Display device and method of manufacturing same

Abstract

A display device and a method of manufacturing the same are disclosed. The display device includes a substrate, a pixel circuit layer disposed on the substrate and including a thin film transistor, a display element layer disposed on the pixel circuit layer and including a pixel electrode, a capping layer disposed on the display element layer and including an organic material, and an encapsulation layer disposed on the capping layer. The encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer disposed on the first inorganic encapsulation layer, and a second inorganic encapsulation layer disposed on the organic encapsulation layer. The capping layer includes a first capping layer portion and a second capping layer portion disposed on the first capping layer portion and in contact with the first inorganic encapsulation layer, the second capping layer portion having a hydrogen concentration higher than a hydrogen concentration of the first capping layer portion.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority of Korean Patent Application No. 10 - 2023 - 0182086, filed with the Korean Intellectual Property Office on December 14, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical field

[0003] Embodiments relate to a display device and a method of manufacturing a display device. Background art

[0004] Mobile electronic devices have been widely used. In addition to small electronic devices such as mobile phones, tablet personal computers (PCs) have recently been widely used as mobile electronic devices.

[0005] To support various functions, such mobile electronic devices include a display device for providing visual information (such as images or videos) to a user. Recently, as other parts for driving the display device have become smaller, the proportion occupied by the display device in the electronic device has gradually increased, and a structure that can be bent from a flat state into an angled structure has also been developed. Summary of the invention

[0006] Embodiments may provide improved adhesion between a capping layer and a first inorganic encapsulation layer.

[0007] In addition, embodiments may provide improved adhesion between an organic encapsulation layer and a second inorganic encapsulation layer.

[0008] However, these aspects are examples, and embodiments are not limited thereto.

[0009] Additional aspects will be partially set forth in the detailed description below, and will be partially apparent from the description, or may be learned by practicing the embodiments of the present disclosure.

[0010] According to an embodiment, a display device includes a substrate, a pixel circuit layer disposed on the substrate and including thin - film transistors, a display element layer disposed on the pixel circuit layer and including pixel electrodes, a capping layer disposed on the display element layer and including an organic material, and an encapsulation layer disposed on the capping layer, wherein the encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer disposed on the first inorganic encapsulation layer, and a second inorganic encapsulation layer disposed on the organic encapsulation layer, wherein the capping layer includes a first capping layer portion and a second capping layer portion disposed on the first capping layer portion and in contact with the first inorganic encapsulation layer, and the second capping layer portion has a higher hydrogen concentration than the first capping layer portion.

[0011] In the present embodiment, the second cover layer portion may include an oxygen material combined with hydrogen.

[0012] In the present embodiment, the second cover layer portion may be more hydrophobic than the first cover layer portion.

[0013] In the present embodiment, the upper surface of the second cover layer portion may include an uneven shape.

[0014] In the present embodiment, the organic encapsulation layer may include a first organic encapsulation layer portion and a second organic encapsulation layer portion disposed on the first organic encapsulation layer portion and in contact with the second inorganic encapsulation layer, and the second organic encapsulation layer portion has a higher hydrogen concentration than the first organic encapsulation layer portion.

[0015] In the present embodiment, the second organic encapsulation layer portion may include an oxygen material combined with hydrogen.

[0016] In the present embodiment, the second organic encapsulation layer portion may be more hydrophobic than the first organic encapsulation layer portion.

[0017] In the present embodiment, the upper surface of the second organic encapsulation layer portion may include an uneven shape.

[0018] According to an embodiment, a method of manufacturing a display device includes placing a substrate on a pedestal inside a chamber, forming a pixel circuit layer on the substrate, forming a display element layer on the pixel circuit layer, forming a cover layer on the display element layer, performing a hydrogen plasma treatment on the cover layer, forming a first inorganic encapsulation layer on the cover layer, forming an organic encapsulation layer on the first inorganic encapsulation layer, and forming a second inorganic encapsulation layer on the organic encapsulation layer, wherein the cover layer includes a first cover layer portion and a second cover layer portion formed on the first cover layer portion and in contact with the first inorganic encapsulation layer, and the second cover layer portion has a higher hydrogen concentration than the first cover layer portion.

[0019] In the present embodiment, when performing the hydrogen plasma treatment on the cover layer, the exposure time of the cover layer to hydrogen may be set to about 10 seconds to about 60 seconds.

[0020] In the present embodiment, when performing the hydrogen plasma treatment on the cover layer, the distance between the pedestal and the head portion configured to eject hydrogen may be set to about 1000 mils to about 1500 mils.

[0021] In the present embodiment, when performing the hydrogen plasma treatment on the cover layer, the internal pressure of the chamber may be set to about 1000 millitorr to about 1500 millitorr.

[0022] In the present embodiment, when performing hydrogen plasma treatment on the cover layer, the flow rate of hydrogen ejected from the head portion can be set to about 20,000 sccm (standard cubic centimeters per minute) to about 40,000 sccm.

[0023] In the present embodiment, the second cover layer portion may include an oxygen material combined with hydrogen.

[0024] In the present embodiment, the second cover layer portion may be more hydrophobic than the first cover layer portion.

[0025] In the present embodiment, the upper surface of the second cover layer portion may include an uneven shape.

[0026] In the present embodiment, the method may further include performing hydrogen plasma treatment on the organic encapsulation layer, where the organic encapsulation layer may include a first organic encapsulation layer portion and a second organic encapsulation layer portion formed on the first organic encapsulation layer portion and in contact with the second inorganic encapsulation layer, and the second organic encapsulation layer portion has a higher hydrogen concentration than the first organic encapsulation layer portion.

[0027] In the present embodiment, the second organic encapsulation layer portion may include an oxygen material combined with hydrogen.

[0028] In the present embodiment, the second organic encapsulation layer portion may be more hydrophobic than the first organic encapsulation layer portion.

