KR20230161299A - Display apparatus and manufacturing the same - Google Patents

Abstract

The present invention provides a display element including a pixel electrode, a light-emitting layer containing a light-emitting material, and a counter electrode, a first bank layer having a first opening exposing a central portion of the pixel electrode, and disposed on the first bank layer, a second bank layer having a second opening overlapping the first opening, and a residual sacrificial layer located between the first bank layer and the second bank layer and overlapping the second bank layer; A display device is provided in which the top surface of the bank layer and the inner surface of the second bank layer defining the second opening are liquid-repellent.

Description

Display device and manufacturing method thereof {Display apparatus and manufacturing the same}

The present invention relates to a display device and a method of manufacturing the same.

Generally, a display device includes a plurality of pixels that receive electrical signals and emit light in order to display an image. A pixel of an Organic Light Emitting Display Device (OLED) includes an organic light emitting diode as a display element. The organic light emitting diode includes a pixel electrode, a light emitting layer, and a counter electrode. The light-emitting layer of an organic light-emitting diode can be formed by discharging ink containing a light-emitting material onto the pixel electrode.

However, in these conventional display devices and their manufacturing methods, there was a problem in that it was difficult to form a uniform thickness of the light emitting layer of the organic light emitting diode. The present invention is intended to solve various problems including the problems described above, and its purpose is to provide a display device that displays high-quality images by improving the thickness uniformity of the light-emitting layer and a method of manufacturing the same. However, these tasks are illustrative and do not limit the scope of the present invention.

According to one aspect of the present invention, a display element including a pixel electrode, a light-emitting layer including a light-emitting material, and a counter electrode, a first bank layer having a first opening exposing a central portion of the pixel electrode, and an upper portion of the first bank layer. It is disposed in and includes a second bank layer having a second opening overlapping the first opening and a residual sacrificial layer located between the first bank layer and the second bank layer and overlapping the second bank layer; , the upper surface of the second bank layer and the inner surface of the second bank layer defining the second opening are provided with a display device having liquid repellency.

In one embodiment, the inner surface of the remaining sacrificial layer is located between the inner surface of the first bank layer defining the first opening and the inner surface of the second bank layer, and the boundary of the light emitting layer is the remaining sacrificial layer. It may be located on the inner surface of or the inner surface of the first bank layer adjacent to the inner surface of the remaining sacrificial layer.

In one embodiment, the surface of the first bank layer may have lyophilic properties.

In one embodiment, the top surface of the pixel electrode may have lyophilic properties.

In one embodiment, the lower surface of the second bank layer in contact with the remaining sacrificial layer may have lyophilic properties.

In one embodiment, a plurality of pixel electrodes are provided to be spaced apart from each other along a first direction, a plurality of first openings are provided corresponding to each of the plurality of pixel electrodes, and the second openings are provided in plurality of the plurality of pixel electrodes. It may have a line shape extending in the first direction so as to overlap the first openings.

In one embodiment, the light emitting layer may be provided integrally along the first direction.

In another embodiment, a plurality of the pixel electrodes may be provided to be spaced apart from each other along a first direction, and a plurality of the first openings and the second openings may be provided to correspond to each of the plurality of pixel electrodes.

In one embodiment, a plurality of light emitting layers may be formed to correspond to each of the plurality of pixel electrodes.

In one embodiment, the thickness of the first bank layer may be 200 nm to 500 nm.

In one embodiment, the thickness of the second bank layer may be 500 nm to 1,000 nm.

In one embodiment, the remaining sacrificial layer may include tungsten oxide (WO _x ), molybdenum oxide (MoO _x ), or a mixture thereof.

According to another aspect of the present invention, forming a pixel electrode on a substrate, forming a first bank layer having a first opening exposing a central portion of the pixel electrode, and forming a sacrificial layer on the first bank layer. forming a second bank layer having a second opening overlapping the first opening on the sacrificial layer, performing plasma treatment on the front surface of the substrate where the second bank layer is located. forming a remaining sacrificial layer by removing the sacrificial layer exposed through the second opening, and forming a light-emitting layer by discharging ink containing a light-emitting material on the pixel electrode. A manufacturing method is provided.

In one embodiment, the inner surface of the remaining sacrificial layer is located between the inner surface of the first bank layer defining the first opening and the inner surface of the second bank layer defining the second opening, and the light emitting layer is positioned between the inner surface of the first bank layer defining the first opening. The boundary of the ink containing the material may be located on the inner side of the remaining sacrificial layer or on the inner side of the first bank layer adjacent to the inner side of the remaining sacrificial layer.

In one embodiment, in the plasma treatment step, the top surface of the second bank layer, the inner surface of the second bank layer, and the top surface of the sacrificial layer exposed through the second opening may have liquid repellency. .

In one embodiment, the sacrificial layer may include tungsten oxide (WO _x ), molybdenum oxide (MoO _x ), or a mixture thereof.

In one embodiment, the sacrificial layer may have a thickness of 20 nm to 50 nm.

In one embodiment, the surface of the first bank layer and the top surface of the pixel electrode may have lyophilic properties.

In one embodiment, a plurality of pixel electrodes are formed to be spaced apart from each other along a first direction, a plurality of first openings are formed corresponding to each of the plurality of pixel electrodes, and the second openings are formed in a plurality of the plurality of pixel electrodes. It may be formed to have a line shape extending in the first direction so as to overlap the first openings.

In one embodiment, in forming the light-emitting layer, ink containing the light-emitting material may be discharged along the first direction, and the light-emitting layer may be formed integrally along the first direction.

In one embodiment, a plurality of pixel electrodes may be formed to be spaced apart from each other along a first direction, and a plurality of first openings and second openings may be formed to correspond to each of the plurality of pixel electrodes.

In one embodiment, in forming the light-emitting layer, a plurality of light-emitting layers may be formed to correspond to each of the plurality of pixel electrodes.

Other aspects, features and advantages in addition to those described above will become apparent from the following drawings, claims and detailed description of the invention.

According to an embodiment of the present invention as described above, a display device that displays high-quality images by improving the thickness uniformity of the light-emitting layer and a method of manufacturing the same can be implemented. Of course, the scope of the present invention is not limited by this effect.

1 is a perspective view schematically showing a display device according to an embodiment of the present invention.
Figure 2 is an equivalent circuit diagram of one pixel included in a display device according to an embodiment of the present invention.
Figure 3a is a cross-sectional view schematically showing a display device according to an embodiment of the present invention.
Figure 3b is a cross-sectional view schematically showing a display device according to an embodiment of the present invention.
Figure 4 is a plan view schematically showing a display device according to an embodiment of the present invention.
Figure 5 is a plan view schematically showing a display device according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view schematically showing a cross-section of the display device of FIG. 5 taken along line I-I'.
Figure 7 is a cross-sectional view schematically showing a cross-section taken along line II-II' of the display device of Figure 5.
Figure 8 is a plan view schematically showing a display device according to an embodiment of the present invention.
FIG. 9 is a cross-sectional view schematically showing a cross-section taken along line III-III' of the display device of FIG. 8.
FIG. 10 is a cross-sectional view schematically showing a cross-section taken along line IV-IV' of the display device of FIG. 8.
11 to 16 are cross-sectional views sequentially showing a method of manufacturing a display device according to an embodiment of the present invention.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be assigned the same reference numerals and redundant description thereof will be omitted. .

In this specification, terms such as first and second are used not in a limiting sense but for the purpose of distinguishing one component from another component.

In this specification, singular expressions include plural expressions, unless the context clearly dictates otherwise.

In this specification, terms such as include or have mean that the features or components described in the specification exist, and do not exclude in advance the possibility of adding one or more other features or components.

In this specification, when a part of a membrane, region, component, etc. is said to be on or on another part, it does not only mean that it is directly on top of the other part, but also when another membrane, region, component, etc. is interposed between them. Includes.

