Display device

Abstract

A display device is provided. The display device includes: a substrate including a bending area at which the display device is bendable; an organic light emitting element disposed on the substrate; an encapsulation layer covering an upper surface and a side surface of the organic light emitting element; and a bending region protection layer covering the bending region of the substrate. The upper surface of the encapsulation layer includes a nanostructure defined by nano-sized protrusions and recesses of the upper surface of the encapsulation layer, and the bending region is disposed apart from the encapsulation layer along the substrate.

Description

[0001] This application is a divisional application of application No. 201910953496.7 entitled “Display device and manufacturing method thereof” filed with the State Intellectual Property Office of China on October 9, 2019. Technical Field

[0002] The present disclosure relates to a display device and a method for manufacturing the display device. Background Art

[0003] Flexible display devices using substrates that are lightweight, impact-resistant, and easily flexible have been developed. Flexible display devices are gaining attention as next-generation display devices that can be used in portable and wearable devices as well as televisions ("TVs") and computer monitors.

[0004] In addition, when a flexible substrate is used, an end portion of the display panel, in which a pad (or a pad) is located, may be bent, thereby reducing a dead space and a bezel width. Summary of the invention

[0005] Exemplary embodiments of the invention provide a display device and a method for manufacturing the display device, for reducing or effectively preventing damage to the display device generated during a manufacturing process, simplifying the manufacturing process, and reducing material costs, thereby improving productivity and yield of the manufactured display device.

[0006] A display device according to an exemplary embodiment includes: a substrate including a bending area; an organic light emitting element disposed on the substrate, the display device being bendable at the bending area; an encapsulation layer covering an upper surface and a side surface of the organic light emitting element; and a bending area protective layer covering the bending area of ​​the substrate. The upper surface of the encapsulation layer includes a nanostructure defined by nano-sized protrusions and recesses of the upper surface of the encapsulation layer, and the bending area protective layer is disposed separately from the encapsulation layer along the substrate.

[0007] The bending area protection layer may include a cured portion of an ultraviolet curable material.

[0008] The ultraviolet curable material may include at least one of an acrylate polymer, a polyurethane, and an acrylate material including SiO.

[0009] The ultraviolet curable material may include at least one of an acrylic resin, a butyl rubber, a vinyl acetate resin, an ethylene vinyl acetate ("EVA") resin, a natural rubber, a nitrile, a silicone resin, a silicone rubber, and a styrene block polymer.

[0010] The adhesion of the bending area protective layer may be from about 50 gf / inch (gram force per inch) to about 200 gf / inch.

[0011] The maximum thickness of the bending area protection layer may be about 50 μm (micrometers) to about 150 μm.

[0012] A support member disposed on a rear surface of the substrate may further be included, and the support member may define an opening overlapping the bending region.

[0013] Along the substrate, the support member defining the opening overlapping the bending region may overlap the bending region protection layer covering the bending region by about 100 μm to about 200 μm.

[0014] A driving integrated circuit chip may further be included, and the bending area protection layer may be disposed along the substrate separately from the driving integrated circuit chip.

[0015] An upper protective layer removably attachable to the encapsulation layer, a polarizing film disposed on an upper surface of the encapsulation layer, and a window panel disposed on the polarizing film may also be included.

[0016] Removing the upper protective layer from the encapsulation layer may allow the upper surface of the encapsulation layer to be disposed to be exposed outside the encapsulation layer, and a nanostructure may be formed.

[0017] The nanostructure may be formed in the shape of a closed line extending along the edge of the encapsulation layer.

[0018] An adhesive support layer disposed between the substrate and the bending region protection layer at the bending region of the substrate may also be included.

[0019] The adhesive support layer may include at least one of an acrylic resin, a butyl rubber, a vinyl acetate resin, an ethylene vinyl acetate ("EVA") resin, a natural rubber, a nitrile, a silicone resin, a silicone rubber, and a styrene block polymer.

[0020] The adhesive support layer may have a higher adhesion than the bending area protective layer.

[0021] A method for manufacturing a display device according to an exemplary embodiment includes the following steps: providing a substrate including a bending region at which the display device is bendable; disposing an encapsulation layer covering each of an upper surface and a side surface of an organic light emitting element on the substrate; disposing an upper protective layer on the encapsulation layer covering each of an upper surface and a side surface of the organic light emitting element, and disposing the bending region protective layer in the bending region of the substrate; and removing the upper protective layer from the encapsulation layer covering each of an upper surface and a side surface of the organic light emitting element. The disposing step of disposing both the upper protective layer and the bending region protective layer includes applying an ultraviolet curable material to the encapsulation layer and the bending region of the substrate, respectively, and curing the ultraviolet ("UV") ray curable material to form the upper protective layer and the bending region protective layer spaced apart from each other along the substrate.

[0022] The ultraviolet curable resin may include at least one of an acrylate polymer, a polyurethane, and an acrylate material containing SiO.

[0023] The step of providing both the upper protective layer and the bending area protective layer may provide the upper protective layer having a maximum thickness of about 100 μm to about 150 μm and the bending area protective layer having a maximum thickness of about 50 μm to about 150 μm.

[0024] The step of providing the upper protective layer may include providing a single layer of an ultraviolet curable material having a thickness of about 10 micrometers to about 20 micrometers a plurality of times and curing the single layer to provide the upper protective layer having a maximum thickness of about 100 micrometers to about 150 micrometers.

[0025] It may further include forming an adhesive support layer between the substrate and the upper protective layer and attaching the substrate to the upper protective layer using the adhesive support layer.

[0026] The adhesive support layer may include at least one of an acrylic resin, a butyl rubber, a vinyl acetate resin, an ethylene vinyl acetate ("EVA") resin, a natural rubber, a nitrile, a silicone resin, a silicone rubber, and a styrene block polymer.