[0029] In the present embodiment, the upper surface of the second organic encapsulation layer portion may include an uneven shape. Description of the Drawings

[0030] The above and other aspects, features, and advantages of specific embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0031] Figure 1 is a schematic plan view of a display device according to an embodiment;

[0032] Figure 2 is a schematic cross-sectional view of a display device according to an embodiment;

[0033] Figure 3 is an equivalent circuit diagram of any pixel in a display device according to an embodiment;

[0034] Figure 4 is a schematic cross-sectional view of a display device according to an embodiment;

[0035] Figure 5 is a schematic cross-sectional view of a device for manufacturing a display device according to an embodiment; and

[0036] Figure 6It is a schematic flowchart of a method for manufacturing a display device according to an embodiment. Detailed Embodiment

[0037] Reference will now be made in detail to embodiments shown in the accompanying drawings by way of example, in which like reference numerals will always refer to like elements. In this regard, the present embodiments may have different forms and should not be construed as limited to the description set forth herein. Accordingly, the embodiments will be described only by referring to the drawings to explain aspects of the present description.

[0038] As used herein, the term "or" means a logical "or", such that unless the context clearly indicates otherwise, the statement "A, B, or C" means "A and B and C", "A and B but not C", "A and C but not B", "B and C but not A", "A but not B and not C", "B but not A and not C", and "C but not A and not B". Throughout this disclosure, the statement "at least one of a, b, and c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0039] Since this description allows for various changes and many embodiments, specific embodiments will be shown in the drawings and described in the written description. Through the following detailed description of one or more embodiments in conjunction with the drawings, the effects and features of one or more embodiments and methods for implementing them will become apparent. However, the present embodiments may have different forms and should not be construed as limited to the description set forth herein.

[0040] One or more embodiments will be described in more detail below with reference to the drawings. Those elements that are the same or corresponding to each other are given the same reference numerals regardless of the figure numbers, and their repeated description is omitted.

[0041] Although such terms as "first" and "second" may be used to describe various elements, these elements do not necessarily have to be limited by the above terms. The above terms are only used to distinguish one element from another.

[0042] Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" used herein are also intended to include the plural forms.

[0043] It should be understood that the terms "include", "comprise", and "have" as used herein specify the presence of the described features or elements, but do not exclude the addition of one or more other features or elements.

[0044] It should also be understood that when a layer, region, or element is referred to as being on another layer, region, or element, it can be directly or indirectly on the other layer, region, or element. That is, for example, there may be intervening layers, regions, or elements.

[0045] For convenience of explanation, the dimensions of the elements in the drawings may be exaggerated or reduced. For example, since the dimensions and thicknesses of the elements in the drawings are arbitrarily shown for convenience of explanation, the following embodiments are not limited thereto.

[0046] The x-axis, y-axis, and z-axis are not limited to the three axes of a rectangular coordinate system and can be interpreted in a broader sense. For example, the x-axis, y-axis, and z-axis may be perpendicular to each other, or may represent different directions that are not perpendicular to each other.

[0047] When an embodiment can be implemented in different ways, a specific process sequence may be performed differently from the described sequence. For example, two consecutively described processes may be performed substantially simultaneously or in an order opposite to the described order.

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

[0049] Referring to Figure 1 , the display device 1 manufactured according to an embodiment may include a display area DA and a peripheral area PA positioned outside the display area DA. The display device 1 can provide an image through an array of a plurality of pixels PX two-dimensionally arranged in the display area DA. In Figure 1 , the display area DA of the display device 1 may be positioned in a plane defined by an x-axis direction and a y-axis direction intersecting the x-axis direction, and the z-axis direction may be the thickness direction of the display device 1.

[0050] The peripheral area PA is an area where no image is provided and may completely or partially surround the display area DA. In the peripheral area PA, drivers for supplying electrical signals or power to pixel circuits corresponding to each of the plurality of pixels PX may be arranged. Pads may be arranged in the peripheral area PA as areas where electronic components or printed circuit boards can be electrically connected.

[0051] Hereinafter, it is assumed that the display device 1 includes an organic light-emitting diode (OLED) as a light-emitting element, but the display device 1 described herein is not limited thereto. In another embodiment, the display device 1 may be a light-emitting display device including an inorganic light-emitting diode, that is, an inorganic light-emitting display device. The inorganic light-emitting diode may include a PN junction diode including an inorganic semiconductor-based material. When a voltage is applied to the PN junction diode in the forward direction, holes and electrons are injected, and light of a specific color may be emitted by converting the energy generated by the recombination of the holes and electrons into light energy. The above-mentioned inorganic light-emitting diode may have a width of several micrometers to several hundreds of micrometers, and in some embodiments, the inorganic light-emitting diode may be referred to as a micro LED. In another embodiment, the display device 1 may be a quantum dot light-emitting display device.

[0052] The display device 1 can be used not only as a display screen of portable electronic devices such as mobile phones, smartphones, tablet personal computers (PCs), mobile communication terminals, electronic notebooks, e-books, portable multimedia players (PMPs), navigation systems, and ultra-mobile PCs (UMPCs), but also as a display screen of various products such as televisions, notebook computers, monitors, billboards, and Internet of Things (IoT) devices. In addition, the display device 1 according to an embodiment can be used in wearable devices such as smartwatches, watch phones, glasses-type displays, and head-mounted displays (HMDs). In addition, the display device 1 according to an embodiment can be used as an instrument panel of a vehicle, a central information display (CID) placed on the center dashboard or instrument panel of the vehicle, an in-vehicle mirror display replacing the side mirror of the vehicle, or a display screen placed on the back of the front seat for entertainment of the rear seat of the vehicle.

[0053] Figure 2 is a schematic cross-sectional view of the display device 1 according to an embodiment, and may correspond to a cross-section of the display device 1 taken along Figure 1 the line II-II'.

