Mask assembly and manufacturing method thereof

Abstract

The invention discloses a mask assembly and a manufacturing method thereof. The mask assembly according to the present invention comprises: a mask support part in which a plurality of cell opening parts are defined; a mask disposed on the mask support portion and including a plurality of cell regions overlapping the plurality of cell openings and a peripheral region surrounding the plurality of cell regions; and a tension portion disposed below the mask support portion and overlapping the peripheral region. One side of the tension part and the other side of the tension part opposite to the one side of the tension part are respectively fixed from the mask supporting part.

Description

TECHNICAL FIELD

[0001] The present application relates to a mask assembly and a manufacturing method thereof, and more particularly, to a mask assembly and a manufacturing method thereof with improved reliability. BACKGROUND

[0002] A display panel includes a plurality of pixels. Each of the pixels includes a driving element such as a transistor and a display element such as an organic light emitting diode. The display element can be formed by laminating an electrode and a light emitting pattern on a substrate.

[0003] The light emitting pattern is patterned using a mask having holes defined therein to form in a predetermined area. The light emitting pattern can be formed in an area exposed through the holes of the mask. The shape of the light emitting pattern can be controlled according to the shape of the holes. On the other hand, in order to produce a large number of display panels, production equipment needs to be repeatedly used, and thus, research is needed to provide production equipment with improved reliability. SUMMARY

[0004] An object of the present application is to enable a mask included in a mask assembly and a mask support portion to be closely attached to an object substrate without sagging under a load.

[0005] A mask assembly according to an embodiment of the present application includes a mask support portion having a plurality of unit opening portions defined therein, a mask disposed on the mask support portion and including a plurality of unit regions overlapping the plurality of unit opening portions and a peripheral region surrounding the plurality of unit regions, and a tension portion disposed under the mask support portion and overlapping the peripheral region. One side of the tension portion and the other side of the tension portion opposite to the one side of the tension portion are fixed from the mask support portion, respectively.

[0006] A manufacturing method of a mask assembly according to an embodiment of the present application includes a step of forming a preliminary mask frame having electrical conductivity, a step of forming a preliminary mask on the preliminary mask frame, a step of forming a plurality of holes through the preliminary mask to form a mask, a step of forming a plurality of unit opening portions in the preliminary mask frame to form a mask frame, and a step of fixing a tension portion not overlapping the plurality of unit opening portions in a plane to the mask frame.

[0007] The mask assembly of the present application can include a mask support portion, a mask disposed on the mask support portion, and a tension portion disposed under the mask support portion. One side of the tension portion is fixed to a first portion of the mask support portion, and the other side of the tension portion is fixed to a second portion of the mask support portion, so that a compressive stress can be provided to the first portion of the mask support portion and the second portion of the mask support portion. As a result, the mask disposed on the mask support portion can be prevented from sagging downward under the mask support portion due to a tensile stress to provide a mask with improved reliability. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a cross-sectional view of an evaporation apparatus according to an embodiment of the present application.

[0009] Figure 2 is a plan view of a mask assembly according to an embodiment of the present application.

[0010] Figure 3a is a cross-sectional view of a mask assembly according to an embodiment of the present application, corresponding to line I-I' of Figure 2

[0011] Figure 3b is a cross-sectional view of a mask assembly according to an embodiment of the present application, corresponding to line II-II' of Figure 2

[0012] Figure 4 is a plan view of a mask assembly according to an embodiment of the present application.

[0013] Figure 5 is a plan view of a mask assembly according to an embodiment of the present application.

[0014] Figure 6 is a plan view of a display panel manufactured using the mask assembly shown in Figure 2

[0015] Figure 7 is a view schematically showing a cross-section of any one of the pixels shown in Figure 6

[0016] Figure 8 is a view for explaining an evaporation process shown in Figure 1

[0017] Figures 9a to 9e is a cross-sectional view showing one step in a manufacturing method of a mask assembly according to an embodiment of the present application.

[0018] Figures 10a to 10c is a cross-sectional view showing one step in a manufacturing method of a mask assembly according to an embodiment of the present application.

[0019] (Explanation of Reference Numerals)

[0020] MA: mask assembly MKS: mask support portion

[0021] MK: mask TP: tension portion

[0022] OP-C: plurality of unit opening portions CA: plurality of unit areas

[0023] EA: peripheral area DETAILED DESCRIPTION ​​​​​

[0024] The present application can be implemented in various modifications and can have various forms, and specific embodiments will be illustrated in the drawings and described in detail herein. However, it should be understood that these are not intended to limit the present application to specific disclosed forms, but to include all modifications, equivalents, and alternatives included within the concept and technical scope of the present application.

[0025] In this specification, when referring to a certain constituent element (or region, layer, part, etc.) "on" another constituent element, "connected to" or "coupled to" another constituent element, it means that the certain constituent element can be directly provided / connected / coupled on or to another constituent element or a third constituent element can be provided between them.

[0026] The same reference numerals refer to the same constituent elements. In addition, in the drawings, the thickness, proportions, and dimensions of the constituent elements are exaggerated for effective explanation of the technical content.

[0027] "and / or" includes all combinations of one or more of the relevant structures.

[0028] The first, second, and the like terms can be used to describe various constituent elements, but the above-described constituent elements are not limited by the above terms. The above terms are used only for the purpose of distinguishing one constituent element from other constituent elements. For example, a first constituent element can be named a second constituent element, and similarly, a second constituent element can be named a first constituent element, without departing from the scope of the present application. The singular expression includes the plural expression unless clearly indicated otherwise in the context.

[0029] In addition, the terms "below", "lower", "above", "upper", and the like are used to describe the relative relationship of the structures shown in the drawings. The above terms are relative concepts, and are described based on the direction indicated in the drawings.

