Patent Publication Number: US-2022216452-A1

Title: Display Apparatus, Structure And Manufacturing Apparatus Of Flexible Display Apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 16/709,569 filed on Dec. 10, 2019 which claims priority to Republic of Korea Patent Application No. 10-2018-0167954, filed on Dec. 21, 2018, each of which is hereby incorporated by reference in its entirety for all purposes. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a flexible display apparatus, a manufacturing apparatus, and a structure of the flexible display apparatus. 
     Discussion of the Related Art 
     A display apparatus is widely used as a display screen of various electronic devices such as a mobile communication terminal, an electronic diary, an electronic book, a portable multimedia player (PMP), a navigator, an Ultra Mobile PC (UMPC), a mobile phone, a smart phone, a tablet personal computer (PC), a watch phone, an electronic pad, a wearable device, a portable information device, a vehicle control display device, a television, a notebook computer, and a monitor. 
     Since each of a liquid crystal display apparatus, a light emitting display apparatus, a quantum dot display apparatus, and an electrophoresis display apparatus among display apparatuses is able to become a thin profile, studies and development for embodying them as flexible display apparatuses are ongoing. In the flexible display apparatus, a display portion that includes a thin film transistor and lines are formed on a flexible substrate. Since the flexible display apparatus is able to display an image even though it is bent like a paper, the flexible display apparatus may be used for various display fields. 
     A flexible display apparatus of the related art may comprise a flexible display panel and a cover window coupled to a front surface of the flexible display panel by an adhesive member to protect the flexible display panel. 
     Recently, the cover window of the flexible display apparatus is changing from a two-dimensional shape having a plate shape to a three-dimensional (3D) shape having a curved portion. 
     However, bonding between the flexible display panel and the cover window becomes uneven due to the 3D shape of the cover window during a conventional process of attaching the flexible display panel to the cover window using an adhesive member, whereby bubbles are generated by such an uneven bonding between the flexible display panel and the cover window. The bubbles cause a process defect and deteriorate productivity. Particularly, a problem may occur in that cracks are generated in the display panel and the cover window due to the bubbles and therefore cause a defect in quality of the display apparatus. 
     SUMMARY 
     An object of the present disclosure is to provide a flexible display apparatus, a manufacturing apparatus, and a structure of the flexible display apparatus, in which a cover window having a 3D shape and a flexible display panel may uniformly be bonded to each other. 
     In addition to the objects of the present disclosure as mentioned above, additional objects and features of the present disclosure will be clearly understood by those skilled in the art from the following description of the present disclosure. 
     In accordance with an aspect of the present disclosure, the above and other objects can be accomplished by the provision of a manufacturing apparatus configured to bond a display panel to a cover window having a flat portion between a first curvature portion and a second curvature portion, and may comprise a first attachment portion configured to press a first adhesive surface of the display panel to the flat portion of the cover window, and a 3D attachment portion configured to press a first edge adhesive surface and a second edge adhesive surface of the display panel to the first curvature portion and the second curvature portion of the cover window, respectively, and not press the first adhesive surface of the display panel. 
     In accordance with another aspect of the present disclosure, the above and other objects can be accomplished by the provision of a manufacturing apparatus configured to bond a display panel to a cover window having a flat portion between a first curvature portion and a second curvature portion, and may comprise a 3D attachment portion configured to press a first edge adhesive surface and a second edge adhesive surface of the display panel to the first curvature portion and the second curvature portion of the cover window, respectively, and not press a first adhesive surface of the display panel between the first edge adhesive surface and the second edge adhesive surface of the display panel, wherein the 3D attachment portion may include a window supporting member configured to support the cover window, and a 3D attachment unit overlapping the window supporting member and having a 3D pressurizing pad configured to press the first edge adhesive surface and the second edge adhesive surface of the display panel to the first curvature portion and the second curvature portion of the cover window, respectively, and not press the first adhesive surface of the display panel. 
     In accordance with still another aspect of the present disclosure, the above and other objects can be accomplished by the provision of a structure comprising a cover window of which both edges have a shape of a specific angle or more, and at least one layer attached to an inner surface of the cover window without bubbles by an attachment process that does not use a diaphragm. 
     In accordance with still another aspect of the present disclosure, the above and other objects can be accomplished by the provision of a display apparatus comprising a substrate having a pixel array portion, and a cover window covering the substrate, wherein both edges of the cover window have a shape of a specific angle or more, and at least one layer may be attached to an inner surface of the cover window. 
     According to the present disclosure, the display panel may be bonded to a curved window having a 3D shape without bubbles or with fewer bubbles than a display panel bonded to a curved window using a conventional manufacturing process, whereby bonding quality between the cover window and the display panel may be improved. 
     In addition to the effects of the present disclosure as mentioned above, additional advantages and features of the present disclosure will be clearly understood by those skilled in the art from the above description of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view illustrating an electronic device including a flexible display apparatus according to one embodiment of the present disclosure. 
         FIG. 2  is a cross-sectional view taken along line I-I′ shown in  FIG. 1 . 
         FIG. 3  is an enlarged view illustrating a portion A shown in  FIG. 2 . 
         FIG. 4  is a view conceptually illustrating a manufacturing apparatus of a flexible display apparatus according to one embodiment of the present disclosure. 
         FIG. 5  is a view illustrating a first attachment portion according to one embodiment shown in  FIG. 4 . 
         FIGS. 6A, 6B, and 6C  are views illustrating an attachment process of a first attachment portion according to one embodiment of the present disclosure. 
         FIG. 7  is a view illustrating a second attachment portion according to one embodiment shown in  FIG. 4 . 
         FIGS. 8A and 8B  are views illustrating an attachment process of a second attachment portion according to one embodiment of the present disclosure, which is shown in  FIG. 7 . 
         FIG. 9  is a view illustrating a 3D attachment portion according to one embodiment shown in  FIG. 4 . 
         FIG. 10  is a perspective view illustrating a 3D pressurizing pad shown in  FIG. 9 . 
         FIGS. 11A and 11B  are views illustrating an attachment process of a 3D attachment portion according to one embodiment of the present disclosure, which is shown in  FIGS. 9 and 10 . 
         FIG. 12  is a view illustrating a 3D attachment portion according to another embodiment shown in  FIG. 4 . 
         FIG. 13  is a perspective view illustrating a 3D pressurizing pad shown in  FIG. 12 . 
         FIGS. 14A and 14B  are views illustrating an attachment process of a 3D attachment portion according to another embodiment of the present disclosure, which is shown in  FIGS. 12 and 13 . 
         FIG. 15  is a view illustrating a 3D attachment portion according to other embodiment shown in  FIG. 4 . 
         FIG. 16  is a perspective view illustrating a 3D pressurizing pad shown in  FIG. 15 . 
         FIGS. 17A and 17B  are views illustrating an attachment process of a 3D attachment portion according to other embodiment of the present disclosure, which is shown in  FIGS. 15 and 16 . 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Advantages and features of the present disclosure, and implementation methods thereof will be clarified through following embodiments described with reference to the accompanying drawings. The present disclosure may, however, be configured in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Further, the present disclosure is only defined by scopes of claims. 
     A shape, a size, a ratio, an angle, and/or a number disclosed in the drawings for describing embodiments of the present disclosure are merely an example, and thus, the present disclosure is not limited to the illustrated details. Like reference numerals refer to like elements throughout the specification. In the following description, when the detailed description of the relevant known function or configuration is determined to unnecessarily obscure the important point of the present disclosure, the detailed description will be omitted. 
     In a case where ‘comprise,’ ‘have,’ and ‘include’ described in the present specification are used, another part may be added unless ‘only’ is used. The terms of a singular form may include plural forms unless referred to the contrary. 
     In construing an element, the element is construed as including an error range although there is no explicit description. 
     In describing a position relationship, for example, when the position relationship is described as ‘upon,’ ‘above,’ ‘below,’ and ‘next to,’ one or more portions may be arranged between two other portions unless ‘just’ or ‘direct’ is used. 
     In describing a time relationship, for example, when the temporal order is described as ‘after,’ ‘subsequent,’ ‘next,’ and ‘before,’ a case which is not continuous may be included unless ‘just’ or ‘direct’ is used. 
     It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. 
     The term “at least one” should be understood as including any and all combinations of one or more of the associated listed items. For example, the meaning of “at least one of a first item, a second item, and a third item” denotes the combination of all items proposed from two or more of the first item, the second item, and the third item as well as the first item, the second item, or the third item. 
     Features of various embodiments of the present disclosure may be partially or overall coupled to or combined with each other, and may be variously inter-operated with each other and driven technically as those skilled in the art can sufficiently understand. The embodiments of the present disclosure may be carried out independently from each other, or may be carried out together in co-dependent relationship. 
     Hereinafter, a flexible display apparatus and a manufacturing apparatus and a structure of the flexible display apparatus according to the present disclosure will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       FIG. 1  is a perspective view illustrating an electronic device including a flexible display apparatus according to one embodiment of the present disclosure,  FIG. 2  is a cross-sectional view taken along line I-I′ shown in  FIG. 1 , and  FIG. 3  is an enlarged view illustrating a portion A shown in  FIG. 2 . 
     Referring to  FIGS. 1 to 3 , the electronic device according to one embodiment of the present disclosure may include a cover window  10 , a flexible display module  30 , and a middle frame  50 . Since a scale of each of the cover window  10 , the flexible display module  30  and the middle frame  50  shown in  FIGS. 1 and 2  is different from an actual scale for convenience of description, the present disclosure is not limited to the shown scale. 
     The cover window  10  may serve to protect the flexible display module  30  from external impact by covering a front surface and a side of the flexible display module  30 . 
     The cover window  10  according to one embodiment may be made of a transparent plastic material, a glass material, or a reinforcing glass material. As an example, the cover window  10  may have one or more of a deposited structure of sapphire glass and gorilla glass. As another example, the cover window  10  may include a transparent plastic material such as polyethylene terephthalate (PET). The cover window  10  may be made of reinforcing glass in consideration of scratch-resistant and transparency properties. In this case, the cover window  10  may be expressed as a cover glass. 
     The cover window  10  according to one embodiment may include a flat window  11  and a curved window  13 . 
     The flat window  11  is a center portion of the cover window  10 , and may be a transparent area through which light is transmitted. The flat window  11  may have a flat shape. For example, the flat window  11  may be expressed as a front portion, flat portion, or front window. 
     The curved window  13  may be curved from an edge of the flat window  11  in a curved shape having a preset curvature radius. In some embodiments, the shortest distance between the curved window  13  and the flat window  11  may be 2.0 mm or more. A height from the flat window  11  to the curved window  13  may be 2.0 mm or more, for example, at least 4.0 mm. A width of the curved window (or both edges)  13  may be 3.0 mm or more. 
     The curved window  13  according to one embodiment may include a first curvature portion  13   a  curved from one side (e.g., left edge) of the flat window  11 , and a second curvature portion  13   b  curved from the other side (e.g., right edge) of the flat window  11 . In this case, the cover window  10  has a double-sided bending structure (or both-edge bending structure) in which left and right edge areas are curved, whereby an esthetic sense of the electronic device may be improved, and a bezel area in a short-side direction of the electronic device may be reduced. 
     Each of the first curvature portion  13   a  and the second curvature portion  13   b  may include a curved portion CP and a sidewall SW. 
     The curved portion CP may be curved from the flat window  11  at a specific angle of 60° or more. 
     As an example, the curved portion CP may have a curved shape section having at least one curvature between an end of the flat window  11  and the sidewall SW based on a second plane configured by a first length direction X and a height direction Z. 
     As another example, the curved portion CP may have a fan shaped section having a central angle of an acute angle based on the second plane For example, the curved portion CP may have a fan-shaped (or a sector shaped) section having a central angle of 90°. 
     The sidewall SW may be extended from the end of the curved portion CP to have a certain length. An angle θ between the sidewall SW and the flat window  11  may be, but is not limited to, 60° or more. For example, the angle θ between the sidewall SW and the flat window  11  may range from 80° to 90°. 
     The curved window  13  according to one embodiment, as shown in  FIG. 1 , may be curved from all edge areas of the flat window  11  in a curved shape having a preset curvature radius. Therefore, the edge area of the flat window  11  may have a curved structure by the curved window  13 . In this case, the cover window  10  has a four-sided bending structure which is fully curved, whereby an esthetic sense of the electronic device may be improved, and a bezel area in each of a long-side direction and a short-side direction of the electronic device may be reduced. 