[0054] Referring to Figure 2 , the display device 1 may include a stacked structure of a substrate 100, a pixel circuit layer PCL, a display element layer DEL, a cover layer CPL, and a packaging layer 300.

[0055] The substrate 100 may have a multilayer structure including a base layer and an inorganic layer, and the base layer includes a polymer resin. For example, the substrate 100 may include a base layer containing a polymer resin and a barrier layer containing an inorganic insulating material. For example, the substrate 100 may include a first base layer 101, a first barrier layer 102, a second base layer 103, and a second barrier layer 104 that are sequentially stacked on each other. The first base layer 101 and the second base layer 103 may include polyimide (PI), polyethersulfone (PES), polyarylate, polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polycarbonate, triacetyl cellulose (TAC), or cellulose acetate propionate (CAP). The first barrier layer 102 and the second barrier layer 104 may include an inorganic insulating material such as silicon oxide, silicon oxynitride, or silicon nitride. The substrate 100 may be flexible.

[0056] The pixel circuit layer PCL is disposed on the substrate 100. Figure 2 The pixel circuit layer PCL is shown, and the pixel circuit layer PCL includes a thin film transistor TFT and buffer layers 111, a first gate insulating layer 112, a second gate insulating layer 113, an interlayer insulating layer 114, a first planarization insulating layer 115, and a second planarization insulating layer 116 disposed below or above the elements of the thin film transistor TFT.

[0057] The buffer layer 111 may reduce or prevent foreign substances, moisture, or external air from penetrating from below the substrate 100, and may provide a flat surface on the substrate 100. The buffer layer 111 may include an inorganic insulating material such as silicon oxide, silicon oxynitride, or silicon nitride, and may have a single-layer or multi-layer structure including the above materials.

[0058] The thin film transistor TFT on the buffer layer 111 may include a semiconductor layer Act, and the semiconductor layer Act may include polycrystalline silicon (poly-Si). Alternatively, the semiconductor layer Act may include amorphous silicon (a-Si), an oxide semiconductor, or an organic semiconductor. The semiconductor layer Act may include a channel region C and a drain region D and a source region S respectively disposed on both sides of the channel region C. The gate electrode GE included in the thin film transistor TFT may overlap with the channel region C.

[0059] The gate electrode GE may include a low-resistance metal material. The gate electrode GE may include a conductive material containing molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may have a multi-layer or single-layer structure including the above materials.

[0060] The first gate insulating layer 112 between the semiconductor layer Act and the gate electrode GE may include an inorganic insulating material such as silicon oxide (SiO2), silicon nitride (SiN x) silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO x ) Zinc oxide (ZnO x ) may be zinc oxide (ZnO) or zinc peroxide (ZnO2).

[0061] The second gate insulating layer 113 may cover the gate electrode GE. Similar to the first gate insulating layer 112, the second gate insulating layer 113 may include an inorganic insulating material such as silicon dioxide (SiO2), silicon nitride (SiN x ) silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO x ) Zinc oxide (ZnO x ) may be zinc oxide (ZnO) or zinc peroxide (ZnO2).

[0062] The upper electrode Cst2 of the storage capacitor Cst may be disposed on the second gate insulating layer 113. The upper electrode Cst2 may overlap with the underlying gate electrode GE. In this regard, the gate electrode GE and the upper electrode Cst2 that overlap with each other with the second gate insulating layer 113 interposed therebetween may constitute the storage capacitor Cst. That is, the gate electrode GE may be used as the lower electrode Cst1 of the storage capacitor Cst.

[0063] As described above, the storage capacitor Cst and the thin film transistor TFT may overlap each other. In some embodiments, the storage capacitor Cst may not overlap with the thin film transistor TFT.

[0064] The upper electrode Cst2 may include aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), or copper (Cu), and may have a single-layer or multi-layer structure including the above materials.

[0065] The interlayer insulating layer 114 may cover the upper electrode Cst2. The interlayer insulating layer 114 may include an inorganic insulating material such as silicon dioxide (SiO2), silicon nitride (SiN x ) silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO x ) Zinc oxide (ZnO x ) may be zinc oxide (ZnO) or zinc peroxide (ZnO2). The interlayer insulating layer 114 may have a single-layer or multi-layer structure including the above inorganic insulating materials.

[0066] Each of the drain electrode DE and the source electrode SE included in the thin film transistor TFT may be located on the interlayer insulating layer 114. The drain electrode DE and the source electrode SE may be respectively connected to the drain region D and the source region S through contact holes defined in the underlying insulating layer. The drain electrode DE and the source electrode SE may include a highly conductive material. The drain electrode DE and the source electrode SE may include a conductive material containing molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may have a multi-layer or single-layer structure including the above materials. In an embodiment, the drain electrode DE and the source electrode SE may have a multi-layer structure of titanium (Ti) / aluminum (Al) / titanium (Ti).

[0067] The first planarization insulating layer 115 may at least partially cover the drain electrode DE and the source electrode SE. The first planarization insulating layer 115 may include an organic insulating material, such as a common commercial polymer (such as polymethyl methacrylate (PMMA) or polystyrene (PS)), a polymer derivative having a phenolic group, an acrylic polymer, an imide polymer, an aryl ether polymer, an amide polymer, a fluorine polymer, a parylene polymer, a vinyl alcohol polymer, and blends thereof.

[0068] The second planarization insulating layer 116 may be disposed on the first planarization insulating layer 115. The second planarization insulating layer 116 may include the same material as that of the first planarization insulating layer 115, and may include an organic insulating material, such as a common commercial polymer (such as PMMA or PS), a polymer derivative having a phenolic group, an acrylic polymer, an imide polymer, an aryl ether polymer, an amide polymer, a fluorine polymer, a parylene polymer, a vinyl alcohol polymer, and blends thereof.