[0030] Unless defined differently, all terms used in this specification (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. In addition, terms defined in generally used dictionaries should be interpreted as having the same meaning as the context of the relevant technology, unless explicitly defined herein, and should not be interpreted as ideal or overly formal meanings.

[0031] The terms "include" or "have" and the like should be understood as specifying the presence of features, numbers, steps, operations, constituent elements, components, or combinations thereof described in the specification, and do not preclude the presence or addition of one or more other features, numbers, steps, operations, constituent elements, components, or combinations thereof.

[0032] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings.

[0033] Figure 1 is a cross-sectional view of an evaporation apparatus according to an embodiment of the present application. The evaporation apparatus DD according to an embodiment of the present application can be used to form at least a part of functional layers included in a display panel DP (refer to Figure 6 ) to be described below. For example, the evaporation apparatus DD can be used for an evaporation process of an emission layer EML (refer to Figure 6 ) of the display panel DP (refer to Figure 7 ).

[0034] Referring to Figure 1 , the evaporation apparatus DD can include a chamber CB, an evaporation unit EU, a fixing unit PU, a stage ST, and a mask assembly MA. The evaporation apparatus DD according to an embodiment of the present application can further include additional mechanical devices for implementing an in-line system.

[0035] The chamber CB can include a bottom surface providing an inner space, a top surface, and a sidewall connecting the bottom surface and the top surface. The bottom surface of the chamber CB can be parallel to a plane defined by the first direction DR1 and the second direction DR2, and a normal direction of the bottom surface of the chamber CB can be parallel to the third direction DR3. In the present specification, "on a plane" is defined with reference to a plane parallel to the plane defined by the first direction DR1 and the second direction DR2.

[0036] The evaporation unit EU, the fixing unit PU, the stage ST, the mask assembly MA, and a process substrate M-SUB can be disposed in the inner space of the chamber CB. The chamber CB can form a closed space, and an evaporation condition can be set to be vacuum. The chamber CB can have at least one gate, and the chamber CB can be opened and closed by the gate. The mask assembly MA and the process substrate M-SUB can be in and out through the gate provided in the chamber CB.

[0037] The fixing unit PU can be disposed on the evaporation unit EU inside the chamber CB. The fixing unit PU can fix the mask assembly MA. For example, the fixing unit PU according to an embodiment can include a jig or a robot arm holding the mask assembly MA. The fixing unit PU can include a magnet for closely attaching the mask assembly MA and the process substrate M-SUB. For example, the magnet can generate a magnetic force, and thus an attractive force can be applied to the mask assembly MA, and thus the process substrate M-SUB disposed between the mask assembly MA and the fixing unit PU can be closely attached to the mask assembly MA.

[0038] The process substrate M-SUB can be a process target to be evaporated with an evaporation material DM. For example, the process substrate M-SUB can include a support substrate and an emission layer EML (refer to Figure 7) corresponding synthetic resin layer. The support substrate can be removed in the latter half of the manufacturing process of the display panel. According to the structure formed through the evaporation process, the process substrate M-SUB can include a portion of the structure of the display panel DP (refer to Figure 7 ) formed on the base substrate BS (refer to Figure 6 ).

[0039] The evaporation unit EU can be disposed inside the cavity CB to face the fixing unit PU. The evaporation unit EU can include a space to accommodate the evaporation material DM and at least one nozzle to spray the evaporation material DM. The evaporation material DM can include inorganic, metal, or organic substances that can be sublimated or vaporized. The evaporation material DM can be evaporated on the process substrate M-SUB in a predetermined pattern through the mask assembly MA.

[0040] The mask assembly MA can include a mask MK and a mask support part MKS. The mask MK can be disposed on the mask support part MKS to be combined with the mask support part MKS.

[0041] A plurality of holes OH can be defined in the mask MK. An area adjacent to the outer edge of the mask MK can be supported by the mask support part MKS. The upper surface of the mask MK can face the object to be processed. For example, the upper surface of the mask MK can face the process substrate M-SUB.

[0042] The plurality of holes OH of the mask MK can overlap the plurality of unit opening parts OP-C in a plan view. The plurality of holes OH can define an area on the process substrate M-SUB where the evaporation pattern is formed. That is, the evaporation material DM can pass through the plurality of unit opening parts OP-C and the plurality of holes OH to be formed on the evaporation surface of the process substrate M-SUB in a predetermined pattern corresponding to the plurality of holes OH.

[0043] The mask MK can include a silicon series inorganic substance. For example, the mask MK can include at least one of silicon oxide (SiO x ) and silicon nitride (SiN x ). However, the present application is not limited thereto. The mask MK can include a metal substance. For example, the mask MK can also include a metal material such as nickel (Ni), cobalt (Co), titanium (Ti), chromium (Cr), tungsten (W), molybdenum (Mo), etc. that can be electroplated.

[0044] The mask support MKS supports the mask MK. Multiple unit openings OP-C can be defined within the mask support MKS. These multiple unit openings OP-C can be holes extending from the top to the bottom of the mask support MKS. The bottom of the mask MK can be exposed through the multiple unit openings OP-C. That is, the vapor deposition material DM in the vapor deposition apparatus DD can pass through the mask MK via the multiple unit openings OP-C. The vapor deposition material DM can be vapor deposited onto the processing substrate M-SUB through the multiple unit openings OP-C.

[0045] The mask support MKS may include a mask frame MF and a lower layer BL. The mask frame MF can directly support the mask MK. The mask frame MF may include a conductive material. The mask frame MF may include silicon. For example, the mask frame MF is formed from a silicon wafer and may include monocrystalline silicon. However, the invention is not limited thereto. The mask frame MF may have a predetermined rigidity. For example, the mask frame MF may include metallic materials such as stainless steel (SUS), Invar alloy, nickel (Ni), and cobalt (Co).

