresponding one of the plurality of third openings may be smaller than the one of the plurality of second openings.

[0025] According to an embodiment, a method for manufacturing a display device may include: arranging a display substrate in a chamber; manufacturing a mask assembly; arranging the mask assembly to face the display substrate; and depositing a deposition material on the display substrate by passing through the mask assembly. Manufacturing the mask assembly may include sequentially stacking a first metal layer, a second metal layer, a third metal layer, and a fourth metal layer, the first metal layer and the third metal layer including the same material.

[0026] In an embodiment, manufacturing the mask assembly may further include: dry etching the fourth metal layer to form a plurality of first openings; and wet etching the third metal layer to form a plurality of second openings. The plurality of second openings may overlap with the plurality of first openings in a plan view.

[0027] In an embodiment, the second metal layer may be used as an etch stop layer when wet etching the third metal layer.

[0028] In an embodiment, manufacturing the mask assembly may further include disposing a protection member to cover portions of the second metal layer exposed by the plurality of second openings and the fourth metal layer.

[0029] In an embodiment, manufacturing the mask assembly may further include wet-etching the first metal layer using the second metal layer as an etch stop layer to form an opening corresponding to the cell region and overlapping the plurality of first openings in a plan view.

[0030] Other aspects, features, and advantages besides those described above will become apparent from the accompanying drawings, claims and detailed description of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0032] Figure 1 is a schematic perspective view of a display device according to an embodiment;

[0033] Figure 2 is a schematic cross-sectional view of a display device according to an embodiment;

[0034] Figure 3is a schematic cross-sectional view of an apparatus for manufacturing a display device according to an embodiment;

[0035] Figure 4 is a schematic perspective view of a mask assembly according to an embodiment;

[0036] Figure 5 It can be used along Figure 4 A schematic cross-sectional view of the mask sheet according to the embodiment corresponding to a cross section of the mask sheet taken along line V-V'; and

[0037] Figures 6 to 12 is a schematic cross-sectional view illustrating a method of manufacturing a display device according to an embodiment. DETAILED DESCRIPTION

[0038] The embodiments shown in the accompanying drawings will now be referred to in detail, wherein the same reference numerals represent the same elements throughout. In this regard, the embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Therefore, the embodiments are described below only by reference to the accompanying drawings to explain the aspects of the description. As used herein, the term "and / or" includes any and all combinations of one or more of the relevant listed items. Throughout the disclosure, the expression "at least one of a, b, and c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0039] Various modifications may be made to the embodiments, and specific embodiments will be shown in the drawings and described in the detailed description section. The effects and features of the embodiments and methods for implementing the same will become more apparent with reference to the following detailed description in conjunction with the drawings. However, the embodiments may be implemented in various forms and are not limited to the embodiments presented below.

[0040] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

[0041] Although the terms "first", "second", etc. may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another element. Therefore, without departing from the teachings of the present disclosure, the first element discussed below may be referred to as the second element.

[0042] The terms used herein are used to describe the purpose of specific embodiments, and are not intended to be limiting. As used herein, the singular forms "one", "a kind of" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. In addition, when used in this specification, the terms "include", "comprise", "include", "include" and / or "include" specify the existence of stated features, integral bodies, steps, operations, elements, components and / or its groups, but do not exclude the existence or addition of one or more other features, integral bodies, steps, operations, elements, components and / or its groups. It should also be noted that, as used herein, the terms "substantially", "about" and other similar terms are used as approximate terms, and are not used as degree terms, and therefore, are used to explain the inherent deviations of the values ​​measured, calculated and / or provided that will be recognized by those of ordinary skill in the art.

[0043] When an element, such as a layer, is referred to as being "on," "connected to," or "coupled to" another element or layer, it may be directly on, directly connected to, or directly coupled to another element or layer, or there may be intervening elements or layers. However, when an element or layer is referred to as being "directly" "on," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. For this purpose, the term "connected" may refer to a physical connection, an electrical connection, and / or a fluid connection with or without intervening elements.

[0044] For the convenience of explanation, the size of the elements in the drawings may be exaggerated. For example, since the size and thickness of the elements in the drawings are arbitrarily shown for the convenience of explanation, the following embodiments are not limited thereto.

[0045] In the following embodiments, the X-axis, Y-axis, and Z-axis are not limited to the three axes of the rectangular coordinate system and can be interpreted in a broader sense. For example, the X-axis, Y-axis, and Z-axis can be perpendicular to each other, or can represent different directions that are not perpendicular to each other.

[0046] When a certain embodiment can be implemented differently, a specific process order can be performed differently from the described order. For example, two processes described successively can be performed substantially simultaneously, or in the reverse order of the described order.

[0047] Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. It will also be understood that terms, such as those defined in general dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless clearly defined in the specification.

[0048] Figure 1 is a schematic perspective view of a display device 1 according to an embodiment.

[0049] refer to Figure 1 , the display device 1 may include a display area DA and a peripheral area PA arranged adjacent to the display area DA. The display device 1 may provide an image through an array of a plurality of pixels PX in the display area DA. The pixel PX may be defined as an emission area in which a light-emitting element driven by a pixel circuit emits light. For example, an image may be provided by light emitted by the light-emitting element through the pixel PX. Not only the light-emitting element and the pixel circuit, but also various signal wirings and power wirings electrically connected to the pixel circuit, etc. may be arranged in the display area DA.

[0050] The peripheral area PA, which is an area where no image is provided, may completely or partially surround the display area DA. Various wirings, driving circuits, etc. for supplying electrical signals or power to the display area DA may be arranged in the peripheral area PA.