[0069] The display element layer DEL may be disposed on the pixel circuit layer PCL having the above structure. The display element layer DEL may include an organic light emitting diode OLED as a display element (i.e., a light emitting element), and the organic light emitting diode OLED may include a stacked structure of a pixel electrode 210, an intermediate layer 220, and a common electrode 230. For example, the organic light emitting diode OLED may emit red light, green light, or blue light, or may emit red light, green light, blue light, or white light. The organic light emitting diode OLED may emit light through an emission region, and the emission region may be defined as a pixel PX.

[0070] The pixel electrode 210 of the organic light emitting diode OLED may be electrically connected to the thin film transistor TFT through contact holes defined in the second planarization insulating layer 116 and the first planarization insulating layer 115 and a contact metal CM disposed on the first planarization insulating layer 115. That is, the pixel electrode 210 may be disposed above the substrate 100.

[0071] The pixel electrode 210 may include a conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), or aluminum zinc oxide (AZO). In another embodiment, the pixel electrode 210 may include a reflective layer containing silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), or a compound thereof. In another embodiment, the pixel electrode 210 may further include a layer formed of ITO, IZO, ZnO, or In2O3 on / under the above reflective layer.

[0072] A bank layer 117 including an opening 117OP exposing the central portion of the pixel electrode 210 is disposed on the pixel electrode 210. The bank layer 117 may include an organic insulating material or an inorganic insulating material. The opening 117OP may define an emission region of light emitted from the organic light emitting diode OLED. For example, the size / width of the opening 117OP may correspond to the size / width of the emission region. Thus, the size or width of the pixel PX may depend on the size or width of the corresponding opening 117OP of the bank layer 117.

[0073] The intermediate layer 220 may include an emission layer 222 corresponding to the pixel electrode 210. The emission layer 222 may include a polymer organic material or a low molecular weight organic material that emits light of a specific color. Alternatively, the emission layer 222 may include an inorganic light emitting material or quantum dots. That is, the intermediate layer 220 may be disposed on the pixel electrode 210 to emit light.

[0074] In an embodiment, the intermediate layer 220 may include a first functional layer 221 and a second functional layer 223 disposed under and on the emission layer 222, respectively. For example, the first functional layer 221 may include a hole transport layer (HTL), or an HTL and a hole injection layer (HIL). The second functional layer 223 is an element disposed on the emission layer 222 and may include an electron transport layer (ETL) or an electron injection layer (EIL). Similar to the common electrode 230 described below, the first functional layer 221 or the second functional layer 223 may be a common layer that completely covers the substrate 100.

[0075] The common electrode 230 may be disposed above the pixel electrode 210 and may overlap with the pixel electrode 210. The common electrode 230 may be disposed on the intermediate layer 220. The common electrode 230 may include a conductive material having a low work function. For example, the common electrode 230 may include a (semi)transparent layer containing silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), or an alloy thereof. Alternatively, the common electrode 230 may further include a layer such as ITO, IZO, ZnO, or In2O3 on the (semi)transparent layer including the above materials. The common electrode 230 may be formed as a single body to completely cover the substrate 100.

[0076] The cover layer CPL may be disposed on the display element layer DEL and may cover the display element layer DEL. That is, the cover layer CPL may be disposed on the common electrode 230. Compared with the common electrode 230, the cover layer CPL may have a high refractive index. According to one or more embodiments, a cover layer CPL having a relatively high refractive index is disposed on the common electrode 230, and due to the cover layer CPL, the reflectivity of the light emitted from the intermediate layer 220 at the common electrode 230 increases. Therefore, the resonance efficiency of the microcavity is improved, and thus the out-coupling efficiency of the organic light-emitting diode OLED is increased.

[0077] In this regard, the reflection at the common electrode 230 may be a concept including not only the reflection at the lower surface of the common electrode 230 but also the reflection at the interface between the common electrode 230 and the cover layer CPL and the reflection at the interface between the cover layer CPL and the encapsulation layer 300.

[0078] The cover layer CPL may include an organic material. According to an embodiment, the cover layer CPL may include a triamine derivative, a carbazole biphenyl derivative, an aromatic diamine derivative, or tris(8-hydroxyquinolinato)aluminum (Alq3).

[0079] The encapsulation layer 300 may be disposed on the cover layer CPL. That is, the encapsulation layer 300 may be disposed on the display element layer DEL and may cover the display element layer DEL. The encapsulation layer 300 may include at least one inorganic encapsulation layer and at least one organic encapsulation layer.

[0080] In Figure 2 the embodiment shown, the encapsulation layer 300 includes a first inorganic encapsulation layer 310, an organic encapsulation layer 320, and a second inorganic encapsulation layer 330 that are sequentially stacked on each other. That is, the organic encapsulation layer 320 may be disposed on the first inorganic encapsulation layer 310, and the second inorganic encapsulation layer 330 may be disposed on the organic encapsulation layer 320.

[0081] The first inorganic encapsulation layer 310 and the second inorganic encapsulation layer 330 may include one or more inorganic materials among aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon oxide, silicon nitride, and silicon oxynitride. The organic encapsulation layer 320 may include a polymer-based material. Examples of the polymer-based material may include acrylic-based resins, epoxy-based resins, polyimides, and polyethylene. In an embodiment, the organic encapsulation layer 320 may include an acrylate. The organic encapsulation layer 320 may be formed by curing a monomer or coating with a polymer. The organic encapsulation layer 320 may be transparent.

[0082] Although not shown, a touch sensor layer may be provided on the encapsulation layer 300, and an optical function layer may be provided on the touch sensor layer. The touch sensor layer may obtain coordinate information according to an external input (e.g., a touch event). The optical function layer may reduce the reflectance of light (external light) incident on the display device from the outside, or may improve the color purity of the light emitted from the display device. In an embodiment, the optical function layer may include a phase retarder or a polarizer. The phase retarder may be a film type or a liquid crystal coating type, and may include a λ / 2 phase retarder or a λ / 4 phase retarder. 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 specific arrangement manner. The phase retarder and the polarizer may further include a protective film.