[0027] According to exemplary embodiments, damage to a display device that may occur in a manufacturing process may be reduced or effectively prevented, the manufacturing process may be simplified, and material costs may be reduced, thereby improving productivity and yield of the manufactured display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other advantages and features of the present disclosure will become more apparent by further describing exemplary embodiments of the present disclosure in detail with reference to the accompanying drawings, in which: Figure 1 is a top view of an exemplary embodiment of a display device.

[0029] Figure 2 is along Figure 1 The line II-II in the Figure 1 A cross-sectional view of a display device.

[0030] Figure 3 is a flowchart illustrating an exemplary embodiment of a method of manufacturing a display device.

[0031] Figure 4 is based on Figure 3 A cross-sectional view of an exemplary embodiment of a display device that is not bent is provided by a manufacturing method.

[0032] Figure 5 It is shown Figure 4 A cross-sectional view of a curved display device.

[0033] Figure 6 is a top view illustrating an exemplary embodiment of an upper surface of an encapsulation layer of a display device.

[0034] Figure 7 and Figure 8 is a cross-sectional view of a modified exemplary embodiment of a display device.

[0035] Fig. 9 is an image of an exemplary embodiment of an upper protective layer on an encapsulation layer of a display device. DETAILED DESCRIPTION

[0036] The invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the invention.

[0037] In order to clearly explain the invention, parts that are not directly related to the invention are omitted, and the same reference numerals are attached to the same or similar constituent elements throughout the specification.

[0038] In addition, for better understanding and ease of description, the size and thickness of each configuration shown in the drawings are arbitrarily shown, but the invention is not limited thereto. In the drawings, the thickness of layers, films, panels, regions, etc. are exaggerated for clarity. In the drawings, the thickness of some layers and regions are exaggerated for better understanding and ease of description.

[0039] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being in relation to another element such as "on" another element, it can be directly on the other element, or intervening elements may also be present. In contrast, when an element is referred to as being in relation to another element such as "directly on" another element, there are no intervening elements.

[0040] In addition, in the specification, the wording " on" or "on "Above" means located above or below an object part, and does not necessarily mean located on the upper side of an object part based on the direction of gravity. Relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element shown in the figures. It will be understood that relative terms are intended to include different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one figure is turned over, elements described as being on the "lower" side of other elements would subsequently be positioned on the "upper" side of the other elements. Thus, the exemplary term "lower" can include both the "lower" and "upper" orientations, depending on the specific orientation in the figures. Similarly, if the device in one figure is turned over, elements described as being "below" or "beneath" other elements would subsequently be positioned "above" the other elements. Thus, the exemplary terms "below" or "under" "Below" can include both above and below.

[0041] It will be understood that, although the terms "first", "second", and "third", etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or part from another region, layer, or part. Therefore, the first "element", "component", "region", "layer", or "part" discussed below may be named as a second element, component, region, layer, or part without departing from the teachings herein.

[0042] The terms used herein are only for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms "one", "one (kind / person)" and "the (said)" are intended to include plural forms including "at least one (kind / person)". "At least one (kind / person)" is not interpreted as limiting "one (kind / person)". "Or (or)" means "and / or". As used herein, the term "and / or" includes any combination and all combinations of one or more related listed items. In addition, unless explicitly given to the contrary, the word "include" and its variations will be understood to mean including the stated elements but not excluding any other elements.

[0043] Furthermore, in this specification, the phrase "on a plane" or "top view" means observing a target portion from the top, and the phrase "on a cross section" means observing a cross section formed by vertically cutting the target portion from the side.

[0044] As used herein, "about" or "substantially" is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will also be understood that, unless so explicitly defined herein, terms (such as those defined in common dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and in the present disclosure, and will not be interpreted in an idealized or overly formal sense.

[0046] Exemplary embodiments are described herein with reference to schematically illustrated cross-sectional views as ideal embodiments. Thus, variations in the illustrated shapes, such as those caused by manufacturing techniques and / or tolerances, will be expected. Therefore, the embodiments described herein should not be construed as being limited to the specific shapes of the regions illustrated herein, but rather to include deviations in shape, such as those caused by manufacturing. For example, regions illustrated or described as being flat may typically have rough and / or nonlinear features. In addition, illustrated sharp corners may be rounded. Therefore, the regions illustrated in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shapes of the regions and are not intended to limit the scope of the current claims.

[0047] Reference Figure 1 and Figure 2 A display device according to an exemplary embodiment will be described.

[0048] Figure 1 is a top view of an exemplary embodiment of a display device. Figure 2 is along Figure 1 The line II-II in the Figure 1 A cross-sectional view of a display device.

[0049] Reference Figure 1 The display device includes a display panel 100. The display device may be an organic light emitting diode display, a liquid crystal display, or an electrophoretic display. An exemplary embodiment in which the display device is an organic light emitting diode display is described below as an example.

[0050] The display panel 100 includes a display area DA where an image is displayed and a non-display area PA where no image is displayed. The display area DA includes a plurality of pixels PX, which are areas where images are displayed. In the display area DA, a plurality of signal lines including a plurality of gate lines 131, a plurality of data lines 132, and a plurality of drive voltage lines 133 are provided or formed. Each pixel PX includes a pixel circuit connected to the plurality of signal lines and an organic light emitting element whose light emission is controlled by the pixel circuit. The non-display area PA is an area where elements or wirings for generating and transmitting various signals applied to the display area DA are provided. The pixels PX can be driven or controlled using various signals applied to the display area DA via elements or wirings in the non-display area PA.