[0046] The lower layer (BL) can overlap with and be positioned below the mask frame (MF). The lower layer (BL) can include the same material as the mask (MK). Figure 1 Unlike the case shown, the lower layer BL can be integrally formed with the mask MK. Multiple unit openings OP-C can be formed by penetrating the mask frame MF and the lower layer BL.

[0047] The stage ST can be positioned between the vapor deposition unit EU and the stationary unit PU to support the mask support MKS. The stage ST can be positioned outside the movement path of the vapor deposition material DM supplied from the vapor deposition unit EU toward the processing substrate M-SUB.

[0048] Alternatively, the stage ST may provide a mounting surface for the mask support MKS, the mounting surface being parallel to the first direction DR1 and the second direction DR2. According to one embodiment, the mounting surface of the stage ST may be provided parallel to the bottom surface of the cavity CB for a horizontal vapor deposition process. However, it is not limited to this; the mounting surface of the stage ST may be provided perpendicular to the bottom surface of the cavity CB for a vertical vapor deposition process.

[0049] Figure 2 This is a plan view of a mask assembly according to an embodiment of the present invention. Figure 3a Is with Figure 2 The cross-sectional view of the mask assembly according to an embodiment of the present invention is shown in the figure corresponding to line I-I'. Figure 3b Is with Figure 2 A cross-sectional view of a mask assembly according to an embodiment of the present invention, corresponding to line II-II'. Figure 2This is a planar view of the mask assembly observed on DR3 from a third-party perspective. Figure 2 The mask support MKS located below the mask MK is not shown in the figure (see reference). Figure 1 ).

[0050] Reference Figure 2 In a mask MK, multiple element regions CA and surrounding regions EA on a plane can be defined. The multiple element regions CA can be connected to multiple element openings OP-C (see reference). Figure 1 Correspondingly formed. Multiple holes OH penetrating the mask MK along the thickness direction, i.e., the third direction DR3, can be defined overlapping with multiple unit regions CA. In each of the multiple unit regions CA, the multiple holes OH can be arranged spaced apart from each other. As an example of the invention, multiple holes OH arranged along the first direction DR1 and the second direction DR2 are shown, but are not limited thereto; the multiple holes OH can be formed with the display panel DP (refer to...). Figure 6 EML (referencing) light-emitting layer Figure 7 The pattern shape is defined accordingly.

[0051] The mask MK can have a circular shape on a plane. The shape of the mask MK can be the same as that of the mask support MKS (see reference). Figure 1 The shape corresponds to that of the mask MK. The area of ​​the mask MK can be equal to or greater than the area of ​​the mask support MKS. Unlike the case shown, the shape of the mask MK can be polygonal.

[0052] According to one embodiment of the present invention, the mask assembly MA may further include a tension section TP. The tension section TP may be disposed in the mask support section MKS (see reference MKS). Figure 1 Below, the tension section TP may overlap with the surrounding region EA. That is, the tension section TP may not overlap with multiple unit regions CA. The tension section TP may include a first tension section TP1 and a second tension section TP2. The first tension section TP1 and the second tension section TP2 may each be provided in multiple ways. The first tension section TP1 may extend in the first direction DR1 and be arranged in the second direction DR2. The second tension section TP2 may extend in the second direction DR2 and be arranged in the first direction DR1.

[0053] Refer to together Figure 2 as well as Figure 3aThe first tension portion TP1 can include fixing portions FP1, FP2 and a connection portion CP. The fixing portions FP1, FP2 can include a first fixing portion FP1 corresponding to one side of the first tension portion TP1 and a second fixing portion FP2 corresponding to the other side of the first tension portion TP1. The connection portion CP can connect the first fixing portion FP1 and the second fixing portion FP2. The first fixing portion FP1 can be located on the left side, i.e., in a direction opposite to the first direction DR1, with the connection portion CP as a reference, and the second fixing portion FP2 can be located on the right side, i.e., in the first direction DR1, with the connection portion CP as a reference. The first fixing portion FP1 and the second fixing portion FP2 can each fix the connection portion CP to the mask support portion MKS.

[0054] According to an embodiment of the present application, the connection portion CP can include a metal wire. That is, the connection portion CP can process a metal or the like into a wire shape as a metal wire. For example, the connection portion CP can include steel, aluminum (Al), or an alloy thereof. The first fixing portion FP1 and the second fixing portion FP2 can each include a bonding material that fixes the connection portion CP to the mask support portion MKS. For example, the first fixing portion FP1 and the second fixing portion FP2 can each include at least any one of copper (Cu), nickel (Ni), gold (Au), silver (Ag), aluminum (Al), tin (Sn), indium (In), bismuth (Bi), zinc (Zn), antimony (Sb), germanium (Ge), and cadmium (Cd). However, each of the first fixing portion FP1 and the second fixing portion FP2 is not limited to this as long as it is a substance that can be easily bonded regardless of the material. Although not shown, the second tension portion TP2 can also include fixing portions FP1, FP2 and a connection portion CP, and the same description as described above can be applied.