In this specification, when membranes, regions, components, etc. are said to be connected, the membranes, regions, and components are directly connected, or/and other membranes, regions, and components are interposed between the membranes, regions, and components. This also includes cases where it is indirectly connected. For example, in this specification, when membranes, regions, components, etc. are said to be electrically connected, when the membranes, regions, components, etc. are directly electrically connected, and/or other membranes, regions, components, etc. are interposed. indicates a case of indirect electrical connection.

In this specification, “A and/or B” refers to A, B, or A and B. And, “at least one of A and B” indicates the case of A, B, or A and B.

In this specification, the x-axis, y-axis, and z-axis are not limited to the three axes in the Cartesian coordinate system, but can be interpreted in a broad sense including these. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but may also refer to different directions that are not orthogonal to each other.

In cases where an embodiment can be implemented differently in this specification, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially at the same time, or may be performed in an order opposite to that in which they are described.

In the drawings, the sizes of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are shown arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is shown.

In this specification, a display device is a device that displays images and may be a portable mobile device such as a game console, multimedia device, or ultra-small PC. Display devices to be described later include a liquid crystal display device, an electrophoretic display device, an organic light emitting display device, an inorganic light emitting display device, and a field emission display device ( Field Emission Display, Surface-conduction Electron-emitter Display, Quantum dot display, Plasma Display, Cathode Ray Display, etc. can do. Hereinafter, a display device according to an embodiment of the present invention will be described by taking an organic light emitting display device as an example. However, various types of display devices as described above may be used in embodiments of the present invention.

Figure 1 is a perspective view schematically showing a display device 1 according to an embodiment of the present invention.

Referring to FIG. 1 , the display device 1 may include a display area (DA) and a non-display area (NDA) on the substrate 100 .

The display area (DA) can implement an image. In the display area DA, a plurality of pixels PX may be arranged two-dimensionally on a plane. In this specification, each pixel (PX) refers to a sub-pixel that emits different colors, and each pixel (PX) may be, for example, one of a red sub-pixel, a green sub-pixel, and a blue sub-pixel. You can. The display device 1 can provide an image using light emitted from a plurality of pixels (PX).

The non-display area (NDA) is an area that does not provide an image, and pixels (PX) are not arranged. The non-display area (NDA) may entirely surround the display area (DA). In the non-display area (NDA), drivers or voltage wiring, etc. may be placed to provide electrical signals or power to the pixels (PX). The non-display area (NDA) may include a pad portion (not shown), which is an area where electronic devices, printed circuit boards, etc. can be electrically connected.

The display area DA may have a polygonal shape. For example, the display area DA may have a rectangular shape with a horizontal length greater than a vertical length, as shown in FIG. 1 . Alternatively, the display area DA may have a square shape. Alternatively, the display area DA may have various shapes, such as an ellipse or a circle.

Figure 2 is an equivalent circuit diagram of one pixel (PX) included in a display device according to an embodiment of the present invention.

Referring to FIG. 2 , the pixel PX may include a pixel circuit (PC) and a display element connected to the pixel circuit (PC), for example, an organic light emitting diode (OLED). The pixel circuit (PC) may include a first thin film transistor (T1), a second thin film transistor (T2), and a storage capacitor (Cst). Each pixel (PX) may emit, for example, red, green, or blue light, or may emit red, green, blue, or white light through an organic light emitting diode (OLED).

The second thin film transistor (T2) is a switching thin film transistor, connected to the scan line (SL) and the data line (DL), and is connected to the data line (DL) according to the switching voltage or switching signal (Sn) input from the scan line (SL). ) can be transmitted to the first thin film transistor (T1). The storage capacitor (Cst) is connected to the second thin film transistor (T2) and the driving voltage line (PL), and is connected to the voltage received from the second thin film transistor (T2) and the first power voltage (ELVDD) supplied to the driving voltage line (PL). The voltage corresponding to the difference can be stored.

The first thin film transistor (T1) is a driving thin film transistor, which is connected to the driving voltage line (PL) and the storage capacitor (Cst), and emits an organic light emitting diode (OLED) from the driving voltage line (PL) in response to the voltage value stored in the storage capacitor (Cst). The driving current flowing through the OLED can be controlled. Organic light-emitting diodes (OLEDs) can emit light with a certain brightness by driving current. The opposing electrode (eg, cathode) of the organic light emitting diode (OLED) may be supplied with the second power voltage (ELVSS).

Figure 2 illustrates that the pixel circuit (PC) includes two thin film transistors and one storage capacitor. However, in other embodiments, the number of thin film transistors and the number of storage capacitors vary depending on the design of the pixel circuit (PC). may be changed.

Figure 3a is a cross-sectional view schematically showing a display device 1 according to an embodiment of the present invention. Figure 3b is a cross-sectional view schematically showing a display device 1 according to another embodiment of the present invention.

Referring to FIG. 3A, the display device 1 may include a display layer (DPL) and a thin film encapsulation layer (TFE) on the substrate 100. The display layer (DPL) may include a pixel circuit layer (PCL) including a pixel circuit and insulating layers, and a display element layer (DEL) disposed on the pixel circuit layer (PCL) and including a plurality of display elements.

The substrate 100 may include glass, metal, or polymer resin. Polymer resins include, for example, polyethersulphone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, and polyphenylene sulfide. , polyarylate, polyimide, polycarbonate, cellulose acetate propionate, or mixtures thereof. Of course, the substrate 100 includes two layers containing such a polymer resin and an inorganic material (such as silicon oxide (SiO _x ), silicon nitride (SiN _x ), silicon oxynitride (SiON), etc.) sandwiched between the layers. Various modifications are possible, such as having a multi-layer structure including a barrier layer.

The display element layer DEL may include display elements, for example, organic light emitting diodes. The pixel circuit layer (PCL) may include a pixel circuit connected to an organic light emitting diode and insulating layers. For example, the pixel circuit layer (PCL) may include a plurality of transistors, a plurality of storage capacitors, and insulating layers interposed between them.

The display elements may be covered with an encapsulation material such as a thin film encapsulation layer (TFE). The thin film encapsulation layer (TFE) may include at least one inorganic encapsulation layer and at least one organic encapsulation layer covering the display element layer (DEL). The inorganic encapsulation layer is aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), hafnium oxide (HfO ₂ ), zinc oxide (ZnO), silicon oxide (SiO _x ), and silicon. It may include an inorganic insulating material such as nitride (SiN _x ) or silicon oxynitride (SiON). The organic encapsulation layer may include a polymer-based material. Polymer-based materials may include acrylic resin, epoxy resin, polyimide, and polyethylene. In one embodiment, the organic encapsulation layer may include acrylate.

Referring to FIG. 3B, the display device 1 may include a display layer (DPL) and a sealing substrate 400 on the substrate 100. A sealing member 300 may be disposed between the substrate 100 and the sealing substrate 400. The sealing substrate 400 may be a transparent member. The substrate 100 and the sealing substrate 400 may be joined by a sealing member 300, so that the internal space between the substrate 100 and the sealing substrate 400 is sealed. At this time, moisture absorbents or fillers, etc. may be located in the internal space. The sealing member 300 may be a sealant, and in another embodiment, the sealing member 300 may be made of a material that is hardened by a laser. For example, the sealing member 300 may be a frit. Specifically, the sealing member 300 may be made of an organic sealant such as urethane resin, epoxy resin, or acrylic resin, or an inorganic sealant such as silicone. As the urethane-based resin, for example, urethane acrylate can be used. As the acrylic resin, for example, butyl acrylate, ethyl helsyl acrylate, etc. can be used. Meanwhile, the sealing member 300 may be made of a material that hardens by heat.

In some embodiments, the display element layer DEL may be covered by the sealing substrate 400 and the sealing member 300 of FIG. 3B along with the thin film encapsulation layer (TFE) of FIG. 3A.