[0083] An adhesive member may be provided between the touch sensor layer and the optical function layer. As the adhesive member, a general adhesive member known in the art may be used without limitation. The adhesive member may be a pressure-sensitive adhesive (PSA).

[0084] Figure 3 is an equivalent circuit diagram of any one pixel PX in the display device 1 according to an embodiment.

[0085] Each pixel PX may include a pixel circuit PC and a display element, such as an organic light-emitting diode OLED, connected to the pixel circuit PC. The pixel circuit PC may include a first thin-film transistor T1, a second thin-film transistor T2, and a storage capacitor Cst. For example, each pixel PX may emit red light, green light, blue light, or white light through the organic light-emitting diode OLED.

[0086] The second thin-film transistor T2, as a switching thin-film transistor, may be connected to a scan line SL and a data line DL, and may be configured to transfer a data voltage input from the data line DL to the first thin-film transistor T1 based on a switching voltage input from the scan line SL. The storage capacitor Cst may be connected to the second thin-film transistor T2 and a driving voltage line PL, and may store a voltage corresponding to the difference between the voltage received from the second thin-film transistor T2 and a first power supply voltage ELVDD supplied to the driving voltage line PL.

[0087] A first thin film transistor T1 for driving a thin film transistor may be connected to a driving voltage line PL and a storage capacitor Cst, and may be configured to control a driving current flowing from the driving voltage line PL through an organic light emitting diode OLED in response to a voltage value stored in the storage capacitor Cst. The organic light emitting diode OLED may emit light with a specific luminance according to the driving current. A common electrode (e.g., a cathode) of the organic light emitting diode OLED may receive a second power supply voltage ELVSS.

[0088] Although Figure 3 The pixel circuit PC including two thin film transistors and one storage capacitor is shown, but one or more embodiments are not limited thereto. The number of thin film transistors and the number of storage capacitors may be differently modified according to the design of the pixel circuit PC. For example, in addition to the above two thin film transistors, the pixel circuit PC may further include four or five or more thin film transistors.

[0089] Figure 4 is a schematic cross-sectional view of a display device 1 according to an embodiment, and is Figure 2 an enlarged view of region A of

[0090] Referring to Figure 2 and Figure 4 , the cover layer CPL may include a first cover layer portion CPL1 and a second cover layer portion CPL2.

[0091] The second cover layer portion CPL2 may be disposed on the first cover layer portion CPL1. The first cover layer portion CPL1, the second cover layer portion CPL2, and the first inorganic encapsulation layer 310 may be sequentially stacked on each other in a direction away from the substrate 100 (e.g., the +z axis direction). The second cover layer portion CPL2 and the first inorganic encapsulation layer 310 may be in contact with each other. The first cover layer portion CPL1 and the second cover layer portion CPL2 may be integrally formed with each other.

[0092] When a hydrogen plasma treatment is performed on an upper portion of the cover layer CPL, the cover layer CPL may be divided into a first cover layer portion CPL1 and a second cover layer portion CPL2. That is, the second cover layer portion CPL2 disposed relatively above may have a higher hydrogen concentration than the first cover layer portion CPL1.

[0093] Due to the hydrogen plasma treatment of the cover layer CPL, hydrogen can combine with the oxygen of the cover layer CPL. Therefore, the second cover layer portion CPL2 may include an oxygen material combined with hydrogen. In addition, the oxygen in the second cover layer portion CPL2 can combine with hydrogen to form water and be discharged to the outside. Therefore, the second cover layer portion CPL2 can be more hydrophobic than the first cover layer portion CPL1. Since the hydrophobicity of the second cover layer portion CPL2 in contact with the first inorganic encapsulation layer 310 is enhanced, the adhesiveness to the inorganic material can be improved. Therefore, the adhesiveness between the cover layer CPL and the first inorganic encapsulation layer 310 can be improved.

[0094] The cover layer CPL including an organic material may have a surface energy lower than that of the surface of the first inorganic encapsulation layer 310 including an inorganic material. Due to the hydrogen plasma treatment of the cover layer CPL, the surface temperature of the cover layer CPL increases, and the surface energy increases, and thus, the difference in surface energy between the cover layer CPL and the first inorganic encapsulation layer 310 can be reduced. Therefore, the adhesiveness between the cover layer CPL and the first inorganic encapsulation layer 310 can be improved.

[0095] Since electrons collide with the surface of the second cover layer portion CPL2 during the process of performing hydrogen plasma treatment on the cover layer CPL, a part of the second cover layer portion CPL2 may be etched. Therefore, the second cover layer portion CPL2 may include an uneven shape. That is, the surface roughness of the second cover layer portion CPL2 can increase. In addition, the contact area between the second cover layer portion CPL2 and the first inorganic encapsulation layer 310 can increase. In addition, as a part of the second cover layer portion CPL2 is etched, foreign substances on the surface of the second cover layer portion CPL2 can be removed. Therefore, the adhesiveness between the cover layer CPL and the first inorganic encapsulation layer 310 can be improved.

[0096] The organic encapsulation layer 320 may include a first organic encapsulation layer portion 321 and a second organic encapsulation layer portion 322. The second organic encapsulation layer portion 322 may be disposed on the first organic encapsulation layer portion 321. The first organic encapsulation layer portion 321, the second organic encapsulation layer portion 322, and the second inorganic encapsulation layer 330 may be sequentially stacked on one another in a direction away from the substrate 100 (e.g., the +z-axis direction). The second organic encapsulation layer portion 322 and the second inorganic encapsulation layer 330 may be in contact with each other. The first organic encapsulation layer portion 321 and the second organic encapsulation layer portion 322 may be integrally formed with each other.