[0051] When viewed from a direction perpendicular to its surface (in a plan view), the display device 1 may have an approximately rectangular shape. Figure 1 As shown in , the display device 1 may generally have a rectangular shape in a plan view, the rectangular shape having a short side extending in the x direction, for example, and a long side extending in the y direction, for example. The corner where the short side intersects the long side may have a right angle shape or a rounded shape with a curvature. However, the shape of the display device 1 is not limited to a rectangular shape, and the display device 1 may have various shapes including a polygonal shape such as a triangle, a circular shape, an elliptical shape, an amorphous shape, etc. in a plan view.

[0052] Although Figure 1 The display device 1 is shown to include a flat display surface, but the present disclosure is not limited thereto. In another embodiment, the display device 1 may include a three-dimensional display surface or a curved display surface. In the case where the display device 1 includes a three-dimensional display surface, the display device 1 may include a plurality of display areas in different directions, such as a polygonal columnar display surface. In another embodiment, in the case where the display device 1 includes a curved display surface, the display device 1 may be implemented in various shapes. For example, the display surface may be flexible, foldable, rollable, etc.

[0053] The display device 1 can be used not only as a display screen of portable electronic devices such as mobile phones, smart phones, tablet personal computers (PCs), mobile communication terminals, electronic notepads, electronic books, portable multimedia players (PMPs), navigation devices, ultra-mobile PCs (UMPCs), etc., but also as a display screen of various products such as televisions, notebook computers, monitors, billboards, the Internet of Things (IOT), etc. In addition, the display device 1 according to the embodiment can be used in wearable devices such as smart watches, watch phones, glasses-type displays, and head-mounted displays (HMDs). In addition, the display device 1 according to the embodiment can be used as a dashboard of a vehicle, a central information display (CID) set on a central dashboard or instrument panel of a vehicle, an interior mirror display instead of a side mirror of a vehicle, or a display screen set at the rear surface of a front seat as an entertainment device for a rear seat of a vehicle.

[0054] In the following description, although the display device 1 is described as including an organic light emitting diode (OLED) as a light emitting element, the display device 1 is not limited thereto. In another embodiment, the display device 1 may be a light emitting display device including an inorganic light emitting diode, such as an inorganic light emitting display device. In another embodiment, the display device 1 may be a quantum dot light emitting display device.

[0055] Figure 2 is a schematic cross-sectional view of a display device 1 according to an embodiment.

[0056] refer to Figure 2 The display device 1 may include a substrate 100, a pixel circuit layer 110 including a thin film transistor TFT, a via insulating layer 120 on the pixel circuit layer 110, and a first organic light emitting diode OLED1, a second organic light emitting diode OLED2, and a third organic light emitting diode OLED3 disposed on the via insulating layer 120. The display device 1 may further include an encapsulation layer 300 disposed on the first organic light emitting diode OLED1, the second organic light emitting diode OLED2, and the third organic light emitting diode OLED3, and a color filter layer 400 disposed on the encapsulation layer 300.

[0057] The substrate 100 may have an upper surface extending in a plane defined by the x-direction and the y-direction. The substrate 100 may include a semiconductor material, such as a group IV semiconductor, a group III-V compound semiconductor, or a group II-VI compound semiconductor. The substrate 100 may include a silicon layer. For example, the substrate 100 may be a semiconductor substrate including a semiconductor material. However, the substrate 100 is not limited to a semiconductor substrate. For example, the substrate 100 may include glass or a polymer resin including polyethersulfone, polyarylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyimide, polycarbonate, cellulose triacetate, cellulose acetate propionate, etc., or a combination thereof. In an embodiment, the substrate 100 may have a multilayer structure including a barrier layer (not shown) and a base layer including the above-mentioned polymer resin. In the following description, the case where the substrate 100 includes a semiconductor material is described in detail.

[0058] The pixel circuit layer 110 may be disposed on the substrate 100. The pixel circuit layer 110 may include an insulating layer and a pixel circuit connected to the organic light emitting diode OLED. The pixel circuit layer 110 may include an interlayer insulating layer 111 disposed on the substrate 100 and at least one thin film transistor TFT.

[0059] The thin film transistor TFT may include a gate dielectric layer GO, a gate electrode GE, and an active area ACT.

[0060] The active area ACT may be arranged in the substrate 100. For example, the active area ACT may be formed as a portion of the substrate 100. The active area ACT may extend in a first direction (e.g., an x ​​direction) in the substrate 100. When a portion of the substrate 100 is recessed, the active area ACT may be disposed in the recessed portion of the substrate 100. The active area ACT may include a channel area C and a drain area D and a source area S arranged at opposite sides of the channel area C. Each of the drain area D and the source area S may be a region doped with impurities in the substrate 100 including a semiconductor material. The channel area C may overlap with the gate electrode GE in a plan view.

[0061] The gate dielectric layer GO may be disposed between the gate electrode GE and the active area ACT. The gate dielectric layer GO may include an inorganic insulating material, such as silicon oxide (SiO 2 ), silicon nitride (SiN X ), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), Tantalum Oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ), zinc oxide (ZnO 2 )wait.

[0062] The gate electrode GE may be disposed above the active area ACT. The gate electrode GE may extend in a direction such as the y direction and intersect the active area ACT in a plan view. The channel region C of the thin film transistor TFT may be formed on the active area ACT intersecting with the gate electrode GE in a plan view. The gate electrode GE may be disposed on the gate dielectric layer GO. The gate electrode GE may include a conductive material. For example, the gate electrode GE may include a metal nitride such as titanium nitride (TiN), tantalum nitride (TaN) or tungsten nitride (WN) and / or a metal such as aluminum (Al), tungsten (W), copper (Cu), molybdenum (Mo), etc. or a semiconductor material such as doped polysilicon. The gate electrode GE may be formed as a multilayer or a single layer including the above-mentioned materials.