     Additionally, the cover window  10  may further include a design (or decoration) layer provided on a rear edge area. The design layer may be printed on the rear (back) edge area of the cover window  10 , which faces the flexible display module  30 , at least one time to cover a non-display area where an image is not displayed in the electronic device. 
     The flexible display module  30  may include a flexible light emitting display panel, a flexible organic light emitting display panel, a flexible electrophoresis display panel, a flexible electro-wetting display panel, a flexible micro light emitting diode display panel, or a flexible quantum dot light emitting display panel. In the following description, for purposes of explanation, it is assumed that the flexible display panel is a flexible organic light emitting display panel. 
     The flexible display module  30  may include at least one layer attached to an inner surface of the cover window  10  of which at least two edge areas are curved at a specific angle or more. The flexible display module  30  may be integrated into the inner surface of the cover window  10  by a bonding process using an elastic pad by an adhesive member  20  not a diaphragm mode, whereby one structure such as an electronic device may be configured together with the cover window  10 . 
     The flexible display module  30  may be coupled with the rear surface (or back surface) of the cover window  10  to display an image and/or sense a user&#39;s touch. The flexible display module  30  may be bonded to the flat window  11  and the curved window  13  of the cover window  10  through a bonding process using an elastic pad by the adhesive member  20  and not the diaphragm mode. The adhesive member  20  may include a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The adhesive member  20  may be expressed as a transparent adhesive member, a transparent adhesive sheet, or a panel bonding member. 
     As shown in the embodiment of  FIG. 2 , the flexible display module  30  according to one embodiment may include a flat display portion  30   a  configured to display an image toward the flat window  11  of the cover window  10 , a first bending display portion  30   b  configured to bend from one edge of the flat display portion  30   a  in a curved shape to display an image toward the first curvature portion  13   a  of the curved window  13  of the cover window  10 , and a second bending display portion  30   c  configured to bend from the other edge of the flat display portion  30   a  in a curved shape to display an image toward the second curvature portion  13   b  of the curved window  13  of the cover window  10 . 
     The flexible display module  30  according to one embodiment may include a flexible display panel  31  including display portions  30   a ,  30   b , and  30   c , and a heat dissipating sheet portion  33  coupled to the rear surface (back surface) of the flexible display panel  31 . 
     The flexible display panel  31  may display images on the display portions  30   a ,  30   b  and  30   c  that include the flat display portion  30   a , the first bending display portion  30   b  and the second bending display portion  30   c.    
     In the flexible display panel  31 , the flat display portion  30   a  may uniformly be attached to at least a part of or the entire flat window  11  without bubbles or with fewer bubbles than a flexible display panel attached to a flat portion of a window using conventional manufacturing processes. The first bending display portion  30   b  may uniformly be attached to the first curvature portion  13   a  curved from the flat window  11  without bubbles or with fewer bubbles than a flexible display panel attached to a curved portion of a window using conventional manufacturing processes to have a specific angle or more, for example, 60° or more. The second bending display portion  30   c  may uniformly be attached to the second curvature portion  13   b  curved from the flat window  11  without bubbles or with fewer bubbles than a flexible display panel attached to a curved portion of a window using conventional manufacturing processes to have a specific angle or more, for example, 60° or more. In this case, the flat display portion  30   a  may uniformly be attached to at least a part of or the entire flat window  11  without bubbles or with reduced bubbles by a pre-attachment process using a pre-attachment elastic pad configured to locally pressurize the flat display portion  30   a , and the first and second bending display portions  30   b  and  30   c  may uniformly be attached to the curvature portions  13   a  and  13   b , respectively, without bubbles or with reduced bubbles by an attachment process (or a main-attachment process) using an attachment elastic pad (or a main-attachment elastic pad) configured to locally pressurize the bending display portions  30   b  and  30   c  and not the flat display portion  30   a . The first bending display portion  30   b  and the second bending display portion  30   c  may be attached to the curved window  13  even by the diaphragm manner. However, in the diaphragm manner in conventional processes, since a film (or membrane) of the diaphragm is not modified to (or deformed into) a shape, which follows a 3D shape of the curved window  13  curved at an angle of 60° or more, bubbles may be generated between the curved window  13  and the flexible display panel  31 . On the other hand, if the attachment elastic pad configured to locally pressurize the bending display portions  30   b  and  30   c  is used, the attachment elastic pad having a relatively high strain compared with the film of the diaphragm may elastically be deformed in a shape that follows a 3D shape of the curved window  13  curved at an angle of 60° or more, whereby the attachment elastic pad may uniformly bond the curved window  13  to the flexible display panel  31  without bubbles or with reduced bubbles by pressurizing the flexible display panel  31  to be suitable for the 3D shape of the curved window  13 . 
     The flexible display panel  31  according to one embodiment may include a flexible substrate  31   a , a pixel array portion  31   b , a gate driving circuit GDC, an encapsulation portion  31   c , a touch electrode portion  31   e , a functional film  31   g , and a back plate BP. 
     The flexible substrate  31   a  may be defined as a base substrate of the flexible display panel  31 . The flexible substrate  31   a  according to one embodiment may include a flexible plastic material, for example, opaque or colored polyimide (PI). The flexible substrate  31   a  according to another embodiment may be made of a thin type glass material having flexibility. 
     The pixel array portion  31   b  according to one embodiment may be formed on the display portions  30   a ,  30   b , and  30   c  defined on the flexible substrate  31   a  to display an image on the flat display portion  30   a , the first bending display portion  30   b , and the second bending display portion  30   c.    
     The pixel array portion  31   b  may include a plurality of pixels provided in a pixel area defined by signal lines provided on the flexible substrate  31   a , displaying images in accordance with signals supplied to signal lines. The signal lines may include gate lines, data lines, and pixel driving power lines. 
     Each of the plurality of pixels may include a pixel circuit layer including a driving thin film transistor provided in the pixel area, an anode electrode electrically connected with the driving thin film transistor, a light emitting diode layer formed on the anode electrode, and a cathode electrode electrically connected with the light emitting diode layer. 
     The driving thin film transistor is provided in a transistor area of each pixel area defined on the flexible substrate  31   a , and may include a gate electrode, a gate insulating film, a semiconductor layer, a source electrode, and a drain electrode. In this case, the semiconductor layer of the thin film transistor may include a silicon such as a-Si, poly-Si, or low temperature poly-Si, or may include an oxide such as Indium-Gallium-Zinc-Oxide (IGZO). 
     The anode electrode is provided in an opening area defined in each pixel area in a pattern shape and therefore electrically connected with the driving thin film transistor. 
     The light emitting diode layer according to one embodiment may include an organic light emitting diode formed on the anode electrode. The organic light emitting diode may be configured to emit light of the same color per pixel, for example, white light, or may be configured to emit light of a color different per pixel, for example, red light, green light, or blue light, among other colors. 
     The light emitting diode layer according to another embodiment may include a micro light emitting diode element electrically connected with each of the anode electrode and the cathode electrode. The micro light emitting diode element is a light emitting diode configured in the form of an integrated circuit (IC) or chip, and may include a first terminal electrically connected with the anode electrode and a second terminal electrically connected with the cathode electrode. 
     The cathode electrode may commonly be connected with the light emitting diodes of the light emitting diode layers provided in the respective pixel areas. 
     The gate driving circuit GDC may be formed on first and/or second edge areas of the flexible substrate  31   a  and therefore connected with one end and/or the other end of each of a plurality of gate lines provided on the flexible substrate  31   a . The gate driving circuit GDC may generate a gate signal in response to a gate control signal supplied through a display pad portion provided in the flexible substrate  31   a  and supply the generated gate signal to each of the plurality of gate lines. The gate driving circuit may be a gate built-in circuit formed together with the manufacturing process of the thin film transistor of the pixel, but is not limited thereto. 
     The encapsulation portion  31   c  may be formed on the flexible substrate  31   a  to surround the pixel array portion  31   b , thereby preventing oxygen or water from being permeated, or reducing an amount of oxygen or water or other contaminants being permeated, into the light emitting diode layer of the pixel array portion  31   b . The encapsulation portion  31   c  according to one embodiment may be formed in a multi-layered structure in which an organic material layer and an inorganic material layer are alternately deposited. In this case, the inorganic material layer may serve to shield oxygen or water from being permeated, or mitigate any permeation of oxygen or water or other contaminants, into the light emitting diode layer of the pixel array portion  31   b . The organic material layer may be formed to be relatively thicker than the inorganic material layer to cover particles that may be generated during a manufacturing process. For example, the encapsulation portion  31   c  may include a first inorganic film, an organic film on the first inorganic film, and a second inorganic film on the organic film. In this case, the organic film may be defined as a particle cover layer. 
     The touch electrode portion  31   e  serves as a touch sensor arranged on the encapsulation portion  31   c , sensing a user&#39;s touch. 
     The touch electrode portion  31   e  according to one embodiment may include a touch electrode layer arranged on the encapsulation portion  31   c  overlapped with the pixel array portion  31   b , and a dielectric layer covering the touch electrode layer. Optionally, the touch electrode portion  31   e  may be formed on a touch buffer layer covering the encapsulation portion  31   c . For example, the touch electrode layer may include a plurality of touch driving electrodes arranged on the encapsulation portion  31   c  overlapped with the pixel array portion  31   b  at constant intervals, and a plurality of touch sensing electrodes electrically insulated from the plurality of touch driving electrodes. The touch sensing electrodes may be arranged on the same layer as the touch driving electrodes, or the touch sensing electrodes and the touch driving electrodes may be arranged on their respective layers different from each other by interposing the dielectric layer therebetween. 
     The touch electrode portion  31   e  according to another embodiment may be replaced with a capacitance type touch panel known to one skilled in the art. In this case, the touch panel may be attached onto the encapsulation portion  31   c  by a transparent adhesive member  31   d . In this case, the transparent adhesive member  31   d  may include a pressure sensitive adhesive (PSA) or an optically clear resin (OCR). 
     The functional film  31   g  may be attached onto the touch electrode portion  31   e  by a transparent adhesive member  31   f.    
     The functional film  31   g  according to one embodiment may include a polarizing film for improving outdoor visibility and contrast ratio for an image displayed on the flexible display panel  31  by preventing or reducing reflection of external light. For example, the functional film  31   g  may include an optical isotropic lower film, a polarizing film coupled and supported onto the optical isotropic lower film, and an optical isotropic upper film coupled and supported onto the polarizing film. The polarizing film may include a circular polarizer that shields external light incident through the cover window  10  and reflected by a thin film transistor and/or lines arranged on the pixel array portion  31   b  from progressing to the cover window  10 . The optical isotropic lower film of the function film  31   g  may be attached onto the touch electrode portion  31   e  by the transparent adhesive member  31   f.    
     The back plate BP is attached to the rear surface (back surface) of the flexible substrate  31   a  overlapped with the pixel array portion  31   b  to maintain the rear surface (or back surface) of the flexible substrate  31   a  overlapped with the pixel array portion  31   b  in a flat state. For example, the back plate BP may be, but is not limited to, polyethylene terephthalate (PET). 
     The heat dissipating sheet portion  33  may be attached to at least a part of or the entire rear surface of the back plate BP. The heat dissipating sheet portion  33  may serve to protect the flexible display panel  31  from impact and dissipate heat of the flexible display panel  31 . The heat dissipating sheet portion  33  according to one embodiment may include a heat dissipating sheet, a cushion member, and an adhesive member. 
     The heat dissipating sheet (or heat radiation sheet) may include a heat dissipating layer having a metal material with relatively high heat conductivity. The heat dissipating sheet according to one embodiment may include a metal layer such as copper (Cu). The heat dissipating sheet according to another embodiment may include a metal layer such as Cu and a graphite layer coated on the metal layer. The heat dissipating sheet may have a heat dissipation function, a ground function, and a function of protecting the rear surface of the flexible display panel  31 . 
     The cushion member may include a foam tape coupled to the heat dissipating sheet. The cushion member may serve to attenuate impact. 
     The adhesive member may be coupled with the cushion member. The adhesive member may include an uneven structure (or embossing structure) formed on a surface. The uneven structure of the adhesive member is able to omit a process for removing bubbles generated between the back plate BP and the heat dissipating sheet portion  33  by preventing or mitigating bubbles from being generated between the back plate BP and the heat dissipating sheet portion  33  during attachment between the back plate BP and the heat dissipating sheet portion  33 . 