[0051] The non-display area PA of the display panel 100 includes a bending area BA. The bending area BA is an area where the display panel 100 and therefore the display device is bendable relative to the bending axis. Components, elements, wiring, etc. of the display panel 100 may be bendable at the bending area BA. The display panel 100 is bendable at the bending area BA so that the bent display device sets a portion of the non-display area PA at the rear surface of the display panel 100 opposite to its front surface (the image is viewable at the front surface), thereby reducing the dead zone caused by the non-display area PA. The dead zone can be defined by a portion of the non-display area PA where signal lines, elements, wiring, etc. are omitted but still occupy space within the display device.

[0052] Reference Figure 2 The display device includes a substrate 110 , a thin film transistor array panel 120 , an organic light emitting element 125 , an encapsulation layer 130 , a support member 140 , an upper protective layer 150 , and a bending area protective layer 160 .

[0053] The display device and its components may be arranged in a plane defined by a first direction and a second direction intersecting each other. Figure 1 In the embodiment, the horizontal direction may represent one of the first direction and the second direction, and the vertical direction may represent the other of the first direction and the second direction. The bending axis in the bending area BA may be along Figure 1 The thickness of the display device and its components extends along a third direction intersecting each of the first direction and the second direction. Figure 2 , the horizontal direction may represent the first direction and / or the second direction, and the vertical direction represents the thickness direction.

[0054] The substrate 110 may include a flexible material such as plastic that may be bent, folded, or rolled. In an exemplary embodiment, for example, the substrate 110 may include polyimide ("PI"), polyethylene naphthalate ("PEN"), polycarbonate ("PC"), polyarylate ("PAR"), polyetherimide ("PEI"), polyethersulfone ("PES"), etc. The substrate 110 is divided into Figure 1 The display area DA and the non-display area PA described in the embodiment of the present invention include the display area DA and the non-display area PA, and the non-display area PA includes the bending area BA. The display area DA and the non-display area PA may define the entire planar area of ​​the substrate 110, without being limited thereto.

[0055] The thin film transistor array panel 120 is disposed on the substrate 110 in the display area DA of the substrate 110. The thin film transistor array panel 120 includes at least one thin film transistor and a plurality of signal lines including a plurality of gate lines, a plurality of data lines, and a plurality of driving voltage lines. The thin film transistors may be respectively disposed in each pixel PX among the plurality of pixels PX, and may be connected to the plurality of signal lines at the pixel PX.

[0056] The organic light emitting element 125 is disposed on the thin film transistor array panel 120. The organic light emitting element 125 may be disposed in each pixel PX among the plurality of pixels PX. The organic light emitting element 125 may include a pixel electrode, a common electrode, and an organic emission layer. The thin film transistors and the pixel electrodes of the thin film transistor array panel 120 are connected to each other, thereby controlling light emission at the pixel PX. The pixel PX may include a light emitting region at which light is emitted from the organic light emitting element 125. Holes and electrons are injected from the pixel electrode and the common electrode into the organic emission layer, and the excitons in which the holes and electrons are combined drop from an excited state to a ground state, thereby achieving light emission.

[0057] According to an exemplary embodiment, a touch sensing layer (not shown) for sensing a touch on the display device and / or the display panel 100 may be further included and disposed above or below the organic light emitting element 125 .

[0058] The encapsulation layer 130 covering the organic light emitting element 125 is disposed on the organic light emitting element 125. The encapsulation layer 130 covers the side surface and the upper surface of the organic light emitting element 125, thereby encapsulating the organic light emitting element 125 on the substrate 110. Since the organic light emitting element 125 is susceptible to moisture and oxygen, the encapsulation layer 130 seals the organic light emitting element 125 to block external moisture and oxygen from flowing in from the outside of the encapsulation layer 130.

[0059] The encapsulation layer 130 may include a plurality of layers, and may be formed of a composite layer including both an inorganic layer and an organic layer or include a composite layer including both an inorganic layer and an organic layer. The encapsulation layer 130 may be formed of three layers in which an inorganic layer, an organic layer, and an inorganic layer are sequentially arranged or formed or include three layers in which an inorganic layer, an organic layer, and an inorganic layer are sequentially arranged or formed. Here, the inorganic layer may include at least one of a metal oxide, a metal nitride oxide, a silicon oxide, a silicon nitride, and a silicon oxynitride. The organic layer may include a polymer series material or be formed of a polymer series material, without being limited thereto.

[0060] The support member 140 is disposed below the substrate 110 on a rear surface of the substrate 110 opposite to a front surface on which the thin film transistor array panel 120, the organic light emitting element 125, and the encapsulation layer 130 are disposed. The support member 140 may have a function of protecting and supporting the substrate 110. The support member 140 may define or include an opening therein overlapping the bending area BA. Therefore, since the support member 140 is not disposed in the bending area BA, the display panel 100 may be easily bent in the bending area BA.

[0061] The upper protective layer 150 is disposed on the encapsulation layer 130. In an exemplary embodiment of manufacturing a display device, the upper protective layer 150 may be disposed or formed by spraying an ultraviolet ("UV") curable resin and curing the UV curable resin (eg, UV curable resin) with ultraviolet light, such as by an inkjet printing method.

[0062] The UV curable resin may include an ultraviolet curable material. The ultraviolet curable material as a material that can be cured with ultraviolet rays may include at least one of an acrylate polymer (e.g., a polymer including an acrylate), a polyurethane, and an acrylate material including SiO (e.g., an acrylate material including SiO), without being limited thereto. The ultraviolet curable material may include any one of a variety of materials that can be cured with ultraviolet rays. The UV curable resin may further include a photoinitiator, a heat stabilizer, an antioxidant, an antistatic agent, and / or a slip agent.