[0055] The tension portions TP1, TP2 can each overlap at least one of the plurality of unit regions CA with respect to the first direction DR1 or the second direction DR2. For example, the first tension portion TP1 can overlap at least one of the plurality of unit regions CA when viewed in the second direction DR2, and the second tension portion TP2 can overlap at least one of the plurality of unit regions CA when viewed in the first direction DR1. In Figure 2 It is shown in FIG. 1 that the tension portions TP1, TP2 extend to the outermost periphery of the plurality of unit regions CA, but the present application is not limited thereto, and the tension portions TP1, TP2 can be disposed in a part of the peripheral region EA that divides the plurality of unit regions CA. That is, the fixing portions FP1, FP2 can be disposed in a part of the peripheral region EA that divides the plurality of unit regions CA (for example, the separation region DVA (see FIG. 2)). Figure 4

[0056] The tension portions TP1, TP2 of the present application can fix the mask support portion MKS (see FIG. 1) to the substrate W.​Figure 1 ) The compression stress of each other is provided to the mask support part MKS. The fixing parts FP1, FP2 of the first tension part TP1 can be fixed to the mask support part MKS corresponding thereto to provide a force pulling the mask support part MKS in the first direction DR1 and the direction opposite to the first direction DR1. Specifically, it can be that the first fixing part FP1 provides a force pulling the part of the corresponding mask support part MKS in the first direction DR1, and the second fixing part FP2 provides a force pulling the part of the corresponding mask support part MKS in the direction opposite to the first direction DR1. As a result, it can prevent the mask MK disposed on the mask support part MKS from sagging under the mask support part MKS to be in contact with the display panel DP (refer to Figure 6 ) in the light emitting layer EML (refer to Figure 7 ) of the display panel DP (refer to Figure 1 ) in the evaporation process of the mask MK. As a result, it can provide the display panel DP having reliability.

[0057] Referring to Figure 3a , the mask support part MKS of the present application can further include inorganic layers IL1, IL2. The inorganic layers IL1, IL2 can include a first inorganic layer IL1 disposed between the mask frame MF and the mask MK, and a second inorganic layer IL2 disposed between the mask frame MF and the lower layer BL. The first inorganic layer IL1 can be disposed between the mask frame MF and the mask MK to adhere the mask frame MF and the mask MK. In addition, the second inorganic layer IL2 can be disposed between the mask frame MF and the lower layer BL to adhere the mask frame MF and the lower layer BL.

[0058] The inorganic layers IL1, IL2 can include inorganic substances having an adhesion force higher than the adhesion force between each of the mask frame MF and the mask MK and the lower layer BL to adhere each of the mask frame MF and the mask MK and the lower layer BL. For example, the inorganic layers IL1, IL2 can include silicon series inorganic substances. The silicon series inorganic substances are not limited to any substance as long as they can be deposited as a film by chemical vapor deposition. Specifically, the inorganic layers IL1, IL2 can include at least one of silicon oxide (SiO x ) and silicon nitride (SiN x ). In Figure 3a and Figure 3b , the first inorganic layer IL1 and the second inorganic layer IL2 are shown as separate layers, but the first inorganic layer IL1 and the second inorganic layer IL2 can be integrally formed.

[0059] Referring to Figure 2 and Figure 3bThe mask assembly MA according to an embodiment of the present application can further include an alignment portion ALP. The alignment portion ALP can be disposed on the mask support portion MKS. In particular, the alignment portion ALP can be disposed on the first inorganic layer IL1. The alignment portion ALP can be disposed in correspondence with the plurality of cell opening portions OP-C. For example, the alignment portion ALP can be disposed in correspondence with a peripheral region EA of the mask MK which divides the plurality of cell regions CA from each other. The alignment portion ALP is a mark for the plurality of cell opening portions OP-C to be formed in correspondence with the plurality of cell regions CA when the plurality of cell opening portions OP-C are formed. According to the formation of the alignment portion ALP, the plurality of cell opening portions OP-C can be formed in correspondence with the plurality of cell regions CA.

[0060] Figure 4 is a plan view of a mask assembly according to an embodiment of the present application.

[0061] Referring to Figure 4 , the peripheral region EA can include a division region DVA which divides the plurality of cell regions CA and a dummy region DMA which surrounds the division region DVA. For example, it can be that the division region DVA is a region disposed between the plurality of cell regions CA and the dummy region DMA is a region which surrounds the plurality of cell regions CA and the division region DVA. As illustrated, the division region DVA and the dummy region DMA can be connected to be integrated.

[0062] According to an embodiment of the present application, a tension portion TPa can be disposed in the division region DVA. The tension portion TPa can be integrally formed. The tension portion TPa can include a portion extending in the first direction DR1 and the second direction DR2. The tension portion TPa can be provided in a bar form. The tension portion TPa can be disposed under the mask support portion MKS (refer to Figure 1 ) such that the tension portion TPa is entirely fixed to the mask support portion MKS. As a result, it is possible to prevent the mask MK disposed on the mask support portion MKS from sagging under the mask support portion MKS to provide the mask MK having reliability.

[0063] Figure 5 is a plan view of a mask assembly according to an embodiment of the present application.

[0064] Referring to Figure 5 , the tension portion TPb can be provided in a sheet form. For example, the tension portion TPb can overlap a portion of the division region DVA and the dummy region DMA in a plan view. The tension portion TPb can not overlap the plurality of cell regions CA. Unlike the case illustrated in Figure 5 , the tension portion TPb can overlap an entire region of the division region DVA and the dummy region DMA in a plan view.

[0065] Figure 6 is a plan view of a mask assembly according to an embodiment of the present application.Figure 2 A plan view of a display panel manufactured by the mask assembly shown.

[0066] Referring to Figure 6 The display panel DP can have a rectangular shape having a short side extending in a first direction DR1 and a long side extending in a second direction DR2, but the shape of the display panel DP is not limited thereto. The display panel DP can include a display area DA and a non-display area NDA surrounding the display area DA.

[0067] The display panel DP can be a light-emitting display panel. The display panel DP can be an organic light-emitting display panel or a quantum dot light-emitting display panel. The light-emitting layer of the organic light-emitting display panel can include an organic light-emitting substance. The light-emitting layer of the quantum dot light-emitting display panel can include quantum dots, quantum rods, or the like. Hereinafter, the display panel DP will be described as an organic light-emitting display panel.

[0068] The display panel DP can include a plurality of pixels PX, a plurality of scan lines SL1 to SLm, a plurality of data lines DL1 to DLn, a plurality of light-emitting lines EL1 to ELm, first and second control lines CSL1, CSL2, first and second power lines PLL1, PLL2, a connection line CNL, and a plurality of pads PD. m and n are natural numbers greater than 1.

