Display device and method for manufacturing display device

Abstract

A display device and a method of manufacturing the display device are provided. The display device includes a substrate including a first flat region, a second flat region, and a bending region disposed between the first flat region and the second flat region; a display unit overlapping the first flat region and disposed on a surface of the substrate; a first protective layer disposed on an opposite surface of the substrate opposite to the surface of the substrate and overlapping the first flat region; and a second protective layer disposed on the opposite surface of the substrate and overlapping the second flat region. The first protective layer and the second protective layer include a cured member including a photocurable resin, the first protective layer including a first inclined portion having a first inclination angle at an end portion of the first protective layer, and the second protective layer including a second inclined portion having a second inclination angle at an end portion of the second protective layer, and the first protective layer and the second protective layer include a heat dissipation material having thermal conductivity.

Description

[0001] This application is a divisional application of the invention patent application with application date of June 12, 2020, application number 202010540323.5, and invention name “Display Device”. Technical Field

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

[0003] Display devices such as liquid crystal display devices and organic light emitting display devices may be manufactured by forming various layers and elements on a substrate.

[0004] A glass substrate may be used as a substrate for a display device, but the glass substrate is generally heavy and fragile. In addition, since the glass substrate has a hard property, it may be difficult to deform the display device.

[0005] Recently, a display device using a substrate having characteristics of flexibility, lightness, impact resistance, and easy deformation has been developed. A display device using a flexible substrate can be designed to bend an edge of a display panel having a pad portion, and thus, a dead space can be reduced compared to a display device using a substrate having rigid characteristics such as a glass substrate. Summary of the invention

[0006] Example embodiments relate to a display device and a method of manufacturing the display device which simplifies a process by selectively patterning a protective layer on a surface of a substrate and makes it easy to bend by forming an end portion of the protective layer to be inclined.

[0007] According to an exemplary embodiment, a display device includes: a substrate having a first flat area, a second flat area, and a curved area arranged between the first flat area and the second flat area; a display unit overlapping the first flat area and arranged on a surface of the substrate; a first protective layer arranged on a relative surface of the substrate opposite to the surface of the substrate and overlapping the first flat area; and a second protective layer arranged on the relative surface of the substrate and overlapping the second flat area, wherein the first protective layer and the second protective layer include a curing member containing a photocurable resin, the first protective layer includes a first inclined portion at an end thereof, the second protective layer includes a second inclined portion at an end thereof, the first inclined portion has a first inclination angle with the relative surface of the substrate, the second inclination portion has a second inclination angle with the relative surface of the substrate, and each of the first inclination angle and the second inclination angle is greater than or equal to approximately 10 degrees and less than or equal to approximately 90 degrees.

[0008] In an exemplary embodiment, the first inclination angle and the second inclination angle may be in the range of about 30 degrees to about 45 degrees.

[0009] In example embodiments, as the first and second inclination angles decrease, strain received by the substrate at the bending region may decrease.

[0010] In an exemplary embodiment, during bending of the display device, a maximum value of the strain may be about 1.4%, and the value of the strain is defined as: (strain length) / (initial length)×100(%).

[0011] In an exemplary embodiment, the first inclined portion may be disposed at a portion where the first flat region is adjacent to the curved region, and the second inclined portion may be disposed at a portion where the second flat region is adjacent to the curved region.

[0012] In an exemplary embodiment, the photocurable resin may include at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO, and the photocurable resin may also include at least one material selected from acrylic-based resins, butyl rubber, vinyl acetate resins, ethylene vinyl acetate ("EVA") resins, natural rubber, nitrile, silicate resins, silicone rubber, and styrene block polymers.

[0013] In example embodiments, each of the first protective layer and the second protective layer may include a first auxiliary layer, a second auxiliary layer, and a third auxiliary layer sequentially stacked one on another from opposite surfaces of the substrate.

[0014] In example embodiments, the third auxiliary layer may include a heat dissipation material having thermal conductivity.

[0015] In exemplary embodiments, the heat dissipation material may be a carbon composite material including at least one selected from graphite, carbon nanotubes ("CNTs"), carbon fibers, and graphene.

[0016] In exemplary embodiments, the third auxiliary layer may further include a dispersant including dispersing the photocurable resin.

[0017] In an exemplary embodiment, the first auxiliary layer may include at least one material selected from acrylic resins, butyl rubber, vinyl acetate resins, ethylene vinyl acetate resins, natural rubber, nitrile, silicate resins, silicone rubber, and styrene block polymers, and the second auxiliary layer may include at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO.

[0018] In exemplary embodiments, at the bending region, connection parts may be disposed on opposite surfaces of the substrate, and the connection parts may include the same material as the second auxiliary layer.

[0019] In exemplary embodiments, the first protective layer and the second protective layer may be spaced apart from each other, and a space between the first protective layer and the second protective layer may overlap the bending region.

[0020] In an exemplary embodiment, the display device may further include a polarizing layer arranged on the display unit, the display device may further include a driving unit overlapping the second flat area and arranged on the surface of the substrate, the first protective layer may overlap the display unit and the polarizing layer, and the second protective layer may overlap the driving unit.

[0021] According to an exemplary embodiment, a display device includes: a substrate having a first flat area, a second flat area, and a curved area arranged between the first flat area and the second flat area; a display unit overlapping the first flat area and arranged on a surface of the substrate; a first protective layer arranged on an opposite surface of the substrate opposite to the surface of the substrate and overlapping the first flat area; and a second protective layer arranged on an opposite surface of the substrate and overlapping the second flat area, wherein the first protective layer and the second protective layer include a curing member containing a photocurable resin, the first protective layer includes a first inclined portion having a first inclination angle at an end thereof, the second protective layer includes a second inclined portion having a second inclination angle at an end thereof, and the first protective layer and the second protective layer include a heat dissipation material having thermal conductivity.

[0022] In an exemplary embodiment, the first inclination angle and the second inclination angle may be greater than or equal to about 10 degrees and less than or equal to about 90 degrees.

[0023] In exemplary embodiments, the heat dissipation material may be a carbon composite material including at least one material selected from graphite, CNT, carbon fiber, and graphene.

[0024] In exemplary embodiments, the first protective layer and the second protective layer may further include a dispersant containing a dispersed photocurable resin.

[0025] In an exemplary embodiment, a method for manufacturing a display device includes: providing a display unit including a plurality of thin film transistors on one surface of a substrate; and applying a photocurable resin on an opposite surface of the substrate overlapping with the one surface of the substrate and curing it to form a first protective layer and a second protective layer, wherein the photocurable resin is applied by an inkjet process.

[0026] In an exemplary embodiment, the coating of the photocurable resin may include: coating the photocurable resin by a printing device including a nozzle, the nozzle may spit out droplets of the photocurable resin, the display device may include a first flat area provided with a display unit, a curved area adjacent to the first flat area, and a second flat area adjacent to the curved area, the nozzle may spit out fewer droplets of the photocurable resin from the first flat area toward the curved area, and may spit out fewer droplets of the photocurable resin from the second flat area toward the curved area.

[0027] In an exemplary embodiment, coating the photocurable resin includes coating the photocurable resin by a printing device including a nozzle, the nozzle spitting out droplets of the photocurable resin, the display device includes a first flat area provided with a display unit, a curved area adjacent to the first flat area, and a second flat area adjacent to the curved area, and the nozzle spits out fewer droplets of the photocurable resin from the first flat area toward the curved area, and spits out fewer droplets of the photocurable resin from the second flat area toward the curved area.

[0028] In an exemplary embodiment, the substrate includes a first planar region, a second planar region, and a curved region disposed between the first planar region and the second planar region; the first protective layer overlaps the first planar region; and the second protective layer overlaps the second planar region.

[0029] In an exemplary embodiment, the first protective layer includes a first inclined portion at an end of the first protective layer, and the second protective layer includes a second inclined portion at an end of the second protective layer, the first inclined portion has a first inclination angle with respect to a surface relative to the substrate, the second inclination angle has a second inclination angle with respect to a surface relative to the substrate, and each of the first inclination angle and the second inclination angle is greater than or equal to approximately 10 degrees and less than or equal to approximately 90 degrees.

[0030] In an exemplary embodiment, the first inclination angle and the second inclination angle are in a range of about 30 degrees to about 45 degrees.

[0031] In an exemplary embodiment, as the first tilt angle and the second tilt angle decrease, the strain received by the substrate at the bending region decreases.

[0032] In an exemplary embodiment, a maximum value of strain on one portion of the substrate during bending of the display device is about 1.4%, and a value of the strain is defined as: (strain length) / (initial length)×100(%).

[0033] In an exemplary embodiment, the substrate includes a first flat area, a second flat area, and a curved area arranged between the first flat area and the second flat area, the first inclined portion is formed at a portion where the first flat area is adjacent to the curved area, and the second inclined portion is formed at a portion where the second flat area is adjacent to the curved area.

[0034] In an exemplary embodiment, the photocurable resin includes at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO; and the photocurable resin also includes at least one material selected from acrylic-based resins, butyl rubber, vinyl acetate resins, ethylene vinyl acetate resins, natural rubber, nitrile, silicate resins, silicone rubber, and styrene block polymers.

[0035] In an exemplary embodiment, each of the first protective layer and the second protective layer includes a first auxiliary layer, a second auxiliary layer, and a third auxiliary layer sequentially stacked one on another from opposite surfaces of the substrate.

[0036] In an exemplary embodiment, the third auxiliary layer includes a heat dissipation material having thermal conductivity.

[0037] In an exemplary embodiment, the heat dissipation material is a carbon composite material including at least one material selected from graphite, carbon nanotubes, carbon fibers, and graphene.

[0038] In an exemplary embodiment, the third auxiliary layer further includes a dispersant containing a dispersed photocurable resin.

[0039] In an exemplary embodiment, the first auxiliary layer includes at least one material selected from acrylic resins, butyl rubber, vinyl acetate resins, ethylene vinyl acetate resins, natural rubber, nitrile, silicate resins, silicone rubber, and styrene block polymers; and the second auxiliary layer includes at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO.

[0040] In an exemplary embodiment, the substrate includes a first planar area, a second planar area, and a curved area disposed between the first and second planar areas, the connection portion is disposed on opposite surfaces of the substrate at the curved area, and the connection portion includes the same material as the second auxiliary layer.