A touch electrode layer (not shown) may be disposed on the thin film encapsulation layer (TFE) and/or the sealing substrate 400, and an optical function layer (not shown) may be disposed on the touch electrode layer. The touch electrode layer can acquire coordinate information according to an external input, for example, a touch event. The optical functional layer can reduce the reflectance of light (external light) incident from the outside toward the display device 1. Alternatively, the optical functional layer can improve the color purity of light emitted from the display device 1. In one embodiment, the optical functional layer may include a phase retarder and/or a polarizer. The phase retarder may be a film type or a liquid crystal coating type, /2 phase retardant and/or /4 may include a phase retardant. The polarizer may also be a film type or a liquid crystal coating type. The film type may include a stretched synthetic resin film, and the liquid crystal coating type may include liquid crystals arranged in a predetermined arrangement. The phase retarder and polarizer may further include a protective film.

In another embodiment, the optical functional layer may include a black matrix and color filters. Color filters may be arranged taking into account the color of light emitted from each pixel of the display device 1. Each of the color filters may contain red, green, or blue pigments or dyes. Alternatively, each of the color filters may further include quantum dots in addition to the pigments or dyes described above. Alternatively, some of the color filters may not contain the above-mentioned pigments or dyes, but may contain scattering particles such as titanium oxide.

An adhesive member may be disposed between the touch electrode layer and the optical function layer. The adhesive member may be any general material known in the art without limitation. In one embodiment, the adhesive member may be a pressure sensitive adhesive (PSA).

FIG. 4 is a plan view schematically showing a display device according to an embodiment of the present invention, FIG. 5 is a cross-sectional view schematically showing a cross section along line I-I' of the display device of FIG. 4, and FIG. This is a cross-sectional view schematically showing the cross-section along the line II-II' of the display device.

Referring to FIG. 4, a plurality of pixel electrodes 210 arranged two-dimensionally on a plane may be disposed in the display area DA. The pixel electrodes 210 may be arranged to be spaced apart by a predetermined distance in the first direction (eg, -y direction) and the second direction (eg, x direction). For example, the first pixel electrode 211 and the second pixel electrode 212 are spaced apart by a predetermined distance along the first direction (e.g. -y direction), and the first pixel electrode 211 and the third pixel electrode ( 213) may be spaced apart by a predetermined distance along the second direction (eg, x direction).

In one embodiment, when viewed on a plane, the pixel electrodes 210 may have various shapes, such as rectangular, diamond, square, circular, or oval shapes. In this regard, Figure 4 shows that the pixel electrodes 210 have a rectangular shape with long sides in the first direction (eg, -y direction), but the present invention is not limited thereto.

In one embodiment, the pixel electrode 210 may include a conductive material including molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), and a multilayer or It can be formed as a single layer. In one embodiment, the pixel electrode 210 is made of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium oxide (In ₂ O ₃ ). It may include a conductive oxide such as indium oxide (IGO), indium gallium oxide (IGO), or aluminum zinc oxide (AZO). In one embodiment, the pixel electrode 210 is made of silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), and neodymium (Nd). , may include a reflective film containing iridium (Ir), chromium (Cr), or a compound thereof. In one embodiment, the pixel electrode 210 may have a multilayer structure of ITO/Ag/ITO.

In one embodiment, the surface of the pixel electrode 210 may have lyophilic properties. In this specification, lyophilicity refers to the property of having excellent affinity for a given solution, and as a different property, lyophilicity refers to the property of repelling a given solution and preventing the solution from permeating well.

For example, a given solution has excellent surface bonding strength with a lyophilic surface, so the surface tension of a given solution placed on a lyophilic surface may decrease. A given solution has a low surface bonding force with a liquid-repellent surface, and a given solution disposed on a liquid-repellent surface may have high surface tension.

As the lyophilicity increases or the surface tension decreases, the contact angle, which is the angle formed between the tangent to the surface of the given solution and one surface on which the given solution is located, may decrease. Likewise, as the liquid repellency increases or the surface tension increases, the contact angle between a given surface and one side where the given solution is located may increase.

Here, the predetermined solution may be an ink containing a light-emitting material forming a light-emitting layer, or a solvent for the ink. In this specification, a surface having lyophilicity may be a surface having a contact angle of 5° or less based on a methyl benzonate (MeB) solution. Additionally, the surface having liquid repellency may be a surface having a contact angle of 60° or more based on the methylbenzonate solution.

The first bank layer 121 may be arranged to cover the edges of each of the plurality of pixel electrodes 210. In other words, the first bank layer 121 may have a plurality of first openings 121OP exposing the center of each pixel electrode 210. The first openings 121OP may be arranged to be spaced apart from each other by a predetermined distance in a first direction (e.g., -y direction) and a second direction (e.g., x direction) on a plane, corresponding to the pixel electrodes 210. there is.

For example, the first bank layer 121 has a 1-1 opening (121OP1) exposing the center of the first pixel electrode 211 and a 1-2 opening (121OP2) exposing the center of the second pixel electrode 212. ) and a first-third opening 121OP3 exposing the center of the third pixel electrode 213. The 1-1 opening (121OP1) and the 1-2 opening (121OP2) are spaced apart by a predetermined distance along the first direction (e.g. -y direction), and the 1-1 opening (121OP1) and the 1-3 opening The openings 121OP3 may be spaced apart by a predetermined distance along the second direction (eg, x direction).

In one embodiment, as shown in FIG. 4, the first opening 121OP may have a rectangular shape with long sides in the first direction (e.g., -y direction), similar to the corresponding pixel electrode 210. there is. In one embodiment, the first opening 121OP may have a shape different from that of the corresponding pixel electrode 210. The light emitting area of the display element can be defined by the first opening 121OP, and hereinafter, the shape and position of the pixel in this specification may mean the shape and position of the light emitting area of the display element.

In one embodiment, as shown in FIG. 4, the first bank layer 121 has a partition extending in a first direction (eg, -y direction) and a partition extending in a second direction (eg, x direction). It may have an intersecting grid shape.

The first bank layer 121 may include an inorganic insulating material or an organic insulating material. In one embodiment, the first bank layer 121 may include silicon oxide (SiO _x ), silicon nitride (SiN _x ), silicon oxynitride (SiON), etc. In one embodiment, the first bank layer 121 may include an epoxy-based polymer, an acrylic-based polymer, or a mixture thereof.

The surface of the first bank layer 121 may have lyophilic properties. Alternatively, at least the top surface of the first bank layer 121 exposed through the second opening 125OP and the inner surface of the first bank layer 121 defining the first opening 121OP may have lyophilic properties.

The second bank layer 125 may be located on the first bank layer 121. In one embodiment, the second bank layer 125 may include second openings 125OP that expose the central portions of the pixel electrodes 210 arranged along the first direction (eg, -y direction). The second openings 125OP have a line shape extending along a first direction (eg, -y direction) and may overlap a plurality of first openings 121OP. In this regard, Figure 4 shows the line-shaped 2-1 opening 125OPL1 exposing the central portions of the first pixel electrode 211 and the second pixel electrode 212, and the 1-1 opening 121OP1 and the second pixel electrode 212. It is shown overlapping with 1-2 openings (121OP2). The line-shaped 2-2 opening 125OPL2 may be spaced apart from the 2-1 opening 125OPL1 by a predetermined distance in the second direction (eg, x direction).

In one embodiment, the second bank layer 125 may cover edges extending in the first direction (eg, -y direction) of the pixel electrodes 210 on a plane. For example, as shown in FIG. 4, the second bank layer 125 may have a partition extending in the first direction (eg, -y direction). The partition wall extending in the first direction (eg, -y direction) of the second bank layer 125 may overlap with the partition wall extending in the first direction (eg, -y direction) of the first bank layer 121. . The partition wall extending in the second direction (eg, x direction) of the first bank layer 121 may be exposed through the second opening 125OP. For example, a portion of the first bank layer 121 located between the 1-1 opening 121OP1 and the 1-2 opening 121OP2 may be exposed by the line-shaped 2-1 opening 125OPL1.