[0069] The pixels PX can be disposed in the display area DA. The scan driving part SDV and the light-emitting driving part EDV can be disposed in the non-display area NDA adjacent to the long sides of the display panel DP, respectively. The data driving part DDV can be disposed in the non-display area NDA adjacent to any one of the short sides of the display panel DP. The data driving part DDV can be adjacent to the lower end of the display panel DP when viewed in plan.

[0070] The scan lines SL1 to SLm can extend in the first direction DR1 to be connected to the pixels PX and the scan driving part SDV. The data lines DL1 to DLn can extend in the second direction DR2 to be connected to the pixels PX and the data driving part DDV. The light-emitting lines EL1 to ELm can extend in the first direction DR1 to be connected to the pixels PX and the light-emitting driving part EDV.

[0071] The first power line PLL1 can extend in the second direction DR2 to be disposed in the non-display area NDA. The first power line PLL1 can be disposed between the display area DA and the light-emitting driving part EDV, but is not limited thereto, and can be disposed between the display area DA and the scan driving part SDV.

[0072] The connecting line CNL can extend along the first direction DR1 and be arranged along the second direction DR2. The connecting line CNL can be connected to the first power line PLL1 and the pixel PX. A first voltage can be applied to the pixel PX through the interconnected first power line PLL1 and connecting line CNL.

[0073] The second power line PLL2 can be configured in the non-display area NDA. The second power line PLL2 can extend along the long side of the display panel DP and the other short side of the display panel DP where the data driver unit DDV is not configured. The second power line PLL2 can be configured on the outer periphery of the scan driver unit SDV and the light emission driver unit EDV.

[0074] Although not shown, a second power supply line PLL2 may extend toward the display area DA and connect to pixel PX. A second voltage having a lower level than the first voltage may be applied to pixel PX through the second power supply line PLL2.

[0075] The first control line CSL1 can be connected to the scan driver unit SDV, and extends towards the lower end of the display panel DP when viewed in a flat surface. The second control line CSL2 can be connected to the light-emitting driver unit EDV, and extends towards the lower end of the display panel DP when viewed in a flat surface. The data driver unit DDV can be disposed between the first control line CSL1 and the second control line CSL2.

[0076] The pad PD can be configured on the display panel DP. The pad PD can be located adjacent to the lower end of the display panel DP, more so than the data driver unit DDV. The data driver unit DDV, the first power line PLL1, the second power line PLL2, the first control line CSL1, and the second control line CSL2 can be connected to the pad PD. Alternatively, data lines DL1 to DLn can be connected to the data driver unit DDV, and the data driver unit DDV can be connected to the pad PD corresponding to the data lines DL1 to DLn.

[0077] It can be done Figure 2 The multiple unit regions CA shown form the light-emitting elements of the display panel DP. This is done on the fabricated substrate M-SUB (see reference). Figure 1 A unit area corresponding to this display panel (DP) can be defined within the DP. The unit area can be cut after the light-emitting elements are formed within it. As a result, it is possible to manufacture... Figure 6 The display panel shown is DP.

[0078] Although not shown, a timing controller for controlling the operation of the scan drive unit (SDV), the data drive unit (DDV), and the light emission drive unit (EDV), as well as a voltage generation unit for generating the first and second voltages, can be disposed on a printed circuit board. The timing controller and the voltage generation unit can be connected to corresponding pads (PD) via the printed circuit board.

[0079] The scan driving section SDV can generate a plurality of scan signals, which are applied to the pixel PX through the scan lines SL1 to SLm. The data driving section DDV can generate a plurality of data voltages, which are applied to the pixel PX through the data lines DL1 to DLn. The emission driving section EDV can generate a plurality of emission signals, which are applied to the pixel PX through the emission lines EL1 to ELm.

[0080] The pixel PX can receive the data voltage in response to the scan signal. The pixel PX can display an image by emitting light of a luminance corresponding to the data voltage in response to the emission signal. The emission time of the pixel PX can be controlled by the emission signal.

[0081] The wiring can include the data lines DL1 to DLn. The pad connected to the wiring can include Figure 6 The display panel DP in which the emission layer of the pixel PX is not formed can be defined as the aforementioned processed substrate M-SUB.

[0082] The cross-sectional structure of the processed substrate M-SUB (refer to Figure 1 ) will be described in Figure 7 . The pad PD can be formed in the processed substrate M-SUB, and the processed substrate M-SUB can be defined as a state in which the printed circuit substrate is not connected. The pad PD can be connected to a ground terminal, and the pad PD and the data lines DL1 to DLn can be grounded.

[0083] Figure 7 is a diagram exemplarily showing a cross section of any one of the pixels shown in Figure 6 .

[0084] Referring to Figure 6 and Figure 7 together, the pixel PX can be disposed on the base substrate BS and include the transistor TR and the emission element OLED. The transistor TR and the emission element OLED of the pixel PX can be connected to the aforementioned data lines DL1 to DLn and the first and second power lines PLL1, PLL2. The transistor TR and the emission element OLED of the pixel PX can be connected to the pad PD through the data lines DL1 to DLn and the first and second power lines PLL1, PLL2.

[0085] The emission element OLED can include a first electrode AE, a second electrode CE, a hole control layer HCL, an electron control layer ECL, and an emission layer EML. The first electrode AE can be an anode electrode, and the second electrode CE can be a cathode electrode.

[0086] The transistor TR and the light emitting element OLED can be arranged on the base substrate BS. One transistor TR is exemplarily shown, but substantially one pixel PX can include a plurality of transistors for driving the light emitting element OLED and at least one capacitor.