[0041] In an exemplary embodiment, the substrate includes a first flat area, a second flat area, and a curved area arranged between the first flat area and the second flat area, the first protective layer and the second protective layer are spaced apart from each other, and a space between the first protective layer and the second protective layer overlaps the curved area.

[0042] In an exemplary embodiment, the inclination of the end portions of the first protective layer and the second protective layer is controlled by adjusting the amount of droplets of the photocurable resin ejected to the substrate.

[0043] In an exemplary embodiment, the first protective layer and the second protective layer are provided without a separate adhesive layer.

[0044] In the exemplary embodiment, when the printing device is arranged at a side close to the curved area, the amount of the ejected droplets is low.

[0045] In the exemplary embodiment, the liquid droplets spitted at each position of the second flat region combine with each other and flow toward the curved region to form the second inclined portion.

[0046] According to example embodiments, by selectively patterning a protective layer, a process may be simplified to provide a display device and a method of manufacturing the display device.

[0047] According to example embodiments, by inclining the end of the protective layer, strain received by the substrate during bending can be effectively controlled, thereby providing a display device that can be easily bent and a method of manufacturing the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above and other features of the embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0049] Figure 1 is a perspective view schematically showing a portion of a display device according to an exemplary embodiment;

[0050] Figure 2 is along Figure 1 A sectional view taken along line II-II;

[0051] Figure 3 The substrate is shown in the unfolded state. Figure 2 a cross-sectional view of a portion of a display device;

[0052] Figure 4 It is shown Figure 2 a diagram of the strain depending on the tilt angle in the first and second parts of ;

[0053] Figure 5 It is shown Figure 2 Graphs of strain depending on the tilt angle in the third and fourth parts of ;

[0054] Figure 6 is based on Figure 5 A cross-sectional view of a display device of a comparative example;

[0055] Figure 7 is based on Figure 5 A cross-sectional view of a display device of a comparative example;

[0056] Figure 8 is a schematic cross-sectional view of a display device according to an alternative exemplary embodiment;

[0057] Fig. 9is a schematic cross-sectional view of a display device according to another alternative exemplary embodiment;

[0058] Fig.10 It is shown that according to Fig. 9 A schematic cross-sectional view of a state in which a substrate is unfolded in a display device according to an exemplary embodiment of the present invention;

[0059] Fig.11 is a schematic cross-sectional view of a display device according to another alternative exemplary embodiment;

[0060] Fig.12 is a schematic cross-sectional view of a display device according to another alternative exemplary embodiment;

[0061] Fig.13 It is shown that according to Fig.12 A cross-sectional view of a state in which a substrate is folded in a display device according to an exemplary embodiment of the present invention;

[0062] Fig.14 is a schematic cross-sectional view of a display device according to another alternative exemplary embodiment;

[0063] Fig.15 is a schematic cross-sectional view of a display device according to another alternative exemplary embodiment;

[0064] Fig.16 is a cross-sectional view of a thin film transistor and a light emitting element of a display unit according to an exemplary embodiment;

[0065] Fig.17 is a schematic top view illustrating a method of manufacturing a display device according to an exemplary embodiment; and

[0066] Fig.18 is a schematic cross-sectional view illustrating a method of manufacturing a display device according to an exemplary embodiment. DETAILED DESCRIPTION

[0067] Hereinafter, the present invention will be described more fully with reference to the accompanying drawings showing various embodiments of the present invention. However, the present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0068] The drawings and description are to be regarded as illustrative in nature, and not restrictive.Throughout the specification, like symbols refer to like elements.

[0069] In addition, in the drawings, for better understanding and ease of description, the size and thickness of each element are arbitrarily represented, and the present invention is not limited thereto. In the drawings, for clarity, the thickness of layers, films, panels, regions, etc. are exaggerated. In the drawings, for better understanding and ease of description, the thickness of some layers and regions is exaggerated.

[0070] It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, the element may be directly on the other element, or there may be an intermediate element. Conversely, when an element is referred to as being "directly" "on" another element, there is no intermediate element. In addition, in this specification, the term "on" or "above" means being positioned on or below an object portion, and does not necessarily mean being positioned on the upper side of an object portion based on the direction of gravity.

[0071] It should be understood that although the terms "first", "second", "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 other elements, components, regions, layers or parts. Therefore, the "first element, component, region, layer or part" discussed below may be referred to as a second element, component, region, layer or part without departing from the teachings herein.

[0072] The terms used herein are for the purpose of describing specific embodiments only and are not intended to be limiting. Unless the content clearly states otherwise, the singular forms "a", "an" and "the" as used herein are also intended to include plural forms, and include "at least one". "Or" means "and / or". As used herein, the term "and / or" includes any and all combinations of one or more of the relevant listed items. It should also be understood that when the terms "comprise" and / or "comprising" or "include" and / or "including" are used in this specification, it indicates the presence of the stated features, regions, integers, steps, operations, elements and / or parts, but does not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, parts and / or clusters thereof.

[0073] Furthermore, in the specification, the phrase "on a plane" means observing an object portion from the top, and the phrase "in a cross section" means observing a vertically cut cross section of the object portion from the side.

[0074] Spatially relative terms such as "beneath", "below", "lower", "above", "upper", etc. may be used herein for convenience of description to describe the relationship of one element or feature to other elements or features as shown in the figures. It should be understood that in addition to the orientation shown in the drawings, spatially relative terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is turned over, the elements described as being "below" or "beneath" other elements or features will subsequently be oriented to be above the other elements or features. Therefore, the exemplary term "below" may include both the orientations of above and below. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

[0075] As used herein, "about" or "approximately" includes the stated value and mean within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, taking into account the measurements and errors associated with measurement of the particular quantity (i.e., limitations of the measurement system).

[0076] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It should also be understood that, unless explicitly defined as such herein, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and the present disclosure, and will not be interpreted in an idealized or overly formal sense.

[0077] Exemplary embodiments are described herein with reference to schematically illustrated cross-sectional views as idealized embodiments. Thus, variations in the illustrated shapes resulting from, for example, manufacturing techniques and / or tolerances are expected. Therefore, the embodiments described herein should not be construed as being limited to the specific regional shapes shown herein, but rather include deviations in shape resulting from, for example, manufacturing. For example, a region shown or described as being flat may typically have rough and / or nonlinear features. In addition, the sharp angles shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shape of the regions, and are not intended to limit the scope of the claims.

[0078] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0079] Now refer to Figures 1 to 3 A display device according to an exemplary embodiment is described. Figure 1is a perspective view schematically showing a portion of a display device according to an exemplary embodiment, Figure 2 is along Figure 1 A sectional view taken along line II-II of FIG. Figure 3 The substrate is shown in the unfolded state. Figure 2 A cross-sectional view of a portion of a display device.

[0080] In an exemplary embodiment of a display device, as shown in FIG. Figure 1 and Figure 2 As shown in FIG. 1 , a portion of the substrate 100 is bent or folded.

[0081] The substrate 100 may include at least one of various materials having flexible or bendable properties. In one exemplary embodiment, for example, the substrate 100 may include a polymer resin such as polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate, polyimide (PI), polycarbonate (PC), cellulose acetate propionate (CAP), or the like.

[0082] The substrate 100 includes a first flat region F1 and a second flat region F2 and a curved region BA disposed between the first flat region F1 and the second flat region F2. The substrate 100 may include a curved region BA curved relative to a curved axis BX parallel to an extending direction of the x-axis. Herein, the z-axis may be an axis in a direction parallel to a thickness direction of the substrate 100, the x-axis may be an axis in a direction parallel to a width or length direction of the substrate 100, and the y-axis may be an axis in a direction perpendicular to the x-axis and the z-axis.

[0083] The first planar region F1 of the substrate 100 overlaps the display unit 200 and the polarizing layer 400. In an exemplary embodiment, as shown in FIG. Figure 2 As shown in , the first flat area F1 may include a partial area outside the display unit 200, but is not limited thereto. The display unit 200 and the polarizing layer 400 are arranged on one surface of the substrate, and hereinafter, one surface on which the display unit 200 and the polarizing layer 400 are arranged is referred to as a first surface PL1. Figures 1 to 3 It is shown that the edges of the display unit 200 and the polarizing layer 400 coincide with each other (or are aligned), but it is not limited thereto. Alternatively, the edges of the display unit 200 and the polarizing layer 400 may not coincide with each other.

[0084] The display unit 200 may include a plurality of thin film transistors and light emitting elements connected thereto, which will be referred to later. Fig.16Herein, for the convenience of description, an exemplary embodiment in which the display unit 200 includes a light emitting element is described, but it is not limited thereto. Alternatively, the display unit 200 may include other types of light emitting or control elements, such as a liquid crystal element.

[0085] Although not shown in the drawings, an exemplary embodiment of the display device may further include a touch unit (not shown) disposed between the display unit 200 and the polarization layer 400. The touch unit may acquire coordinate information by detecting external touch information and generate an input signal corresponding thereto. The touch unit may be provided as a separate unit to be mounted on the display unit 200, or may be directly formed on the display unit 200 to be embedded therein.

[0086] The polarization layer 400 may be disposed on the display unit 200. The polarization layer 400 may reduce reflection of external light. When external light passes through the polarization layer 400 and is reflected by the display unit 200 and then passes through the polarization layer 400 again, the phase of the external light may be changed. As a result, the phase of the reflected light is different from the phase of the external light entering the polarization layer 400, and thus destructive interference may occur between the reflected light and the external light.

[0087] In an exemplary embodiment, an adhesive layer (not shown) may be disposed between the polarizing layer 400 and the display unit 200. The adhesive layer may be a transparent adhesive layer. In an exemplary embodiment, for example, the adhesive layer may include an optically clear adhesive ("OCA"), an optically clear resin ("OCR"), or a pressure sensitive adhesive ("PSA").

[0088] The second flat area F2 and the curved area BA may include a non-display area corresponding to an outer or peripheral portion of the display unit 200 .

[0089] The driving unit 500 may be arranged in the second flat region F2 of the substrate 100. The driving unit 500 may be arranged on the first surface PL1 of the substrate 100. The driving unit 500 may be connected to a pad unit arranged on the substrate 100 to supply data signals and gate signals (hereinafter collectively referred to as "signals") to the gate lines and the data lines. In an exemplary embodiment, the driving unit 500 may be a driver integrated circuit ("IC") and may be arranged or mounted on the pad unit of the substrate 100. In such an embodiment, the pad unit may be directly electrically connected to the driver IC.