[0063] The interlayer insulating layer 111 may be disposed on the substrate 100 and may cover the thin film transistor TFT. The interlayer insulating layer 111 may include at least one of oxide, nitride, and oxynitride. The interlayer insulating layer 111 may have a single layer or multi-layer structure.

[0064] The drain electrode DE and the source electrode SE may be disposed on the interlayer insulating layer 111. The drain electrode DE and the source electrode SE may be connected to the drain region D and the source region S of the active region ACT, respectively, via contact holes in the interlayer insulating layer 111. The drain electrode DE and the source electrode SE may each include a material having excellent conductivity. The drain electrode DE and the source electrode SE may each include a conductive material such as Mo, Al, Cu, titanium (Ti), etc., and may be formed as a multilayer or single layer including the above materials.

[0065] The via insulating layer 120 may be disposed on the pixel circuit layer 110. The via insulating layer 120 may cover the drain electrode DE and the source electrode SE. The via insulating layer 120 may include an organic insulating material such as a general polymer such as polymethyl methacrylate (PMMA) and polystyrene (PS), a polymer derivative having a phenol group, an acrylic polymer, an imide-based polymer, an aromatic ether-based polymer, an amide-based polymer, a fluorine-based polymer, a p-xylene-based polymer, a vinyl alcohol-based polymer, and a blend thereof.

[0066] The first organic light emitting diode OLED1, the second organic light emitting diode OLED2, and the third organic light emitting diode OLED3 may be disposed on the via insulating layer 120. The first organic light emitting diode OLED1, the second organic light emitting diode OLED2, and the third organic light emitting diode OLED3 may each have a stacked structure of a pixel electrode 210, an emission layer 220, and a counter electrode 230. In an embodiment, the first organic light emitting diode OLED1, the second organic light emitting diode OLED2, and the third organic light emitting diode OLED3 may each emit white light. In another embodiment, the first organic light emitting diode OLED1, the second organic light emitting diode OLED2, and the third organic light emitting diode OLED3 may respectively emit red light, green light, and blue light, or may each emit one of red light, green light, blue light, and white light. The first organic light emitting diode OLED1, the second organic light emitting diode OLED2, and the third organic light emitting diode OLED3 may emit light, and the region from which the light is emitted may be defined as a first emission region EA1, a second emission region EA2, and a third emission region EA3.

[0067] The pixel electrode 210 may be disposed on the via insulating layer 120 and may be electrically connected to the thin film transistor TFT through a contact hole in the via insulating layer 120. The pixel electrodes 210 of the first organic light emitting diode OLED1, the second organic light emitting diode OLED2, and the third organic light emitting diode OLED3 may be arranged separately from each other.

[0068] The pixel electrode 210 may include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In 2 O 3 ), indium gallium oxide (IGO) or aluminum zinc oxide (AZO). In another embodiment, the pixel electrode 210 may include a reflective film containing silver (Ag), magnesium (Mg), Al, platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr) or a compound thereof. In another embodiment, the pixel electrode 210 may also include a conductive oxide of ITO, IZO, ZnO or In above / below the above-mentioned reflective film. 2 O 3 The film formed.

[0069] A pixel defining layer 130 having an opening 130OP exposing a central portion of the pixel electrode 210 may be disposed on the pixel electrode 210. The pixel defining layer 130 may include an organic insulating material and / or an inorganic insulating material. The opening 130OP may define an emission region of light emitted from each of the first organic light emitting diode OLED1, the second organic light emitting diode OLED2, and the third organic light emitting diode OLED3. For example, the size / width of the opening 130OP may correspond to the size / width of the emission areas EA1, EA2, and EA3. Therefore, the size and / or width of the pixel PX may depend on the size and / or width of the opening 130OP corresponding to the pixel defining layer 130.

[0070] The emission layer 220 may be disposed on the pixel electrode 210, corresponding to the pixel electrode 210. The emission layer 220 may include a polymer or a low molecular weight organic material for emitting light of a certain color. In another embodiment, the emission layer 220 may include an inorganic light emitting material or a quantum dot.

[0071] In an embodiment, a first functional layer (not shown) and a second functional layer (not shown) may be disposed below and above the emission layer 220. The first functional layer may include, for example, a hole transport layer (HTL), or an HTL and a hole injection layer (HIL). The second functional layer disposed on the emission layer 220 may include an electron transport layer (ETL) and / or an electron injection layer (EIL). The first functional layer and / or the second functional layer may be a common layer formed to completely cover the substrate 100, such as the counter electrode 230 to be described below.

[0072] The counter electrode 230 may be disposed above the pixel electrode 210 and may overlap the pixel electrode 210 in a plan view. The counter electrode 230 may be disposed on the emission layer 220. The counter electrode 230 may include a conductive material having a low work function. For example, the counter electrode 230 may include a (semi) transparent layer including Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, lithium (Li), calcium (Ca), etc. or an alloy thereof. In an example, the counter electrode 230 may also include a (semi) transparent layer including ITO, IZO, ZnO or In on the (semi) transparent layer including the above materials. 2 O 3 The counter electrode 230 may be integrally formed to entirely cover the substrate 100 .