[0087] The display area DA can include a light emitting area PA corresponding to the pixel PX and a non-light emitting area NPA around the light emitting area PA. The light emitting element OLED can be arranged on the light emitting area PA.

[0088] The base substrate BS can include a flexible plastic substrate. For example, the base substrate BS can include a transparent polyimide (PI). It can be that a buffer layer BFL, which is an inorganic layer, is arranged on the base substrate BS.

[0089] A semiconductor pattern can be arranged on the buffer layer BFL. The semiconductor pattern can include polysilicon. But not limited thereto, the semiconductor pattern can also include amorphous silicon or metal oxide.

[0090] The semiconductor pattern can be doped with an N-type dopant or a P-type dopant. The semiconductor pattern can include a high-doped region and a low-doped region. The high-doped region can have a higher conductivity than the low-doped region, and substantially function as a source electrode and a drain electrode of the transistor TR. The low-doped region can substantially correspond to an active region (or a channel region) of the transistor TR.

[0091] The source S, the active region A, and the drain D of the transistor TR can be formed from the semiconductor pattern. A first insulating layer INS1 can be arranged on the semiconductor pattern. A gate G of the transistor TR can be arranged on the first insulating layer INS1. A second insulating layer INS2 can be arranged on the gate G. A third insulating layer INS3 can be arranged on the second insulating layer INS2.

[0092] A connection electrode CNE can be arranged between the transistor TR and the light emitting element OLED to connect the transistor TR and the light emitting element OLED. The connection electrode CNE can include a first connection electrode CNE1 and a second connection electrode CNE2.

[0093] The first connection electrode CNE1 can be arranged on the third insulating layer INS3 and connected to the drain D through a first contact hole CH1 defined in the first to third insulating layers INS1-INS3. A fourth insulating layer INS4 can be arranged on the first connection electrode CNE1. A fifth insulating layer INS5 can be arranged on the fourth insulating layer INS4.

[0094] The second connection electrode CNE2 can be disposed on the fifth insulating layer INS5. The second connection electrode CNE2 can be connected to the first connection electrode CNE1 through a second contact hole CH2 defined in the fourth insulating layer INS4 and the fifth insulating layer INS5. The sixth insulating layer INS6 can be disposed on the second connection electrode CNE2. The first to sixth insulating layers INS1 to INS6 can be inorganic layers or organic layers.

[0095] The first electrode AE can be disposed on the sixth insulating layer INS6. The first electrode AE can be connected to the second connection electrode CNE2 through a third contact hole CH3 defined in the sixth insulating layer INS6. The pixel definition film PDL exposing a predetermined portion of the first electrode AE can be disposed on the first electrode AE and the sixth insulating layer INS6. An opening portion PX_OP for exposing the predetermined portion of the first electrode AE can be defined in the pixel definition film PDL.

[0096] The hole control layer HCL can be disposed on the first electrode AE and the pixel definition film PDL. The hole control layer HCL can be commonly disposed in the light emitting area PA and the non-light emitting area NPA. The hole control layer HCL can include a hole transport layer and a hole injection layer.

[0097] The light emitting layer EML can be disposed on the hole control layer HCL. The light emitting layer EML can be disposed in an area corresponding to the opening portion PX_OP. The light emitting layer EML can include an organic substance and / or an inorganic substance. The light emitting layer EML can generate light of any one color among red, green, and blue.

[0098] The electron control layer ECL can be disposed on the light emitting layer EML and the hole control layer HCL. The electron control layer ECL can be commonly disposed in the light emitting area PA and the non-light emitting area NPA. The electron control layer ECL can include an electron transport layer and an electron injection layer.

[0099] The second electrode CE can be disposed on the electron control layer ECL. The second electrode CE can be commonly disposed in the pixel PX. Layers from the buffer layer BFL to the light emitting element OLED can be defined as a pixel layer.

[0100] The thin film encapsulation layer TFE can be disposed on the light emitting element OLED. The thin film encapsulation layer TFE can be disposed on the second electrode CE to cover the pixel PX. The thin film encapsulation layer TFE can include at least two inorganic layers and an organic layer between the inorganic layers. The inorganic layer can protect the pixel PX from moisture / oxygen. The organic layer can protect the pixel PX from foreign substances such as dust particles.

[0101] A first voltage can be applied to the first electrode AE through the transistor TR, and a second voltage having a level lower than the first voltage can be applied to the second electrode CE. Holes and electrons injected into the light-emitting layer EML can recombine to form excitons, and the light-emitting element OLED can emit light while the excitons transition to a ground state.

[0102] Figure 8 is a view for explaining Figure 1 a deposition process.

[0103] Referring to Figure 1 , Figure 6 and Figure 8 , a layer provided with the first electrode AE from the base substrate BS can be defined as a processed substrate M-SUB. As described above, the transistor TR can be connected to the pad PD through the data line DL1-DLn. That is, the processed substrate M-SUB can include the data line DL1-DLn defined as the aforementioned wiring and the pad PD connected to the data line DL1-DLn.

[0104] A mask MK can be disposed in a manner facing the processed substrate M-SUB. The mask MK can be disposed in proximity to the processed substrate M-SUB. The deposition material DM can be provided on the processed substrate M-SUB through a plurality of holes OH defined in the mask MK. The light-emitting layer EML can be formed on the processed substrate M-SUB by the deposition material DM.

[0105] Figures 9a to 9e is a sectional view showing a step in a manufacturing method of a mask assembly according to an embodiment of the present application.

[0106] Referring to Figure 9a , a step of forming a preliminary mask frame PF-P and a step of forming a preliminary inorganic layer IL-P can be performed.