The second bank layer 125 may include an organic insulating material. For example, the second bank layer 125 may include an epoxy-based photosensitive resin, an acrylic-based photosensitive resin, or a mixture thereof. In one embodiment, the second bank layer 125 may include positive photosensitive resin. In one embodiment, the second bank layer 125 may be photosensitive polyimide. The top surface of the second bank layer 125 and the inner surface of the second bank layer 125 defining the second opening 125OP may be liquid-repellent. On the other hand, in one embodiment, the lower surface of the second bank layer 125 may have lyophilic properties.

As described above, in this specification, the location and shape of the pixel may correspond to the location and shape of the light emitting area defined by the first opening 121OP of the first bank layer 121. For example, the first pixel (PX1) corresponds to the 1-1 opening (121OP1), the second pixel (PX2) corresponds to the 1-2 opening (121OP2), and the third pixel (PX3) corresponds to the 1-1 opening (121OP1). It can support 3 districts (121OP3).

The first pixel (PX1) and the second pixel (PX2) are arranged along the first direction (e.g. -y direction) to form a first column, and the third pixel (PX3) and fourth pixel (PX4) are in the first column. They are arranged along a direction (e.g., -y direction) to form the second column, and the fifth pixel (PX5) and the sixth pixel (PX6) are arranged along the first direction (e.g., -y direction) to form the third row. It can be achieved. Likewise, the first pixel (PX1), the third pixel (PX3), and the fifth pixel (PX5) are arranged along the second direction (e.g., x direction) to form the first row, and the second pixel (PX2) The fourth pixel (PX4) and the sixth pixel (PX6) may be arranged along the second direction (eg, x direction) to form the second row.

Pixels arranged in the same row may emit light in the same color. For example, the first pixel (PX1) and the second pixel (PX2) emit light in the first color, the third pixel (PX3) and the fourth pixel (PX4) emit light in the second color, and the fifth pixel (PX5) and the sixth pixel (PX6) can emit light in a third color. Here, the first color, second color, and third color may be red, green, or blue, respectively. Accordingly, pixels arranged in the same row may include the same light emitting material.

Figure 4 shows that the size (or area) of each pixel is the same, but the size (or area) of the pixel may be different depending on the color it emits. For example, the size (or area) of a pixel that emits green light may be smaller than the size (or area) of a pixel that emits red or blue light.

Referring to Figures 5 and 6, a pixel circuit layer (PCL) may be disposed on the substrate 100. The pixel circuit layer (PCL) includes a first transistor (TR1), a second transistor (TR2), and a third transistor (TR3), a buffer layer 111 disposed below or/and above the components of the transistors, and a first gate insulation. It may include a layer 113, a second gate insulating layer 115, an interlayer insulating layer 117, and a planarization layer 119. Here, the first transistor (TR1), the second transistor (TR2), and the third transistor (TR3) may correspond to the first thin film transistor (T1) shown in FIG. 2. Since the structure of the second transistor TR2 and the third transistor TR3 are the same or similar to the structure of the first transistor TR1, overlapping descriptions thereof will be omitted.

The buffer layer ₁₁₁ may include an inorganic insulating material _such as silicon nitride (SiN . The buffer layer 111 may serve to increase the smoothness of the upper surface of the substrate 100 and prevent or minimize impurities from penetrating into the semiconductor layer (Act) from the substrate 100, etc.

The first transistor TR1 includes a semiconductor layer (Act), and the semiconductor layer (Act) may include polysilicon. Alternatively, the semiconductor layer (Act) may include amorphous silicon, an oxide semiconductor material, or an organic semiconductor material.

The gate electrode (GE) may overlap a portion of the semiconductor layer (Act). The gate electrode (GE) may include a conductive material. For example, the gate electrode GE may include a conductive material such as molybdenum (Mo), aluminum (Al), or titanium (Ti), and may have a multi-layer structure or a single-layer structure including the above materials.

The first gate insulating layer 113 between the semiconductor layer (Act) and the gate electrode (GE) is made of silicon oxide (SiO ₂ ), silicon nitride (SiN _x ), silicon oxynitride (SiON), and aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), hafnium oxide (HfO ₂ ), or zinc oxide (ZnO ₂ ).

The second gate insulating layer 115 may be provided to cover the gate electrode GE. Similar to the first gate insulating layer 113, the second gate insulating layer 115 is made of silicon oxide (SiO _x ), silicon nitride (SiN _x ), silicon oxynitride (SiON), aluminum oxide (Al ₂ O ₃ ), It may include an inorganic insulating material such as titanium oxide (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), hafnium oxide (HfO ₂ ), or zinc oxide (ZnO ₂ ).

The upper electrode (CE2) of the storage capacitor (Cst) may be disposed on the second gate insulating layer 115. The upper electrode (CE2) may overlap the gate electrode (GE) below it. At this time, the gate electrode GE and the upper electrode CE2 that overlap with the second gate insulating layer 115 therebetween may form a storage capacitor Cst. That is, the gate electrode (GE) can function as the lower electrode (CE1) of the storage capacitor (Cst).

In this way, the storage capacitor Cst and the first transistor TR1 may be arranged to overlap. In some embodiments, the storage capacitor Cst may be arranged not to overlap the first transistor TR1.

The upper electrode (CE2) is aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), and iridium (Ir). , may contain conductive materials such as chromium (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), or copper (Cu), and may have a single-layer or multi-layer structure of the foregoing materials. You can have

The interlayer insulating layer 117 may cover the upper electrode (CE2). The interlayer insulating layer 117 is made of silicon oxide (SiO ₂ ), silicon nitride (SiN _x ), silicon oxynitride (SiON), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), and tantalum oxide (Ta ₂ O ₅ ), hafnium oxide (HfO ₂ ), or zinc oxide (ZnO ₂ ). The interlayer insulating layer 117 may have a single-layer structure or a multi-layer structure including the above-described inorganic insulating material.

The drain electrode (SD1) and the source electrode (SD2) may each be located on the interlayer insulating layer 117. The drain electrode (SD1) and the source electrode (SD2) are connected to the semiconductor layer (Act) through contact holes provided in the first gate insulating layer 113, the second gate insulating layer 115, and the interlayer insulating layer 117, respectively. Can be electrically connected. The drain electrode (SD1) and the source electrode (SD2) may include a material with good conductivity. The drain electrode (SD1) and the source electrode (SD2) may contain a conductive material including molybdenum (Mo), aluminum (Al), copper (Cu), or titanium (Ti), and may include the above materials. It may have a multi-layer structure or a single-layer structure. In one embodiment, the drain electrode (SD1) and the source electrode (SD2) may have a multilayer structure of Ti/Al/Ti. In one embodiment, one of the drain electrode (SD1) and the source electrode (SD2) may be omitted, and a portion of the semiconductor layer (Act) may be made conductive to replace it.

The planarization layer 119 covers the first transistor TR1 and may include a contact hole exposing a portion of the first transistor TR1. The planarization layer 119 may include an organic insulating layer. The planarization layer 119 is made of general-purpose polymers such as polymethylmethacrylate (PMMA) or polystyrene (PS), polymer derivatives with phenolic groups, acrylic polymers, imide polymers, aryl ether polymers, amide polymers, fluorine polymers, p- It may include organic insulating materials such as xylene-based polymers, vinyl alcohol-based polymers, and blends thereof.

A display element layer (DEL) may be disposed on the pixel circuit layer (PCL). The display element layer (DEL) includes the first organic light-emitting diode (OLED1), the second organic light-emitting diode (OLED2), and the third organic light-emitting diode (OLED3), and a first organic light-emitting diode (OLED1) disposed below or/and above the components of the organic light-emitting diode (OLED3). It may include a first bank layer 121, a remaining sacrificial layer 123, and a second bank layer 125. Since the structure of the second organic light emitting diode (OLED2) and the third organic light emitting diode (OLED3) are the same or similar to the structure of the first organic light emitting diode (OLED1), overlapping descriptions thereof will be omitted.