[0073] The encapsulation layer 300 may be disposed on the counter electrode 230. The encapsulation layer 300 may be disposed to cover the organic light emitting diodes OLED1, OLED2, and OLED3. The encapsulation layer 300 may include at least one inorganic encapsulation layer and at least one organic encapsulation layer. In an embodiment, the encapsulation layer 300 may include a first inorganic encapsulation layer 310, an organic encapsulation layer 320 on the first inorganic encapsulation layer 310, and a second inorganic encapsulation layer 330.

[0074] The first inorganic encapsulating layer 310 and the second inorganic encapsulating layer 330 may each include Al 2 O 3 、TiO 2 、 2 O 5 , HfO 2 、ZnO 2 、SiO 2 、SiN X and at least one inorganic material of SiON. The organic encapsulation layer 320 may include a polymer-based material. In an embodiment, the organic encapsulation layer 320 may include an acrylic resin, an epoxy-based resin, polyimide, polyethylene, etc. In an embodiment, the organic encapsulation layer 320 may include an acrylate. The organic encapsulation layer 320 may be formed by curing a monomer or coating a polymer. The organic encapsulation layer 320 may have transparency.

[0075] The color filter layer 400 may be disposed on the encapsulation layer 300. The color filter layer 400 may include a first color filter 400A, a second color filter 400B, and a third color filter 400C. Each of the first color filter 400A, the second color filter 400B, and the third color filter 400C may be arranged to correspond to the pixel electrodes 210 of the organic light emitting diodes OLED1, OLED2, and OLED3, respectively. For example, the first color filter 400A may be arranged to overlap the pixel electrode 210 of the first organic light emitting diode OLED1 in a direction perpendicular to the substrate 100 (e.g., in the z direction). For example, the second color filter 400B may be arranged to overlap the pixel electrode 210 of the second organic light emitting diode OLED2 in a direction perpendicular to the substrate 100 (e.g., in the z direction). For example, the third color filter 400C may be arranged to overlap the pixel electrode 210 of the third organic light emitting diode OLED3 in a direction perpendicular to the substrate 100 (e.g., in the z direction).

[0076] The first color filter 400A, the second color filter 400B, and the third color filter 400C may each include a photosensitive resin. The first color filter 400A, the second color filter 400B, and the third color filter 400C may each include a pigment or dye having a color.

[0077] The first color filter 400A, the second color filter 400B, and the third color filter 400C may each transmit red light, green light, or blue light. For example, the first color filter 400A may be a red color filter that selectively transmits red light in the light emitted from the emission layer 220. For example, the first color filter 400A may only allow light with a wavelength in the range of about 630nm to about 780nm to pass. For example, the second color filter 400B may be a green color filter that selectively transmits green light in the light emitted from the emission layer 220. For example, the second color filter 400B may only allow light with a wavelength in the range of about 495nm to about 570nm to pass. For example, the third color filter 400C may be a blue color filter that selectively transmits blue light in the light emitted from the emission layer 220. For example, the third color filter 400C may only allow light with a wavelength in the range of about 450nm to about 495nm to pass.

[0078] Figure 3 is a schematic cross-sectional view of an apparatus 2 for manufacturing a display device according to an embodiment.

[0079] refer to Figure 3 , the device 2 for manufacturing a display device can be used to manufacture the above-mentioned display device 1, but the present disclosure is not limited thereto.

[0080] An apparatus 2 for manufacturing a display device may include a chamber 10 , a first support 20 , a second support 30 , a mask assembly 500 , a deposition source 50 , a magnetic unit 60 , a vision unit 70 , and a pressure regulator 80 .

[0081] A space may be formed in the chamber 10, and the display substrate DS and the mask assembly 500 may be accommodated in the space. A portion of the chamber 10 may be formed to be open, and the gate valve 11 may be installed in the open portion of the chamber 10. The open portion of the chamber 10 may be opened or closed according to the operation of the gate valve 11.

[0082] The display substrate DS as a part of the display device when the display device is manufactured may be a substrate 100 in a state where at least one of an organic layer, an inorganic layer, and a metal layer to be described below is deposited on the substrate 100. In another embodiment, the display substrate DS may be a substrate 100 on which one of an organic layer, an inorganic layer, and a metal layer is deposited.

[0083] The first support 20 may support the display substrate DS. The first support 20 may be in the form of a plate fixed in the chamber 10. In another embodiment, the first support 20 may be in the form of a shuttle in which the display substrate DS is placed and which moves linearly in the chamber 10. In another embodiment, the first support 20 may include an electrostatic chuck or an adhesive chuck fixed in the chamber 10 or arranged in the chamber 10 and moved inside the chamber 10.

[0084] The second support 30 may support the mask assembly 500. The second support 30 may be disposed in the chamber 10. The second support 30 may finely adjust the position of the mask assembly 500. The second support 30 may include a separate driving unit, an alignment unit, etc. to move the mask assembly 500 in different directions.

[0085] In another embodiment, the second support 30 may be in the form of a shuttle, and the second support 30 may support the mask assembly 500 and transfer the mask assembly 500. For example, the second support 30 may move to the outside of the chamber 10, and support the mask assembly 500 and enter the inside of the chamber 10 from the outside of the chamber 10.

[0086] In this embodiment, the first support 20 and the second support 30 may be integrally formed, and the first support 20 and the second support 30 may include a movable shuttle. The first support 20 and the second support 30 may have a structure that fixes the mask assembly 500 and the display substrate DS when the display substrate DS is placed on the mask assembly 500, and may linearly move the display substrate DS and the mask assembly 500 at the same time.

[0087] In the following description, for convenience of explanation, an embodiment in which the first support 20 and the second support 30 are respectively formed and arranged at different positions in the chamber 10 is described in detail.