     The middle frame  50  may support the cover window  10  and cover the rear surface of the flexible display module  30 . The middle frame  50  may be arranged on the outmost side of the electronic device, and may include a plastic material or a metal material. The middle frame  50  may include a metal material having a color coating layer. The middle frame  50  according to one embodiment may be made of a metal material, for example, aluminum material, which has relatively high heat conductivity, to improve heat dissipation performance of the electronic device. 
     The middle frame  50  according to one embodiment may include a middle plate  51  and a middle sidewall  53 . 
     The middle plate  51  may be arranged on the rear surface of the flexible display module  30 . In this case, the middle plate  51  may include at least one open portion through which a cable for electrical connection between a display driving circuit connected to the flexible display panel  31  and a host driving system passes, and at least one recessed portion in which various electronic circuit components built in the electronic device are arranged. 
     The middle sidewall  53  may vertically be coupled with a side of the middle plate  51  to support the curved window  13  of the cover window  10 . For example, the middle sidewall  53  may be coupled with the curved window  13  of the cover window  10  by a double-sided tape or a waterproof tape. In this case, waterproof performance of the electronic device may be improved, and permeation of particles may be avoided or mitigated. 
     The electronic device according to one embodiment of the present disclosure may further include a back cover  70  for covering the rear surface (or back surface) of the middle frame  50 . 
     The back cover  70  may be coupled to the middle sidewall  53  to face the rear surface of the middle plate  51  and therefore provides a circuit storage space  71  on the rear surface of the middle frame  50  by covering the rear surface (or back surface) of the middle frame  50 . The circuit storage space  71  may be provided between the middle plate  51  of the middle frame  50  and the back cover  70  to store a host driving system, a memory, a battery, etc. The back cover  70  may detachably be coupled to the middle sidewall  53  for battery exchange according to battery discharge in the middle of using the electronic device, or may be coupled to the middle sidewall  53  detachably during disassembly for repair of the electronic device. 
     The back cover  70  according to one embodiment may be arranged on the rear surface of the outmost of the electronic device, and may include at least one of a plastic material, a metal material, and a glass material and may include a color coating layer. For example, the back cover  70  according to one embodiment may be a flat glass having a transparent, semi-transparent, or opaque color coating layer. 
     The back cover  70  according to another embodiment may have the same shape as that of the cover window  10 , and may include a glass material having a color coating layer. For example, the back cover  70  according to another embodiment may have a symmetrical structure with the cover window  10  by interposing the middle frame  50 , and may include a transparent, semi-transparent, or opaque color coating layer. 
       FIG. 4  is a view conceptually illustrating a manufacturing apparatus of a flexible display apparatus according to one embodiment of the present disclosure, and illustrates an apparatus (or manufacturing system) for bonding the cover window and the flexible display panel shown in  FIGS. 2 and 3  to each other. 
     Referring to  FIG. 4  together with  FIGS. 2 and 3 , the manufacturing apparatus of the flexible display apparatus according to one embodiment of the present disclosure may bond a flexible display panel  31  (hereinafter, referred to as “display panel  31 ”) to a cover window  10  including a flat window  11  and a curved window  13  curved from the flat window  11 . The manufacturing apparatus of the flexible display apparatus according to one embodiment of the present disclosure may be a 3D laminating apparatus or window laminating apparatus. 
     The manufacturing apparatus of the flexible display apparatus according to one embodiment may include a first transfer portion TP 1 , a first attachment portion  100 , a second transfer portion TP 2 , a second attachment portion  300 , a third transfer portion TP 3 , and a 3D attachment portion  500 . 
     The first transfer portion TP 1  loads each of the cover window  10  and the display panel  31  in the first attachment portion  100 . For example, the first transfer portion TP 1  may pick up one cover window  10  from a window cassette in which a plurality of cover windows  10  are loaded or a conveyer belt through the cover windows  10  are continuously retransferred, and may load the picked-up cover windows  10  in the first attachment portion  100 . The second transfer portion TP 2  may pick up one display panel  31  from a panel cassette in which a plurality of display panels  31  are loaded or a conveyer belt through the display panels  31  are continuously retransferred, and may load the picked-up display panels  31  in the first attachment portion  100 . The first transfer portion TP 1  according to one embodiment may include at least one first transfer robot for loading each of the cover window  10  and the display panel  31  in the first attachment portion  100  by using a loading arm that includes a pick-up unit. 
     An adhesive sheet (or an adhesive member)  20  is attached to a front surface of the display panel  31  picked up in the first transfer portion TP 1 . In this case, one surface of the adhesive sheet  20  is attached to the functional film  31   g  of the display panel  31 , and the other surface of the adhesive sheet  20  is covered by a protective film (or delamination film). The display panel  31  to which the adhesive sheet  20  is attached may be categorized (or divided) into a second adhesive surface having a first adhesive surface to be attached to the flat window  11  of the cover window  10 , and at least one edge adhesive surface to be attached to the curved window  13  of the cover window  10 . The second adhesive surface (A 2  as shown in  FIG. 7 ) has a greater area than the first adhesive surface (A 1  as shown in  FIG. 5 ). The second adhesive surface may be between a first edge adhesive surface and a second edge adhesive surface. The first adhesive surface of the display panel  31  may be overlapped with a middle portion of the display panel  31 , the second adhesive surface of the display panel  31  may be overlapped with a flat display portion, and the edge adhesive surface of the display panel  31  may be overlapped with a bending display portion. 
     The first attachment portion  100  is loaded with each of the display panel  31  and the cover window  10  from the first transfer portion TP 1 , and therefore attaches (or pre-attaches) the first adhesive surface of the display panel  31  to one portion of the cover window  10 . At this stage, not all portions of the second adhesive surface of the display panel  31  may be attached yet (or contacted) to the inner surface of the cover window  10 . 
     The first attachment portion  100  according to one embodiment may align a position of the cover window  10  and a position of the display panel  31 , which are loaded from the first transfer portion TP 1 , delaminate or peel the protective film of the adhesive sheet attached to the display panel  31 , and then attach (or pre-attach) the first adhesive surface of the display panel  31  to one portion of the cover window  10 . The first adhesive surface of the display panel  31  and one portion of the cover window  10  may be parallel or aligned with a long-side length direction (or second direction Y) of the display panel  31 . One portion of the cover window  10  according to one embodiment may be one portion of the flat window  11 , for example, middle portion. In this case, the first adhesive surface of the display panel  31  and the middle portion of the cover window  10  may be arranged at a middle portion of a short-side length direction of the display panel  31  in parallel or aligned with a second direction Y. The first attachment portion  100  may attach (or pre-attach) the first adhesive surface of the display panel  31  to one portion of the cover window  10  in the atmosphere of a normal pressure. 
     The second transfer portion TP 2  draws (or unloads) the cover window  10  to which the first adhesive surface of the display panel  31  is attached, out of the first attachment portion  100  and loads the cover window  10  in the second attachment portion  300 . The second transfer portion TP 2  according to one embodiment may include a second transfer robot for picking up the cover window  10  to which the first adhesive surface of the display panel  31  is attached, from the first attachment portion  100  by using a loading arm that includes a pick-up unit and loading the picked-up cover window  10  in the second attachment portion  300 . For example, the second transfer robot may pick up the cover window  10  by vacuum adsorbing the rear surface of the display panel  31  overlapped with the first adhesive surface of the display panel  31  attached to one portion of the cover window  10  through the pick-up unit. In this case, the pick-up unit of the second transfer robot may vacuum adsorb the rear surface of the back plate BP overlapped with the first adhesive surface of the display panel  31 . 
     The second attachment portion  300  is loaded with the cover window  10  to which the first adhesive surface of the display panel  31  is attached, from the second transfer portion TP 2 , and therefore attaches (or pre-attaches) the second adhesive surface (A 2  as shown in  FIG. 7 ) of the display panel  31  to at least a part of or the entire flat window. In this case, the edge adhesive surface of the display panel  31  may not yet be attached to the curved window  13  of the cover window  10 , and an edge end of the display panel  31  may be in contact with the sidewall SW of the curved window  13  in a non-attachment state. 
     The second attachment portion  300  according to one embodiment may align a position of the cover window  10  loaded from the second transfer portion TP 2 , pressurize (or compress) the second adhesive surface of the display panel  31  and attach (pre-attach) the second adhesive surface of the display panel  31  to the flat window  11  of the cover window  10 . Therefore, the second adhesive surface including the first adhesive surface (and not the edge adhesive surface of the display panel  31 ) may be attached to at least a part of or the entire flat window  11  of the cover window  10 . The second attachment portion  300  may attach the second adhesive surface of the display panel  31  to at least a part of or the entire flat window  11  of the cover window  10  in the atmosphere of a normal pressure. 
     The third transfer portion TP 3  draws (or unloads) the cover window  10  to which the second adhesive surface of the display panel  31  is attached, out of the second attachment portion  300  and loads the cover window  10  in a 3D attachment portion  500 . The third transfer portion TP 3  according to one embodiment may include a third transfer robot for picking up the cover window  10  to which the second adhesive surface of the display panel  31  is attached, from the second attachment portion  300  by using a loading arm that includes a pick-up unit and loading the picked-up cover window  10  in the 3D attachment portion  500 . For example, the third transfer robot may pick up the cover window  10  by vacuum adsorbing the rear surface of the display panel  31  overlapped with the second adhesive surface of the display panel  31  attached to the flat window  11  of the cover window  10  through the pick-up unit. In this case, the pick-up unit of the third transfer robot may vacuum adsorb the rear surface of the back plate BP overlapped with the second adhesive surface of the display panel  31 . 
     The 3D attachment portion  500  is loaded with the cover window  10  to which the second adhesive surface of the display panel  31  is attached, from the third transfer portion TP 3 , and therefore attaches (or pre-attaches) the edge adhesive surface of the display panel  31  to at least a part of or the entire curved window  13  of the cover window  10 . 
     The 3D attachment portion  500  according to one embodiment may align a position of the cover window  10  loaded from the third transfer portion TP 3 , pressurize (or compress) the edge adhesive surface of the display panel  31 , and attach (or pre-attach) the edge adhesive surface of the display panel  31  to the curved window  13  of the cover window  10 . Therefore, the edge adhesive surface of the display panel  31  may be attached to the curved window  13  of the cover window  10  and therefore bonded to the inner surface of the cover window  10 . 
     The 3D attachment portion  500  according to one embodiment may perform an attachment process between the edge adhesive surface of the display panel  31  and the curved window  13  of the cover window  10  in the atmosphere of vacuum. For example, since the curved window  13  of the cover window  10  includes a 3D shape having a curved portion CP and a sidewall SW, if the attachment process is performed in the atmosphere of a normal pressure and not the atmosphere of vacuum, bubbles may be generated between the curved portion CP of the curved window  13  and the edge adhesive surface of the display panel  31  or in the adhesive sheet  20 , whereby a process defect may be generated due to an uneven bonding between the curved window  13  and the edge adhesive surface of the display panel  31 . 
     The manufacturing apparatus of the flexible display apparatus according to one embodiment of the present disclosure may further include a fourth transfer portion TP 4  and a hardening portion  700 . 
     The fourth transfer portion TP 4  draws (or unloads) the cover window  10  to which the adhesive surfaces of the display panel  31  are each attached, out of the 3D attachment portion  500  and loads the cover window  10  in the hardening portion  700 . The fourth transfer portion TP 4  according to one embodiment may include a fourth transfer robot for picking up the cover window  10  to which the display panel  31  is fully attached, from the 3D attachment portion  500  by using a loading arm that includes a pick-up unit and loading the picked-up cover window  10  in the hardening portion  700 . For example, the fourth transfer robot may pick up the cover window  10  by vacuum adsorbing the rear surface of the display panel  31  attached to the inner surface of the cover window  10  through the pick-up unit. In this case, the pick-up unit of the fourth transfer robot may vacuum adsorb the rear surface of the back plate BP. 