In one embodiment, the first pixel electrode 211 may be disposed on the pixel circuit layer (PCL). The first pixel electrode 211 may be electrically connected to the drain electrode (SD1) or the source electrode (SD2) of the first transistor (TR1) through a contact hole penetrating the planarization layer (119). As shown in FIGS. 4 and 5 , the second pixel electrode 212 may be arranged to be spaced apart from the first pixel electrode 211 by a predetermined distance in a first direction (eg, -y direction). As shown in FIGS. 4 and 6 , the third pixel electrode 213 may be disposed at a predetermined distance from the first pixel electrode 211 in the second direction (eg, x-direction).

The first bank layer 121 may be disposed on the pixel circuit layer (PCL). The first bank layer 121 includes a 1-1 opening 121OP1 exposing the central portion of the first pixel electrode 211, a 1-2 opening 121OP2 exposing the central portion of the second pixel electrode 212, and It may have a 1-3 opening 121OP3 exposing the central portion of the third pixel electrode 213. The 1-1 opening (121OP1) defines the light emitting area (EA1) of the first organic light emitting diode (OLED1), and the 1-2 opening (121OP2) defines the light emitting area (EA2) of the second organic light emitting diode (OLED2). and the 1-3 opening 121OP3 may define the light emitting area EA3 of the third organic light emitting diode OLED3. Additionally, the first bank layer 121 serves to prevent arcs from occurring at the edges of the pixel electrodes 210 by increasing the distance between the edges of the pixel electrodes 210 and the opposing electrode 230.

The first bank layer 121 may have a first thickness t1. The first thickness t1 may be about 200 nm to about 500 nm.

The second bank layer 125 may be disposed on the first bank layer 121. The second bank layer 125 may have a second opening 125OP that overlaps the first opening 121OP and exposes the center of the pixel electrodes 210. In one embodiment, the second opening 125OP may have a line shape extending along a first direction (eg, -y direction), as shown in FIG. 4 .

In this regard, FIGS. 4 to 6 show that the line-shaped 2-1 opening 125OPL1 exposes the central portions of the first pixel electrode 211 and the second pixel electrode 212, and the 1-1 opening 121OP1 ) and overlapping with the 1-2 opening (121OP2). The line-shaped 2-2 opening 125OPL2 may be spaced apart from the line-shaped 2-1 opening 125OPL1 by a predetermined distance in a second direction (eg, x direction).

Therefore, as shown in FIG. 5, the upper surface 121US1 of the first bank layer 121 between the 1-1 opening 121OP1 and the 1-2 opening 121OP2 is a line-shaped 2-1 opening. It can be exposed by (125OPL1). On the other hand, as shown in FIG. 6, the second bank layer 125 is located on the upper surface 121US2 of the first bank layer 121 between the 1-1 opening 121OP1 and the 1-3 opening 121OP3. can be located

The second bank layer 125 may have a second thickness t2. The second thickness t2 is greater than the first thickness t1 and may be sufficient to separate the ink containing the light-emitting material. For example, the second thickness t2 may be about 500 nm to 1,000 nm.

A remaining sacrificial layer 123 may be located between the first bank layer 121 and the second bank layer 125. The remaining sacrificial layer 123 may be positioned overlapping the second bank layer 125 in a plane view. Since the remaining sacrificial layer 123 is located only in the area overlapping with the second bank layer 125, the remaining sacrificial layer 123 may have the same or almost the same pattern as the second bank layer 125 on a plane. The remaining sacrificial layer 123 may have a third opening that overlaps the second opening 125OP.

The remaining sacrificial layer 123 may include a material removed by a developer such as water or tetramethylammonium hydroxide (TMAH) solution. For example, the remaining sacrificial layer 123 may include tungsten oxide (WO _x ), molybdenum oxide (MoO _x ), or a mixture thereof.

The boundary of the first opening 121OP extending in the first direction (eg, -y direction) may overlap the boundary of the second opening 125OP. For example, as shown in FIG. 6, the inner surface 121SS of the first bank layer 121 defining the first opening 121OP is the inner surface 123SS of the remaining sacrificial layer 123 defining the third opening. ) and may be continuous with the inner surface 125SS of the second bank layer 125 defining the second opening 125OP.

The first light emitting layer 221 may be disposed on the first pixel electrode 211. For example, the first light emitting layer 221 may be disposed to correspond to the 1-1 opening 121OP1. In one embodiment, one light emitting layer may be disposed across a plurality of pixel electrodes 210 located within the same second opening 125OP. For example, as shown in FIG. 5, the first light emitting layer 221 extends across the upper surface 121US1 of the first bank layer 121 between the 1-1 opening 121OP1 and the 1-2 opening 121OP2. In other words, it may be provided integrally with the first pixel electrode 211 and the second pixel electrode 212. The first light emitting layer 221 may overlap the line-shaped 2-1 opening 125OPL1.

The first light-emitting layer 221 may include a polymer or low-molecular organic material that emits a predetermined color. At this time, the first light-emitting layer 221 may be formed by discharging ink containing a light-emitting material onto the first pixel electrode 211 and the second pixel electrode 212. For example, the first light emitting layer 221 may be formed through an inkjet printing process.

Although not shown, the first light emitting layer 221 may include a first functional layer and/or a second functional layer below and above, respectively. For example, the first functional layer may include a hole transport layer (HTL), or may include a hole transport layer and a hole injection layer (HIL). The second functional layer may be selectively disposed. The second functional layer may include an electron transport layer (ETL) and/or an electron injection layer (EIL).

The first light emitting layer 221 may have a concave shape that becomes thicker from the center toward the edge of the first opening 121OP. The boundary 221BP along the first direction (e.g., -y direction) of the first light emitting layer 221 is the inner surface of the remaining sacrificial layer 123 or the first bank layer adjacent to the inner surface of the remaining sacrificial layer 123 ( 121) may be located on the inner surface (121SS).

The second light emitting layer 222 may be disposed on the third pixel electrode 213. The second light emitting layer 222 may overlap the line-shaped 2-2 opening 125OPL2, and the second bank layer 125 located between the 2-1 opening 125OPL1 and the 2-2 opening 125OPL2. ) may be spaced apart from the first light emitting layer 221. The first light-emitting layer 221 may include a light-emitting material that emits a first color, and the second light-emitting layer 222 may include a light-emitting material that emits a second color. Since the second light-emitting layer 222 has the same or similar structure as the first light-emitting layer 221, overlapping descriptions will be omitted.

The counter electrode 230 may be disposed to cover the first light emitting layer 221, the first bank layer 121, and the second bank layer 125. The counter electrode 230 may be made of a conductive material with a low work function. For example, the counter electrode 230 is made of silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), and iridium ( It may include a (semi) transparent layer containing Ir), chromium (Cr), lithium (Li), calcium (Ca), or an alloy thereof. Alternatively, the counter electrode 230 may further include a layer such as ITO, IZO, ZnO, or In ₂ O ₃ on the (semi) transparent layer containing the above-mentioned material.

Although not shown, in one embodiment, a thin film encapsulation layer or an encapsulation substrate may be disposed on the counter electrode 230.

Embodiments of the present invention can improve the uniformity of the thickness of the light emitting layer by adjusting the positions of the first bank layer 121 and the remaining sacrificial layer 123. In embodiments of the present invention, with the inner surface 123SS of the remaining sacrificial layer 123 interposed therebetween, the inner surface 121SS of the first bank layer 121 has lyophilicity, and the second bank layer 125 The inner surface (125SS) may have liquid repellency. Therefore, when ink containing a light-emitting material is discharged to form a light-emitting layer, the boundary of the ink containing the light-emitting material is the inner surface 123SS of the remaining sacrificial layer 123 or the second adjacent to the remaining sacrificial layer 123. It may be located on the inner surface (121SS) of the first bank layer (121). When the solvent of the ink containing the light-emitting material evaporates and shrinks in volume during the drying process, the inner surface 123SS of the remaining sacrificial layer 123 or the first bank layer 121 adjacent to the remaining sacrificial layer 123 The border of ink located on the inner surface (121SS) may change less than the center. Accordingly, by adjusting the positions of the first bank layer 121 and the remaining sacrificial layer 123, the uniformity of the thickness of the light emitting layer can be improved.