[0063] The upper protective layer 150 may include a cured portion of the above-mentioned ultraviolet curable material. That is, the upper protective layer 150 may include at least one cured portion among an acrylate polymer, a polyurethane, and an acrylate material including SiO. In addition, the upper protective layer 150 may further include a photoinitiator, a heat stabilizer, an antioxidant, an antistatic agent, or a slip agent that remains in the upper protective layer 150 after the UV curable resin used to form the upper protective layer 150 is cured.

[0064] According to an exemplary embodiment, the upper protective layer 150 as a cured portion of the material layer may include at least one of an acryl resin (e.g., a resin including an acryl material), butyl rubber, vinyl acetate resin, ethylene vinyl acetate ("EVA") resin, natural rubber, nitrile, silicone resin, silicone rubber, and styrene block polymer. Since the upper protective layer 150 also includes at least one of these materials, the upper protective layer 150 may have a predetermined adhesion to the encapsulation layer 130. The adhesion of the upper protective layer 150 to the encapsulation layer 130 may be about 3 grams force / inch (gf / inch) to about 10 gf / inch.

[0065] The upper protective layer 150 is removably disposed on the encapsulation layer 130. In an exemplary embodiment, the upper protective layer 150 is disposed on the encapsulation layer 130 to protect the encapsulation layer 130, such as during a manufacturing process, and is subsequently removed. The upper protective layer 150 may be disposed in the display area DA along the entire encapsulation layer 130, without being limited thereto. The upper protective layer 150 may be selectively disposed in some areas on the encapsulation layer 130 in the display area DA, and / or may have different thicknesses for each area of ​​the encapsulation layer 130 in the display area DA.

[0066] The maximum thickness of the upper protective layer 150 may be about 100 micrometers (μm) to about 150 μm. The thickness of the upper protective layer 150 is the height in the vertical direction or thickness direction relative to the upper surface of the substrate 110. The thickness of the upper protective layer 150 may gradually decrease as the distance to the end of the upper protective layer 150 decreases. In a cross-section, the upper surface of the upper protective layer 150 may have an inclined shape bent at the end, and the inclination of the upper surface of the upper protective layer 150 relative to the substrate 110 may increase as the distance to the end of the upper protective layer 150 decreases.

[0067] The bending area protective layer 160 is disposed on the substrate 110 in the bending area BA of the substrate 110, and is spaced apart from the upper protective layer 150 and the encapsulation layer 130 along the substrate 110 without contacting the upper protective layer 150 and the encapsulation layer 130. The bending area protective layer 160 covers the bending area BA, and relaxes stress applied to wirings (not shown) disposed in the bending area BA of the substrate 110 during bending of the display device, thereby reducing or effectively preventing cracks in the wirings (particularly portions of the wirings) disposed in the bending area BA.

[0068] In an exemplary embodiment of manufacturing a display device, the bending area protective layer 160 can be provided or formed by injecting a UV curable resin and curing the UV curable resin with ultraviolet rays, such as by an inkjet printing method. The UV curable resin may include an ultraviolet curable material. The ultraviolet curable material refers to a material that can be cured with ultraviolet rays, and the details are as described in the description of the upper protective layer 150.

[0069] The bending area protective layer 160 may include a cured portion of an ultraviolet curable material as described in the description of the upper protective layer 150, and thus a detailed description thereof is omitted herein. The bending area protective layer 160 may include the same material as the upper protective layer 150. The bending area protective layer 160 and the upper protective layer 150 may be portions of the same material layer among the layers disposed on the substrate 110, respectively. However, according to an exemplary embodiment, the bending area protective layer 160 and the upper protective layer 150 may be disposed or formed to include different materials and / or may be portions of different material layers among the layers disposed on the substrate 110, respectively.

[0070] The bending area protective layer 160 may further include a photoinitiator, a heat stabilizer, an antioxidant, an antistatic agent, or a slip agent that remains in the bending area protective layer 160 after the UV curable resin used to form the bending area protective layer 160 is cured.

[0071] In addition, according to an exemplary embodiment, the bending area protection layer 160 may further include at least one of an acryl resin, a butyl rubber, a vinyl acetate resin, an ethylene vinyl acetate ("EVA") resin, a natural rubber, a nitrile, a silicone resin, a silicone rubber, and a styrene block polymer. Due to the inclusion of these materials, the bending area protection layer 160 may have a predetermined adhesiveness. The adhesiveness of the bending area protection layer 160 with respect to a lower layer such as the substrate 110 in contact therewith may be higher than the adhesiveness of the upper protection layer 150 with respect to a lower layer such as the encapsulation layer 130. In an exemplary embodiment, for example, the adhesiveness of the bending area protection layer 160 may be about 50 gf / inch to about 200 gf / inch.

[0072] The maximum thickness of the bending area protection layer 160 may be about 50 μm to about 150 μm. The thickness of the bending area protection layer 160 is a height in a vertical direction with respect to the upper surface of the substrate 110 .

[0073] The bending area protective layer 160 may overlap a portion of the support member 140 close to the display area DA and a portion of the support member 140 in the non-display area PA, the portion of the support member 140 in the non-display area PA being disposed in a direction toward an end of the display device (e.g., in the direction of the display area DA). Figure 2 The farthest right side) is located outside the bending area BA.

[0074] The width of the overlapping region where the bending region protective layer 160 and the supporting member 140 overlap each other may be about 100 μm to about 200 μm. The width of the overlapping region is the distance where the bending region protective layer 160 and the supporting member 140 overlap each other taken in the normal direction of the bending axis. Figure 2 , the width is taken in a horizontal direction that is orthogonal to the bending axis located in the bending area BA. That is, the bending area protection layer 160 may extend and be disposed to an area 100 μm to 200 μm away from the bending area BA at each side of the opposite sides of the bending area BA. In this way, since a portion of the bending area protection layer 160 overlaps with the support member 140, cracks of the wiring disposed in the bending area BA may be reduced or effectively prevented.