[0088] The deposition source 50 may be arranged to face the mask assembly 500. The deposition source 50 may contain a deposition material and apply heat to the deposition material to evaporate or sublime the deposition material. The deposition source 50 may be fixed in the chamber 10 or arranged in the chamber 10 and may be linearly movable in one direction.

[0089] The mask assembly 500 may be arranged in the chamber 10. The mask assembly 500 may include a mask frame 510 and a mask sheet 520, which will be described in detail below. The deposition material may pass through the mask assembly 500 and be deposited on the display substrate DS. In an embodiment, the deposition material may pass through the mask assembly 500 and form the above-mentioned emission layer 220.

[0090] The magnetic unit 60 may be arranged in the chamber 10 to face the display substrate DS and / or the mask assembly 500. The magnetic unit 60 may apply a force toward the display substrate DS to the mask assembly 500 by applying a magnetic force to the mask assembly 500. For example, the magnetic unit 60 may prevent the mask sheet 520 from sagging and also bring the mask sheet 520 close to the display substrate DS. For example, the magnetic unit 60 may maintain a uniform distance between the mask sheet 520 and the display substrate DS.

[0091] The vision unit 70 may be arranged in the chamber 10, and may detect the positions of the display substrate DS and the mask assembly 500. The vision unit 70 may include a camera for capturing images of the display substrate DS and the mask assembly 500. Based on the image captured by the vision unit 70, the positions of the display substrate DS and the mask assembly 500 may be recognized, and the deformation of the mask assembly 500 may be confirmed. In addition, based on the image captured by the vision unit 70, the first support 20 may finely adjust the position of the display substrate DS, or the second support 30 may finely adjust the position of the mask assembly 500. In the following description, an embodiment in which the second support 30 finely adjusts the position of the mask assembly 500 to align the arrangement of the display substrate DS and the mask assembly 500 is described in detail.

[0092] The pressure regulator 80 may be connected to the chamber 10 and may adjust the pressure in the chamber 10. For example, the pressure regulator 80 may adjust the pressure in the chamber 10 to be the same as or similar to the atmospheric pressure. For example, the pressure regulator 80 may adjust the pressure in the chamber 10 to be the same as or similar to a vacuum state.

[0093] The pressure regulator 80 may include a connection pipe 81 connected to the chamber 10 and a pump 82 mounted on the connection pipe 81. According to the operation of the pump 82, external air may be introduced through the connection pipe 81, or gas in the chamber 10 may move to the outside through the connection pipe 81.

[0094] Figure 4 is a schematic perspective view of a mask assembly 500 according to an embodiment.

[0095] refer to Figure 4 , the mask assembly 500 may include a mask frame 510 and a mask sheet 520 .

[0096] The mask frame 510 may be formed by connecting a plurality of side surfaces, and may include an opening area OA defined by the side surfaces. For example, the opening area OA may be surrounded by the side surfaces, and the opening area OA may be formed by penetrating the center of the mask frame 510. Support bars (not shown) may be arranged in parallel in one direction and span the mask frame 510 (e.g., the opening area OA of the mask frame 510). In another embodiment, the support bars spanning the opening area OA may be a grid type.

[0097] In an embodiment, the mask frame 510 may have a rectangular shape in a plan view. However, the present disclosure is not limited thereto, and the shape of the mask frame 510 is not limited thereto, and may be set to various types of polygonal shapes. In the following description, for ease of explanation, an embodiment in which the mask frame 510 has a rectangular shape in a plan view is described.

[0098] The mask sheet 520 may be disposed on the mask frame 510. For example, the mask sheet 520 may be arranged to cover the opening area OA of the mask frame 510. In an embodiment, the mask sheet 520 may include at least one mask sheet. In the case where the mask sheet 520 includes two or more mask sheets, the mask sheets 520 may be arranged on the mask frame 510 in parallel with each other. For example, the mask sheet 520 may be arranged in a direction (e.g., Figure 4 The two electrodes are arranged parallel to each other in the x-direction (for example, Figure 4 In an implementation, the mask sheet 520 may be fixed to the mask frame 510 by welding.

[0099] The mask sheet 520 may include an opening pattern 520P for depositing a deposition material on the display substrate DS. When manufacturing a display device, the display substrate DS may be a part of the display device. In an embodiment, the display substrate DS as a mother substrate may include a plurality of units. The unit may be cut to form a plurality of display devices. For example, the deposition material may be deposited on the unit of the display substrate DS, and the display substrate DS may be cut along the unit to manufacture a plurality of display devices.

[0100] The opening pattern 520P may be arranged in a region corresponding to each unit of the display substrate DS. For example, the opening pattern 520P may be arranged in the unit region SA of the mask sheet 520. Figure 4 As shown in , the opening pattern 520P may include a plurality of through holes. The opening pattern 520P may correspond to a pattern of an emission layer, for example, forming an emission layer of a display device. In an embodiment, the above-mentioned display device may be a display device for achieving ultra-high resolution. The minimum width of a portion of the emission layer of the display device may be less than or equal to about 3 μm. For example, the minimum width of a portion of the emission layer of the display device may be in the range of about 2 μm to about 3 μm. However, the present disclosure is not limited thereto, and the minimum width of a portion of the emission layer may be less than or equal to about 2 μm.

[0101] Figure 5 It can be used along Figure 4 A cross section of the mask sheet taken along line VV′ corresponds to a schematic cross-sectional view of the mask sheet according to the embodiment. Figure 5 The through holes 520TH forming the opening pattern 520P are schematically illustrated.