In addition, since the upper surface 125US of the second bank layer 125 has liquid repellency, ink containing a light-emitting material does not overflow onto the upper surface of the second bank layer 125, and the light-emitting layer is more accurately formed at the desired location. can do.

FIG. 7 is a plan view schematically showing a display device according to an embodiment of the present invention, FIG. 8 is a cross-sectional view schematically showing a cross section along line III-III' of the display device of FIG. 7, and FIG. 9 is a cross-sectional view schematically showing a display device of FIG. 7. This is a cross-sectional view schematically showing the cross-section along line IV-IV' of the display device.

FIG. 7 is similar to FIG. 5 , but differs in that the second bank layer 125 has second openings 125OP corresponding to each of the first openings 121OP. Hereinafter, overlapping descriptions will be omitted and description will focus on differences.

Referring to FIG. 7, a plurality of pixel electrodes 210 arranged two-dimensionally on a plane may be disposed in the display area DA. The pixel electrodes 210 may be arranged to be spaced apart by a predetermined distance in the first direction (eg, -y direction) and the second direction (eg, x direction). For example, the first pixel electrode 211 and the second pixel electrode 212 are spaced apart by a predetermined distance along the first direction (e.g. -y direction), and the first pixel electrode 211 and the third pixel electrode ( 213) may be spaced apart by a predetermined distance along the second direction (eg, x direction).

The first bank layer 121 may be arranged to cover the edges of each of the plurality of pixel electrodes 210. In other words, the first bank layer 121 may have a plurality of first openings 121OP exposing the center of each pixel electrode 210. The first openings 121OP may be arranged to be spaced apart from each other by a predetermined distance in a first direction (e.g., -y direction) and a second direction (e.g., x direction) on a plane, corresponding to the pixel electrodes 210. there is.

For example, the first bank layer 121 has a 1-1 opening (121OP1) exposing the center of the first pixel electrode 211 and a 1-2 opening (121OP2) exposing the center of the second pixel electrode 212. ) and a first-third opening 121OP3 exposing the center of the third pixel electrode 213. The 1-1 opening (121OP1) and the 1-2 opening (121OP2) are spaced apart by a predetermined distance along the first direction (e.g. -y direction), and the 1-1 opening (121OP1) and the 1-3 opening The openings 121OP3 may be spaced apart by a predetermined distance along the second direction (eg, x direction).

The second bank layer 125 may be located on the first bank layer 121. In one embodiment, the second bank layer 125 exposes the center of the pixel electrodes 210 arranged along the first direction (e.g., -y direction) and opens a second opening corresponding to each of the first openings 121OP. (125OP) may be included. For example, the 2-1 opening 125OP1 overlaps the 1-1 opening 121OP1 exposing the center of the first pixel electrode 211, and the 2-2 opening 125OP2 overlaps the second pixel electrode 212. ), and the 2-3 opening (125OP3) overlaps with the 1-3 opening (121OP3) exposing the center of the third pixel electrode 213. You can. The 2-1 opening (125OP1) and the 2-2 opening (125OP2) are arranged to be spaced apart from each other by a predetermined distance in the first direction (e.g. -y direction), and the 2-1 opening (125OP1) and the second opening (125OP1) -The three openings 125OP3 may be arranged to be spaced apart from each other by a predetermined distance in the second direction (eg, x direction).

In one embodiment, as shown in FIG. 7, the second bank layer 125 includes a partition extending in a first direction (eg, -y direction) and a partition extending in a second direction (eg, x direction). It may have an intersecting grid shape. In one embodiment, the second bank layer 125 may cover the top surface of the first bank layer 121.

Referring to Figures 8 and 9, the first bank layer 121 may be disposed on the pixel circuit layer (PCL). The first bank layer 121 includes a 1-1 opening 121OP1 exposing the central portion of the first pixel electrode 211, a 1-2 opening 121OP2 exposing the central portion of the second pixel electrode 212, and It may have a 1-3 opening 121OP3 exposing the central portion of the third pixel electrode 213. The 1-1 opening (121OP1) defines the light emitting area (EA1) of the first organic light emitting diode (OLED1), and the 1-2 opening (121OP2) defines the light emitting area (EA2) of the second organic light emitting diode (OLED2). and the 1-3 opening 121OP3 may define the light emitting area EA3 of the third organic light emitting diode OLED3.

The second bank layer 125 may be disposed on the first bank layer 121. The second bank layer 125 may have a second opening 125OP that overlaps the first opening 121OP and exposes the center of the pixel electrodes 210. The 2-1 opening (125OP1) overlaps the 1-1 opening (121OP1) exposing the center of the first pixel electrode 211, and the 2-2 opening (125OP2) overlaps the 1-1 opening (121OP1) exposing the center of the first pixel electrode 211. It may overlap with the 1-2 opening (121OP2) exposing the center, and the 2-3 opening (125OP3) may overlap with the 1-3 opening (121OP3) exposing the center of the third pixel electrode 213. .

A remaining sacrificial layer 123 may be located between the first bank layer 121 and the second bank layer 125. The remaining sacrificial layer 123 may be positioned overlapping the second bank layer 125 in a plane view. Since the remaining sacrificial layer 123 is located only in the area overlapping with the second bank layer 125, the remaining sacrificial layer 123 may have the same or almost the same pattern as the second bank layer 125 on a plane. The remaining sacrificial layer 123 may have a third opening that overlaps the second opening 125OP.

The 1-1 light emitting layer 221a is disposed on the first pixel electrode 211, the 1-2 light emitting layer 221b is disposed on the second pixel electrode 212, and the 2-1 light emitting layer 222a may be disposed on the third pixel electrode 213. Here, the 1-1 light emitting layer 221a and the 1-2 light emitting layer 221b are oriented in the first direction (e.g., -y direction) with the first bank layer 121 and the second bank layer 125 interposed therebetween. may be separated. The 1-1 light emitting layer 221a and the 2-1 light emitting layer 222a may be spaced apart in a second direction (e.g., x direction) with the first bank layer 121 and the second bank layer 125 interposed therebetween. there is.

Each of the 1-1st emission layer 221a, the 1-2nd emission layer 221b, and the 2-1st emission layer 222a may have a concave shape that becomes thicker from the center toward the edge of the first opening 121OP. The boundary 221BP of the 1-1 light emitting layer 221a is located on the inner side of the remaining sacrificial layer 123 or the inner side 121SS of the first bank layer 121 adjacent to the inner side of the remaining sacrificial layer 123. can do.

In this embodiment, as the 1-1st emission layer 221a and the 1-2nd emission layer 221b are separated by the second bank layer 125, neighboring pixels in the first direction (e.g., -y direction) The leakage current between them can be reduced.

The 1-1 light emitting layer 221a and the 1-2 light emitting layer 221b may include a light emitting material that emits a first color, and the 2-1 light emitting layer 222a may include a light emitting material that emits a second color. You can.

The counter electrode 230 may be disposed to cover the first light emitting layer 221, the first bank layer 121, and the second bank layer 125. Although not shown, in one embodiment, a thin film encapsulation layer or an encapsulation substrate may be disposed on the counter electrode 230.

10 to 16 are cross-sectional views sequentially showing a method of manufacturing a display device according to an embodiment of the present invention. 10 to 16 sequentially illustrate a method of manufacturing the first pixel PX1 and the third pixel PX3 adjacent to each other in the second direction (eg, x direction).

Referring to FIG. 10, a pixel circuit layer (PCL) including at least one transistor is formed on a substrate 100, and a first pixel electrode 211 and a third pixel electrode ( 213) can be formed.