[0075] Reference Figures 3 to 5 An exemplary embodiment of a method of manufacturing a display device is described below. Figure 3 is a flowchart showing an exemplary embodiment of a method for manufacturing a display device, Figure 4 is based on Figure 3 A cross-sectional view of an exemplary embodiment of a display device is provided by a manufacturing method. Figure 5 It is shown Figure 4 A cross-sectional view of a curved display device.

[0076] The substrate 110 is disposed or formed on a base substrate or a carrier substrate (not shown), such as being attached to the base substrate or the carrier substrate (not shown). The base substrate and the substrate 110 may be removably attached to each other. On the substrate 110, a thin film transistor array panel 120 and an organic light emitting element 125 are disposed or formed in a display area DA of the substrate 110, such that both the thin film transistor array panel 120 and the organic light emitting element 125 are encapsulated by an encapsulation layer 130 in the display area DA of the substrate 110. A conductive wiring (not shown) is disposed or formed in a non-display area PA of the substrate 110. The base substrate attached to the substrate 110 is to ensure a favorable total thickness and rigidity for handling the substrate 110 and the layers disposed on the substrate 110 during the manufacture of the display device. The base substrate may be a flexible substrate.

[0077] like Figure 3 As shown in FIG. 1 , on the substrate 110, an upper protective layer 150 and a bending area protective layer 160 are disposed or formed on the encapsulation layer 130 in the bending area BA and in the display area DA, respectively, by an inkjet printing method. Figure 2 )(S101).

[0078] To form the upper protective layer 150 and the bending area protective layer 160, a UV curable resin may be sprayed in a predetermined volume at predetermined positions (e.g., at the display area DA and at the non-display area PA) along the substrate 110 by a nozzle of an inkjet printing device, and the UV curable resin may be cured with ultraviolet (“UV”) rays.

[0079] In a conventional flexible organic light-emitting device, an encapsulation layer is provided or formed to encapsulate a display substrate, thereby reducing or effectively preventing moisture and oxygen from penetrating into an organic material as a light-emitting material. However, the encapsulation layer of a conventional flexible organic light-emitting device is relatively easily damaged by external scratches or indentations or scratches caused by foreign materials generated during a subsequent manufacturing process, and these indentations or scratches cause defects such as black spots in the conventional flexible organic light-emitting device.

[0080] In order to solve these problems, for a substrate of a conventional flexible organic light-emitting device, an upper protective film including or formed of a polyethylene terephthalate ("PET") film is attached to an encapsulation layer to protect the encapsulation layer during a subsequent manufacturing process. However, a process of attaching the upper protective film is additionally used to manufacture the conventional flexible organic light-emitting device, which reduces productivity and yield of the manufactured conventional flexible organic light-emitting device. In addition, since the upper protective layer can be disposed or formed only on the entire surface of the substrate having the encapsulation layer thereon, selective coating is not possible for a separate portion of the upper protective layer.

[0081] However, according to one or more exemplary embodiments, the upper protective layer 150 and the bending area protective layer 160 may be provided or formed at the same time, thereby simplifying the process. Since they are provided or formed at the same time, the upper protective layer 150 and the bending area protective layer 160 may use the same material layer and / or be provided in the same process or formed by the same process, so that the upper protective layer 150 and the bending area protective layer 160 of the display device are respectively parts of the same material layer. In addition, since the upper protective layer 150 may be provided or formed only locally in some areas by an inkjet printing method, as opposed to providing the upper protective layer 150 on the entire substrate of a conventional display panel, the material cost may be reduced. That is, the upper protective layer 150 may be provided or formed only in the area where the encapsulation layer 130 of the display panel is provided, rather than providing or forming the upper protective layer 150 on the entire substrate of a conventional display panel.

[0082] The injection and curing process of the UV curable resin for setting or forming the upper protective layer 150 on the encapsulation layer 130 may be repeatedly performed several times. Specifically, a single process of injecting the UV curable resin into the substrate 110 at a thickness of about 10 μm to about 20 μm at the area where the upper protective layer 150 is to be set or formed and curing the UV curable resin injected by the single process with ultraviolet rays is repeated several times to increase the thickness of the cured UV resin, thereby setting or forming the upper protective layer 150 with a total thickness of about 100 μm to about 150 μm. That is, in an exemplary embodiment, a single layer of the UV curable resin having a thickness of about 10 μm to about 20 μm is set and cured multiple times to set the upper protective layer 150 with a maximum thickness of about 100 μm to about 150 μm. If a relatively large amount of UV curable resin is cured at one time, the curing time increases, and all parts of the UV curable resin cannot be uniformly cured. However, in an exemplary embodiment, the UV curable resin sprayed at a thickness of about 100 μm to about 150 μm in a single process may be cured at one time in one single process.

[0083] In order to arrange or form the bending area protection layer 160 in the bending area BA, a UV curable resin may be injected and cured at a thickness of about 50 μm to about 150 μm along an area arranged in the bending area BA and extending from the bending area BA by about 100 μm to about 200 μm. That is, the total width of the bending area protection layer 160 may include the width of the bending area BA plus two distances extending from opposite sides of the bending area BA by about 100 μm to about 200 μm, respectively. In this way, the bending area protection layer 160 extending from the bending area BA to the display area DA is arranged or formed so as not to overlap with the encapsulation layer 130 and the upper protective layer 150.

[0084] As described above, the UV curable resin may include an ultraviolet curable material, and its detailed description is as follows. Figure 2 The same as described in , so repeated description is omitted here.