[0102] refer to Figure 5 , the mask sheet 520 may include a first metal layer 521 , a second metal layer 522 , a third metal layer 523 and a fourth metal layer 524 .

[0103] The first metal layer 521 may be disposed on the mask frame 510. The first metal layer 521 as a support layer of the mask sheet 520 may include invar. Invar may be an alloy of iron and nickel in which the nickel content is, for example, about 37%. Since invar has a relatively low thermal expansion coefficient, the first metal layer 521 may reduce thermal deformation while maintaining the mechanical strength of the mask sheet 520.

[0104] In an embodiment, the first metal layer 521 may include a first opening 521OP. The first opening 521OP may be an opening corresponding to the cell area SA. For example, the first opening 521OP may overlap the cell area SA in a plan view. Therefore, the first metal layer 521 may surround the cell area SA in a plan view.

[0105] In an embodiment, the inner surface of the first opening 521OP may be inclined. For example, the radius of the through hole 520TH may decrease as the distance from the lower surface of the first metal layer 521 increases. The slope of the inner surface of the first opening 521OP may prevent a shadow phenomenon even for various incident angles of the deposited material.

[0106] In an embodiment, the thickness of the first metal layer 521 may be in the range of about 10 μm to about 15 μm. For example, the thickness of the first metal layer 521 may be about 15 μm. Since the first metal layer 521 is arranged along the periphery of the unit area SA, even if the first metal layer 521 has a thickness greater than that of the second to fourth metal layers 522 to 524, the first metal layer 521 may enhance the mechanical strength of the mask sheet 520 without causing a shadow phenomenon.

[0107] The second metal layer 522 may be disposed on the first metal layer 521. The second metal layer 522 may be used as an etching stop layer during the production of the first opening 521OP of the first metal layer 521 in the manufacturing process of the mask sheet 520 to be described below. In an embodiment, the second metal layer 522 may include at least one of tantalum nitride (TaN) and titanium nitride (TiN). For example, the second metal layer 522 may include TaN and have a low thermal expansion coefficient. In an embodiment, the thermal expansion coefficient of the second metal layer 522 may be about 3.0*10 -6 / K to about 4.0*10 -6 / K. For example, the thermal expansion coefficient of the second metal layer 522 may be about 3.6*10 -6 / K.

[0108] In an embodiment, the second metal layer 522 may include a second opening 522OP. The second opening 522OP may be provided in plurality and may be arranged in the cell area SA. In addition, the second opening 522OP may overlap with the first opening 521OP in a plan view and may be arranged within the periphery of the first opening 521OP.

[0109] In addition, the inner surface of the second opening 522OP may be inclined. For example, the radius of the second opening 522OP may decrease as the distance from the lower surface of the second metal layer 522 increases. The slope of the inner surface of the second opening 522OP may prevent a shadow phenomenon even for various incident angles of the deposited material.

[0110] In an embodiment, the thickness of the second metal layer 522 may be in a range of about 0.05 μm to about 0.15 μm. For example, the thickness of the second metal layer 522 may be about 0.1 μm. For example, the thickness of the second metal layer 522 may be less than the thickness of the first metal layer 521 .

[0111] The third metal layer 523 may be disposed on the second metal layer 522. The third metal layer 523 may reduce thermal deformation of the mask sheet 520 while supporting the mask sheet 520. The third metal layer 523 and the first metal layer 521 may include the same material, and in an embodiment, the third metal layer 523 may include Invar. Since Invar has a relatively low thermal expansion coefficient, the third metal layer 523 may reduce thermal deformation while maintaining the mechanical strength of the mask sheet 520.

[0112] In an embodiment, the third metal layer 523 may include a third opening 523OP. The third opening 523OP may be provided in plurality, and the third opening 523OP may be arranged in the unit area SA. In an embodiment, the third opening 523OP may overlap with the first opening 521OP in a plan view, and may be arranged within the periphery of the first opening 521OP in a plan view. In an embodiment, each of the third openings 523OP may overlap with each of the second openings 522OP in a plan view, thereby forming a through hole 520TH. The size of the third opening 523OP may be smaller than the size of the second opening 522OP. For example, in a plan view, the third opening 523OP may be arranged within the periphery of the second opening 522OP.

[0113] In an embodiment, the inner surface of the third opening 523OP may be inclined. For example, the radius of the third opening 523OP may decrease as the distance from the lower surface of the third metal layer 523 increases. The slope of the inner surface of the third opening 523OP may prevent a shadow phenomenon even for various incident angles of the deposited material.

[0114] In an embodiment, the thickness of the third metal layer 523 may be in a range of about 0.3 μm to about 0.7 μm. For example, the thickness of the third metal layer 523 may be about 0.5 μm. For example, the thickness of the third metal layer 523 may be less than the thickness of the first metal layer 521 and greater than the thickness of the second metal layer 522.

[0115] Therefore, the mask sheet 520 according to the embodiment may include a dual invar layer, such as a first metal layer 521 and a third metal layer 523. The first opening 521OP of the first metal layer 521 may be formed corresponding to the size of the cell area SA, and the first metal layer 521 may be used as a support layer. The third metal layer 523, which basically forms the through hole 520TH through which the deposition material finally passes, may be formed in a thin invar layer, so that the shadow phenomenon can be prevented, and the heat resistance and mechanical strength can be enhanced.

[0116] The fourth metal layer 524 may be disposed on the third metal layer 523. The fourth metal layer 524 may be a final layer through which the deposition material passes, and may protect the outer surface of the mask sheet 520. In an embodiment, the fourth metal layer 524 may include TiN. TiN may be a hard material having a Mohs hardness greater than or equal to about 9, and may protect the mask sheet 520 from being scratched by external impact, etc.