The upper surfaces of the first pixel electrode 211 and the third pixel electrode 213 may have lyophilic properties.

Referring to FIG. 11, the first bank layer 121 may be formed on the pixel circuit layer (PCL). The first bank layer 121 is formed by forming an inorganic insulating material film or an organic insulating material film, and then forming a 1-1 opening 121OP1 so that the center of each of the first pixel electrode 211 and the third pixel electrode 213 is exposed. And the first-third opening (121OP3) can be formed by patterning.

In one embodiment, the first bank layer 121 may include silicon oxide (SiO _x ), silicon nitride (SiN _x ), silicon oxynitride (SiON), etc. In one embodiment, the first bank layer 121 may include an epoxy-based polymer, an acrylic-based polymer, or a mixture thereof.

In one embodiment, the first bank layer 121 may be formed to have a first thickness t1. The first thickness t1 may be determined by considering the position of the boundary of the ink when the ink containing the light-emitting material is ejected. The first thickness t1 may be about 200 nm to about 500 nm. The top surface of the first bank layer 121 and the inner surface 121SS of the first bank layer 121 defining the first opening 121OP may have lyophilic properties.

Referring to FIG. 12, the sacrificial layer 122 can be formed to cover the first pixel electrode 211, the third pixel electrode 213, and the first bank layer 121.

In one embodiment, the sacrificial layer 122 may include a material that is removed by a developer such as water or a tetramethylammonium hydroxide (TMAH) solution. For example, the sacrificial layer 122 may include tungsten oxide (WO _x ), molybdenum oxide (MoO _x ), or a mixture thereof.

In one embodiment, the sacrificial layer 122 may have a third thickness t3. The third thickness t3 may be determined by considering the thickness at which the sacrificial layer 122 is removed by a developer in the step of forming the second bank layer 125, which will be described later. For example, the third thickness t3 is such that the sacrificial layer 122 remains at the exposed top surface 211US of the first pixel electrode 211 and the exposed top surface 213US of the third pixel electrode 213 even after at least one photolithography process. ) and may be sufficient to cover the inner surface 121SS of the first bank layer 121. In one embodiment, the third thickness t3 may be about 20 nm to 50 nm.

Referring to FIG. 13, the second bank layer 125 may be formed on the sacrificial layer 122. The second bank layer 125 can be formed by forming an organic insulating material film and then patterning the second openings 125OP to expose the central portions of each of the first and third pixel electrodes 211 and 213. .

As described above, in one embodiment, the second openings 125OP may have a line shape extending in the first direction (eg, -y direction). In another embodiment, the second openings 125OP may have a shape corresponding to each of the first openings 121OP. In this regard, Figure 13 shows that the second bank layer 125 has a 2-1 opening (125OP1) corresponding to the 1-1 opening (121OP1) and a 2-3 opening corresponding to the 1-3 opening (121OP3). It is shown having (125OP3).

In one embodiment, the second bank layer 125 may include an epoxy-based photosensitive resin, an acrylic-based photosensitive resin, or a mixture thereof. In one embodiment, the second bank layer 125 may include positive photosensitive resin. In one embodiment, the second bank layer 125 may be photosensitive polyimide. Before plasma treatment, the surface of the second bank layer 125 may have lyophilic properties.

The second bank layer 125 may be formed to have a second thickness t2. The second thickness t2 is greater than the first thickness t1 and may be sufficient to separate the ink containing the light-emitting material. For example, the second thickness t2 may be about 500 nm to 1,000 nm.

In the process of patterning the 2-1st opening 125OP1 and the 2-3rd opening 125OP3, a portion of the sacrificial layer 122 may be removed, thereby reducing the thickness of the sacrificial layer 122. Even after the second bank layer 125 is formed, the sacrificial layer 122 remains on the top surface 211US of the first pixel electrode 211, the top surface 213US of the third pixel electrode 213, and the top surface 213US of the first bank layer 121. It can cover the inner side (121SS).

The surface of the sacrificial layer 122 exposed through the second bank layer 125 and the second opening 125OP may be plasma treated to make it liquid-repellent. In one embodiment, tetrafluoromethane (CF ₄ ) plasma treatment may be performed on the surface of the sacrificial layer 122 exposed through the second bank layer 125 and the second opening 125OP.

Through plasma processing, the surface of the sacrificial layer 122 exposed through the upper surface 125US of the second bank layer 125, the inner surface 125SS of the second bank layer 125, and the second opening 125OP is It may have liquid repellency.

On the other hand, the top surface 211US of the first pixel electrode 211, the top surface 213US of the third pixel electrode 213, and the inner surface 121SS of the first bank layer 121 are covered by the sacrificial layer 122. may still be lyophilic. In one embodiment, the lower surface of the second bank layer 125 may still have lyophilic properties.

Referring to FIG. 14 , the sacrificial layer exposed by the second opening 125OP can be removed using a developer to form the remaining sacrificial layer 123. Here, the developer may be water or TMAH (tetramethylammonium hydroxide) solution.

Since the remaining sacrificial layer 123 remains only in the area covered by the second bank layer 125, the remaining sacrificial layer 123 may have the same or almost the same pattern as the second bank layer 125 on a plane. The remaining sacrificial layer 123 may have a third opening that overlaps the second opening 125OP.

The top surface 211US of the first pixel electrode 211, the top surface 213US of the third pixel electrode 213, and the inner surface 121SS of the first bank layer 121 exposed by removing the sacrificial layer are still lyophilic. You can have

The inner surface 121SS of the first bank layer 121 may be continuous with the inner surface 123SS of the remaining sacrificial layer 123 and the inner surface 125SS of the second bank layer 125. Boundary by the inner surface 123SS of the remaining sacrificial layer 123, the inner surface 121SS of the first bank layer 121 located at the lower portion has lyophilic properties, and the second bank layer 125 located at the upper portion thereof has lyophilic properties. The inner surface (125SS) may have liquid repellency.

Referring to FIG. 15, ink containing a light-emitting material is ejected to form a first light-emitting layer forming material 221P on the first pixel electrode 211, and a second light-emitting layer forming material 221P is formed on the third pixel electrode 213. The light emitting layer forming material 222P can be formed.

In one embodiment, the first light-emitting layer forming material 221P and the second light-emitting layer forming material 222P may be formed through an inkjet printing process.

The top surface 211US of the first pixel electrode 211, the top surface 213US of the third pixel electrode 213, and the inner surface 121SS of the first bank layer 121 have lyophilic properties, thereby forming a first light-emitting layer. It is possible to suppress or prevent the material 221P and the second light emitting layer forming material 222P from being applied unevenly.

Since the top surface 125US of the second bank layer 125 has liquid repellency, the first light-emitting layer forming material 221P and the second light-emitting layer forming material 222P are attached to the top surface 125US of the second bank layer 125. may not be formed. Therefore, even in a high-resolution display device, the light emitting layer can be formed more accurately at a desired location.

In one embodiment, the first light-emitting layer forming material 221P and the second light-emitting layer forming material 222P may have a convex shape with a thick center in consideration of surface tension and volume shrinkage after drying.

As described above, the inner surface 121SS of the first bank layer 121 may have lyophilic properties, and the inner surface 125SS of the second bank layer 125 may have liquid-repellent properties. Accordingly, the boundary 221BPa of the first light-emitting layer forming material 221P and the boundary 222BPa of the second light-emitting layer forming material 222P are connected to the inner surface 123SS of the remaining sacrificial layer 123 or the remaining sacrificial layer 123. It may be located on the inner surface 121SS of the adjacent first bank layer 121.

Referring to FIG. 16, the first light-emitting layer forming material 221P and the second light-emitting layer forming material 222P may be dried to form the first light-emitting layer 221 and the second light-emitting layer 222.

Since the top surface 211US of the first pixel electrode 211, the top surface 213US of the third pixel electrode 213, and the inner surface 121SS of the first bank layer 121 are lyophilic, they may be removed during the drying process. It is possible to suppress or prevent the first light emitting layer 221 and the second light emitting layer 222 from being formed unevenly.