[0090] In an exemplary embodiment, the flexible circuit board 800 may be connected to the pad unit of the substrate 100, and the IC may be mounted on the flexible circuit board 800. The flexible circuit board 800 may be arranged on the first surface PL1 of the substrate 100. The flexible circuit board 800 may be applicable to a chip on film ("COF"), a chip on plastic ("COP"), or a flexible printed circuit ("FPC"), and the IC may be arranged or mounted on the flexible circuit board 800 to supply a signal to the display unit 200.

[0091] A protective layer (710, 720) may be arranged on the rear surface of the substrate 100. The rear surface of the substrate 100 on which the protective layer (710, 720) is arranged is another surface of the substrate 100 opposite to the first surface PL1 on which the display unit 200 is arranged. Hereinafter, the other surface of the substrate 100 will be referred to as the second surface PL2. In this embodiment, the protective layer (710, 720) is arranged on the second surface PL2 of the substrate 100.

[0092] In example embodiments, the display device may include a first protective layer 710 overlapping the first planar region F1 on the second surface PL2 of the substrate 100 and a second protective layer 720 overlapping the second planar region F2 on the second surface PL2 of the substrate 100 .

[0093] An empty space defined between the first protective layer 710 and the second protective layer 720 may overlap the bending area BA. In such an embodiment, any layer may not be disposed on the second surface PL2 of the substrate 100 corresponding to the bending area BA.

[0094] The first protective layer 710 may overlap the first planar region F1 and may also overlap the display unit 200 and the polarizing layer 400. The first protective layer 710 may be in direct contact with the substrate 100.

[0095] In an exemplary embodiment, the first protective layer 710 has a first inclined portion 711 at an end portion of the first flat region F1 adjacent to the curved region BA. In such an embodiment, the end portion of the first protective layer 710 may be formed to be inclined. Figures 1 to 3 , but the first protective layer 710 may also have an inclined portion at an end opposite to the end having the first inclined portion 711 .

[0096] In this embodiment, since the end of the first protective layer 710 can be formed to be inclined, a space in the bending area BA can be effectively ensured during bending. In this embodiment, by controlling the angle of the first inclined portion 711 of the first protective layer 710, the strain applied to the substrate 100 in the bending area BA can be effectively controlled or reduced, thereby facilitating bending.

[0097] The first inclined portion 711 of the first protective layer 710 may have a shape inclined toward the second surface PL2 of the substrate 100. The first inclined portion 711 of the first protective layer 710 may be thinner toward the end. The first inclined portion 711 may have a smooth cross-section. Accordingly, the first protective layer 710 may have a smooth shape without any protruding portion.

[0098] Reference Figure 3 In an exemplary embodiment, the outermost point where the first inclined portion 711 of the first protective layer 710 intersects the second surface PL2 of the substrate 100 is referred to as a first contact point Q1. That is, the edge of the first protective layer 710 is located at the first contact point Q1. Figure 3 , the first contact point Q1 is shown as a point, but refer to Figure 1 , the first contact point Q1 may define a straight line substantially parallel to the bending axis BX.

[0099] exist Figure 3 In the figure, a straight line perpendicular to the substrate 100 at the first contact point Q1 is referred to as a first straight line l1, which is an imaginary line. The first inclined portion 711 of the first protective layer 710 has a first inclined angle θ1. The first inclined angle θ1 is an angle between the first inclined portion 711 at the first contact point Q1 and the substrate 100.

[0100] The first inclination angle θ1 has a value greater than or equal to about 10 degrees and less than or equal to about 90 degrees, and the strain of the substrate 100 can be significantly reduced when bent within the corresponding range. In an exemplary embodiment, for example, the first inclination angle θ1 can be in the range of about 30 degrees to about 45 degrees, and when bent within the corresponding range, the reduction degree of the strain borne by the substrate 100 is maximized, thereby allowing stable and effective bending of the substrate 100.

[0101] In an exemplary embodiment, the second protective layer 720 may overlap the second planar region F2 , and may overlap a portion of the driving unit 500 and the flexible circuit board 800 .

[0102] The second protective layer 720 has a second inclined portion 721 at an end portion where the second flat area F2 thereof is adjacent to the bent area BA. The second protective layer 720 may have an inclined portion at an end portion opposite to an end portion of the second inclined portion 721. That is, the second protective layer 720 may have an inclined portion even in a portion where the substrate 100 overlaps with the flexible circuit board 800.

[0103] In an exemplary embodiment, as described above, the end of the second protective layer 720 may be formed to be inclined, thereby effectively ensuring a space in the bending area BA during bending. In such an embodiment, by adjusting the angle of the second inclined portion 721 of the second protective layer 720, the strain borne by the substrate 100 in the bending area BA may be effectively controlled or reduced, thereby facilitating bending.

[0104] The second inclined portion 721 of the second protective layer 720 may have a shape inclined toward the second surface PL2 of the substrate 100. The second inclined portion 721 of the second protective layer 720 may have a thickness that becomes thinner toward the end. The second inclined portion 721 may have a cross-section of a smooth shape. Accordingly, the second protective layer 720 may have a smooth shape without any protruding portion.

[0105] Reference Figure 3 The outermost point where the second inclined portion 721 of the second protective layer 720 intersects the second surface PL2 of the substrate 100 is referred to as the second contact point Q2. That is, the edge of the second protective layer 720 is located at the second contact point Q2. Figure 3 , the second contact point Q2 is shown as a point, but refer to Figure 1 , the second contact point Q2 can define a straight line substantially parallel to the bending axis BX.

[0106] exist Figure 3 In the figure, the straight line perpendicular to the substrate 100 at the second contact point Q2 is called the second straight line l2, which is an imaginary line. The second inclined portion 721 of the second protective layer 720 has a second inclined angle θ2. The second inclined angle θ2 is the angle between the second inclined portion 721 at the second contact point Q2 and the substrate 100.

[0107] The second inclination angle θ2 has a value greater than or equal to about 10 degrees and less than or equal to about 90 degrees, and the strain of the substrate 100 can be significantly reduced when bent within the corresponding range. In an exemplary embodiment, for example, the second inclination angle θ2 can be in the range of about 30 degrees to about 45 degrees, and when bent within the corresponding range, the reduction degree of the strain borne by the substrate 100 is maximized, thereby promoting stable and free bending of the substrate 100.

[0108] The first inclination angle θ1 and the second inclination angle θ2 may be different from each other or may be the same as each other.

[0109] Reference Figure 3 as well as Figure 2 , four parts P1, P2, P3 and P4 are defined in the substrate 100.

[0110] First, the first portion P1, the second portion P2, and the third portion P3 on the side of the curved area BA will be described. The boundary portion where the curved area BA of the substrate 100 and the first flat area F1 intersect is referred to as the first portion P1. The boundary portion where the curved area BA of the substrate 100 and the second flat area F2 intersect is referred to as the third portion P3. In the curved area BA of the substrate 100, the portion located between the first portion P1 and the third portion P3 is referred to as the second portion P2. The second portion P2 may be the middle portion of the curved area BA, but the position of the second portion P2 is not limited to the curved area BA.

[0111] The second portion P2 is a region corresponding to a space between the first protective layer 710 and the second protective layer 720 , and no constituent element may be positioned on the second surface PL2 of the second portion P2 of the substrate 100 .

[0112] Reference Figure 3 , the first portion P1 of the substrate 100 may be arranged on the first straight line l1 as a boundary between the first flat area F1 and the curved area BA. The third portion P3 of the substrate 100 may be arranged on the second straight line l2 as a boundary between the second flat area F2 and the curved area BA. That is, the first portion P1 may overlap the first straight line l1, and the third portion P3 may overlap the second straight line l2.

[0113] like Figure 2 and Figure 3 As shown in , the boundary portion where the substrate 100 intersects with the display unit 200 and the polarizing layer 400 is referred to as a fourth portion P4. According to an alternative exemplary embodiment, the edges of the display unit 200 and the polarizing layer 400 may not coincide. In such an embodiment, the fourth portion P4 may be a boundary portion of the substrate that intersects (or overlaps with the edge of) any one of the display unit 200 and the polarizing layer 400.

[0114] When from Figure 3 The expanded state is bent to Figure 2 In the bending state, the first portion P1, the second portion P2, the third portion P3 and the fourth portion P4 of the substrate 100 are subjected to stress and then deformed. In this embodiment, the display device includes a first inclined portion 711 and a second inclined portion 721 located on the ends of the first protective layer 710 and the second protective layer 720, so that interference in the bending area BA can be minimized. In this embodiment, by controlling the first inclination angle θ1 and the second inclination angle θ2 of the first inclination portion 711 and the second inclination angle θ2 of the first inclination portion 711 and the second inclination portion 721 (for example, setting them to predetermined values), the strain of the substrate 100 when bending can be effectively controlled, thereby allowing stable and easy bending of the substrate 100.

[0115] Will refer to later Figure 4 and Figure 5The strain received when each portion of the substrate 100 is bent is described in detail.

[0116] The first protective layer 710 is a layer formed by curing a photocurable resin applied by a printing process (eg, an inkjet process). In the process of curing the photocurable resin, the first inclined portion 711 of the first protective layer 710 may be tapered toward the substrate 100. Fig.17 and Fig.18 The process of forming the first protection layer 710 is described in detail.

[0117] Next, materials included in the first protective layer 710 and the second protective layer 720 will be described.

[0118] The first protective layer 710 may be formed using a photocurable resin. The photocurable resin may include at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO, but is not limited thereto. In such an embodiment, the first protective layer 710 may include any conventional material for forming a photocurable resin. In an exemplary embodiment, for example, the photocurable resin may further include a photoinitiator, a thermal stabilizer, an antioxidant, an antistatic agent, or a slip agent.

[0119] In an exemplary embodiment, the photocurable resin may further include at least one material selected from acrylic resin, butyl rubber, vinyl acetate resin, ethylene vinyl acetate ("EVA") resin, natural rubber, nitrile, silicate resin, silicone rubber, and styrene block polymer. In such an embodiment, in the case where the photocurable resin further includes at least one material selected from the above materials, the photocurable resin may have improved adhesive strength.

[0120] The first protective layer 710 may include a curing member of the above-mentioned photocurable resin. That is, the first protective layer 710 may include a curing member, and the curing member includes at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO. In an exemplary embodiment, the first protective layer 710 may further include a photoinitiator, a heat stabilizer, an antioxidant, an antistatic agent, or a slip agent that remains in the first protective layer 710 after the photocurable resin is cured.