[0117] In an embodiment, the fourth metal layer 524 may include a fourth opening 524OP. The fourth opening 524OP may be provided in plurality, and the fourth opening 524OP may be arranged in the unit area SA. In an embodiment, the fourth opening 524OP may overlap with the first opening 521OP in a plan view, and may be arranged within the periphery of the first opening 521OP in a plan view. In an embodiment, each of the fourth openings 524OP may overlap with each of the second openings 522OP and each of the third openings 523OP in a plan view, thereby forming a through hole 520TH. The size of the fourth opening 524OP may be smaller than the size of the third opening 523OP. For example, in a plan view, the fourth opening 524OP may be arranged within the periphery of the third opening 523OP.

[0118] In an embodiment, the minimum width W of a portion of the fourth opening 524OP may be less than or equal to about 3 μm. For example, the minimum width W of a portion of the fourth opening 524OP may be in the range of about 2 μm to about 3 μm. The width W of the fourth opening 524OP may correspond to the size of the emission layer of the above-mentioned display device. For example, as the deposition material passes through the fourth opening 524OP and is deposited on the display substrate DS, a micro-emission layer for ultra-high resolution may be formed.

[0119] In an embodiment, the inner surface of the fourth opening 524OP may be inclined. For example, the radius of the fourth opening 524OP may decrease as the distance from the lower surface of the fourth metal layer 524 increases. The slope of the inner surface of the fourth opening 524OP may prevent a shadow phenomenon even for various incident angles of the deposited material.

[0120] In an embodiment, the thickness of the fourth metal layer 524 may be in a range of about 0.05 μm to about 0.15 μm. For example, the thickness of the fourth metal layer 524 may be about 0.1 μm. In an embodiment, the thickness of the fourth metal layer 524 may be the same as the thickness of the second metal layer 522, and the thickness of the fourth metal layer 524 may be less than the thickness of the first metal layer 521 and the thickness of the third metal layer 523.

[0121] Therefore, in the mask sheet 520 according to the embodiment, the sum of the thicknesses of the second metal layer 522 to the fourth metal layer 524 that basically form the through hole 520TH may be less than about 1 μm. Therefore, since the mask sheet 520 having a very thin structure is provided in the unit area SA where the opening pattern 520P is formed, the shadow phenomenon can be prevented and the deposition quality can be improved. In addition, thermal deformation can be prevented by the invar layer (e.g., the first metal layer 521 and the third metal layer 523) having strong mechanical strength.

[0122] Figures 6 to 12 2 is a schematic cross-sectional view illustrating a method of manufacturing a display device according to an embodiment. The method of manufacturing a display device according to an embodiment may be used to manufacture the above-mentioned display device, but the present disclosure is not limited thereto.

[0123] refer to Figure 6 , a device for manufacturing a display device, such as a mask sheet 520, can be manufactured. A first metal layer 521, a second metal layer 522, a third metal layer 523, and a fourth metal layer 524 can be stacked in sequence. As described above, the first metal layer 521 and the third metal layer 523 can each include invar. The second metal layer 522 can include TaN, and the fourth metal layer 524 can include TiN.

[0124] In an embodiment, the second metal layer 522 may be formed on the first metal layer 521 by a vapor deposition method (e.g., sputtering). The third metal layer 523 may be formed on the second metal layer 522 by an electroforming method. The fourth metal layer 524 may be formed on the third metal layer 523 by a vapor deposition method (e.g., sputtering).

[0125] refer to Figure 7, a portion of the fourth metal layer 524 may be dry-etched to form a fourth opening 524OP. The fourth metal layer 524, which is the final layer through which the deposition material passes, may be arranged closest to the display substrate DS. Therefore, the fourth opening 524OP may be formed as a micro opening suitable for deposition for ultra-high resolution by dry etching capable of precise processing.

[0126] refer to Figure 8 , a portion of the third metal layer 523 may be wet etched to form a third opening 523OP. The third opening 523OP may be formed to overlap with the fourth opening 524OP in a plan view. In addition, the third opening 523OP having a size larger than the fourth opening 524OP may be formed by wet etching. During the formation of the third opening 523OP, the second metal layer 522 may be used as an etching stop layer to prevent the layer below the third metal layer 523 from being etched. For example, the second metal layer 522 may include TiN, and the TiN may not be etched by the etchant of the third metal layer 523 including invar.

[0127] refer to Fig. 9 , the protection member 600 may be arranged to cover the top surface of the fourth metal layer 524. The protection member 600 may cover the fourth metal layer 524, and cover the upper surface of the second metal layer 522 exposed by the fourth opening 524OP and the third opening 523OP. In the manufacturing process of the mask sheet 520, the protection member 600 may not only protect the fourth metal layer 524, but also protect the etched fourth opening 524OP and the third opening 523OP.

[0128] refer to Fig.10 , a portion of the first metal layer 521 may be wet-etched to form a first opening 521OP. As described above, the first opening 521OP may be formed to a size corresponding to the cell area SA. During the formation of the first opening 521OP, the second metal layer 522 may be used as an etching stop layer to prevent the layer above the second metal layer 522 from being etched. For example, the second metal layer 522 may include TiN, and the TiN may not be etched by the etchant of the first metal layer 521 including invar.

[0129] refer to Fig.11 , a portion of the second metal layer 522 may be dry-etched to form a second opening 522OP. The second opening 522OP may be formed to overlap with the fourth opening 524OP and the third opening 523OP in a plan view. In addition, the size of the second opening 522OP may be formed to be larger than the size of the third opening 523OP.