[0107] The preliminary mask frame PF-P can include a rectangle in a cross section. The preliminary mask frame PF-P can include an electrically conductive material. The preliminary mask frame PF-P can include silicon. For example, the preliminary mask frame PF-P is formed of a silicon wafer and can include single-crystal silicon. However, the present application is not limited thereto. The preliminary mask frame PF-P can have a predetermined rigidity. For example, the preliminary mask frame PF-P can include a metal material such as stainless steel (SUS), an Invar alloy, nickel (Ni), or cobalt (Co). Although not shown, the preliminary mask frame PF-P can have a circular shape when viewed in the third direction DR3.

[0108] The preliminary inorganic layer IL-P can cover the preliminary mask frame PF-P. That is, the preliminary inorganic layer IL-P can be integrally formed around the preliminary mask frame PF-P. The preliminary inorganic layer IL-P can include a silicon series inorganic substance. The silicon series inorganic substance is not limited to any substance as long as it can be deposited as a film by chemical vapor deposition. Specifically, the preliminary inorganic layer IL-P can include at least one of silicon oxide (SiO x ) and silicon nitride (SiN x ).

[0109] Referring to Figure 9b , an alignment portion ALP can be formed on the preliminary inorganic layer IL-P. The alignment portion ALP can be disposed in correspondence with the plurality of cell opening portions OP-C (refer to Figure 9e ). The alignment portion ALP is a mark for the plurality of cell opening portions OP-C to be formed in correspondence with the plurality of cell areas CA (refer to Figure 2 ) when the plurality of cell opening portions OP-C are formed. According to the formation of the alignment portion ALP, the plurality of cell opening portions OP-C can be formed in correspondence with the plurality of cell areas CA.

[0110] Referring to Figure 9c , a preliminary mask MK-P can be formed on the preliminary inorganic layer IL-P. The preliminary mask MK-P can cover the preliminary inorganic layer IL-P. That is, the preliminary mask MK-P can be integrally formed around the preliminary inorganic layer IL-P.

[0111] The preliminary mask MK-P can include a silicon series inorganic substance. For example, the preliminary mask MK-P can include at least one of silicon oxide (SiO x ) and silicon nitride (SiN x ). The preliminary mask MK-P can be adhered to the preliminary inorganic layer IL-P.

[0112] Referring to Figure 9c and Figure 9d , a step of performing first etching on the preliminary mask MK-P to form a mask MK, a lower layer BL, and a dummy portion DMP connecting the mask MK and the lower layer BL can be performed. Specifically, an upper surface of the preliminary mask MK-P can be etched to form a plurality of holes OH in the mask MK. Also, at the same time, a lower surface of the preliminary mask MK-P can be etched, so that a plurality of lower opening portions OP-B corresponding to the plurality of cell opening portions OP-C (refer to Figure 9e ) to be described later are formed in the lower layer BL. The first etching can be performed by dry etching.

[0113] In an embodiment of the present application, the dummy portion DMP can be omitted. The mask MK and the lower layer BL can be integrally formed. That is, the mask MK and the lower layer BL can be formed as one body. Figure 1The mask MK and the lower layer BL shown have the same structure as each other.

[0114] Referring to Figure 9d and Figure 9e A step of performing a second etching of the preliminary mask frame PF-P and the preliminary inorganic layer IL-P to form the mask frame PF and the inorganic layer IL can be performed. Specifically, a lower portion of the preliminary mask frame PF-P and the preliminary inorganic layer IL-P can be etched to form a plurality of cell opening portions OP-C in the mask frame PF and a plurality of inorganic opening portions OP-L1, OP-L2 in the inorganic layer IL.

[0115] The plurality of lower opening portions OP-B, the plurality of cell opening portions OP-C, and the plurality of inorganic opening portions OP-L1, OP-L2 can be formed side by side with respect to the third direction DR3. However, the present application is not limited thereto, and depending on etching rates of the lower layer BL, the mask frame PF, and the inorganic layer IL, the plurality of lower opening portions OP-B, the plurality of cell opening portions OP-C, and the plurality of inorganic opening portions OP-L1, OP-L2 can be formed to have different widths from each other.

[0116] Figures 10a to 10c is a cross-sectional view showing a step in a manufacturing method of a mask assembly according to an embodiment of the present application.

[0117] Referring to Figure 10a A step of inverting the lower layer BL, the mask frame PF, the inorganic layer IL, and the mask MK upside down can be performed. Although not shown, the plurality of lower opening portions OP-B, the plurality of cell opening portions OP-C, and the plurality of inorganic opening portions OP-L1, OP-L2 can be formed in the lower layer BL, the mask frame PF, and the inorganic layer IL, respectively, before the step of inverting the lower layer BL, the mask frame PF, the inorganic layer IL, and the mask MK upside down is performed. Figure 9e A phenomenon in which the mask MK disposed on the inorganic layer IL sags in a direction opposite to the third direction DR3 due to a load of the mask MK can occur during the process of the mask MK shown. A step of inverting the mask MK upside down to dispose the mask MK bent in the third direction DR3 on the substrate SB can be performed.

[0118] Referring to Figure 10b and Figure 10c A step of fixing the tension portion TP to the lower layer BL can be performed. Specifically, a first fixing step of fixing the first fixing portion FP1 to a portion (e.g., a first portion) of the lower layer BL and a second fixing step of fixing the second fixing portion FP2 to another portion (e.g., a second portion) of the lower layer BL can be performed.

[0119] The tension portion TP can be fixed to the first portion of the lower layer BL by the bonder WBD, and after that, the second portion of the lower layer BL is pulled in the direction opposite to the first direction DR1 to fix the tension portion TP to the second portion of the lower layer BL. The first fixing portion FP1 and the second fixing portion FP2 can include a bonding material. For example, the first fixing portion FP1 and the second fixing portion FP2 can include at least any one of copper (Cu), nickel (Ni), gold (Au), silver (Ag), aluminum (Al), tin (Sn), indium (In), bismuth (Bi), zinc (Zn), antimony (Sb), germanium (Ge), and cadmium (Cd), respectively. The bonding material can be provided at the first portion and the second portion of the lower layer BL, and the tension portion TP can be fixed to the first portion and the second portion of the lower layer BL by heat treatment.