     The hardening portion  700  is loaded with the cover window  10  to which the display panel  31  is fully attached, from the fourth transfer portion TP 4 , and therefore hardens the adhesive sheet  20  interposed between the display panel  31  and the cover window  10 . The hardening portion  700  according to one embodiment may include a retransfer tray for supporting the cover window  10  loaded from the fourth transfer portion TP 4 , a retransfer conveyer belt for continuously transferring the retransfer tray, and a light irradiation unit arranged on and/or below the retransfer conveyer belt. 
     The manufacturing apparatus of the flexible display apparatus according to one embodiment of the present disclosure described as above may uniformly bond the cover window  10  having the 3D shape to the display panel  31  without bubbles or with reduced bubbles between the display panel  31  and the cover window  10  of the 3D shape by sequentially (or individually) attaching the display panel  31  to each of the flat window  11  and the curved window  13  of the cover window  10  through a separate local attachment process. Particularly, the manufacturing apparatus of the flexible display apparatus according to one embodiment of the present disclosure may uniformly bond the display panel  31  to the inner surface of the cover window  10  of which both edges have a shape of a specific angle or more, without bubbles or with reduced bubbles by pressurizing the edge adhesive surface of the display panel  31  in a shape that follows the 3D shape of the curved widow  13  by a local attachment process through the 3D attachment portion using an elastic deformation pad that follows the 3D shape of the curved window  13  and without using a diaphragm mode. Therefore, in the present disclosure, bonding quality between the cover window  10  and the display panel  31  may be improved, whereby productivity and yield of the electronic device including the flexible display apparatus may be improved. 
       FIG. 5  is a view illustrating a first attachment portion according to one embodiment shown in  FIG. 4 . 
     Referring to  FIG. 5  together with  FIG. 4 , the first attachment portion  100  according to one embodiment of the present disclosure may include a first window supporting stage  110 , a panel supporting stage  130 , and a first attachment unit  150 . 
     The first window supporting stage  110  may support the cover window  10  loaded from the first transfer portion TP 1 . The first window supporting stage  110  according to one embodiment may include a first window supporting groove  111  corresponding to a 3D shape of the cover window  10  and a plurality of window adsorption holes arranged on the bottom of the first window supporting groove  111 . The first window supporting stage  110  may vacuum adsorb the cover window  10  supported in the first window supporting groove  111  through the plurality of window adsorption holes. In this case, the front surface of the cover window  10  may be in contact with the bottom of the first window supporting groove  111 , and the inner surface (or panel bonding surface) of the cover window  10  may directly face an upper portion of the first window supporting stage  110  or the panel supporting stage  130 . For example, the cover window  10  may be supported in the first window supporting stage  110  in a state that the front surface and the inner surface are inverted up and down. The first window supporting stage  110  may be expressed as a window adsorption stage or window clamp stage. 
     The panel supporting stage  130  may support the rear surface of the display panel  31  loaded from the first transfer portion TP 1 . The panel supporting stage  130  according to one embodiment may include a plurality of panel adsorption holes arranged on a panel support surface facing the first window supporting stage  110  and a pad through hole  131  overlapped with the first adhesive surface A 1  of the display panel  31  and/or one portion of the cover window  10 . The panel supporting stage  130  may vacuum adsorb the rear surface of the display panel  31  loaded from the first transfer portion TP 1  through the plurality of panel adsorption holes. In this case, the rear surface of the display panel  31 , for example, the back plate of the display panel  31  may be supported by being adsorbed in the panel adsorption holes, and the front surface of the display panel  31  may face or directly face the first window supporting stage  110 . A protective film PF of the adhesive sheet may be arranged on a forefront surface of the display panel  31  loaded from the first transfer portion TP 1 . 
     The pad through hole  131  (or pad through opening  131 ) may have a width wider than a first width W 1  of the first adhesive surface A 1  defined in the display panel  31  in a first direction X. Also, the pad through hole  131  may have a length equal to or longer than a long side length of the display panel  31  in a second direction Y. For example, the pad through hole  131  may be formed by vertically passing through the panel supporting stage  130  to have a rectangular shape including a pair of short-sides in (e.g., parallel with) the first direction X and a pair of long-sides in (e.g., parallel with) the second direction Y on a plane. 
     The first attachment unit  150  may attach the first adhesive surface A 1  of the display panel to one portion of the flat window  11  by passing through the panel supporting stage  130 . The first attachment unit  150  according to one embodiment may include a first pressurizing pad  151 , a first pad supporting block  153 , and a first pad lifting unit  155 . 
     The first pressurizing pad (or first pre-attachment pad)  151  may attach the first adhesive surface A 1  of the display panel  31  supported in the panel supporting stage  130  to one portion of the flat window  11  by passing through the pad through hole  131  provided in the panel supporting stage  130 . The first pressurizing pad  151  may be an elastic pad or elastic deformation pad, but is not limited thereto. 
     The first pressurizing pad  151  according to one embodiment may be configured to be inserted into the pad through hole  131  provided in the panel supporting stage  130 . For example, the first pressurizing pad  151  may have a bar shape including a width narrower than the width of pad through hole  131  and the same as the first width W 1  of the first adhesive surface A 1  defined in the display panel  31  and a length shorter than the length of the pad through hole  131 . An upper surface of the first pressurizing pad  151  may be fixed to the first pad supporting block  153 . A lower surface of the first pressurizing pad  151  is a panel pressurizing surface  151   a  for pressurizing the first adhesive surface A 1  of the display panel  31  and may have a convex curved shape. 
     The first pressurizing pad  151  according to one embodiment may be made of an elastic material at least partially deformed to prevent or mitigate any damage or scratch of the display panel  31  from occurring during a contact with the display panel  31 . For example, the first pressurizing pad  151  may include at least one of polymer silicon, urethane rubber, and synthetic resin. The first pressurizing pad  151  made of such an elastic material may pressurize the first adhesive surface A 1  of the display panel  31  to one portion of the flat window  11  while being elastically deformed in accordance with a direct contact with the rear surface of the display panel  31  overlapped with the first adhesive surface A 1  of the display panel  31 . 
     The first pad supporting block (or the first pad stage)  153  may support the first pressurizing pad  151 . The first pad supporting block  153  according to one embodiment may include a metal material. For example, the first pad supporting block  153  may include an aluminum material. 
     The first pad lifting unit  155  may support the first pad supporting block  153  to lift the first pad supporting block  153 . The first pad lifting unit  155  according to one embodiment may include a pneumatic cylinder or hydraulic cylinder having a pad lifting axis  156  coupled with the first pad supporting block  153 . 
     The first attachment unit  150  according to one embodiment may further include a coating layer formed on the panel pressurizing surface  151   a  of the first pressurizing pad  151 . The coating layer may prevent or mitigate damage or scratch of the display panel  31  occurring due to a physical contact between the panel pressurizing surface  151   a  and the display panel  31  by reducing friction between the panel pressurizing surface  151   a  and the display panel  31  and may facilitate detachment between the first pressurizing pad  151  and the display panel  31 . The coating layer according to one embodiment may be made of a material having a friction coefficient of 0.05 to 0.1, and may be made of a material having the same elastic rate as that of the first pressurizing pad  151  or an elastic ratio of 200 to 400. For example, the coating layer may include polytetrafluoroethylene (PTFE) having an elastic rate of 200 to 400 and a friction coefficient of 0.05 to 0.1. 
     The first attachment portion  100  according to one embodiment of the present disclosure may further include a stage driving unit  170 . 
     The stage driving unit  170  may include a first alignment stage  171  and a first stage lifting unit  173 . 
     The first alignment stage  171  supports the panel supporting stage  130  and the first attachment unit  150 , and aligns a position of the display panel  31  supported in the panel supporting stage  130  and a position of the cover window  10  supported in the first window supporting stage  110 . For example, the first alignment stage  171  may support the panel supporting stage  130  through a plurality of support members  172  and support the first attachment unit  150 . In this case, the first pad lifting unit  155  of the first attachment unit  150  may be arranged between the first alignment stages  171  and therefore coupled with a lower surface of the first alignment stage  171 , and the first pressurizing pad  151  may be arranged on the pad through hole  131  provided in the panel supporting stage  130 . 
     The first alignment stage  171  according to one embodiment may be configured as a UVW stage, e.g., configured to adjusted in the X, Y, and Z directions using motors. The first alignment stage  171  aligns the position of the display panel  31  and the position of the cover window  10  by simultaneously moving the panel supporting stage  130  and the first attachment unit  150  in the X-axis direction and/or Y-axis direction. Since the UVW stage has elements known in the art, its detailed description will be omitted. 
     The first stage lifting unit  173  may lower or raise the first alignment stage  171  in accordance with an attachment process order. For example, the first stage lifting unit  173  may include a pneumatic cylinder or hydraulic cylinder having a stage lifting axis  174  provided in a ceiling frame of a base frame provided in the first attachment portion  100  and coupled with the first alignment stage  171 . 
     The first attachment portion  100  according to one embodiment of the present disclosure may further include a film delamination unit  190 . 
     The film delamination unit  190  is loaded in the first attachment portion  100  from the first transfer portion TP 1  and delaminates or peels the protective film PF of the adhesive sheet attached to the display panel  31  supported in the panel supporting stage  130 . The film delamination unit  190  according to one embodiment may include a clamp unit  191  and a clamp transfer unit  193 . 
     The clamp unit  191  may clamp a delamination grip provided in the protective film PF of the adhesive sheet attached to the display panel  31  if the panel supporting stage  130  of the display panel  31  is supported by the first transfer portion TP 1  and aligned with the cover window  10 . The clamp unit  191  according to one embodiment may include a clamp for clamping the delamination grip of the protective film PF and a clamp lifting unit for lifting the clamp so that the clamp can clamp the delamination grip. 
     The clamp transfer unit  193  delaminates or peels the protective film PF clamped in the clamp unit  191  from the display panel  31  by horizontally moving the clamp unit  191  in the first direction X. The clamp transfer unit  193  according to one embodiment may include a linear motor, a pneumatic cylinder, or a hydraulic cylinder. Optionally, the clamp transfer unit  193  may be configured to horizontally move the clamp unit  191  in the second direction Y. For example, if the clamp unit  191  clamps the delamination grip of the protective film PF by the horizontal movement and the lifting, the clamp transfer unit  193  moves the clamp unit  191  horizontally in the first direction X so that the protective film PF may be delaminated or peeled from the display panel  31  by the horizontal movement of the clamp unit  191 .  FIGS. 6A, 6B, and 6C  are views illustrating an attachment process of a first attachment portion according to one embodiment of the present disclosure. 
     The attachment process of the first attachment portion according to one embodiment of the present disclosure will be described with reference to  FIGS. 6A to 6C . 
     The first window supporting stage  110  adsorbs and supports the cover window  10  loaded from the first transfer portion TP 1 . The panel supporting stage  130  adsorbs and supports the display panel  31  loaded from the first transfer portion TP 1  in a state that it raises to a panel loading position in accordance with driving of the stage driving unit  170 . 
     The stage driving unit  170  aligns the position of the display panel  31  supported in the panel supporting stage  130  and the position of the cover window  10  supported in the first window supporting stage  110  by moving the panel supporting stage  130  in the X-axis direction and/or Y-axis direction through driving of the first alignment stage  171 . 
     As shown in  FIG. 6A , the film delamination unit  190  clamps the delamination grip provided in the protection film PF of the adhesive sheet attached to the display panel  31  through the clamp unit  191 , and delaminates or peels the protective film PF clamped in the clamp unit  191  from the display panel  31  by horizontally moving the clamp unit  191  through driving of the clamp transfer unit  193 . 
     Optionally, the delamination process of the protection film PF may be performed before the alignment process between the display panel  31  and the cover window  10 . 
     As shown in  FIG. 6B , the stage driving unit  170  lowers the panel supporting stage  130  to a pre-attachment process position set on the first window supporting stage  110 . Subsequently, the first attachment unit  150  pressed or attaches the first adhesive surface A 1  of the display panel  31  to one portion of the flat window  11  of the cover window  10  supported in the first window supporting stage  110  through the first pressurizing pad  151  by descending the first pad supporting block  153  through driving of the first pad lifting unit  155 . In this case, the first pressurizing pad  151  may press or attach the first adhesive surface A 1  of the display panel  31  to one portion of the flat window  11  by pressurizing the rear surface of the display panel  31  overlapped with the first adhesive surface A 1  of the display panel  31  supported in the panel supporting stage  130  by passing through the pad through hole  131  of the panel supporting stage  130  in accordance with descending of the first pad supporting block  153 . Therefore, the first adhesive surface A 1  of the display panel  31  may be pressed or attached to one portion of the flat window  11  by a pressurizing pressure according to elastic deformation of the first pressurizing pad  151 . 