[0121] The first protective layer 710 may also include at least one material selected from acrylic resin, butyl rubber, vinyl acetate resin, EVA resin, natural rubber, nitrile, silicate resin, silicone rubber, and styrene block polymer. In this embodiment, in the case where the first protective layer 710 further includes at least one material selected from the above materials, the first protective layer 710 may have improved adhesive strength, for example, at about 10 gf / in 2(gram-force per square inch) to about 50 gf / in 2 The bonding strength is within the range of

[0122] The maximum thickness t1 of the first protective layer 710 may be in the range of about 75 μm (micrometers) to about 100 μm. If the maximum thickness t1 of the first protective layer 710 is less than about 75 μm, it may be difficult to protect the substrate 100 and the display unit 200 only by the first protective layer 710. If the maximum thickness t1 of the first protective layer 710 is greater than about 100 μm, the thickness of the display device may be excessively increased, resulting in overgrowth.

[0123] The second protective layer 720 is a layer formed by curing a photocurable resin applied by a printing process (eg, an inkjet process). In the process of curing the photocurable resin, the second inclined portion 721 of the second protective layer 720 may be tapered toward the substrate 100. Fig.17 and Fig.18 The process of forming the second protection layer 720 is described in more detail.

[0124] In an exemplary embodiment, the second protective layer 720 may be formed using a photocurable resin. The photocurable resin may include at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO, or may include any conventional material forming the photocurable resin, but is not limited thereto. In an exemplary embodiment, for example, the photocurable resin may further include a photoinitiator, a thermal stabilizer, an antioxidant, an antistatic agent, or a slip agent.

[0125] In an exemplary embodiment, the photocurable resin may further include at least one material selected from acrylic resin, butyl rubber, vinyl acetate resin, EVA resin, natural rubber, nitrile, silicate resin, silicone rubber, and styrene block polymer. In such an embodiment, in the case where the photocurable resin further includes at least one material selected from the above materials, the photocurable resin may have improved adhesive strength. In such an embodiment, the adhesive strength of the second protective layer 720 may be about gf / in 2 To about 50gf / in 2 within the range.

[0126] In this embodiment, when the second protective layer 720 has a predetermined adhesive strength, the lower protective film can be easily bonded to the second protective layer 720 during the manufacturing process. The lower protective film can effectively prevent foreign matter from flowing into the display device or causing scratches during the manufacturing process.

[0127] The second protective layer 720 may include a curing member of the above-mentioned photocurable resin. The second protective layer 720 may include a curing member, and the curing member includes at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO. In an exemplary embodiment, the second protective layer 720 may further include, for example, a photoinitiator, a heat stabilizer, an antioxidant, an antistatic agent, or a slip agent that remains in the second protective layer 720 after the photocurable resin is cured.

[0128] In an exemplary embodiment, the second protective layer 720 may further include at least one material selected from acrylic resin, butyl rubber, vinyl acetate resin, EVA resin, natural rubber, nitrile, silica resin, silicone rubber, and styrene block polymer. In such an embodiment, in the case where the second protective layer 720 further includes at least one material selected from the above materials, the second protective layer 720 may have improved adhesive strength.

[0129] According to an exemplary embodiment, by coating and curing a photocurable resin by a printing process (e.g., an inkjet process) to form the first protective layer 710 and the second protective layer 720, a pattern is easily formed so that the first protective layer 710 and the second protective layer 720 are not arranged in the bending area BA of the substrate 100. In such an embodiment, the first protective layer 710 and the second protective layer 720 can be easily provided without a separate adhesive layer.

[0130] In this embodiment, by smoothing the inclination of each end of the first protective layer 710 and the second protective layer 720, interference between the first protective layer 710 and the second protective layer 720 during bending can be minimized, and stress applied to the substrate 100 during bending can be easily adjusted.

[0131] In the following, reference will be made to Figure 4 and Figure 5 As well as the above Figures 1 to 3 The strain when the substrate 100 is bent is described. Figure 4 It is shown Figure 2 a diagram of the strain depending on the tilt angle in the first and second parts of Figure 5 It is shown Figure 2 Graphs of the strain depending on the tilt angle in the third and fourth parts of FIG.

[0132] exist Figure 4 and Figure 5 , the horizontal axis represents the comparative example and the exemplary embodiment by distinguishing the materials of the first protective layer 710 and the second protective layer 720 and the tilt angle of the first protective layer 710 and the second protective layer 720 , and the vertical axis represents strain.

[0133] exist Figure 4and Figure 5 In the comparative example 1, the first protective layer 710 and the second protective layer 720 are PET films not including a photocurable resin and the inclination angle of the first protective layer 710 and the second protective layer 720 is about 90 degrees. Exemplary Embodiment 1, Exemplary Embodiment 2, Exemplary Embodiment 3, Exemplary Embodiment 4, Exemplary Embodiment 5 and Comparative Example 2 are each a case where the first protective layer 710 and the second protective layer 720 include a photocurable resin. Exemplary Embodiments 1 to 5 and Comparative Example 2 are cases where the inclination angles of the first inclined portion 711 of the first protective layer 710 and the second inclined portion 721 of the second protective layer 720 are 90 degrees, 75 degrees, 60 degrees, 45 degrees, 30 degrees and 10 degrees, respectively.

[0134] Next, refer to Table 1 below. Figure 4 and Figure 5 Each value in Table 1 represents strain in each portion of the substrate 100. Hereinafter, strain represents "(strain length) / (initial length)×100" in each portion of the substrate 100, and its unit is %.

[0135] In the experimental example of Table 1, the maximum strain that can act on the display device is set to 1.4%. That is, when the strain exceeds 1.4%, damage may occur in the light emitting element or the wiring, and it is difficult to bend stably, which may cause defects in the display device. In the case of Comparative Example 2 to be described later, for example, the third portion P3 is subjected to a strain of 1.5%, and thus it may be difficult to use for a display device including a curved portion.

[0136] [Table 1]

[0137]

[0138] In the following we will refer to Figure 4 A description is given of strain applied to the first portion P1 and the second portion P2 of the substrate 100 when bent.

[0139] The first portion P1 of the substrate 100 has strains of 0.49%, 0.44%, 0.33%, 0.31%, 0.24%, 0.29%, and 0.12% in the order of Comparative Example 1, Exemplary Embodiments 1 to 5, and Comparative Example 2. That is, the strain applied to the first portion P1 decreases in the order of Comparative Example 1, Exemplary Embodiments 1 to 5, and Comparative Example 2. As described above, as in Exemplary Embodiments 1 to 5 and Comparative Example 2, when a photocurable resin is used as the first protective layer 710 and the second protective layer 720 of the rear surface (second surface PL2) of the substrate 100, the strain of the first portion P1 can be reduced.

[0140] The second portion P2 of the substrate 100 has strains of 0.56%, 0.58%, 0.57%, 0.57%, 0.54%, 0.53%, and 0.40% in the order of Comparative Example 1, Exemplary Embodiments 1 to 5, and Comparative Example 2. That is, the strain to which the second portion P2 is subjected generally decreases in the order of Exemplary Embodiments 1 to 5, and Comparative Example 2. As in Exemplary Embodiments 1 to 5 and Comparative Example 2, the first protective layer 710 and the second protective layer 720 of the rear surface of the substrate 100 include a photocurable resin, and the first inclination angle θ1 of the first inclined portion 711 of the first protective layer 710 and the second inclination angle θ2 of the second protective layer 720 and the second inclined portion 721 are reduced, so that the strain of the second portion P2 can be reduced.

[0141] The difference between the second portion P2 and the first portion P1 will now be described. In exemplary embodiment 1, the strain of the second portion P2 is increased from 0.56% to 0.58% compared to comparative example 1. However, the second portion P2 is a portion corresponding to an empty space between the first protective layer 710 and the second protective layer 720 arranged on the second surface PL2 of the substrate 100, and the increase in strain may not affect the light emitting element, the signal line, or the like.

[0142] Next, refer to Figure 5 as well as Figure 6 and Figure 7 A description is given of strain applied to the third portion P3 and the fourth portion P4 of the substrate 100 when the first protective layer 710 and the second protective layer 720 have a specific angle. Figure 6 It is shown Figure 5 A cross-sectional view of a comparative example (particularly a display device including a first third portion P3-1), and Figure 7 It is shown Figure 5 A cross-sectional view of a comparative example (particularly a display device including the first fourth portion P4-1).

[0143] Refer again Figure 5 As shown in Table 1, the third portion P3 of the substrate 100 has strains of 0.19%, 0.07%, 0.16%, 0.15%, 0.15%, 0.06% and 1.5% in the order of Comparative Example 1, Exemplary Embodiments 1 to 5, and Comparative Example 2, respectively. In the case of Comparative Example 1 and Exemplary Embodiments 1 to 5, the change in the strain borne by the third portion P3 is substantially small. On the contrary, in the case where the first inclination angle θ1 of the first protective layer 710 and the second inclination angle θ2 of the second protective layer 720 of Comparative Example 2 are approximately 10 degrees, the strain borne by the third portion P3 increases by 1.5% compared with Comparative Example 1 and Exemplary Embodiments 1 to 5. In the following, Figure 5 The third portion P3 of Comparative Example 2 is referred to as the first third portion P3-1.

[0144] Next, refer to Figure 6 A bending state of the display device (particularly, the first third portion P3-1 according to Comparative Example 2) is described. Figure 6 FIG. 2 shows a bending state of the display device in which the second inclination angle θ2 of the second protective layer 720 is about 10 degrees. Figures 1 to 3 Any repeated detailed description of the same or similar constituent elements is described.

[0145] Reference Figure 6 , as the strain borne by the first third portion P3-1 of the substrate 100 is Figure 5 As shown in the figure, it increases rapidly to 1.5%, and Figure 2 , the substrate 100 may sag around the first third portion P3-1. That is, when the second inclination angle θ2 of the second protective layer 720 is about 10 degrees, the second flat region F2 may not maintain a flat shape and may be lower than the horizontal position of the flexible circuit board 800 in the z-axis direction. A portion of the bent area BA adjacent to the second flat region F2 may also sag together with the second flat region F2.