[0120] Unlike the case shown in FIG. 1A, the tension portion TP can not overlap the plurality of holes OH of the mask MK. Specifically, as shown in FIG. 1B, the tension portion TP can be disposed at the peripheral region EA. That is, the tension portion TP can not overlap the plurality of cell regions CA. However, for convenience of explanation, only the case in which the tension portion TP seems to overlap the plurality of cell regions CA (refer to FIG. 1A) is shown in FIG. 1B. Figures 10a to 10c Figure 2 Unlike the case shown in FIG. 1A, the tension portion TP can not overlap the plurality of holes OH of the mask MK. Specifically, as shown in FIG. 1B, the tension portion TP can be disposed at the peripheral region EA. That is, the tension portion TP can not overlap the plurality of cell regions CA. However, for convenience of explanation, only the case in which the tension portion TP seems to overlap the plurality of cell regions CA (refer to FIG. 1A) is shown in FIG. 1B. Figures 10a to 10c Figure 2

[0121] The first portion and the second portion of the lower layer BL can be close to each other with respect to the first direction DR1 by the first fixing step and the second fixing step of the tension portion TP. As a result, the mask MK that is sagged in the direction opposite to the third direction DR3 due to the load can be stretched in the first direction DR1 to prevent sagging in the direction opposite to the third direction DR3, thereby providing the mask MK having reliability.

[0122] The above-described preferred embodiments of the present application have been described, but it will be understood by those skilled in the art or those who have ordinary knowledge in the art that the present application can be variously modified and changed within the scope of the concept and technical field of the present application recited in the appended claims.

[0123] Therefore, the technical scope of the present application is not limited by the contents recited in the detailed description of the specification, but should be defined by the claims.​​​

Claims

1. A mask assembly, wherein, comprises: a mask support portion in which a plurality of unit opening portions are defined; a mask disposed on the mask support portion and including a plurality of unit regions overlapping the plurality of unit opening portions and a peripheral region surrounding the plurality of unit regions; and a tension portion disposed below the mask support portion and overlapping the peripheral region, one side of the tension portion and the other side of the tension portion opposite to the one side are fixed from the mask support portion, respectively.

2. The mask assembly according to claim 1, wherein the tension portion comprises: a first fixed portion corresponding to the one side; a second fixed portion corresponding to the other side; and a connection portion connecting the first fixed portion and the second fixed portion.

3. The mask assembly according to claim 2, wherein the connection portion extends in a first direction and overlaps at least one of the plurality of unit regions in a plane with respect to a second direction perpendicular to the first direction.

4. The mask assembly according to claim 1, wherein the tension portion comprises: a first tension portion extending in a first direction; and a second tension portion extending in a second direction perpendicular to the first direction.

5. The mask assembly according to claim 4, wherein the first tension portion and the second tension portion are provided as a plurality, respectively.

6. The mask assembly according to claim 1, wherein the peripheral region comprises: a separation region dividing the plurality of unit regions; and a dummy region surrounding the separation region.

7. The mask assembly according to claim 6, wherein the tension portion overlaps the separation region and does not overlap the dummy region, the tension portion is fixed from the mask support portion in the entire separation region.

8. The mask assembly according to claim 6, wherein the tension portion overlaps the separation region and the dummy region, the tension portion is fixed from the mask support portion in the entire separation region and the dummy region.

9. The mask assembly according to claim 1, wherein the mask support portion comprises a mask frame and a lower layer disposed below the mask frame, the lower layer comprises the same substance as the mask.

10. The mask assembly according to claim 9, wherein the mask frame comprises a silicon wafer.

11. The mask assembly according to claim 9, wherein the mask support portion further comprises: a first inorganic layer disposed between the mask frame and the mask; and a second inorganic layer disposed between the mask frame and the lower layer.

12. The mask assembly according to claim 1, wherein the mask assembly further comprises: an alignment portion disposed on the mask support portion.

13. The mask assembly according to claim 1, wherein the mask support portion and the mask have a circular shape in a plane, respectively. comprises:

14. A method of manufacturing a mask assembly, wherein, a step of forming a preliminary mask frame having electrical conductivity; a step of forming a preliminary mask on the preliminary mask frame; a step of forming a plurality of holes through the preliminary mask to form a mask; and a step of forming a mask. forming a plurality of unit opening portions in the preliminary mask frame to form a mask frame; and fixing a tension portion, which does not overlap the plurality of unit opening portions on a plane, to the mask frame.

15. The method of manufacturing a mask assembly according to claim 14, wherein the step of fixing the tension portion to the mask frame includes: a first fixing step of fixing one side of the tension portion to a first portion of the mask frame; and a second fixing step of fixing the other side of the tension portion, which is opposite to the one side of the tension portion, to a second portion of the mask frame which is separated from the first portion of the mask frame in a first direction.

16. The method of manufacturing a mask assembly according to claim 15, wherein the first portion and the second portion are brought close to each other in the first direction by the first fixing step and the second fixing step.

17. The method of manufacturing a mask assembly according to claim 15, wherein the mask is stretched in the first direction by the first fixing step and the second fixing step.

18. The method of manufacturing a mask assembly according to claim 14, wherein the method of manufacturing a mask assembly further includes a step of forming an alignment portion on the preliminary mask frame before the step of forming the preliminary mask.

19. The method of manufacturing a mask assembly according to claim 14, wherein the method of manufacturing a mask assembly further includes a step of turning the mask and the mask frame upside down before the step of fixing the tension portion to the mask frame.

20. The method of manufacturing a mask assembly according to claim 14, wherein the mask frame and the mask each have a circular shape on a plane.

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