[0085] The base substrate is removed from the substrate 110 having the upper protective layer 150 and the bending region protective layer 160 on the thin film transistor array panel 120 and the organic light emitting element 125 (which are encapsulated by the encapsulation layer 130 located thereon), and the support member 140 is attached below the substrate 110 from which the base substrate is removed (S102). The support member 140 may be used to support and protect the substrate 110, especially when various layers are disposed or formed thereon. The support member 140 may form the outermost layer of the display device, without being limited thereto.

[0086] Portions of the support member 140 may be spaced apart from each other to define an opening in the support member 140 overlapping the bending area BA. Each portion of the support member 140 overlapping the bending area protective layer 160 may have a width of about 100 μm to about 200 μm along the substrate 110 in a direction orthogonal to the bending axis.

[0087] After attaching the support member 140, a driver integrated circuit chip 200 may be disposed or formed on the end of the substrate 110 located in the non-display area PA thereof. Along the substrate 110, the driver integrated circuit chip 200 located on the end of the substrate 110 may be disposed to be spaced apart from the bending area protection layer 160 covering the bending area BA without contacting the bending area BA. The driver integrated circuit chip 200 may control the display device and output a signal for driving the display panel 100 of the display device. The driver integrated circuit chip 200 may be an integrated driver integrated circuit chip that applies a timing signal for applying a data voltage to the pixel PX, applying a gate voltage to the pixel PX, etc., without being limited thereto.

[0088] The upper protective layer 150 is removed from the substrate 110, specifically, the upper protective layer 150 is removed from the encapsulation layer 130 located on the substrate 110 (S103). The removal of the upper protective layer 150 exposes the encapsulation layer 130 located on the substrate 110. The upper protective layer 150 may be removed by a physical method such as, but not limited to, attaching an adhesive member (e.g., tape) to one end and peeling off the adhesive member and the upper protective layer 150 attached to the adhesive member by an external force. Since the bending area protective layer 160 is disposed or formed not to contact the upper protective layer 150 and the encapsulation layer 130, only the upper protective layer 150 may be removed without removing the bending area protective layer 160. That is, after removing the upper protective layer 150, the bending area protective layer 160 may remain on the substrate 110 on which various layers are disposed or formed.

[0089] The adhesion of the upper protective layer 150 to the encapsulation layer 130 may be lower than the adhesion of the bending area protective layer 160 to the substrate 110. In an exemplary embodiment, for example, the adhesion of the upper protective layer 150 to the lower layer in contact therewith may be about 3 gf / inch to about 10 gf / inch, and the adhesion of the bending area protective layer 160 to the lower layer in contact therewith may be about 50 gf / inch to about 200 gf / inch.

[0090] Since the upper protective layer 150 is removably attachable to the encapsulation layer 130, the upper protective layer 150 is attachable during some manufacturing processes and removable after these processes, so the upper and lower limits of the adhesion are defined. If the adhesion of the upper protective layer 150 to the lower layer in contact with it (such as the encapsulation layer 130) is less than 3gf / inch, there will be a phenomenon that the upper protective layer 150 is peeled off prematurely or the outer part falls off during the process. On the contrary, if the adhesion of the upper protective layer 150 to the lower layer in contact with it (such as the encapsulation layer 130) exceeds 10gf / inch, when the upper protective layer 150 is removed, the encapsulation layer 130 is damaged.

[0091] Unlike the upper protective layer 150 that is removed after some processes of manufacturing, the bending area protective layer 160 that is removably attachable to a lower layer (such as the substrate 110) in contact therewith is not removed and remains on the substrate 110 to eliminate stress acting on the substrate 110 during bending of the display panel 100 and / or the display device. Therefore, if the above-mentioned adhesion of the bending area protective layer 160 is less than about 50 gf / inch, the bending area protective layer 160 may be torn and damaged.

[0092] After the upper protective layer 150 is removed, the polarizing film 170 , the adhesive layer 180 , and the window panel 190 are sequentially disposed or formed on the substrate 110 having various layers thereon ( S104 ).

[0093] The polarizing film 170 can reduce the reflection of external light incident from outside the display device. When the external light passes through the polarizing film 170 and is reflected by the thin film transistor array panel 120 and then passes through the polarizing film 170 again, the phase of the external light can be changed. As a result, extinction interference occurs between the reflected light and the phase of the external light incident to the polarizing film 170, so that the light recognizable from outside the display device can be suppressed and the display quality of the display device can be improved. In addition, since a retarder (not shown) is also included, the reflection of the external light is suppressed by reducing or effectively preventing the external light passing through the retarder and the polarizing film 170 from being reflected by the thin film transistor array panel 120 and returning through the polarizing film 170. However, the invention is not limited, and the polarizing film 170 may include any conventional configuration capable of reducing the reflection of external light.

[0094] The adhesive layer 180 may include an optically clear adhesive ("OCA"), an optically clear resin ("OCR"), and / or a pressure sensitive adhesive ("PSA").

[0095] The window panel 190 is used to protect the display panel 100 and / or the display device from its external environment. The window panel 190 may form the outermost layer of the display panel 100 and / or the display device. The image output from the display panel 100 may be transmitted to the user through the window panel 190. The window panel 190 may include or be formed of a light-transmitting material such as glass, polyethylene terephthalate, and acrylic, but is not limited thereto. Therefore, the window panel 190 may be formed of a light-transmitting material such as glass, polyethylene terephthalate, and acrylic. Figure 4 The display device shown in .

[0096] Figure 4 is based on Figure 3 A cross-sectional view of a display device provided or formed by a manufacturing method. Figure 4 In the embodiment, the display device including the substrate 110 having various layers thereon is flat. The display device which is flat has the non-display area PA disposed adjacent to the display area DA along the substrate 110, and has the substrate 110 and elements or wirings located in the bending area BA of the substrate 110 disposed flat.