[0146] exist Figure 2 In an exemplary embodiment of the display device of FIG. 1 , both the first flat area F1 and the second flat area F2 may be effectively maintained in a flat state, thereby ensuring stability even when the display device is bent.

[0147] exist Figure 6 , the second inclination angle θ2 of the second protective layer 720 is shown to be about 10 degrees to show the shape of the bent state of the first third portion P3 - 1 , and the first inclination angle θ1 of the first protective layer 710 may be greater than about 10 degrees.

[0148] Refer again Figure 5 As shown in Table 1, the fourth portion P4 of the substrate 100 has strains of 0.21%, 0.25%, 0.29%, 0.29%, 0.28%, 0.22% and 0.32% in the order of Comparative Example 1, Exemplary Embodiments 1 to 5 and Comparative Example 2. In the case of Comparative Example 1 and Exemplary Embodiments 1 to 5, the change in the strain borne by the fourth portion P4 is substantially small. On the contrary, in the case where the first inclination angle θ1 of the first protective layer 710 and the second inclination angle θ2 of the second protective layer 720 of Comparative Example 2 are approximately 10 degrees, the strain borne by the fourth portion P4 is increased to 0.32% compared with Comparative Example 1 and Exemplary Embodiments 1 to 5. Hereinafter, Figure 5The fourth portion P4 of Comparative Example 2 is referred to as the first fourth portion P4-1.

[0149] In the following, reference will be made to Figure 7 A description will be given of a bent state of the display device according to Comparative Example 2 (particularly, the first fourth portion P4-1). Figure 7 FIG. 2 shows a bending state of a display device in which the first inclination angle θ1 of the first protective layer 710 is about 10 degrees. Figures 1 to 3 Any repeated detailed description of the same or similar constituent elements is described.

[0150] Reference Figure 7 , as the strain borne by the first fourth portion P4-1 of the substrate 100 is as follows Figure 5 As shown in the figure, it increases to 0.32%, and Figure 2 , the substrate 100 may rise near the first fourth portion P4-1. That is, when the first inclination angle θ1 of the first protective layer 710 is about 10 degrees, the first fourth portion P4-1 of the substrate 100 may rise more in the z-axis direction than the horizontal position of the substrate 100 where the display unit 200 and the polarization layer 400 are arranged. That is, the first flat area F1 does not maintain a flat shape and may swing upward in the z-axis direction in a portion adjacent to the curved area BA. A portion of the curved area BA adjacent to the second flat area F2 may swing upward in the z-axis direction together with the second flat area F2.

[0151] exist Figure 2 In the exemplary embodiment of the display device, the first flat area F1 and the second flat area F2 are both effectively maintained in a flat state so that the display device can ensure stability even in a bent state.

[0152] exist Figure 7 , a case where the first inclination angle θ1 of the first protective layer 710 is about 10 degrees is shown to illustrate the shape of the first fourth portion P4 - 1 in a bent state, and the second inclination angle θ2 of the second protective layer 720 may be greater than about 10 degrees.

[0153] although Figure 6 and Figure 7 As shown as a separate comparative example, when the first inclination angle θ1 and the second inclination angle θ2 are both about 10 degrees, Figure 6 and Figure 7 That is, the first third portion P3-1 of the substrate 100 may have Figure 6 , and the first fourth portion P4-1 of the substrate 100 may have Figure 7 The form shown in .

[0154] Return to reference Figure 4 and Figure 5 As well as the above-mentioned Table 1, strains of the comparative examples and exemplary embodiments in Table 1 will be summarized below.

[0155] In Comparative Example 1, the first portion P1, the second portion P2, the third portion P3, and the fourth portion P4 have strains of 0.49%, 0.56%, 0.19%, and 0.21%, respectively. In Exemplary Embodiment 1, the first portion P1, the second portion P2, the third portion P3, and the fourth portion P4 have strains of 0.44%, 0.58%, 0.07%, and 0.25%, respectively. In Exemplary Embodiment 4, the first portion P1, the second portion P2, the third portion P3, and the fourth portion P4 have strains of 0.24%, 0.54%, 0.15%, and 0.28%, respectively. In Exemplary Embodiment 5, the first portion P1, the second portion P2, the third portion P3, and the fourth portion P4 have strains of 0.29%, 0.53%, 0.06%, and 0.22%, respectively.

[0156] In Exemplary Embodiment 1, even if the first and second inclination angles θ1 and θ2 are about 90 degrees, since the first and second protective layers 710 and 720 include a photocurable resin, strain of the first and third portions P1 and P3 is reduced, which enables more stable bending than Comparative Example 1.

[0157] In Exemplary Embodiment 2 to Exemplary Embodiment 5, the strain to which substrate 100 is subjected is sufficiently reduced, thereby being effectively bent, compared to Comparative Example 1. In particular, in the case of Exemplary Embodiment 4 (45 degrees) and Exemplary Embodiment 5 (30 degrees), the strain to which each of first portion P1, second portion P2, third portion P3, and fourth portion P4 of substrate 100 is subjected is significantly reduced, compared to Comparative Example 1.

[0158] In Comparative Example 2, the strains of the first portion P1, the second portion P2, the third portion P3, and the fourth portion P4 are 0.12%, 0.40%, 1.5%, and 0.32%, respectively. Compared with Comparative Example 1, the strain of the fourth portion P4 increases, and the strain of the third portion P3 exceeds the maximum strain (1.4%). In other words, if the first inclination angle θ1 and the second inclination angle θ2 suddenly become smooth at about 10 degrees, the strain becomes larger instead.

[0159] Accordingly, in an exemplary embodiment, the first inclination angle θ1 and the second inclination angle θ2 may be greater than or equal to about 10 degrees or less than or equal to about 90 degrees, for example, about 30 degrees or more to about 45 degrees or less.

[0160] When the first protective layer 710 and the second protective layer 720 on the rear surface of the substrate 100 include a photocurable resin, as the first inclination angle θ1 of the first protective layer 710 and the second inclination angle θ2 of the second protective layer 720 decrease, the strain borne by the substrate 100 decreases. Moreover, the light emitting element, wiring and the like of the display unit 200 arranged on the substrate 100 or the thin film transistor arranged in the non-display unit is subjected to a reduced strain, thereby effectively preventing the substrate 100 from being damaged due to the strain caused by bending. That is, as the inclination of the first protective layer 710 and the second protective layer 720 decreases, the strain of the substrate 100 decreases, and bending can be stably performed without damaging the display device.

[0161] However, when the first inclination angle θ1 of the first protective layer 710 and the second inclination angle θ2 of the second protective layer 720 are rapidly reduced by about 10 degrees (Comparative Example 2), the strain of the substrate 100 (particularly the third portion P3 and the fourth portion P4 of the substrate 100) does not decrease but increases, and as a result, the deformation of the substrate 100 is severe. As shown in Comparative Example 2, the strain of the first third portion P3-1 rapidly increases to 1.5%, and the strain of the first fourth portion P4-1 also increases to 0.32%.

[0162] Therefore, in exemplary embodiments, the first inclination angle θ1 of the first protective layer 710 and the second inclination angle θ2 of the second protective layer 720 may be greater than or equal to about 10 degrees or less than or equal to about 90 degrees, for example, about 30 degrees or more to 45 degrees or less.

[0163] According to an exemplary embodiment of the display device, as described above, by forming the ends of the first and second protective layers 710 and 720 of the rear surface of the substrate 100 to be inclined, interference in the bending area BA may be minimized by promoting space gap security in the bending area BA.

[0164] According to an exemplary embodiment, by adjusting the first inclination angle θ1 of the end of the first protective layer 710 and the second inclination angle θ2 of the end of the second protective layer 720, the stress borne by the bending area BA can be effectively controlled and can be stably bent. In this embodiment, as the slopes of the ends of the first protective layer 710 and the second protective layer 720 become smooth, the stress applied to the substrate 100 can be reduced during bending, and the strain can be reduced, thereby enabling stable bending.

[0165] Next, refer to Figures 8 to 15 An alternative exemplary embodiment of the display device is described. Figures 1 to 3 Any repeated detailed description of similar or identical constituent elements is described.

[0166] In the following, reference will be made to Figure 8 Exemplary embodiments of a display device in which the orientation of a protective layer is modified are described. Figure 8 is a schematic cross-sectional view of a display device according to an alternative exemplary embodiment.

[0167] Reference Figure 8 In an exemplary embodiment, the first inclined portion 711 of the first protective layer 710 intersects the substrate 100 at the first contact point Q1. In such an embodiment, the edge of the first protective layer 710 is arranged at the first contact point Q1. In such an embodiment, the edge of the first protective layer 710 may substantially coincide with the edges of the display unit 200 and the polarizing layer 400. In such an embodiment, Figure 8 As shown in , the first contact point Q1 and the edges of the display unit 200 and the polarization layer 400 may be arranged on the same imaginary straight line l3 in the z-axis direction.

[0168] When the first protective layer 710 is formed by a printing process, the alignment of the first protective layer 710 can be easily controlled so that the edge of the first protective layer 710 is aligned with the edge of the display unit 200. In an embodiment where the edge of the first protective layer 710 and the edge of the display unit 200 are aligned on substantially the same line, the area occupied by the dead zone or the frame can be reduced.

[0169] Next, refer to Fig. 9 and Fig.10 Other alternative exemplary embodiments of a display device in which the protective layer has a multi-layer structure are described. Fig. 9 is a schematic cross-sectional view of a display device according to other alternative exemplary embodiments, and Fig.10 It is shown that according to Fig. 9 A schematic cross-sectional view of a state in which a substrate is unfolded in a display device according to an exemplary embodiment.

[0170] Reference Fig. 9 and Fig.10 In an exemplary embodiment, at least one of the first protective layer 710 and the second protective layer 720 may include a plurality of layers. In an exemplary embodiment, for example, the first protective layer 710 may include a first auxiliary layer 710a, a second auxiliary layer 710b, and a third auxiliary layer 710c, and the second protective layer 720 may include a first auxiliary layer 720a, a second auxiliary layer 720b, and a third auxiliary layer 720c. In an embodiment, Fig. 9As shown in , the first protective layer 710 may include a first auxiliary layer 710a, a second auxiliary layer 710b and a third auxiliary layer 710c, and the second protective layer 720 may include a first auxiliary layer 720a, a second auxiliary layer 720b and a third auxiliary layer 720c, but are not limited thereto. Alternatively, only one of the first protective layer 710 and the second protective layer 720 may have a multi-layer structure.