[0097] When hydrogen plasma treatment is performed on the upper portion of the organic encapsulation layer 320, the organic encapsulation layer 320 may be divided into the first organic encapsulation layer portion 321 and the second organic encapsulation layer portion 322. That is, the second organic encapsulation layer portion 322 disposed relatively above may have a higher hydrogen concentration than that of the first organic encapsulation layer portion 321.

[0098] Due to the hydrogen plasma treatment of the organic encapsulation layer 320, hydrogen can combine with the oxygen in the organic encapsulation layer 320. Therefore, the second organic encapsulation layer portion 322 may include an oxygen material combined with hydrogen. In addition, the oxygen in the second organic encapsulation layer portion 322 can combine with hydrogen to form water and be discharged to the outside. Therefore, the second organic encapsulation layer portion 322 can be more hydrophobic than the first organic encapsulation layer portion 321. Since the hydrophobicity of the second organic encapsulation layer portion 322 in contact with the second inorganic encapsulation layer 330 is enhanced, the adhesiveness to the inorganic material can be improved. Therefore, the adhesiveness between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 can be improved.

[0099] The organic encapsulation layer 320 including an organic material may have a surface energy lower than that of the second inorganic encapsulation layer 330 including an inorganic material. Due to the hydrogen plasma treatment of the organic encapsulation layer 320, the surface temperature of the organic encapsulation layer 320 increases and the surface energy increases, and thus, the difference in surface energy between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 can be reduced. Therefore, the adhesiveness between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 can be improved.

[0100] Since electrons collide with the surface of the second organic encapsulation layer portion 322 during the process of performing hydrogen plasma treatment on the organic encapsulation layer 320, a part of the second organic encapsulation layer portion 322 can be etched. Therefore, the second organic encapsulation layer portion 322 may include an uneven shape. That is, the surface roughness of the second organic encapsulation layer portion 322 can increase. Therefore, the contact area between the second organic encapsulation layer portion 322 and the second inorganic encapsulation layer 330 can increase. In addition, as a part of the second organic encapsulation layer portion 322 is etched, foreign substances on the surface of the second organic encapsulation layer portion 322 can be removed. Therefore, the adhesiveness between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 can be improved.

[0101] Since the adhesiveness between the cover layer CPL and the first inorganic encapsulation layer 310 is improved and the adhesiveness between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 is improved, the durability of the display device 1 can be improved.

[0102] For example, during the operation of depositing the first inorganic encapsulation layer 310 on the cover layer CPL through a deposition mask, due to the shadow phenomenon, misalignment may occur between the cover layer CPL and the first inorganic encapsulation layer 310. In the present embodiment, even when the adhesiveness between the two elements is reduced due to the misalignment between the cover layer CPL and the first inorganic encapsulation layer 310, the reduction in adhesiveness can be offset.

[0103] For example, due to the difference in compressive stress between the cover layer CPL and the first inorganic encapsulation layer 310, the adhesiveness between the cover layer CPL and the first inorganic encapsulation layer 310 may be reduced, and due to the difference in compressive stress between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330, the adhesiveness between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 may be reduced. In the present embodiment, even when the adhesiveness is reduced due to the difference in compressive stress between two elements, the decrease in adhesiveness can be offset.

[0104] Since the adhesiveness between the cover layer CPL and the first inorganic encapsulation layer 310 is improved, and the adhesiveness between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 is improved, the stability of the manufacturing process can be enhanced.

[0105] For example, during the process of manufacturing the display device 1, in the operation of removing a separate film from the display device 1, the phenomenon of separation occurring at the interface between the cover layer CPL and the first inorganic encapsulation layer 310 can be reduced. In addition, the phenomenon of separation occurring at the interface between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 can be reduced.

[0106] Figure 5 is a schematic cross-sectional view of an apparatus 2 for manufacturing a display device according to an embodiment.

[0107] Referring to Figure 5 , the apparatus 2 for manufacturing a display device may include a chamber 110, a head portion 120, a base 130, a process gas supplier 140, an electrode portion 170, and a pressure controller 190.

[0108] The chamber 110 may have an internal space with an opening portion, and the substrate 100 may be transferred into or out of the chamber 110 through the opening portion. In this regard, a gate valve 1111 may be disposed in the opening portion of the chamber 110 to open / close the opening portion of the chamber 110.

[0109] The head portion 120 may be disposed in the chamber 110 to supply a process gas to the interior of the chamber 110. In this regard, the head portion 120 may have a storage space 123 for storing the process gas. The head portion 120 may include a head body 121 connected to the process gas supplier 140. In addition, the head portion 120 may include a nozzle 122 that connects the storage space 123 to the interior of the chamber 110 and is configured to eject the process gas.

[0110] The susceptor 130 may face the head portion 120. In this regard, the substrate 100 may be placed on the susceptor 130 that can move up and down in the chamber 110. In addition, the susceptor 130 may adjust the temperature of the substrate 100 or apply a specific voltage to the substrate 100. In another embodiment, the susceptor 130 may be connected to an external ground. In the following description, for convenience, the case where the susceptor 130 is connected to an external ground will be mainly described.

[0111] The process gas supplier 140 may be arranged outside the chamber 110 and connected to the head portion 120. In this regard, the process gas supplier 140 may supply the process gas to the storage space 123 of the head portion 120. In this case, the process gas may be supplied to the head portion 120 to form one of an amorphous silicon (a-Si) film, a silicon nitride (SiN x ) film, and a silicon oxide (SiO x ) film. For example, the process gas may include any one of silane (SiH4) gas, hydrogen (H2) gas, ammonia (NH3) gas, and a gas including a doping element. In addition, the process gas may include a carrier gas such as argon (Ar) gas, helium (He) gas, or nitrogen (N2) gas. In this regard, the selection of the process gas may affect the type of film formed by the process gas. In the following description, for convenience, the case where the process gas includes silane and nitrogen will be mainly described.