     As shown in  FIG. 6C , the panel supporting stage  130  freely drops the adsorbed display panel  31  by releasing vacuum adsorption, whereby an end of the edge adhesive surface of the display panel  31  adsorbed to the panel supporting stage  130  may freely be dropped (e.g., by gravity) onto an end of the curved window  13  of the cover window  10  in accordance with self-weight. In this case, the end of the edge adhesive surface of the display panel  31  may be in contact with the end of the curved window  13  in a non-attachment state, e.g., where at least one curvature portion of the display panel  31  is not yet attached or bonded to the cover window  10 . 
     The stage driving unit  170  raises the panel supporting stage  130  connected to the first alignment stage  171  to a panel unloading position (or home position) of the panel supporting stage  130  connected to the first alignment stage  171 . The first attachment unit  150  returns the first pressurizing pad  151  to the home position by raising the first pad supporting block  153  through driving of the first pad lifting unit  155 . In this case, the first attachment portion  100  may return the first pressurizing pad  151  to the home position while the panel supporting stage  130  is returning to the home position, to reduce a process time. 
       FIG. 7  is a view illustrating a second attachment portion according to one embodiment shown in  FIG. 4 . 
     Referring to  FIG. 7  together with  FIG. 4 , the second attachment portion  300  according to one embodiment of the present disclosure may include a second window supporting stage  310  and a second attachment unit  350 . 
     The second window supporting stage  310  may support the cover window  10  to which the first adhesive surface A 1  of the display panel is attached loaded from the second transfer portion TP 2 . The second window supporting stage  310  according to one embodiment may include a second window supporting groove  311  corresponding to a 3D shape of the cover window  10  and a plurality of window adsorption holes arranged on the bottom of the second window supporting groove  311 . The second window supporting stage  310  may vacuum adsorb the cover window  10  supported in the second window supporting groove  311  through the plurality of window adsorption holes. In this case, the front surface of the cover window  10  may be in contact with the bottom of the second window supporting groove  311 , and the display panel  31  attached to one portion of the cover window  10  may face or directly face the second attachment unit  350 . 
     The second attachment unit  350  may press or attach the second adhesive surface A 2  of the display panel  31 , of which first adhesive surface A 1  is attached to one portion of the flat window  11  of the cover window  10 , to at least a part of or the entire flat window  11 . The second attachment unit  350  according to one embodiment may include a second pressurizing pad  351 , a second pad supporting block  353 , and a second pad lifting unit  355 . 
     The second pressurizing pad (or second pre-attachment pad)  351  may press or attach the second adhesive surface A 2  of the display panel  31 , of which first adhesive surface A 1  is attached to one portion of the flat window  11  of the cover window  10 , to at least a part of or the entire flat window  11 . 
     The second pressurizing pad  351  according to one embodiment may be configured to have a size overlapped with at least a part of or the entire flat window  11 . For example, the second pressurizing pad  351  may have a bar shape including a second width W 2  and length of the second adhesive surface defined in the display panel  10 . An upper surface of the second pressurizing pad  351  may be fixed to the second pad supporting block  353 . A lower surface of the second pressurizing pad  351  is a panel pressurizing surface  351   a  for pressurizing the second adhesive surface A 2  of the display panel  31  and may have a convex curved shape. 
     The second pressurizing pad  351  according to one embodiment may be made of an elastic material at least partially deformed to prevent or mitigate any damage or scratch of the display panel  31  from occurring during a contact with the display panel  31 . For example, the second pressurizing pad  351  may include at least one of polymer silicon, urethane rubber, and synthetic resin. The second pressurizing pad  351  made of such an elastic material may pressurize the second adhesive surface A 2  of the display panel  31  to at least a part of or the entire flat window  11  while being elastically deformed in accordance with a direct contact with the rear surface of the display panel  31  overlapped with the second adhesive surface A 2  of the display panel  31 . As another example, the second pressurizing pad  351  may be made of the same elastic material as that of the first pressurizing pad  151  of the first attachment portion  100 . The second pressurizing pad  351  may be an elastic pad or elastic deformation pad, but is not limited thereto. 
     The second pad supporting block (or the second pad stage)  353  may support the second pressurizing pad  351 . The second pad supporting block  353  according to one embodiment may include a metal material. For example, the second pad supporting block  353  may include an aluminum material. 
     The second pad lifting unit  355  may support the second pad supporting block  353  to lift the second pad supporting block  353 . The second pad lifting unit  355  according to one embodiment may include a pneumatic cylinder or hydraulic cylinder having a pad lifting axis  356  coupled with the second pad supporting block  353 . 
     The second attachment unit  350  according to one embodiment may further include a first pad shape guide block  357 . 
     The first pad shape guide block (or a first pad shape guider)  357  may be arranged at a lower edge area of the second pad supporting block  353  to surround an upper portion of the second pressurizing pad  351 . The first pad shape guide block  357  may prevent or mitigate any deformation of upper portion of the second pressurizing pad  351  from occurring by surrounding upper sides of the second pressurizing pad  351  adjacent to a lower surface of the second pad supporting block  353 . Therefore, when the second pressurizing pad  351  pressurizes the display panel  31 , a pressurizing surface  351   a  of the second pressurizing pad  351  and its periphery may elastically be deformed in accordance with a contact with the display panel  31 . 
     The second attachment unit  350  according to one embodiment may further include a coating layer formed on the panel pressurizing surface  351   a  of the second pressurizing pad  351 . 
     The second attachment portion  300  according to one embodiment of the present disclosure may further include a second alignment stage  371 . 
     The second alignment stage  371  supports the second attachment unit  350 , and aligns a position of the second pressurizing pad  351  with a position of the cover window  10  supported in the second window supporting stage  310 . For example, the second alignment stage  371  may be coupled with the second pad lifting unit  355  of the second attachment unit  350 . 
     The second alignment stage  371  according to one embodiment may be configured as a UVW stage. The second alignment stage  371  may align the position of the second pressurizing pad  351  with the position of the cover window  10  by moving the second attachment unit  350  in the X-axis direction and/or Y-axis direction. Since the UVW stage has elements known in the art, its detailed description will be omitted. 
     In some embodiments, if the second pressurizing pad  351  is only lowered or raised on an alignment position set on the second window supporting stage  310 , the second alignment stage  371  may be omitted. 
       FIGS. 8A and 8B  are views illustrating an attachment process of a second attachment portion according to one embodiment of the present disclosure, which is shown in  FIG. 7 . 
     The attachment process of the second attachment portion according to one embodiment of the present disclosure will be described with reference to  FIGS. 8A and 8B . 
     The second window supporting stage  310  adsorbs and supports the cover window  10  to which the first adhesive surface A 1  of the display panel  31  is attached loaded from the second transfer portion TP 2 . 
     The second alignment stage  371  is driven to align the position of the second pressurizing pad  351  with the position of the cover window  10  supported in the second window supporting stage  310  by moving the second pad lifting unit  355  of the second attachment unit  350  in the X-axis direction and/or Y-axis direction. 
     As shown in  FIG. 8A , the second attachment unit  350  presses or attaches the second adhesive surface A 2  of the display panel  31  to at least a part of or the entire flat window  11  of the cover window  10  supported in the second window supporting stage  310  through the second pressurizing pad  351  by descending the second pad supporting block  353  through driving of the second pad lifting unit  355 . In this case, the second pressurizing pad  351  may press or attach the second adhesive surface A 2  of the display panel  31  to at least a part of or the entire flat window  11  by pressurizing the rear surface of the display panel  31  overlapped with the second adhesive surface A 2  of the display panel  31  in accordance with descending of the second pad supporting block  353 . Therefore, the second adhesive surface A 2  of the display panel  31  may be attached to at least a part of or the entire flat window  11  by a pressurizing pressure according to elastic deformation of the second pressurizing pad  351 . At this time, the edge adhesive surface of the display panel  31  is not pressurized by the second pressurizing pad  351 , the edge adhesive surface is not attached to the curved window  13  of the cover window  10 , and the edge end of the display panel  31  may be in contact with the sidewall SW of the curved window  13  in a non-attachment state. 
     As shown in  FIG. 8B , the second attachment unit  350  raises the second pressurizing pad  351  to the panel unloading position (or home position) by raising the second pad supporting block  353  to the home position through driving of the second pad lifting unit  355 . 
       FIG. 9  is a view illustrating a 3D attachment portion according to one embodiment shown in  FIG. 4 , and  FIG. 10  is a perspective view illustrating a 3D pressurizing pad shown in  FIG. 9 , in which the structure of the 3D pressurizing pad shown in  FIG. 7  is modified. 
     Referring to  FIGS. 9 and 10  together with  FIGS. 2 to 4 , the 3D (three-dimensional) attachment portion (or a third attachment portion)  500  according to one embodiment of the present disclosure may include a window supporting member  510  and a 3D attachment unit  550 . 
     The window supporting member  510  may support the cover window  10  to which the second adhesive surface A 2  of the display panel  31  is attached loaded from the third transfer portion TP 3 . The window supporting member  510  according to one embodiment may include a third window supporting groove  511  corresponding to the 3D shape of the cover window  10  and a plurality of window adsorption holes arranged on the bottom of the third window supporting groove  511 . The window supporting member  510  may vacuum adsorb the cover window  10  supported in the third window supporting groove  511  through the plurality of window adsorption holes. In this case, the front surface of the cover window  10  may be in contact with the bottom of the third window supporting groove  511 , and the display panel  10  of which other adhesive surface A 2  is attached to at least a part of or the entire flat window  11  of the cover window  10  may face or directly face the 3D attachment unit  550 . 
     The 3D attachment unit  550  may press or attach the edge adhesive surface A 3  of the display panel (of which second adhesive surface A 2  is attached to at least a part of or the entire flat window  11  of the cover window  10 ) to the curved window  13  of the cover window  10 . The 3D attachment unit  550  according to one embodiment may include a 3D pressurizing pad  551 , a 3D pad supporting block  553 , and a 3D pad lifting unit  555 . 
     The 3D pressurizing pad (or second pre-attachment pad)  551  may press or attach the edge adhesive surface A 3  of the display panel  31  (of which second adhesive surface A 2  is attached to at least a part of or the entire flat window  11  of the cover window  10 ) to the curved window  13  of the cover window  10 . The 3D pressurizing pad  551  may be made of an elastic material at least partially deformed to prevent or mitigate any damage or scratch of the display panel  31  from occurring during a contact with the display panel  31 . For example, the 3D pressurizing pad  551  may include at least one of polymer silicon, urethane rubber, and synthetic resin. The 3D pressurizing pad  551  made of such an elastic material may locally pressurize the edge adhesive surface A 3  of the display panel  31  to the curved window  13  while being elastically deformed in accordance with a direct contact with the edge portion (or bending display portion) of the display panel  31  overlapped with the edge adhesive surface A 3  of the display panel  31 . As another example, the 3D pressurizing pad  551  may be made of the same elastic material as that of the first pressurizing pad  151  of the first attachment portion  100  and/or the second pressurizing pad  351  of the second attachment portion  300 . 
     The second pressurizing pad  551  according to one embodiment may include a pad body  551   a , a first pressurizing portion  551   b , and a second pressurizing portion  551   c.    
     The pad body  551   a  may be configured to have a size overlapped with the inner surface of the cover window  10 . For example, the pad body  551   a  may have a plate shape having a third width W 3  corresponding to a distance between the first curved portion  13   a  and the second curvature portion  13   b  of the cover window  10  and a length L corresponding to a long-side length of the cover window  10 . 
     The first pressurizing portion  551   b  may be protruded from a rear side RS 1  of the pad body  551   a  to have a varying thickness (e.g., an asymmetrical structure up and down from side to side based on the first direction X) and may pressure one side edge (or one side edge adhesive surface) of the display panel  31  to the first curved portion  13   a  of the cover window  10 . The first pressurizing portion  551   b  may not pressure the other side edge or the first adhesive surface of the display panel  31 . 