[0171] Each of the first auxiliary layers 710a and 720a, the second auxiliary layers 710b and 720b, and the third auxiliary layers 710c and 720c may be formed by a separate printing process (eg, an inkjet process).

[0172] The first auxiliary layers 710a and 720a, the second auxiliary layers 710b and 720b, and the third auxiliary layers 710c and 720c may include a curing member of a photocurable resin, for example, independently including a photoinitiator, a thermal stabilizer, an antioxidant, an antistatic agent, or a slip agent.

[0173] Ends of the first auxiliary layer 710a, the second auxiliary layer 710b, and the third auxiliary layer 710c collectively define or form a first inclined portion 711 of the first protective layer 710. Ends of the first auxiliary layer 720a, the second auxiliary layer 720b, and the third auxiliary layer 720c collectively define or form a second inclined portion 721 of the second protective layer 720. The first inclined portion 711 and the second inclined portion 721 may have a shape inclined toward the back side (i.e., the second surface PL2) of the substrate 100.

[0174] In an exemplary embodiment, the ends of the first auxiliary layers 710a and 720a may have a shape covered by the ends of the second auxiliary layers 710b and 720b and the third auxiliary layers 710c and 720c, and the ends of the second auxiliary layers 710b and 720b may have a shape covered by the ends of the third auxiliary layers 710c and 720c. In such an embodiment, the first auxiliary layers 710a and 720a, the second auxiliary layers 710b and 720b, and the third auxiliary layers 710c and 720c may be sequentially stacked.

[0175] The first inclined portion 711 forms an edge at a first contact point Q1 arranged at the second surface PL2 of the substrate 100. That is, the first protective layer 710 intersects with the second surface PL2 of the substrate 100 at the first contact point Q1. The end of the first protective layer 710 adjacent to the bending area BA includes a first inclined portion 711 having a first inclined angle θ1. The first inclined angle θ1 is an angle formed by the first protective layer 710 and the substrate 100 at the first contact point Q1. The first inclined angle θ1 has a value greater than or equal to about 10 degrees and less than or equal to about 90 degrees. In an exemplary embodiment, for example, the first inclined angle θ1 may be about 30 degrees or more to about 90 degrees or less.

[0176] The second inclined portion 721 forms an edge at a second contact point Q2 arranged at the second surface PL2 of the substrate 100. That is, the second protective layer 720 intersects with the second surface PL2 of the substrate 100 at the second contact point Q2. The end of the second protective layer 720 adjacent to the bending area BA includes a second inclined portion 721 having a second inclination angle θ2. The second inclination angle θ2 is an angle between the second protective layer 720 and the substrate 100 at the second contact point Q2. The second inclination angle θ2 has a value greater than or equal to 10 degrees and less than or equal to 90 degrees. In an exemplary embodiment, for example, the second inclination angle θ2 may be 30 degrees or more to 90 degrees or less.

[0177] End portions of the first, second, and third auxiliary layers 710a, 710b, and 710c constituting the first inclined portion 711 and the second inclined portion 721 may have smooth cross-sections.

[0178] The first auxiliary layers 710 a and 720 a may make contact with the second surface PL2 of the substrate 100 .

[0179] The maximum thickness ta of the first auxiliary layers 710a and 720a may be in the range of about 5 μm to about 20 μm. If the maximum thickness ta of the first auxiliary layers 710a and 720a is less than about 5 μm, it may be difficult to provide a desired or effective adhesion level, and if the maximum thickness ta of the first auxiliary layers 710a and 720a is greater than about 20 μm, the thickness occupied by the first protective layer 710 and the second protective layer 720 may increase.

[0180] The first auxiliary layers 710a and 720a may include at least one material selected from acrylic resin, butyl rubber, vinyl acetate resin, EVA resin, natural rubber, nitrile, silicate resin, silicone rubber, and styrene block polymer. The first auxiliary layers 710a and 720a may provide an adhesive force for coupling between the substrate 100 and the first protective layer 710 and between the substrate 100 and the second protective layer 720.

[0181] The second auxiliary layer 710 b is disposed between the first auxiliary layer 710 a and the third auxiliary layer 710 c , and the second auxiliary layer 720 b is disposed between the first auxiliary layer 720 a and the third auxiliary layer 720 c .

[0182] The maximum thickness tb of the second auxiliary layers 710b and 720b may be in the range of about 45 μm to about 80 μm. If the maximum thickness tb of the second auxiliary layers 710b and 720b is less than about 45 μm, it is difficult for the first protective layer 710 and the second protective layer 720 to perform the function of protecting the substrate 100 or the display unit 200. If the maximum thickness tb of the second auxiliary layers 710b and 720b is greater than about 80 μm, the thickness occupied by the first protective layer 710 and the second protective layer 720 may be too large.

[0183] The second auxiliary layers 710b and 720b may include at least one material selected from an acrylate-based compound including an acrylate-based polymer, polyurethane, and SiO. The second auxiliary layers 710b and 720b may allow the first protective layer 710 and the second protective layer 720 to have predetermined elasticity.

[0184] The maximum thickness tb of the second auxiliary layers 710b and 720b may be greater than the maximum thickness ta of the first auxiliary layers 710a and 720a and the maximum thickness tc of the third auxiliary layers 710c and 720c. The second auxiliary layers 710b and 720b may protect the substrate 100 or the display unit 200 from impurities.

[0185] The third auxiliary layer 710c is arranged over the second auxiliary layer 710b, and the third auxiliary layer 720c is arranged over the second auxiliary layer 720b. The third auxiliary layers 710c and 720c are auxiliary layers arranged farthest from the second surface PL2 of the substrate 100.

[0186] The third auxiliary layers 710c and 720c include a heat dissipation material. The heat dissipation material may be a carbon composite material including at least one material selected from graphite, carbon nanotubes ("CNT"), carbon fibers, and graphene. Graphite has desirable properties such as high thermal conductivity and dispersibility and low cost. Carbon nanotubes have high electrical conductivity, and due to the large aspect ratio of carbon nanotubes, high thermal conductivity can be obtained even with a small amount of addition.

[0187] The third auxiliary layers 710 c and 720 c may include at least one material selected from a carbon composite material, a metal composite material including metal particles, and a ceramic composite material including ceramic powder as a heat dissipation material.

[0188] The metal composite material may include metal particles and polymers. The metal particles play a role in improving thermal conductivity. The metal particles may be any one of Al, Ag, Cu and Ni, but are not limited thereto.

[0189] The ceramic composite material may include ceramic powder and polymer. The ceramic powder has thermal conductivity, thereby performing a heat dissipation function. The ceramic powder may be AlN, Al 2 O 3, BN, SiC and BeO, but not limited thereto.

[0190] The heat dissipation material included in the third auxiliary layers 710c and 720c is not limited to the above-mentioned materials.

[0191] The third auxiliary layers 710c and 720c may further include a dispersant. The dispersant allows the material included in the third auxiliary layers 710c and 720c to exist in a powder form. The dispersant may be a photocurable resin for dispersion. When carbon is aggregated together, the dispersed photocurable resin may reduce the heat dissipation effect by acting as particles or impurities. Therefore, a dispersant may be added to independently disperse the particles, thereby maximizing the heat dissipation effect. According to an exemplary embodiment, the heat dissipation material itself may also be used as a dispersant.

[0192] In an exemplary embodiment of the display device, the light emitting element or the circuit board 800 generates heat during the operation of driving the display device. When the display device is under maximum load or used for a long time, excessive heat is generated, causing the electronic components of the display device to overheat, whereby the display device may malfunction and be damaged. Accordingly, in an exemplary embodiment, the third auxiliary layers 710c and 720c can dissipate the heat generated from the display device by including a heat dissipation material, and the heat dissipation effect can be maximized by further including a dispersant.

[0193] The maximum thickness tc of the third auxiliary layers 710c and 720c may be in the range of about 10 μm to about 30 μm. If the maximum thickness tc of the third auxiliary layers 710c and 720c is less than about 10 μm, it may be difficult to perform the function of protecting other auxiliary layers, and if the maximum thickness tc of the third auxiliary layers 710c and 720c is greater than about 30 μm, the thickness of the first protective layer 710 and the second protective layer 720 may be too large.

[0194] Next, refer to Fig.11 Other alternative exemplary embodiments of the display device are described. Fig.11 is a schematic cross-sectional view of a display device according to another alternative exemplary embodiment. Specifically, Fig.11 An exemplary embodiment in which the protective layer has a multi-layer structure and the orientation of each auxiliary layer is modified is shown.

[0195] Reference Fig.11 , each end of the first auxiliary layer 710a and 720a, the second auxiliary layer 710b and 720b, and the third auxiliary layer 710c and 720c may be connected to Fig.10 The difference shown in .

[0196] The end of the first auxiliary layer 710a may be exposed by the second auxiliary layer 710b and the third auxiliary layer 710c, the end of the first auxiliary layer 720a may be exposed by the second auxiliary layer 720b and the third auxiliary layer 720c, and the end of the second auxiliary layer 710b may be exposed by the third auxiliary layer 710c, and the end of the second auxiliary layer 720b may be exposed by the third auxiliary layer 720c.

[0197] For example, the ends of the first auxiliary layers 710a and 720a, the second auxiliary layers 710b and 720b, and the third auxiliary layers 710c and 720c may have a smooth step shape. In such an embodiment, the ends of the first auxiliary layer 710a, the second auxiliary layer 710b, and the third auxiliary layer 710c may not be aligned with each other, and the ends of the first auxiliary layer 720a, the second auxiliary layer 720b, and the third auxiliary layer 720c may not be aligned with each other. The ends of each of the first auxiliary layer 710a, the second auxiliary layer 710b, and the third auxiliary layer 710c may be arranged to be away from the bending area BA in the order of the first auxiliary layer 710a, the second auxiliary layer 710b, and the third auxiliary layer 710c, and the ends of each of the first auxiliary layer 720a, the second auxiliary layer 720b, and the third auxiliary layer 720c may be arranged to be away from the bending area BA in the order of the first auxiliary layer 720a, the second auxiliary layer 720b, and the third auxiliary layer 720c.