[0130] refer to Fig.12 , the protection member 600 may be removed, and thus, the above-mentioned mask sheet 520 may be manufactured.

[0131] Return to reference Figure 3 , the display device 1 can be manufactured by using the mask sheet 520 manufactured by the above method.

[0132] In detail, in the method of manufacturing the display device by using the apparatus 2 for manufacturing the display device including the mask sheet 520 as described above, first, the display substrate DS may be prepared.

[0133] The pressure regulator 80 may maintain the interior of the chamber 10 in a state that is the same as or similar to the atmospheric pressure, and as the gate valve 11 operates, an opening portion of the chamber 10 may be opened.

[0134] The display substrate DS may be loaded into the chamber 10 from the outside. The display substrate DS may be loaded into the chamber 10 by a method. For example, the display substrate DS may be loaded into the chamber 10 from the outside of the chamber 10 by a robot arm or the like disposed outside the chamber 10. In another embodiment, in the case where the first support 20 is in the form of a shuttle, the first support 20 may be transported out of the interior of the chamber 10, the display substrate DS may be placed on the first support 20 by a separate robot arm or the like disposed outside the chamber 10, and the first support 20 may be loaded into the chamber 10 from the outside.

[0135] As described above, the mask assembly 500 may be disposed in the chamber 10. In another embodiment, the mask assembly 500 may be loaded into the chamber 10 from the outside in the same or similar manner as the display substrate DS.

[0136] During loading of the display substrate DS into the chamber 10, the display substrate DS may be placed on the first support 20. The vision unit 70 may detect the positions of the display substrate DS and the mask assembly 500. The positions of the display substrate DS and the mask assembly 500 may be recognized based on an image captured by the vision unit 70. The apparatus 2 for manufacturing a display device may include a separate controller (not shown) so that the positions of the display substrate DS and the mask assembly 500 may be recognized.

[0137] After completing the recognition of the positions of the display substrate DS and the mask assembly 500 , the second support 30 may finely adjust the position of the mask assembly 500 .

[0138] As the deposition source 50 operates, the deposition material may be supplied to the mask assembly 500, and the deposition material having passed through the plurality of pattern holes of the mask sheet 520 may be deposited on the display substrate DS. The deposition source 50 may move in parallel with the display substrate DS and the mask assembly 500, or the display substrate DS and the mask assembly 500 may move in parallel with the deposition source 50. For example, the deposition source 50 may move relative to the display substrate DS and the mask assembly 500. The pump 82 may maintain the pressure in the chamber 10 in a state identical to or similar to vacuum by sucking gas within the chamber 10 and discharging the gas to the outside.

[0139] As described above, the deposition material supplied from the deposition source 50 may pass through the mask assembly 500 and be deposited on the display substrate DS. Thus, at least one of the layers (eg, organic layer, inorganic layer, and metal layer) to be stacked on the display substrate DS may be formed.

[0140] According to an embodiment, a mask assembly and a method of manufacturing a display device capable of achieving precise deposition of a pattern and preventing a shadow phenomenon are provided.

[0141] The effects of the present disclosure are not limited to the above-mentioned effects, and other various effects not described in the present specification can be clearly understood from the above description by those skilled in the art to which the present disclosure belongs.

[0142] The above description is an example of the technical features of the present disclosure, and a person skilled in the art will be able to make various modifications and changes.Therefore, the embodiments of the present disclosure described above can be implemented individually or in combination with each other.

[0143] Therefore, the embodiments disclosed in the present disclosure are not intended to limit the technical spirit of the present disclosure, but are intended to describe the technical spirit of the present disclosure, and the scope of the technical spirit of the present disclosure is not limited by these embodiments. The protection scope of the present disclosure should be interpreted by the attached claims, and it should be understood that all technical spirits within the equivalent scope are included in the scope of the present disclosure.

Claims

1. Mask assembly, It is characterized in that include: a mask frame including an opening area; as well as Mask sheet, Wherein, the mask sheet comprises: a first metal layer disposed on the mask frame and comprising a first opening; a second metal layer disposed on the first metal layer and including a plurality of second openings overlapping the first openings in a plan view; a third metal layer disposed on the second metal layer and including a plurality of third openings overlapping the first openings in a plan view; and The fourth metal layer is disposed on the third metal layer and includes a plurality of fourth openings overlapping the first openings in a plan view.

2. The mask assembly according to claim 1, It is characterized in that The first opening is formed corresponding to the unit area of ​​the mask sheet, and The first metal layer is arranged along the periphery of the unit area.

3. The assembly according to claim 1, It is characterized in that The first metal layer and the third metal layer include the same material.

4. The mask assembly according to claim 1, It is characterized in that The first metal layer and the second metal layer include different materials, and The first metal layer and the fourth metal layer include different materials.

5. The assembly according to claim 1, It is characterized in that The first metal layer includes Invar.

6. The mask assembly according to claim 1, It is characterized in that The second metal layer includes tantalum nitride.

7. The mask assembly according to claim 1, It is characterized in that The thermal expansion coefficient of the second metal layer is 3.0*10 -6 / K to 4.0*10 -6 / K range.

8. The mask assembly according to claim 1, It is characterized in that The fourth metal layer includes titanium nitride.

9. The assembly according to claim 1, It is characterized in that The thickness of the first metal layer is greater than the thickness of the third metal layer.

10. The mask assembly according to claim 9, It is characterized in that The thickness of the third metal layer is greater than the thickness of the second metal layer and the thickness of the fourth metal layer.

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