     The first pressurizing portion  551   b  according to one embodiment may include a first convex surface CS 1  and a first slope surface SS 1 . The first pressurizing portion  551   b  may have a triangular (e.g., a right-angled triangle) cross-sectional structure having the first convex surface CS 1  as a vertex and the first slope surface SS 1  as an oblique side. For example, the first pressurizing portion  551   b  may have a right-angled triangle sectional structure, on the basis of a second plane configured by the first direction X and a height direction Z, with the projection of first convex surface CS 1  on the second plane as a vertex and the projection of the first slope surface SS 1  on the second plane as an oblique. 
     The first convex surface CS 1  may include a curved shape corresponding to a curved shape of the curved portion CP that forms the first curvature portion  13   a  of the cover window  10 . As an example, the first convex surface CS 1  may have a curved shape section having at least one curvature. For example, the projection of the first convex surface CS 1  on the second plane may have a curved shape section having at least one curvature. As another example, the first convex surface CS 1  may have a concentric circle shaped section with the curved portion CP of the first curvature portion  13   a . For example, the projection of the first convex surface CS 1  on the second plane may have a concentric circle shape with the projection of the curved portion CP of the first curvature portion  13   a  on the second plane when the first convex surface CS 1  is in contact with the curved portion CP. Thus, the first convex surface CS 1  may locally pressurize one side edge of the display panel  31  to the first curvature portion  13   a  and therefore press or attach one edge adhesive surface A 3   a  of the display panel  31  to the first curvature portion  13   a  of the cover window  10 . 
     The first slope surface SS 1  may be formed with a slope between the first convex surface CS 1  and a middle portion of the pad body  551   a . The first slope surface SS 1  may be formed with a slope between the first convex surface CS 1  and the pad body  551   a  such that a pressurizing force of the first pressurizing portion  551   b  may locally be transferred to one side edge of the display panel  31  (and not the other side edge or the first adhesive surface of the display panel  31 ) through the first convex surface CS 1 . 
     The second pressurizing portion  551   c  may be protruded from the other rear side RS 2  of the pad body  551   a  to have a varying thickness (e.g., an asymmetrical structure up and down from side to side based on the first direction X) and may pressure another side edge (or one side edge adhesive surface) of the display panel  31  to the second curvature portion  13   b  of the cover window  10 . The second pressurizing portion  551   c  may not pressure the side edge (pressed by the first pressurizing portion  551   b ) or the first adhesive surface of the display panel  31 . 
     The second pressurizing portion  551   c  according to one embodiment may include a second convex surface CS 2  and a second slope surface SS 2 . The second pressurizing portion  551   c  may have a triangular (e.g., a right-angled triangle) cross-sectional structure having the second convex surface CS 2  as a vertex and the second slope surface SS 2  as an oblique side. For example, the second pressurizing portion  551   c  may have a right-angled triangle sectional structure, on the basis of the second plane with the projection of second convex surface CS 2  on the second plane as a vertex and the projection of the second slope surface SS 2  on the second plane as an oblique. The second pressurizing portion  551   c  may be configured to have a symmetrical structure with the first pressurizing portion  551   b  across an axis of symmetry through the middle portion of the pad body  551   a.    
     The second convex surface CS 2  may include a curved shape corresponding to a curved shape of the curved portion CP that forms the second curvature portion  13   b  of the cover window  10 . As an example, the second convex surface CS 2  may have a curved shape section having at least one curvature. For example, the projection of the second convex surface CS 2  on the second plane may have a curved shape section having at least one curvature. As another example, the second convex surface CS 2  may have a concentric circle shaped section with the curved portion CP of the second curvature portion  13   b . For example, the projection of the second convex surface CS 2  on the second plane may have a concentric circle shape with the projection of the curved portion CP of the second curvature portion  13   b  on the second plane when the second convex surface CS 2  is in contact with the curved portion CP. Thus, second convex surface CS 2  may locally pressurize another side edge of the display panel  31  to the second curvature portion  13   b  and therefore press or attach another edge adhesive surface A 3   b  of the display panel  31  to the second curvature portion  13   b  of the cover window  10 . 
     The second slope surface SS 2  may be formed with a slope between the second convex surface CS 2  and the middle portion of the pad body  551   a . The second slope surface SS 2  may be formed with a slope between the second convex surface CS 2  and the middle portion of the pad body  551   a  such that a pressurizing force of the second pressurizing portion  551   c  may locally be transferred to another side edge of the display panel  31  (and not the side edge pressed by the first pressurizing portion  551   b  or the first adhesive surface of the display panel  31 ) through the second convex surface CS 2 . 
     The 3D pressurizing pad  551  according to one embodiment may further include a groove portion  551   d  between the first pressurizing portion  551   b  and the second pressurizing portion  551   c.    
     The groove portion  551   d  may be formed to have a triangle shaped cross-sectional structure or “V” shaped cross-sectional structure between the first pressurizing portion  551   b  and the second pressurizing portion  551   c . For example, the groove portion  551   d  may have a triangle shaped sectional structure or “V” shaped sectional structure, on the basis of the second plane, with the first pressurizing portion  551   b  having the first convex surface CS 1  and the first slope surface SS 1  on the second plane as a first oblique and the second pressurizing portion  551   c  having the second convex surface CS 2  and the second slope surface SS 2  on the second plane as a second oblique. A cross-sectional area of the groove portion  551   d  may gradually be reduced toward the pad body  551   a . The groove portion  551   d  may provide a space for elastic deformation of each of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  when each of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  pressurizes the edge adhesive surfaces A 3   a  and A 3   b , respectively, of the display panel  31 . 
     The 3D pressurizing pad  551  according to one embodiment may further include a slit  551   e  arranged on the middle portion of the pad body  551   a  and formed to be recessed from the groove portion  551   d.    
     The slit  551   e  may be formed to be recessed between one side end of the first pressurizing portion  551   b  and one side end of the second pressurizing portion  551   c . The slit  551   e  may be formed to be recessed to have a certain size from a rear surface of the pad body  551   a  where ends of the first slope surface SS 1  of the first pressurizing portion  551   b  and the second slope surface SS 2  of the second pressurizing portion  551   c  meet. 
     The slit  551   e  according to one embodiment may have a semi-circular shaped cross-sectional structure of which one side is communicated with the groove portion  551   d . For example, the slit  551   e  may include an arc shape having a first curvature radius of 1.5 mm. As shown in the embodiment of  FIG. 13 , the center of the slit  551   e  may be arranged at ⅔ height H 2  of a height H 1  of the 3D pressurizing pad  551 , based on the upper surface of the 3D pressurizing pad  551 . 
     The slit  551   e  may be formed between the first pressurizing portion  551   b  and the second pressurizing portion  551   c  overlapped with the middle portion of the pad body  551   a  in the first direction X to prevent the pressurizing force of the 3D pressurizing pad  551  from being concentrated on any one of the first pressurizing portion  551   b  and the second pressurizing portion  551   c . Also, the slit  551   e  may provide a space where the ends of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  may elastically be deformed when the 3D pressurizing pad  551  is elastically deformed. In this case, if the slit  551   e  does not exist between the ends of the first pressurizing portion  551   b  and the second pressurizing portion  551   c , lifespan of the 3D pressurizing pad  551  may be reduced due to damage of the 3D pressurizing pad  551  resulting from a physical contact or overlap between the ends of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  when the 3D pressurizing pad  551  is elastically deformed. Optionally, the slit  551   e  may be expressed as an eccentric prevention member. 
     The 3D pad supporting block (or the second pad stage)  553  may support the 3D pressurizing pad  551 . The 3D pad supporting block  553  according to one embodiment may include a metal material. For example, the 3D pad supporting block  553  may include an aluminum material. 
     The 3D pad lifting unit  555  may support the 3D pad supporting block  553  to lift the 3D pad supporting block  553 . The 3D pad lifting unit  555  according to one embodiment may include a pneumatic cylinder or hydraulic cylinder having a pad lifting axis  556  coupled with the 3D pad supporting block  553 . 
     The 3D attachment unit  550  according to one embodiment may further include a second pad shape guide block  557 . 
     The second pad shape guide block (or a second pad shape guider)  557  may be arranged at a lower edge area of the 3D pad supporting block  553  to surround an upper portion of the 3D pressurizing pad  551 . The second pad shape guide block  557  may prevent or mitigate deformation of upper portion of the 3D pressurizing pad  551  from occurring by surrounding upper sides of the 3D pressurizing pad  551  adjacent to a lower surface of the 3D pad supporting block  553 . Therefore, when the 3D pressurizing pad  551  pressurizes the display panel  31 , pressurizing portions  551   b  and  551   c  of the 3D pressurizing pad  551  and periphery may elastically be deformed in accordance with a contact with the display panel  31 . 
     The 3D attachment unit  550  according to one embodiment may further include a coating layer formed on the 3D pressurizing pad  551 . 
     The 3D attachment portion  500  according to one embodiment of the present disclosure may further include a third alignment stage  571 . 
     The third alignment stage  571  supports the 3D attachment unit  550  and aligns a position of the 3D pressurizing pad  551  with a position of the cover window  10  supported in the window supporting member  510 . For example, the third alignment stage  571  may be coupled with the 3D pad lifting unit  555  of the 3D attachment unit  550 . 
     The 3D alignment stage  571  according to one embodiment may be configured as a UVW stage. The third alignment stage  571  may align the position of the 3D pressurizing pad  551  with the position of the cover window  10  by moving the 3D attachment unit  550  in the X-axis direction and/or Y-axis direction. Since the UVW stage has elements known to one skilled in the art, its detailed description will be omitted. 
     In some embodiments, if the 3D pressurizing pad  551  is only lowered or raised on an alignment position set on the window supporting stage  510 , the third alignment stage  571  may be omitted. 
       FIGS. 11A and 11B  are views illustrating an attachment process of a 3D attachment portion according to one embodiment of the present disclosure, which is shown in  FIGS. 9 and 10 . 
     The attachment process of the 3D attachment portion according to one embodiment of the present disclosure will be described with reference to  FIGS. 11A and 11B . 
     The window supporting member  510  adsorbs and supports the cover window  10  to which the second adhesive surface A 2  of the display panel  31  is attached loaded from the third transfer portion TP 3 . 
     The third alignment stage  571  is driven to align the position of the 3D pressurizing pad  551  and the position of the cover window  10  supported in the window supporting member  510  by moving the 3D pad lifting unit  555  of the 3D attachment unit  550  in the X-axis direction and/or Y-axis direction. 
     As shown in  FIG. 11A , the 3D attachment unit  550  presses or attaches the edge adhesive surfaces A 3   a  and A 3   b  of the display panel  31  to at least a part of or the entire curved window  13  of the cover window  10  supported in the window supporting member  510  through the 3D pressurizing pad  551  by descending the 3D pad supporting block  553  through driving of the 3D pad lifting unit  555 . In this case, the first pressurizing portion  551   b  of the 3D pressurizing pad  351  may be overlapped with one edge adhesive surface A 3   a  of the display panel  31  in accordance with descending of the 3D pad supporting block  553 . The first pressurizing portion  551   b  may elastically be deformed in accordance with a physical contact with one edge of the display panel  31  due to overlap between the first pressurizing portion  551   b  and the adhesive surface A 3   a . The first pressurizing portion  551   b  may press or attach one edge adhesive surface A 3   a  of the display panel  31  to the first curvature portion  13   a  of the curved window  13  by locally pressurizing one edge adhesive surface A 3   a  of the display panel  31  due to elastic deformation. At the same time, the second pressurizing portion  551   c  of the 3D pressurizing pad  551  may be overlapped with another edge adhesive surface A 3   b  of the display panel  31  in accordance with descending of the 3D pad supporting block  553 . The second pressurizing portion  551   c  may elastically be deformed in accordance with a physical contact with another edge of the display panel  31  due to overlap between the second pressurizing portion  551   c  and the adhesive surface A 3   b . The second pressurizing portion  551   c  may attach another edge adhesive surface A 3   b  of the display panel  31  to the second curvature portion  13   b  of the curved window  13  by locally pressurizing another edge adhesive surface A 3   b  of the display panel  31  due to elastic deformation. At this time, the first pressurizing portion  551   b  of the 3D pressurizing pad  551  may elastically be deformed to the same 3D shape as that of the first curvature portion  13   a  by the groove portion  551   d  and the slit  551   e . Likewise, the second pressurizing portion  551   c  of the 3D pressurizing pad  551  may elastically be deformed to the same 3D shape as that of the second curvature portion  13   b  by the groove portion  551   d  and the slit  551   e . Therefore, the edge adhesive surfaces A 3   a  and A 3   b  of the display panel  31  may be pressed or attached to each of the first curvature portion  13   a  and the second curvature portion  13   b  of the curved window  13 , respectively, by a local pressurizing pressure according to elastic deformation of each of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  of the 3D pressurizing pad  551 , respectively. 