[0112] The process gas supplier 140 may include a plurality of process gas suppliers 140. In this case, since each of the plurality of process gas suppliers 140 stores each process gas and is connected to the head portion 120, each process gas may be independently supplied to the head portion 120.

[0113] The process gas supplier 140 may include a process gas storage part 141 for storing the process gas, and a process gas guiding path 142 that connects the process gas storage part 141 to the head portion 120 and is configured to guide the process gas from the process gas storage part 141 to the storage space 123 of the head portion 120. In addition, the process gas supplier 140 may include a process gas pump 143 arranged on the process gas guiding path 142 to allow the process gas to flow, and a process gas cut-off valve 144 configured to stop or restart the flow of the process gas through the process gas guiding path 142.

[0114] The electrode part 170 may be arranged in the head portion 120. For example, the electrode part 170 may include a plurality of electrode parts 170 in the nozzle 122. In another embodiment, the electrode part 170 may be placed in at least one of the nozzle 122 and the head body 121. In the following description, for convenience, the case where the electrode part 170 is placed in the nozzle 122 will be mainly described.

[0115] The pressure controller 190 can be connected to the chamber 110 and can adjust the internal pressure of the chamber 110 by discharging the internal gas of the chamber 110 to the outside or supplying gas to the chamber 110. In this regard, the pressure controller 190 can include a guiding tube 191 connected to the chamber 110 and a pressure control pump 192 arranged along the guiding tube 191.

[0116] During the operation of the apparatus 2 for manufacturing a display device, after the pressure controller 190 adjusts the internal pressure of the chamber 110 to a level equal to or similar to a specific pressure (e.g., atmospheric pressure or the same pressure as the internal pressure of another chamber), the gate valve 1111 can be operated to open the opening portion of the chamber 110. The substrate 100 can be placed into the chamber 110 from the outside and placed on the pedestal 130. In this regard, the substrate 100 can enter the chamber 110 from the outside by means of, for example, a robotic arm or a shuttle.

[0117] When the substrate 100 is pressed or placed on the pedestal 130, the processing gas supplier 140 can supply the processing gas to the head portion 120. In this regard, a voltage can be applied to the electrode portion 170 to plasmaize the processing gas, so that a part of the processing gas is deposited on the substrate 100. In this case, the apparatus 2 for manufacturing a display device can form one of various layers (or films) of the substrate 100. For example, the apparatus 2 for manufacturing a display device can form an amorphous silicon film on the substrate 100. In another embodiment, the apparatus 2 for manufacturing a display device can form an inorganic film of a thin film encapsulation layer on the substrate 100. In the following description, for convenience, the case where the apparatus 2 for manufacturing a display device forms an inorganic film of a thin film encapsulation layer on the substrate 100 is mainly described.

[0118] During the process of depositing a part of the deposition gas on the substrate 100 as described above, the pressure controller 190 can discharge the internal gas of the chamber 110 to the outside.

[0119] When the above process is completed, the pressure controller 190 can maintain the internal pressure of the chamber 110 in a specific pressure state, and the gate valve 1111 can be operated to open the opening portion of the chamber 110. In addition, a robotic arm or a shuttle outside the chamber 110 can enter the chamber 110 to pull the substrate 100 on which the deposition has been completed to the outside of the chamber 110.

[0120] Figure 6 is a schematic flowchart of a method 3 for manufacturing a display device according to an embodiment.

[0121] In Figure 6 , compared with Figures 1 to 5Like reference numerals in the drawings denote like elements and, thus, their repetitive description will be omitted hereinafter.

[0122] Referring to Figure 2 、 Figure 4 、 Figure 5 and Figure 6 ,the method 3 of manufacturing a display device may include an operation of placing a substrate 100 on a pedestal 130 inside a chamber 110 (operation S1), an operation of forming a pixel circuit layer PCL on the substrate 100 (operation S2), an operation of forming a display element layer DEL on the pixel circuit layer PCL (operation S3), an operation of forming a cover layer CPL on the display element layer DEL (operation S4), an operation of performing a hydrogen plasma treatment on the cover layer CPL (operation S5), an operation of forming a first inorganic encapsulation layer 310 on the cover layer CPL (operation S6), an operation of forming an organic encapsulation layer 320 on the first inorganic encapsulation layer 310 (operation S7), an operation of performing a hydrogen plasma treatment on the organic encapsulation layer 320 (operation S8), and an operation of forming a second inorganic encapsulation layer 330 on the organic encapsulation layer 320 (operation S9).

[0123] Due to the operation of performing a hydrogen plasma treatment on the cover layer CPL (operation S5), the cover layer CPL may be divided into a first cover layer portion CPL1 and a second cover layer portion CPL2.

[0124] For example, in the operation of performing a hydrogen plasma treatment on the cover layer CPL (operation S5), the exposure time of the cover layer CPL to hydrogen may be set to be from about 10 seconds to about 60 seconds, the distance D1 between the pedestal 130 and a head portion 120 configured to eject hydrogen may be set to be from about 1000 mils to about 1500 mils, the internal pressure of the chamber 110 may be set to be from about 1000 mTorr to about 1500 mTorr, the flow rate of hydrogen ejected from the head portion 120 may be set to be from about 20000 sccm to about 40000 sccm, and the power applied to an electrode portion 170 may be set to be at least 2500 W but not more than 7000 W.

[0125] Due to the operation of performing a hydrogen plasma treatment on the organic encapsulation layer 320 (operation S8), the organic encapsulation layer 320 may be divided into a first organic encapsulation layer portion 321 and a second organic encapsulation layer portion 322.

[0126] The operation of performing a hydrogen plasma treatment on the organic encapsulation layer 320 (operation S8) may be performed under the same process conditions as those of the operation of performing a hydrogen plasma treatment on the cover layer CPL (operation S5).