[0198] Next, refer to Figures 12 to 15 An exemplary embodiment in which the protection layer is formed in the bending area BA is described. Fig.12 is a schematic cross-sectional view of a display device according to another alternative exemplary embodiment, Fig.13 It is shown that according to Fig.12 A cross-sectional view of a state in which a substrate is folded in a display device according to an exemplary embodiment of the present invention, Fig.14 is a schematic cross-sectional view of a display device according to other alternative exemplary embodiments, and Fig.15 is a schematic cross-sectional view of a display device according to other alternative exemplary embodiments.

[0199] In an exemplary embodiment, referring to Fig.12 and Fig.13, the second auxiliary layer 710b included in the first protective layer 710 and the second auxiliary layer 720b included in the second protective layer 720 may be connected to each other. The connected portion is referred to as a second connection portion 715b, and the second connection portion 715b may be arranged on the second surface PL2 of the substrate 100 at the bending area BA. The second auxiliary layer 710b included in the first protective layer 710, the second connection portion 715b, and the second auxiliary layer 720b included in the second protective layer 720 may be integrally formed into a single integral unit, thereby forming the same layer. In this embodiment, the second connection portion 715b includes the same material as the second auxiliary layers 710b and 720b. The second auxiliary layers 710b and 720b and the second connection portion 715b may be formed during the same process.

[0200] Reference Fig.13 By arranging the second connection portion 715b in the bending area BA to provide elasticity to the substrate 100 during bending of the display device, bending can be softly achieved and damage to the display device can be effectively prevented. In addition, impurities can be effectively prevented from flowing into the substrate 100.

[0201] Fig.12 and Fig.13 2 shows an exemplary embodiment including a second connection portion 715b integrally formed with the second auxiliary layers 710b and 720b as a single integral unit. Fig.14 and Fig.15 As shown in FIG. 1 , a connection portion including at least one of a first connection portion 715 a and a third connection portion 715 c may be disposed at the bending area BA.

[0202] Reference Fig.14 In an alternative exemplary embodiment, the first auxiliary layer 710a included in the first protective layer 710 and the first auxiliary layer 720a included in the second protective layer 720 may be connected to each other. The connected portion is referred to as a first connection portion 715a, and the first connection portion 715a may be arranged on the second surface PL2 of the substrate 100 in the bending area BA. The first auxiliary layer 710a included in the first protective layer 710 and the first auxiliary layer 720a included in the second protective layer 720 may be integrally formed as a single integral unit, thereby forming the same layer. In such an embodiment, the first connection portion 715a includes the same material as the first auxiliary layers 710a and 720a. The first auxiliary layers 710a and 720a and the first connection portion 715a may be formed in the same process.

[0203] Reference Fig.15, the third auxiliary layer 710c included in the first protective layer 710 and the third auxiliary layer 720c included in the second protective layer 720 may be connected to each other. The connected portion is referred to as a third connection portion 715c, and the third connection portion 715c may be arranged on the second surface PL2 of the substrate 100 in the bending area BA. The third auxiliary layer 710c included in the first protective layer 710 and the third auxiliary layer 720c included in the second protective layer 720 may be integrally formed as a single integral unit, thereby forming the same layer. That is, the third connection portion 715c includes the same material as the third auxiliary layers 710c and 720c. The third auxiliary layers 710c and 720c and the third connection portion 715c may be formed in the same process.

[0204] According to an exemplary embodiment, Figures 12 to 15 As shown in , a connection portion including at least one selected from the first connection portion 715a, the second connection portion 715b, and the third connection portion 715c may be arranged in the bending area BA. The connection portion arranged in the bending area BA may have a single-layer or multi-layer structure. In this embodiment, at least one auxiliary layer is arranged in the bending area BA to prevent impurities from flowing into the substrate 100.

[0205] Next, refer to Fig.16 A thin film transistor and a light emitting element included in the display unit 200 are described. Fig.16 is a cross-sectional view of a thin film transistor and a light emitting element of a display unit according to an exemplary embodiment.

[0206] Reference Fig.16 In an exemplary embodiment of the display unit 200, a buffer layer 111 is disposed on the substrate 100. The buffer layer 111 may overlap the entire surface of the substrate 100. The buffer layer 111 may include a silicon oxide (SiO x ), Silicon Nitride (SiN x ) or the like. The buffer layer 111 may be defined by a single layer or a plurality of layers.

[0207] The buffer layer 111 may provide a flat surface on one surface of the substrate 100 to achieve planarization, and may effectively prevent impurity diffusion and moisture permeation, etc., which may degrade characteristics of the semiconductor layer 151 as described later. According to alternative exemplary embodiments, the buffer layer 111 may be omitted.

[0208] The semiconductor layer 151 of the thin film transistor TFT is disposed on the buffer layer 111. The semiconductor layer 151 includes a channel region 154 and a source region 153 and a drain region 155 disposed at respective sides of the channel region 154.

[0209] The semiconductor layer 151 may include polycrystalline silicon, amorphous silicon, or an oxide semiconductor.

[0210] A gate insulating layer 140 is disposed on the semiconductor layer 151. The gate insulating layer 140 may be disposed to overlap the entire surface of the substrate 100.

[0211] The gate insulating layer 140 may include silicon oxide (SiO x ), Silicon Nitride (SiN x ) or the like.

[0212] A gate conductor including a gate electrode 124 of the thin film transistor TFT is disposed on the gate insulating layer 140. The gate electrode 124 may overlap with a channel region 154 of the semiconductor layer 151.

[0213] An interlayer insulating layer 160 including an inorganic insulating material or an organic insulating material is disposed on the gate electrode 124 .

[0214] In this embodiment, a data conductor including a source electrode 173 and a drain electrode 175 of a thin film transistor TFT, a data line 171, a driving voltage line (not shown), etc. is arranged on the interlayer insulating layer 160. The source electrode 173 and the drain electrode 175 may be connected to the source region 153 and the drain region 155 of the semiconductor layer 151 through contact holes 163 and 165 defined through the interlayer insulating layer 160 and the gate insulating layer 140, respectively.

[0215] The gate electrode 124 , the source electrode 173 , and the drain electrode 175 together with the semiconductor layer 151 form a thin film transistor TFT. Fig.16 The thin film transistor TFT shown in FIG. 1 may be a driving transistor included in one pixel of a light emitting display device. Fig.16 As shown in FIG. 1 , the thin film transistor TFT may be a top-gate transistor in which the gate electrode 124 is arranged above the semiconductor layer 151. However, the structure of the thin film transistor TFT is not limited thereto, and various modifications may be made, for example, the thin film transistor TFT may be a bottom-gate transistor in which the gate electrode 124 is located below the semiconductor.

[0216] A planarization layer 180 is disposed on the interlayer insulating layer 160 and the data conductor. The planarization layer 180 is used to remove and planarize steps to increase emission efficiency of an organic light emitting element ("OLED") to be formed thereon. The planarization layer 180 may overlap and cover the thin film transistor TFT.

[0217] A pixel electrode 191 is disposed on the planarization layer 180 . The pixel electrode 191 may be connected to the drain electrode 175 of the thin film transistor TFT through a contact hole 185 defined through the planarization layer 180 .

[0218] A partition wall 360 is disposed on the planarization layer 180 and the pixel electrode 191. The partition wall 360 may overlap a portion of the pixel electrode 191, and an opening 361 is defined through the partition wall 360 to expose a portion of the pixel electrode 191.

[0219] The partition wall 360 may include an organic insulating material such as polyimide, polyacrylate, and polyamide, but is not limited thereto.

[0220] An emission layer 370 is disposed on the pixel electrode 191. The emission layer 370 includes an emission region. The emission layer 370 may additionally include at least one region selected from a hole injection region, a hole transport region, an electron injection region, and an electron transport region.

[0221] The emission layer 370 may include an organic material that emits primary color light such as red, green, and blue. In an exemplary embodiment, the emission layer 370 may have a structure in which a plurality of organic materials that emit light of different colors are stacked. In such an embodiment, an inorganic material for emitting primary color light such as red, green, and blue may be included.

[0222] A common electrode 270 for transmitting a common voltage is disposed on the emission layer 370 and the partition wall 360 .

[0223] The pixel electrode 191, the emission layer 370, and the common electrode 270 of each pixel form a light-emitting element as an OLED. In an exemplary embodiment, the pixel electrode 191 may be an anode as a hole injection electrode, and the common electrode 270 may be a cathode as an electron injection electrode. Alternatively, the pixel electrode 191 may be a cathode, and the common electrode 270 may be an anode. When holes and electrons from the pixel electrode 191 and the common electrode 270 are injected into the emission layer 370, and then the excitons combined by the injected holes and electrons transition from an excited state to a ground state, light is emitted.

[0224] The encapsulation layer 390 may be disposed on the common electrode 270. The encapsulation layer 390 may include a plurality of inorganic layers, or have a structure in which inorganic layers and organic layers are alternately stacked.

[0225] According to an exemplary embodiment of the display device, in the first protective layer 710 and the second protective layer 720, due to the third auxiliary layers 710c and 720c (refer to Fig. 9 ) includes a heat dissipation material so that heat generated from the light-emitting element or transistor can be dissipated to prevent damage to the display device.

[0226] Next, refer to Fig.17 and Fig.18 An exemplary embodiment of a method of manufacturing a display device is described. Fig.17is a schematic top view showing a method of manufacturing a display device according to an exemplary embodiment, and Fig.18 is a schematic cross-sectional view illustrating a method of manufacturing a display device according to an exemplary embodiment.

[0227] Reference Fig.17 and Fig.18 , shows a top view of the printing device 10 and the substrate 100 viewed from the z-axis direction. Fig.17 , the visible portion of the substrate 100 is the back side (ie, the second surface PL2) of the substrate 100. Fig.18 , the printing device 10 and the substrate 100 are arranged to be spaced apart at a predetermined interval in the z-axis direction.

[0228] The printing device 10 applies the photocurable resin solution while passing through the substrate 100 in the order of the first flat area F1, the curved area BA, and the second flat area F2. Then, the applied photocurable resin solution is cured with light (e.g., ultraviolet rays) to form the first protective layer 710 and the second protective layer 720 on the second surface PL2 of the substrate 100. According to an exemplary embodiment, the printing device 10 may apply the photocurable resin solution while passing through the substrate 100 in the order of the second flat area F2, the curved area BA, and the first flat area F1.

[0229] The printing device 10 includes a head 11 and a nozzle 12 disposed below the head 11. The nozzle 12 may be a multi-nozzle including at least two nozzles having different sizes from each other. In an exemplary embodiment, for example, the nozzle 12 may include a first nozzle 12a and a second nozzle 12b having different sizes from each other.