     As shown in  FIG. 11B , the 3D attachment unit  550  raises the 3D pressurizing pad  551  to the panel unloading position (or home position) by raising the 3D pad supporting block  553  to the home position through driving of the 3D pad lifting unit  555 . 
     The window supporting member  510  releases vacuum adsorption for the cover window  10  bonded to the display panel  31 . Therefore, the cover window  10  supported in the window supporting member  510  and bonded to the display panel  31  may be unloaded from the 3D attachment portion  500  by the fourth transfer portion TP 4 , whereby the display panel  31  and the cover window  10  may be bonded. 
       FIG. 12  is a view illustrating a 3D attachment portion according to another embodiment shown in  FIG. 4 , and  FIG. 13  is a perspective view illustrating a 3D pressurizing pad shown in  FIG. 12 , in which the structure of the 3D pressurizing pad shown in  FIGS. 9 and 10  is modified. Therefore, in the following description, repeated description of the other elements except the 3D pressurizing pad and its related elements will be omitted. 
     Referring to  FIGS. 12 and 13  together with  FIGS. 2 to 4 , in the 3D pressurizing pad  551  of the 3D attachment portion  500  according to another embodiment of the present disclosure, the first pressurizing portion  551   b  may further include a first hollow surface HS 1 . 
     The first hollow surface HS 1  may be formed to be recessed between one side end of the pad body  551   a  and one end of the first convex surface CS 1 . 
     The first hollow surface HS 1  according to one embodiment may have a semi-circle shaped cross-sectional structure recessed from an outer side of the first pressurizing portion  551   b  adjacent to one side end of the pad body  551   a . The first hollow surface HS 1  may provide a space between one side end of the pad body  551   a  and the first convex surface CS 1 . The first hollow surface HS 1  according to another embodiment may include an arc shape having a second curvature radius greater than the first curvature radius of the slit  551   e . In this case, a horizontal line HL extended from the center of the first hollow surface HS 1  of the arc shape may pass through the center of the slit  551   e . Therefore, the first convex surface CS 1  may be locally and elastically deformed to have the same curved shape as that of the first curvature portion  13   a  of the curved window  13 . For this reason, the pressurizing force of the first pressurizing portion  551   b  may locally be transferred to one edge adhesive surface A 3   a  (and not another edge adhesive surface A 3   b ) of the display panel  31 , whereby uniform bonding between the first curvature portion  13   a  of the cover window  10  and one edge adhesive surface A 3   a  of the display panel  31  may be made. 
     In the 3D pressurizing pad  551  of the 3D attachment portion  500  according to another embodiment of the present disclosure, the second pressurizing portion  551   c  may further include a second hollow surface HS 2 . 
     The second hollow surface HS 2  may be formed to be recessed between the other side end of the pad body  551   a  and one end of the second convex surface CS 2 . 
     The second hollow surface HS 2  according to one embodiment may have a semi-circle shaped cross-sectional structure recessed from an outer side of the second pressurizing portion  551   b  adjacent to the other side end of the pad body  551   a . The second hollow surface HS 2  may provide a space between the other side end of the pad body  551   a  and the second convex surface CS 2 . The second hollow surface HS 2  according to another embodiment may include an arc shape having a second curvature radius greater than the first curvature radius of the slit  551   e . In this case, a horizontal line HL extended from the center of the second hollow surface HS 2  of the arc shape may pass through the center of the slit  551   e . Therefore, the second convex surface CS 2  may be locally and elastically deformed to have the same curved shape as that of the second curvature portion  13   b  of the curved window  13 . For this reason, the pressurizing force of the second pressurizing portion  551   c  may locally be transferred to another edge adhesive surface A 3   b  (and not edge adhesive surface A 3   a ) of the display panel  31 , whereby uniform bonding between the second curvature portion  13   b  of the cover window  10  and another edge adhesive surface A 3   b  of the display panel  31  may be made. 
     In the 3D pressurizing pad  551  according to this embodiment described as above, the first pressurizing portion  551   b  and the second pressurizing portion  551   c  may be configured to have a “V” shaped cross-sectional structure of which sides are recessed, while having a symmetrical structure across an axis of symmetry through the middle portion of the pad body  551   a.    
       FIGS. 14A and 14B  are views illustrating an attachment process of a 3D attachment portion according to another embodiment of the present disclosure, which is shown in  FIGS. 12 and 13 . 
     The attachment process of the 3D attachment portion according to another embodiment of the present disclosure will be described with reference to  FIGS. 14A and 14B  together with  FIGS. 12 and 13 . 
     The window supporting member  510  adsorbs and supports the cover window  10  to which the second adhesive surface A 2  of the display panel  31  loaded from the third transfer portion TP 3  is attached. 
     The third alignment stage  571  is driven to align the position of the 3D pressurizing pad  551  and the position of the cover window  10  supported in the window supporting member  510  by moving the 3D pad lifting unit  555  of the 3D attachment unit  550  in the X-axis direction and/or Y-axis direction. 
     As shown in  FIG. 14A , the 3D attachment unit  550  presses or attaches the edge adhesive surfaces A 3   a  and A 3   b  of the display panel  31  to at least a part of or the entire curved window  13  of the cover window  10  supported in the window supporting member  510  through the 3D pressurizing pad  551  by descending the 3D pad supporting block  553  through driving of the 3D pad lifting unit  555 . In this case, the first pressurizing portion  551   b  of the 3D pressurizing pad  551  may elastically be deformed in accordance with a physical contact with one edge of the display panel  31  overlapped with one edge adhesive surface A 3   a  of the display panel  31  in accordance with descending of the 3D pad supporting block  553 . For this reason, the first pressurizing portion  551   b  may attach one edge adhesive surface A 3   a  of the display panel  31  to the first curvature portion  13   a  of the curved window  13  by locally pressurizing one edge adhesive surface A 3   a  of the display panel  31 . At the same time, the second pressurizing portion  551   c  of the 3D pressurizing pad  551  may elastically be deformed in accordance with a physical contact with another edge of the display panel  31  overlapped with another edge adhesive surface A 3   b  of the display panel  31  in accordance with descending of the 3D pad supporting block  553 . For this reason, the second pressurizing portion  551   c  may attach another edge adhesive surface A 3   b  of the display panel  31  to the second curvature portion  13   b  of the curved window  13  by locally pressurizing another edge adhesive surface A 3   b  of the display panel  31 . At this time, the first pressurizing portion  551   b  of the 3D pressurizing pad  551  may elastically be deformed to the same 3D shape as that of the first curvature portion  13   a  by the groove portion  551   d , the slit  551   e , and the first hollow surface HS 1 . Likewise, the second pressurizing portion  551   c  of the 3D pressurizing pad  551  may elastically be deformed to the same 3D shape as that of the second curvature portion  13   b  by the groove portion  551   d , the slit  551   e , and the second hollow surface HS 2 . Therefore, the edge adhesive surface A 3  of the display panel  31  may be pressed or attached to each of the first curvature portion  13   a  and the second curvature portion  13   b  of the curved window  13  by a local pressurizing pressure according to elastic deformation of each of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  of the 3D pressurizing pad  551 , respectively. 
     As shown in  FIG. 14B , the 3D attachment unit  550  raises the 3D pressurizing pad  551  to the panel unloading position (or home position) by raising the 3D pad supporting block  553  to the home position through driving of the 3D pad lifting unit  555 . 
     The window supporting member  510  releases vacuum adsorption for the cover window  10  bonded to the display panel  31 . Therefore, the cover window  10  supported in the window supporting member  510  and bonded to the display panel  31  may be unloaded from the 3D attachment portion  500  by the fourth transfer portion TP 4 , whereby the display panel  31  and the cover window  10  may be bonded. 
       FIG. 15  is a view illustrating a 3D attachment portion according to other embodiment shown in  FIG. 4 , and  FIG. 16  is a perspective view illustrating a 3D pressurizing pad shown in  FIG. 15 , in which the structure of the 3D pressurizing pad shown in  FIGS. 9 and 10  is modified. Therefore, in the following description, repeated description of the other elements except the 3D pressurizing pad and its related elements will be omitted. 
     Referring to  FIGS. 15 and 16  together with  FIGS. 2 to 4 , the 3D pressurizing pad  551  of the 3D attachment portion  500  according to another embodiment of the present disclosure may further include a pad body  551   a , a first pressurizing portion  551   b , and a second pressurizing portion  551   c.    
     The pad body  551   a  may be configured to have a size overlapped with the inner surface of the cover window  10 . For example, the pad body  551   a  may have a plate shape having a third width W 3  corresponding to a distance between the first curved portion  13   a  and the second curvature portion  13   b  of the cover window  10  and a length L corresponding to a long side length of the cover window  10 . 
     The first pressurizing portion  551   b  may be protruded from a rear side RS 1  of the pad body  551   a  to have a varying thickness (e.g., an asymmetrical structure up and down from side to side based on the first direction X) and may pressure one side edge (or one side edge adhesive surface) of the display panel  31  to the first curved portion  13   a  of the cover window  10 . The first pressurizing portion  551   b  may not pressure the other side edge or the first adhesive surface of the display panel  31 . 
     The first pressurizing portion  551   b  according to one embodiment may include a first convex surface CS 1 , a first inner slope surface ISS 1 , and a first outer slope surface OSS 1 . For example, the first pressurizing portion  551   b  may be slanted and protruded from the rear side RS 1  of the pad body  551   a  to the first curvature portion  13   a  of the cover window  10 . 
     The first convex surface CS 1  may include a curved shape corresponding to a curved shape of the curved portion CP that forms the first curvature portion  13   a  of the cover window  10 . As an example, the first convex surface CS 1  may have a curved shape section having at least one curvature. As another example, the first convex surface CS 1  may have a concentric circle shaped section with the curved portion CP of the first curvature portion  13   a . The first convex surface CS 1  may locally pressurize one side edge of the display panel  31  to the first curvature portion  13   a  and therefore press or attach one edge adhesive surface A 3   a  of the display panel  31  to the first curvature portion  13   a  of the cover window  10 . 
     The first inner slope surface ISS 1  may be formed with a slope between the first convex surface CS 1  and the middle portion of the rear surface of the pad body  551   a . The first inner slope surface ISS 1  may be formed with a slope between the first convex surface CS 1  and the middle portion of the pad body  551   a  such that a pressurizing force of the first pressurizing portion  551   b  may locally be transferred to one side edge of the display panel  31  (and not the other side edge or the first adhesive surface of the display panel  31 ) through the first convex surface CS 1 . 
     The first outer slope surface OSS 1  may be formed with a slope between an end of the rear side RS 1  of the middle portion of the pad body  551   a  and one end of the first convex surface CS 1 . The first outer slope surface OSS 1  may be included within the range of 35° to 60° with respect to the rear surface of the pad body  551   a . That is, an angle between the first outer slope surface OSS 1  and the rear surface of the pad body  551   a  may range from 35° to 60°. For example, the angle between the first outer slope surface OSS 1  and the rear surface of the pad body  551   a  may be set to 45° such that the pressurizing force of the first convex surface CS 1  may be transferred to the curved portion CP of the first curvature portion  13   a.    
     The second pressurizing portion  551   c  may be protruded from the other rear side RS 2  of the pad body  551   a  to have a varying thickness (e.g., an asymmetrical structure up and down from side to side based on the first direction X) and may pressure another side edge (or another side edge adhesive surface) of the display panel  31  to the second curvature portion  13   b  of the cover window  10 . The second pressurizing portion  551   c  may not pressure the side edge (pressed by the first pressurizing portion  551   b ) or the first adhesive surface of the display panel  31 . 