[0097] In addition to including the polarizing film 170, the adhesive layer 180, the window panel 190 and the driving integrated circuit chip 200 and excluding the upper protective layer 150, Figure 4 The display device and Figure 2 The display device is similar, so the detailed description of the repeated contents is omitted.

[0098] pass Figure 3 The manufacturing process of removing the upper protective layer 150 (S103) and sequentially attaching the polarizing film 170, the adhesive layer 180 and the window panel 190 to the encapsulation layer 130 (S104), Figure 4 The display device does not include Figure 2 The upper protective layer 150 shown in FIG. Removing the upper protective layer 150 from the encapsulation layer 130 ( S103 ) allows the upper surface of the encapsulation layer 130 to be disposed to be exposed to the outside of the encapsulation layer 130 . Attaching the polarizing film 170 allows the polarizing film 170 to be disposed on the upper surface of the encapsulation layer 130 exposed to the outside of the encapsulation layer 130 by removing the upper protective layer 150 .

[0099] Along the substrate 110 , the driving integrated circuit chip 200 is disposed to be spaced apart from the bending area protective layer 160 in the non-display area PA of the substrate 110 . Figure 4The display device may further include a printed circuit board (“PCB”) (not shown) attached to the display panel 100. The printed circuit board (“PCB”) may be attached to the display panel 100 through the driving integrated circuit chip 200, without being limited thereto. The printed circuit board (“PCB”) may provide the driving integrated circuit chip 200 with a control signal or a driving signal with which the display panel (e.g., the pixel PX) is controlled and / or an image signal or a data signal including information for causing an image to be displayed through the pixel PX from the outside of the driving integrated circuit chip 200.

[0100] The details of the polarizing film 170, the adhesive layer 180, the window panel 190 and the driving integrated circuit chip 200 are similar to those of Figure 3 Those described are the same and are omitted here. According to an exemplary embodiment, another adhesive layer may be included between the encapsulation layer 130 and the polarizing film 170 without being limited thereto.

[0101] Reference Figure 5 , Figure 4 The display panel 100 is bent at the bending area BA. The bent display panel 100 has the driving integrated circuit chip 200 disposed to overlap the display area DA of the display panel 100. When the display panel 100 is bent, the wiring disposed in the bending area BA is stressed, but the bending area protection layer 160 covering the bending area BA and the wiring disposed therein are stressed (e.g., tensile stress) when bent, so that the stress applied to the wiring can be reduced.

[0102] Figure 6 is a top view showing an exemplary embodiment of the upper surface of the encapsulation layer of the display device. Specifically, Figure 6 Indicates that the upper protective layer 150 is removed ( Figure 2 ) is formed on the upper surface of the encapsulation layer 130 after the bending area BA is formed. Therefore, the bending area protection layer 160 is disposed in the bending area BA, but the upper protection layer 150 is removed and does not exist.

[0103] As described above, the upper protective layer 150 and the curved area protective layer 160 of the display device according to one or more exemplary embodiments are both formed by a process of injecting a UV curable resin through an inkjet printing method and curing the injected UV curable resin with ultraviolet rays. When the upper protective layer 150 is disposed or formed on the encapsulation layer 130 by the inkjet printing method, a nanostructure 135 including nano-sized protrusions and recesses is formed at an edge region where the end of the upper protective layer 150 is disposed overlapping the encapsulation layer 130. In an exemplary embodiment, the nanostructure 135 may be a portion of the encapsulation layer 130 that has been deformed due to the removal of the upper protective layer 150. In an exemplary embodiment, the upper protective layer 150 is removed from the upper surface of the encapsulation layer 130 to form a nanostructure 135 defined by nano-sized protrusions and recesses on the upper surface of the encapsulation layer 130. Since the nanostructure 135 includes protrusions and recesses of nanometer units, a bright band-like afterimage can be seen compared to other regions.

[0104] According to an exemplary embodiment, the upper protective layer 150 may be selectively disposed or formed along the substrate 110 (e.g., only on the encapsulation layer 130) and removed from the encapsulation layer 130 of each display panel 100, rather than forming the upper protective layer 150 on the entire substrate 110. In the case where the upper protective layer 150 is selectively disposed or formed along the substrate 110 (e.g., only on the encapsulation layer 130) and removed from the encapsulation layer 130 of each display panel 100, in a top view, the nanostructure 135 may be disposed in a closed line shape extending correspondingly along the length of the edge of the encapsulation layer 130.

[0105] Reference Figure 7 Another exemplary embodiment of a display device will be described.

[0106] Figure 7 is a cross-sectional view of another exemplary embodiment of a display device. Figure 7 The display device further includes a first adhesive support layer 155 and Figure 2 The exemplary embodiments of the present invention are similar to those of the present invention, so that a detailed description of the same constituent elements is omitted and the differences are explained.

[0107] according to Figure 7 The display device of the exemplary embodiment further includes a first adhesive support layer 155 between the encapsulation layer 130 and the upper protective layer 150. The adhesion of the first adhesive support layer 155 to the lower layer in contact therewith (such as the encapsulation layer 130) may be lower than the adhesion of the bending area protective layer 160 to the lower layer (e.g., the substrate 110). In an exemplary embodiment, for example, the adhesion of the first adhesive support layer 155 may be about 3 gf / inch to about 10 gf / inch.

[0108] According to an exemplary embodiment, the first adhesive supporting layer 155 may include at least one of acryl-based resin, butyl rubber, vinyl acetate resin, ethylene vinyl acetate ("EVA") resin, natural rubber, nitrile, silicone resin, silicone rubber, and styrene block polymer.