[0230] Although not shown, the printing apparatus 10 may further include a container for storing the photocurable resin solution and connected to the nozzle 12 .

[0231] exist Fig.17 , a position of the first flat region F1 of the substrate 100 is referred to as a position X1. A position on the right side (ie, closer to the bent region BA) other than the position X1 in the y-axis direction is referred to as a position X2. Fig.18 The shape of the printing device 10 performing the printing process at the position X1 and the position X2 is shown. Figures 1 to 3 Any repeated detailed description of the same or similar constituent elements is described.

[0232] Reference Fig.18, while moving from position X1 to position X2, the printing device 10 sequentially applies the photocurable resin. The nozzle 12 of the printing device 10 may spit out droplets of the photocurable resin. The printing device 10 may spit out the first droplet L1 to the second surface PL2 of the substrate 100 through the nozzle 12 at position X1, and may spit out the second droplet L2 to the second surface PL2 of the substrate 100 through the nozzle 12 at position X2.

[0233] In this embodiment, the nozzle 12 for spitting out the first droplet L1 at the position X1 may be the first nozzle 12a, and the nozzle 12 for spitting out the second droplet L2 at the position X2 may be the second nozzle 12b. Here, the size of the first nozzle 12a may be larger than the size of the second nozzle 12b, and the volume of the first droplet L1 may be larger than the volume of the second droplet L2. In this embodiment, the first nozzle 12a may spit out a larger amount of droplets than the second nozzle 12b.

[0234] Accordingly, the first protective layer 710 is formed with a thickness that becomes thinner from the first flat region F1 toward the curved region BA, thereby forming a first inclined portion 711. In this embodiment, the first droplet L1 and the second droplet L2 ejected onto the substrate 100 are combined and then flow toward the curved region BA to form the first inclined portion 711.

[0235] According to an alternative exemplary embodiment, the sizes of the first nozzles 12a and the second nozzles 12b may be substantially the same as each other, but the number of the first nozzles 12a may be greater than the number of the second nozzles 12b to adjust the amount of spitted liquid droplets.

[0236] The first inclined portion 711 of the first protective layer 710 formed by the above process has a first inclination angle θ1 with the substrate 100 at a first contact point Q1 intersecting the second surface PL2 of the substrate 100. The first inclination angle θ1 has a value greater than or equal to about 10 degrees and less than or equal to about 90 degrees, for example, about 30 degrees or more and about 45 degrees or less.

[0237] Although not shown separately, the printing device 10 may form the second protective layer 720 by an inkjet process like the first protective layer 710. Even in the second flat region F2, when the printing device 10 is arranged at a side close to the curved region BA, the amount of ejected droplets is low. Accordingly, the second protective layer 720 may have a thickness that is thinner from the second flat region F2 toward the curved region BA to form the second inclined portion 721. In this embodiment, the ejected droplets at each position of the second flat region F2 are combined with each other and flow toward the curved region BA to form the second inclined portion 721.

[0238] The second inclined portion 721 of the second protective layer 720 formed by this process has a second inclination angle θ2 with the substrate 100 at a second contact point Q2 intersecting the second surface PL2 of the substrate 100. The second inclination angle θ2 has a value greater than or equal to about 10 degrees (°) and less than or equal to about 90 degrees, and may be, for example, a value of about 30 degrees or more and about 45 degrees or less.

[0239] Reference Fig.18 , an upper protective film (not shown) may be attached to the substrate 100 arranged with the display unit 200 and the polarizing layer 400. After a photocurable resin is coated and cured on the second surface PL2 of the substrate 100 to form the first protective layer 710 and the second protective layer 720, the upper protective film (not shown) may be removed to provide a display device.

[0240] As described above, according to an exemplary embodiment of a method for manufacturing a display device (e.g., an inkjet process), the inclination of the ends of the first protective layer 710 and the second protective layer 720 can be easily controlled by adjusting the amount of droplets of the photocurable resin ejected by the printing device 10 to the substrate 100. Accordingly, bending can be facilitated by reducing the strain borne by the substrate during bending and minimizing interference between the first protective layer 710 and the second protective layer 720.

[0241] In this embodiment, the first protective layer 710 and the second protective layer 720 are formed by coating and curing a photocurable resin using a printing process (eg, an inkjet process), selective patterning can be effectively performed, and accordingly, manufacturing costs can be reduced and processes can be simplified.

[0242] While the invention has been described in conjunction 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. Rather, the inventive concept is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A display device, comprising: a substrate comprising a first flat region, a second flat region, and a curved region disposed between the first flat region and the second flat region; a display unit overlapping the first planar area and arranged on a surface of the substrate; a first protective layer disposed on an opposite surface of the substrate opposite to the surface of the substrate and overlapping the first flat area; as well as a second protective layer disposed on the opposite surface of the substrate and overlapping the second planar area, wherein the first protective layer and the second protective layer include a curing member including a photocurable resin, The first protective layer includes a first inclined portion having a first inclined angle at an end of the first protective layer, The second protective layer includes a second inclined portion having a second inclined angle at an end portion of the second protective layer, and The first protection layer and the second protection layer include a heat dissipation material having thermal conductivity.

2. The display device according to claim 1, wherein: The first inclination angle and the second inclination angle are greater than or equal to 10 degrees and less than or equal to 90 degrees.

3. The display device according to claim 1, wherein: The heat dissipation material is a carbon composite material including at least one material selected from graphite, carbon nanotubes, carbon fibers and graphene.

4. The display device according to claim 1, wherein: The first protective layer and the second protective layer further include a dispersant containing a dispersed photocurable resin.

5. A method for manufacturing a display device, comprising: providing a display unit including a plurality of thin film transistors on a surface of a substrate; as well as applying and curing a photocurable resin on an opposite surface of the substrate opposite to the surface of the substrate to form a first protective layer and a second protective layer, Wherein, the photocurable resin is applied by an inkjet process.

6. The manufacturing method according to claim 5, wherein: Applying the photocurable resin includes applying the photocurable resin by a printing device including a nozzle, The nozzle discharges droplets of the photocurable resin, The display device includes a first flat area provided with the display unit, a curved area adjacent to the first flat area, and a second flat area adjacent to the curved area, and The nozzle discharges a small number of droplets of the photocurable resin from the first flat region toward the curved region, and discharges a small number of droplets of the photocurable resin from the second flat region toward the curved region.

7. The manufacturing method according to claim 5, wherein: The substrate comprises a first flat region, a second flat region, and a curved region disposed between the first flat region and the second flat region; The first protective layer overlaps the first flat area; and The second protection layer overlaps the second planar area.

8. The manufacturing method according to claim 5, wherein: The first protective layer includes a first inclined portion at an end of the first protective layer, The second protective layer includes a second inclined portion at an end of the second protective layer, The first inclined portion has a first inclination angle with the opposite surface of the substrate, The second inclined portion has a second inclination angle with respect to the opposite surface of the substrate, and Each of the first inclination angle and the second inclination angle is greater than or equal to 10 degrees and less than or equal to 90 degrees.

9. The manufacturing method according to claim 8, wherein: The first inclination angle and the second inclination angle are in a range of 30 degrees to 45 degrees.

10. The manufacturing method according to claim 8, wherein: As the first tilt angle and the second tilt angle decrease, the strain borne by the substrate at the bending region decreases.

11. The manufacturing method according to claim 10, wherein: During bending of the display device, the maximum value of the strain on a portion of the substrate is 1.4%, and The value of the strain is defined as: strain length / initial length×100%.

12. The manufacturing method according to claim 8, wherein: The substrate includes a first flat region, a second flat region, and a curved region disposed between the first flat region and the second flat region, The first inclined portion is formed at a portion of the first flat region adjacent to the curved region, and The second inclined portion is formed at a portion of the second flat region adjacent to the curved region.

13. The manufacturing method according to claim 5, wherein: The photocurable resin includes at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethanes, and SiO; and The photocurable resin further comprises at least one material selected from acrylic-based resin, butyl rubber, vinyl acetate resin, ethylene vinyl acetate resin, natural rubber, nitrile, silicate resin, silicone rubber and styrene block polymer.

14. The manufacturing method according to claim 5, wherein: Each of the first protective layer and the second protective layer includes a first auxiliary layer, a second auxiliary layer, and a third auxiliary layer sequentially stacked one on another from the opposite surfaces of the substrate.

15. The manufacturing method according to claim 14, wherein: The third auxiliary layer includes a heat dissipation material having thermal conductivity.

16. The manufacturing method according to claim 15, wherein: The heat dissipation material is a carbon composite material including at least one material selected from graphite, carbon nanotubes, carbon fibers and graphene.

17. The manufacturing method according to claim 15, wherein: The third auxiliary layer further includes a dispersant containing dispersed photocurable resin.

18. The manufacturing method according to claim 14, wherein: The first auxiliary layer comprises at least one material selected from the group consisting of acrylic resin, butyl rubber, vinyl acetate resin, ethylene vinyl acetate resin, natural rubber, nitrile, silicate resin, silicone rubber and styrene block polymer; and The second auxiliary layer includes at least one material selected from acrylate-based compounds including acrylate-based polymers, polyurethane, and SiO.

19. The manufacturing method according to claim 14, wherein: The substrate includes a first flat region, a second flat region, and a curved region disposed between the first flat region and the second flat region, A connection portion is arranged on the opposite surface of the substrate at the bending region, and The connection part includes the same material as the second auxiliary layer.

20. The manufacturing method according to claim 5, wherein: The substrate includes a first flat region, a second flat region, and a curved region disposed between the first flat region and the second flat region, The first protective layer and the second protective layer are spaced apart from each other, and A space between the first protection layer and the second protection layer overlaps the bending area.

21. The manufacturing method according to claim 8, wherein: The inclinations of the end portions of the first protective layer and the second protective layer are controlled by adjusting the amount of droplets of the photocurable resin discharged onto the substrate.

22. The manufacturing method according to claim 5, wherein: The first protective layer and the second protective layer are provided without a separate adhesive layer.

23. The manufacturing method according to claim 6, wherein: When the printing device is arranged at a side close to the curved region, the amount of the ejected droplets is low.

24. The manufacturing method according to claim 23, wherein: The liquid droplets discharged at each position of the second flat area combine with each other and flow toward the curved area to form a second inclined portion.

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