[0127] For example, in the operation of performing hydrogen plasma treatment on the organic encapsulation layer 320 (operation S8), the exposure time of the organic encapsulation layer 320 to hydrogen can be set from about 10 seconds to about 60 seconds, the distance D1 between the susceptor 130 and the head portion 120 configured to eject hydrogen can be set from about 1000 mils to about 1500 mils, the internal pressure of the chamber 110 can be set from about 1000 mTorr to about 1500 mTorr, the flow rate of hydrogen ejected from the head portion 120 can be set from about 20000 sccm to about 40000 sccm, and the power applied to the electrode portion 170 can be set to at least 2500 W but not more than 7000 W.

[0128] According to one or more of the above embodiments, the stability of the process for manufacturing a display device can be improved, and the durability of the display device can be improved.

[0129] The effects of one or more embodiments are not limited thereto, and other unmentioned effects will become apparent to those of ordinary skill in the art from the appended claims.

[0130] It should be understood that the embodiments described herein should be considered only in a descriptive sense and not for purposes of limitation. The description of features or aspects within each embodiment should generally be considered available for other similar features or aspects in other embodiments. Although the embodiments have been described with reference to the figures, those of ordinary skill in the art will understand that various changes in form and detail can be made without departing from the spirit and scope as defined by the appended claims.

Claims

1. A display device, comprising: substrate; A pixel circuit layer, which is disposed on the substrate and includes a thin film transistor; A display element layer, the display element layer is disposed on the pixel circuit layer and includes a pixel electrode; a cover layer disposed on the display element layer and comprising an organic material; as well as an encapsulation layer, the encapsulation layer being arranged on the covering layer, Wherein, the encapsulation layer comprises: a first inorganic encapsulation layer; an organic encapsulation layer, the organic encapsulation layer being disposed on the first inorganic encapsulation layer; and A second inorganic encapsulation layer, wherein the second inorganic encapsulation layer is disposed on the organic encapsulation layer, wherein the covering layer comprises: a first cover layer portion; and A second cover layer portion is disposed on the first cover layer portion and in contact with the first inorganic encapsulating layer, the second cover layer portion having a higher hydrogen concentration than that of the first cover layer portion.

2. The display device according to claim 1, wherein: The second capping layer portion includes an oxygen material combined with hydrogen.

3. The display device according to claim 1, wherein: The second cover layer portion is more hydrophobic than the first cover layer portion.

4. The display device according to claim 1, wherein: An upper surface of the second cover layer portion includes an uneven shape.

5. The display device according to any one of claims 1 to 4, wherein: The organic encapsulation layer comprises: a first organic encapsulation layer portion; and A second organic encapsulating layer portion is disposed on the first organic encapsulating layer portion and contacts the second inorganic encapsulating layer, the second organic encapsulating layer portion having a higher hydrogen concentration than that of the first organic encapsulating layer portion.

6. The display device according to claim 5, wherein: The second organic encapsulating layer portion includes an oxygen material combined with hydrogen.

7. The display device according to claim 5, wherein: The second organic encapsulating layer portion is more hydrophobic than the first organic encapsulating layer portion.

8. The display device according to claim 5, wherein: An upper surface of the second organic encapsulating layer portion includes an uneven shape.

9. A method for manufacturing a display device, the method comprising: placing a substrate on a susceptor inside the chamber; forming a pixel circuit layer on the substrate; forming a display element layer on the pixel circuit layer; forming a cover layer on the display element layer; performing a hydrogen plasma treatment on the cover layer; forming a first inorganic encapsulation layer on the cover layer; forming an organic encapsulation layer on the first inorganic encapsulation layer; as well as forming a second inorganic encapsulation layer on the organic encapsulation layer, Wherein, the covering layer comprises: a first cover layer portion; and A second cover layer portion is formed on the first cover layer portion and in contact with the first inorganic encapsulating layer, the second cover layer portion having a higher hydrogen concentration than that of the first cover layer portion.

10. The method for manufacturing a display device according to claim 9, wherein: When the hydrogen plasma treatment is performed on the capping layer, the time for which the capping layer is exposed to hydrogen is set to 10 seconds to 60 seconds.

11. The method for manufacturing a display device according to claim 9, wherein: When performing the hydrogen plasma treatment on the cap layer, a distance between the susceptor and a head portion configured to spray hydrogen is set to 1000 mil to 1500 mil.

12. The method for manufacturing a display device according to claim 9, wherein: When performing the hydrogen plasma treatment on the cap layer, the internal pressure of the chamber is set to 1000 mTorr to 1500 mTorr.

13. The method for manufacturing a display device according to claim 9, wherein: When the hydrogen plasma treatment is performed on the cap layer, a flow rate of hydrogen sprayed from a head portion is set to 20000 sccm to 40000 sccm.

14. The method for manufacturing a display device according to claim 9, wherein: The second capping layer portion includes an oxygen material combined with hydrogen.

15. The method for manufacturing a display device according to claim 9, wherein: The second cover layer portion is more hydrophobic than the first cover layer portion.

16. The method for manufacturing a display device according to claim 9, wherein: An upper surface of the second cover layer portion includes an uneven shape.

17. The method for manufacturing a display device according to any one of claims 9 to 16, further comprising performing a hydrogen plasma treatment on the organic encapsulation layer, in, The organic encapsulation layer comprises: a first organic encapsulation layer portion; and A second organic encapsulating layer portion is formed on the first organic encapsulating layer portion and contacts the second inorganic encapsulating layer, the second organic encapsulating layer portion having a higher hydrogen concentration than that of the first organic encapsulating layer portion.

18. The method for manufacturing a display device according to claim 17, wherein: The second organic encapsulating layer portion includes an oxygen material combined with hydrogen.

19. The method for manufacturing a display device according to claim 17, wherein: The second organic encapsulating layer portion is more hydrophobic than the first organic encapsulating layer portion.

20. The method for manufacturing a display device according to claim 17, wherein: An upper surface of the second organic encapsulating layer portion includes an uneven shape.

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