[0109] If the first adhesive support layer 155 is further included, appropriate adhesion of the first adhesive support layer 155 to the encapsulation layer 130 can be maintained regardless of the adhesion of the upper protective layer 150 to the lower layer in contact therewith. That is, even if the adhesion of the upper protective layer 150 is not low enough to facilitate removal of the upper protective layer 150 from the lower layer such as the encapsulation layer 130 in contact with the upper protective layer 150, the upper protective layer 150 can be removed from the encapsulation layer 130 together with the first adhesive support layer 155 without damaging the encapsulation layer 130.

[0110] Reference Figure 8 Another exemplary embodiment of a display device will be described. Figure 8 is a cross-sectional view of another exemplary embodiment of a display device. Figure 8 The display device includes the second adhesive support layer 165 and Figure 2 The exemplary embodiments of the present invention are similar to those of the present invention, so a detailed description of the same constituent elements is omitted and the differences are explained.

[0111] according to Figure 8 The display device of the exemplary embodiment further includes a second adhesive support layer 165 between the substrate 110 and the bending area protective layer 160. The adhesion of the second adhesive support layer 165 to the lower layer in contact therewith (such as the substrate 110) may be greater than the adhesion of the upper protective layer 150 to the lower layer in contact therewith (such as the encapsulation layer 130). In an exemplary embodiment, for example, the adhesion of the second adhesive support layer 165 may be about 50 gf / inch to about 200 gf / inch.

[0112] According to an exemplary embodiment, the second adhesive supporting layer 165 may further include at least one of acryl-based resin, butyl rubber, vinyl acetate resin, ethylene vinyl acetate ("EVA") resin, natural rubber, nitrile, silicone resin, silicone rubber, and styrene block polymer.

[0113] If the second adhesive support layer 165 is also included, even if the adhesion of the bending area protection layer 160 is not high enough to remain attached to the substrate 110, the second adhesive support layer 165 can maintain the attachment state of the bending area protection layer 160 on the substrate 110 without removing or peeling the bending area protection layer 160 from the substrate 110.

[0114] An example of forming the upper protective layer 150 on the encapsulation layer 130 according to an exemplary embodiment will now be described. Fig. 9 is an image of an exemplary embodiment of an upper protective layer 150 removably disposed on an encapsulation layer 130 of a display device.

[0115] like Fig. 9 As shown in , the upper protective layer 150 can be disposed or formed on the encapsulation layer 130 to have a total thickness of about 100 μm to about 150 μm by repeatedly performing a single process of spraying and curing a layer of UV curable resin applied to the encapsulation layer 130 by an inkjet printing method.

[0116] While the invention has been described in connection with what are presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but on the contrary is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims.

Claims

1. A display device, comprising: a substrate including a bending region, the display device being bendable at the bending region; An organic light emitting element is disposed on the substrate; as well as An encapsulation layer, covering the upper surface and side surfaces of the organic light-emitting element; At least a portion of the upper surface of the encapsulation layer includes a nanostructure defined by nano-sized protrusions and recesses at an edge of the upper surface.

2. The display device according to claim 1, wherein: In a top view, the nanostructure forms a closed line shape extending along an edge of the encapsulation layer.

3. The display device according to claim 2, comprising: a bending area protection layer, covering the bending area of ​​the substrate, Wherein, along the substrate, the bending area protection layer is disposed separately from the encapsulation layer, and Wherein, the bending area protective layer includes a cured portion of an ultraviolet curable material.

4. The display device according to claim 3, wherein: The ultraviolet curable material includes at least one of an acrylate-containing polymer, a polyurethane, and an SiO-containing acrylate material.

5. The display device according to claim 4, wherein: The ultraviolet curable material includes at least one of a resin including an acryl material, butyl rubber, vinyl acetate resin, ethylene vinyl acetate resin, natural rubber, nitrile, silicone resin, silicone rubber, and styrene block polymer.

6. The display device according to claim 5, wherein: The bending area protective layer has an adhesion of about 50 gf / inch to about 200 gf / inch.

7. The display device according to claim 6, wherein: The maximum thickness of the bending area protective layer is about 50 microns to about 150 microns.

8. The display device according to claim 7, further comprising a supporting member disposed on a rear surface of the substrate, in, The organic light emitting element and the encapsulation layer are disposed on a front surface of the substrate opposite to the rear surface of the substrate, and The support member defines an opening therein overlapping the curved region.

9. The display device according to claim 8, wherein: Along the substrate, the support member defining the opening overlapping the bending region overlaps the bending region protection layer covering the bending region by about 100 micrometers to about 200 micrometers.

10. The display device according to claim 6, further comprising a driver integrated circuit chip disposed on an end portion of the substrate, in, Along the substrate, the bending area protection layer covering the bending area is disposed separately from the driving integrated circuit chip disposed on the end portion of the substrate.

11. The display device according to claim 10, further comprising: an upper protective layer removably attachable to the encapsulation layer, wherein removing a portion of the upper protective layer from the encapsulation layer exposes an upper surface of the encapsulation layer outside the encapsulation layer and forms the nanostructure; a polarizing film disposed on the upper surface of the encapsulation layer exposed to the outside of the encapsulation layer; and The window panel is arranged on the polarizing film. 12 . The display device according to claim 3 , further comprising an adhesive support layer disposed between the substrate and the bending area protective layer at the bending area of ​​the substrate, the substrate being attached to the bending area protective layer using the adhesive support layer.

13. The display device according to claim 12, wherein: The adhesive support layer includes at least one of a resin including an acryl material, butyl rubber, vinyl acetate resin, ethylene vinyl acetate resin, natural rubber, nitrile, silicone resin, silicone rubber, and styrene block polymer.

14. The display device according to claim 13, wherein: The adhesive support layer has a higher adhesiveness than the bending region protective layer.

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