As the solvent of the ink containing the light-emitting material evaporates, each of the first light-emitting layer 221 and the second light-emitting layer 222 may have a concave shape that becomes thicker from the center toward the edge of the first opening 121OP.

At this time, the boundary of the light-emitting layer forming material may not change significantly in position even after the drying process. Accordingly, the boundary 221BP of the first light emitting layer 221 and the boundary 222B of the second light emitting layer 222 are the inner surface 123SS of the remaining sacrificial layer 123 or the first bank adjacent to the remaining sacrificial layer 123. It may be located on the inner surface 121SS of the layer 121.

Thereafter, the counter electrode 230 may be formed on the second bank layer 125, the first light emitting layer 221, and the second light emitting layer 222. The counter electrode 230 may be formed integrally over the entire surface of the substrate 100.

Embodiments of the present invention can selectively impart liquid repellency to the surface of the second bank layer 125 by performing plasma treatment using the sacrificial layer 222. The second bank layer 125 may be formed of a lyophilic material. For example, the second bank layer 125 may be formed of positive photosensitive resin. When the second bank layer 125 includes photosensitive polyimide, when drops of the methylbenzonate solution are dropped on the surface of the second bank layer 125 before plasma treatment, the contact angle of the solution may be about 4.7°. After tetrafluoromethane (CF ₄ ) plasma treatment, the contact angle between the surface of the second bank layer 125 and the methylbenzonate solution may be about 64.4° or more. Even after washing with water, the contact angle between the surface of the second bank layer 125 and the methylbenzonate solution may be about 63.0°.

The top surface 211US of the first pixel electrode 211 and the top surface 213US of the third pixel electrode 213 may have lyophilic properties. When the top surface 211US of the first pixel electrode 211 and the top surface 213US of the third pixel electrode 213 are formed of an ITO layer, the contact angle of the methylbenzonate solution may be about 4.6°. As a comparative example, when plasma treatment is performed without forming a sacrificial layer, the contact angle between the top surface of the first pixel electrode and the top surface of the third pixel electrode and the methylbenzonate solution may be about 15.1° or more. Even after washing with water, the contact angle between the top surface of the first pixel electrode and the top surface of the third pixel electrode and the methylbenzonate solution may be about 12.4°. In this case, the ink containing the light-emitting material may not be uniformly applied to the top surface of the first pixel electrode and the top surface of the third pixel electrode.

If the difference in thickness between the center and the outside of the light-emitting layer increases, light may not be extracted from the outside of the light-emitting layer, thereby reducing the light-emitting area. Embodiments of the present invention selectively provide liquid repellency to the top surface 125US of the second bank layer 125 and the inner surface 125SS of the second bank layer 125 by using plasma treatment applied to the sacrificial layer 222. By providing , the uniformity of the thickness of the light emitting layer can be improved.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the attached patent claims.

1: Display device
100: substrate
111: buffer layer
113: First gate insulating layer
115: second gate insulating layer
117: Interlayer insulation layer
119: Flattening layer
121: First bank layer
121OP: 1st opening
122: Sacrificial Layer
123: Remaining victim layer
125: Second bank layer
125OP: 2nd opening
210: Pixel electrode
221P: First light-emitting layer forming material
221: first light emitting layer
230: Counter electrode
300: Sealing member
400: Sealed substrate

Claims (22)

A display element including a pixel electrode, a light-emitting layer containing a light-emitting material, and a counter electrode;
a first bank layer having a first opening exposing a central portion of the pixel electrode;
a second bank layer disposed on the first bank layer and having a second opening overlapping the first opening; and
A residual sacrificial layer located between the first bank layer and the second bank layer and overlapping the second bank layer,
A display device wherein a top surface of the second bank layer and an inner surface of the second bank layer defining the second opening are liquid-repellent. According to paragraph 1,
The inner surface of the remaining sacrificial layer is located between the inner surface of the first bank layer defining the first opening and the inner surface of the second bank layer,
A display device wherein the boundary of the light emitting layer is located on an inner side of the remaining sacrificial layer or an inner side of the first bank layer adjacent to the inner side of the remaining sacrificial layer. According to paragraph 1,
A display device wherein the surface of the first bank layer has lyophilic properties. According to paragraph 1,
A display device wherein the upper surface of the pixel electrode has lyophilic properties. According to paragraph 1,
A display device wherein a lower surface of the second bank layer in contact with the remaining sacrificial layer has lyophilic properties. According to paragraph 1,
The pixel electrodes are provided in plural numbers spaced apart from each other along a first direction,
A plurality of first openings are provided corresponding to each of the plurality of pixel electrodes,
The second opening has a line shape extending in the first direction to overlap the plurality of first openings. According to clause 6,
A display device, wherein the light emitting layer is provided integrally along the first direction. According to paragraph 1,
The pixel electrodes are provided in plural numbers spaced apart from each other along a first direction,
A display device, wherein a plurality of the first opening and the second opening are provided to correspond to each of the plurality of pixel electrodes. According to clause 8,
A display device wherein a plurality of light emitting layers are formed corresponding to each of the plurality of pixel electrodes. According to paragraph 1,
A display device, wherein the first bank layer has a thickness of 200 nm to 500 nm. According to paragraph 1,
A display device, wherein the second bank layer has a thickness of 500 nm to 1000 nm. According to paragraph 1,
The display device wherein the remaining sacrificial layer includes tungsten oxide (WOx), molybdenum oxide (MoOx), or a mixture thereof. Forming a pixel electrode on a substrate;
forming a first bank layer having a first opening exposing a central portion of the pixel electrode;
forming a sacrificial layer on the first bank layer;
forming a second bank layer on the sacrificial layer and having a second opening overlapping the first opening;
performing plasma treatment on the front surface of the substrate where the second bank layer is located;
forming a remaining sacrificial layer by removing the sacrificial layer exposed through the second opening; and
A method of manufacturing a display device comprising: forming a light-emitting layer by ejecting ink containing a light-emitting material on the pixel electrode. According to clause 13,
The inner surface of the remaining sacrificial layer is located between the inner surface of the first bank layer defining the first opening and the inner surface of the second bank layer defining the second opening,
A method of manufacturing a display device, wherein the boundary of the ink containing the light-emitting material is located on the inner side of the remaining sacrificial layer or the inner side of the first bank layer adjacent to the inner side of the remaining sacrificial layer. In paragraph 13.
In the step of performing the plasma treatment, the top surface of the second bank layer, the inner surface of the second bank layer, and the top surface of the sacrificial layer exposed through the second opening have liquid repellency. According to clause 13,
The sacrificial layer includes tungsten oxide (WOx), molybdenum oxide (MoOx), or a mixture thereof. According to clause 16,
A method of manufacturing a display device, wherein the sacrificial layer has a thickness of 20 nm to 50 nm. According to clause 13,
A method of manufacturing a display device, wherein the surface of the first bank layer and the upper surface of the pixel electrode have lyophilic properties. According to clause 13,
A plurality of pixel electrodes are formed and spaced apart from each other along a first direction,
A plurality of first openings are formed corresponding to each of the plurality of pixel electrodes,
The second opening is formed to have a line shape extending in the first direction to overlap the plurality of first openings. According to clause 19,
In the step of forming the light emitting layer,
Ink containing the light-emitting material is ejected along the first direction,
The method of manufacturing a display device, wherein the light emitting layer is formed integrally along the first direction. According to clause 13,
A plurality of pixel electrodes are formed and spaced apart from each other along a first direction,
A method of manufacturing a display device, wherein a plurality of the first opening and the second opening are formed to correspond to each of the plurality of pixel electrodes. According to clause 21,
In the step of forming the light emitting layer,
A method of manufacturing a display device, wherein a plurality of light emitting layers are formed corresponding to each of the plurality of pixel electrodes.

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