     The second pressurizing portion  551   c  according to one embodiment may include a second convex surface CS 2 , a second inner slope surface ISS 2  and a second outer slope surface OSS 2 . For example, the second pressurizing portion  551   c  may be slanted and protruded from the other rear side RS 2  of the middle portion of the pad body  551   a  to the second curvature portion  13   b  of the cover window  10 . The second pressurizing portion  551   c  may be configured to have a symmetrical structure with the first pressurizing portion  551   b  across an axis of symmetry through the middle portion of the pad body  551   a . Therefore, the first pressurizing portion  551   b  and the second pressurizing portion  551   c  may be configured to have a “V” shaped cross-sectional structure having a symmetrical structure across the axis of symmetry. In this case, the “V” shaped sectional structure of the first pressurizing portion  551   b  and the “V” shaped sectional structure of the second pressurizing portion  551   c  are symmetrical to each other based on the middle portion of the pad body  551   a  based on the first direction X (e.g., across a plane of symmetry in the Y and Z directions). 
     The second convex surface CS 2  may include a curved shape corresponding to a curved shape of the curved portion CP that forms the second curvature portion  13   b  of the cover window  10 . As an example, the second convex surface CS 2  may have a curved shape section having at least one curvature. As another example, the second convex surface CS 2  may have a concentric circle shaped section with the curved portion CP of the second curvature portion  13   b . The second convex surface CS 2  may locally pressurize another side edge of the display panel  31  to the second curvature portion  13   b  and therefore press or attach another edge adhesive surface A 3   b  of the display panel  31  to the second curvature portion  13   b  of the cover window  10 . 
     The second inner slope surface ISS 2  may be formed with a slope between the second convex surface CS 2  and the middle portion of the pad body  551   a . The second inner slope surface ISS 2  may be formed with a slope between the second convex surface CS 2  and the middle portion of the pad body  551   a  such that a pressurizing force of the second pressurizing portion  551   c  may locally be transferred to another side edge of the display panel  31  (and not the side edge pressured by the first pressurizing portion  551   b  or the first adhesive surface of the display panel  31 ) through the second convex surface CS 2 . 
     The second outer slope surface OSS 2  may be formed with a slope between an end of the other rear side RS 2  of the middle portion of the pad body  551   a  and one end of the second convex surface CS 2 . An angle between the second outer slope surface OSS 2  and the rear surface of the pad body  551   a  may range from 35° to 60°. For example, the angle between the second outer slope surface OSS 2  and the rear surface of the pad body  551   a  may be set to 45° such that the pressurizing force of the second convex surface CS 2  may be transferred to the curved portion CP of the second curvature portion  13   b.    
     The 3D pressurizing pad  551  according to one embodiment may further include a groove portion  551   d  between the first pressurizing portion  551   b  and the second pressurizing portion  551   c.    
     The groove portion  551   d  may be formed to have a triangle shaped cross-sectional structure or “V” shaped cross-sectional structure between the first inner slope surface ISS 1  of the first pressurizing portion  551   b  and the second inner slope surface ISS 2  of the second pressurizing portion  551   c . A cross-sectional area of the groove portion  551   d  may gradually be reduced toward the pad body  551   a . The groove portion  551   d  may provide a space for elastic deformation of each of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  when each of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  pressurizes the edge adhesive surfaces A 3   a  and A 3   b  of the display panel  31 , respectively. 
     The 3D pressurizing pad  551  according to one embodiment may further include a slit  551   e  arranged on the middle portion of the pad body  551   a  and formed to be recessed from the groove portion  551   d.    
     The slit  551   e  may be formed to be recessed to have a certain size from the rear surface of the pad body  551   a  where ends of the first inner slope surface ISS 1  of the first pressurizing portion  551   b  and the second inner slope surface ISS 2  of the second pressurizing portion  551   c  meet. 
     The slit  551   e  according to one embodiment may have a semi-circular shaped cross-sectional structure of which one side is communicated with the groove portion  551   d . For example, the slit  551   e  may have a curvature radius of 1.5 mm. As shown in the embodiment of  FIG. 16 , the center of the slit  551   e  may be arranged at ⅔ height H 2  of a height H 1  of the 3D pressurizing pad  551  based on the upper surface of the 3D pressurizing pad  551 . 
     The slit  551   e  may be formed between the first pressurizing portion  551   b  and the second pressurizing portion  551   c  overlapped with the middle portion of the pad body  551   a  in the first direction X to prevent the pressurizing force of the 3D pressurizing pad  551  from being concentrated on any one of the first pressurizing portion  551   b  and the second pressurizing portion  551   c . Also, the slit  551   e  may provide a space where the ends of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  may elastically be deformed, when the 3D pressurizing pad  551  is elastically deformed. In this case, if the slit  551   e  does not exist between the ends of the first inner slope surface ISS 1  and the second inner slope surface ISS 2 , lifespan of the 3D pressurizing pad  551  may be reduced due to damage of the 3D pressurizing pad  551  resulting from a physical contact or overlap between the ends of the first inner slope surface ISS 1  and the second inner slope surface ISS 2  when the 3D pressurizing pad  551  is elastically deformed. Optionally, the slit  551   e  may be expressed as an eccentric prevention member. 
       FIGS. 17A and 17B  are views illustrating an attachment process of a 3D attachment portion according to other embodiment of the present disclosure, which is shown in  FIGS. 15 and 16 . 
     The attachment process of the 3D attachment portion according to other embodiment of the present disclosure will be described with reference to  FIGS. 17A and 17B  together with  FIGS. 15 and 16 . 
     The window supporting member  510  adsorbs and supports the cover window  10  to which the second adhesive surface A 2  of the display panel  31  is attached loaded from the third transfer portion TP 3 . 
     The third alignment stage  571  is driven to align the position of the 3D pressurizing pad  551  and the position of the cover window  10  supported in the window supporting member  510  by moving the 3D pad lifting unit  555  of the 3D attachment unit  550  in the X-axis direction and/or Y-axis direction. 
     As shown in  FIG. 17A , the 3D attachment unit  550  presses or attaches the edge adhesive surfaces A 3   a  and A 3   b  of the display panel  31  to at least a part of or the entire curved window  13  of the cover window  10  supported in the window supporting member  510  through the 3D pressurizing pad  551  by descending the 3D pad supporting block  553  through driving of the 3D pad lifting unit  555 . In this case, the first pressurizing portion  551   b  of the 3D pressurizing pad  551  may elastically be deformed in accordance with a physical contact with one edge of the display panel  31  overlapped with one edge adhesive surface A 3   a  of the display panel  31  in accordance with descending of the 3D pad supporting block  553 . For this reason, the first pressurizing portion  551   b  may attach one edge adhesive surface A 3   a  of the display panel  31  to the first curvature portion  13   a  of the curved window  13  by locally pressurizing one edge adhesive surface A 3   a  of the display panel  31 . At the same time, the second pressurizing portion  551   c  of the 3D pressurizing pad  551  may elastically be deformed in accordance with a physical contact with another edge of the display panel  31  overlapped with another edge adhesive surface A 3   b  of the display panel  31  in accordance with descending of the 3D pad supporting block  553 . For this reason, the second pressurizing portion  551   c  may attach another edge adhesive surface A 3   b  of the display panel  31  to the second curvature portion  13   b  of the curved window  13  by locally pressurizing another edge adhesive surface A 3   b  of the display panel  31 . At this time, the first pressurizing portion  551   b  of the 3D pressurizing pad  551  may elastically be deformed to the same 3D shape as that of the first curvature portion  13   a  by the groove portion  551   d , the slit  551   e , and the first outer slope surface OSS 1 . Likewise, the second pressurizing portion  551   c  of the 3D pressurizing pad  551  may elastically be deformed to the same 3D shape as that of the second curvature portion  13   b  by the groove portion  551   d , the slit  551   e , and the second outer slope surface OSS 2 . Therefore, the edge adhesive surface A 3  of the display panel  31  may be pressed or attached to each of the first curvature portion  13   a  and the second curvature portion  13   b  of the curved window  13  by a local pressurizing pressure according to elastic deformation of each of the first pressurizing portion  551   b  and the second pressurizing portion  551   c  of the 3D pressurizing pad  551 , respectively. 
     As shown in  FIG. 17B , the 3D attachment unit  550  raises the 3D pressurizing pad  551  to the panel unloading position (or home position) by raising the 3D pad supporting block  553  to the home position through driving of the 3D pad lifting unit  555 . 
     The window supporting member  510  releases vacuum adsorption for the cover window  10  bonded to the display panel  31 . Therefore, the cover window  10  supported in the window supporting member  510  and bonded to the display panel  31  may be unloaded from the 3D attachment portion  500  by the fourth transfer portion TP 4 , whereby the display panel  31  and the cover window  10  may be bonded. 
     The manufacturing apparatus of the flexible display apparatus according to the present disclosure may be described as follows. 
     The manufacturing apparatus according to one embodiment of the present disclosure is an apparatus configured to bond a display panel to a cover window having a flat portion between a first curvature portion and a second curvature portion, and may comprise a first attachment portion configured to press a first adhesive surface of the display panel to the flat portion of the cover window, and a 3D attachment portion configured to press a first edge adhesive surface and a second edge adhesive surface of the display panel to the first curvature portion and the second curvature portion of the cover window, respectively, and not press the first adhesive surface of the display panel. 
     According to one embodiment of the present disclosure, the first attachment portion may include a first window supporting stage configured to support the cover window, a panel supporting stage overlapping the first window supporting stage and configured to be loaded with the display panel, and a first attachment unit having a first pressurizing pad configured to press the first adhesive surface of the display panel to the flat portion of the cover window by passing through the panel supporting stage. 
     According to one embodiment of the present disclosure, the panel supporting stage may include a pad through hole overlapping the first adhesive surface of the display panel, and the first pressurizing pad may press the first adhesive surface of the display panel to the flat portion of the cover window by passing through the pad through hole. 
     According to one embodiment of the present disclosure, the first attachment portion may further include a film delamination unit configured to delaminate or peel a protective film of an adhesive sheet of the display panel loaded in the panel supporting stage. 
     According to one embodiment of the present disclosure, further comprising a second attachment portion including a second window supporting stage configured to support the cover window, and a second attachment unit overlapping the second window supporting stage and having a second pressurizing pad configured to press a second adhesive surface of the display panel to the flat portion of the cover window, the second adhesive surface having an area greater than that of the first adhesive surface. 
     According to one embodiment of the present disclosure, the second pressurizing pad may include a convex panel pressurizing surface. 
     According to one embodiment of the present disclosure, the 3D attachment portion may include a window supporting member configured to support the cover window, and a 3D attachment unit overlapping the window supporting member and having a 3D pressurizing pad configured to press the first edge adhesive surface and the second edge adhesive surface of the display panel to the first curvature portion and the second curvature portion of the cover window, respectively, and not press the first adhesive surface of the display panel. 
     A manufacturing apparatus according to one embodiment of the present disclosure is an apparatus configured to bond a display panel to a cover window having a flat portion between a first curvature portion and a second curvature portion, and may comprise a 3D attachment portion configured to press a first the edge adhesive surface and a second edge adhesive surface of the display panel to the first curvature portion and the second curvature portion of the cover window, respectively, and not press a first adhesive surface of the display panel between the first edge adhesive surface and the second edge adhesive surface of the display panel, and the 3D attachment portion may include a window supporting member configured to support the cover window, and a 3D attachment unit overlapping the window supporting member and having a 3D pressurizing pad configured to press the first edge adhesive surface and the second edge adhesive surface of the display panel to the first curvature portion and the second curvature portion of the cover window, respectively, and not press the first adhesive surface of the display panel. 
     According to one embodiment of the present disclosure, the 3D pressuring pad may include a pad body, a first pressurizing portion protruded from a side of the pad body having a varying thickness and configured to press the first edge adhesive surface of the display panel to the first curvature portion, and a second pressurizing portion protruded from another side of the pad body having varying thickness and configured to press the second edge adhesive surface of the display panel to the second curvature portion. 
     According to one embodiment of the present disclosure, the 3D pressurizing pad may further include a groove portion between the first pressurizing portion and the second pressurizing portion. 
     According to one embodiment of the present disclosure, the 3D pressurizing pad may further include a slit arranged on a middle portion of the pad body between the first pressurizing portion and the second pressurizing portion, and formed to be recessed from the groove portion, and a hollow surface formed to be recessed from an outer side of each of the first pressurizing portion and the second pressurizing portion. 
     According to one embodiment of the present disclosure, the slit may include an arc shape having a first curvature radius, and the hollow surface may include another arc shape having a second curvature radius greater than the first curvature radius. 
     According to one embodiment of the present disclosure, a center of the hollow surface is aligned with a center of the slit. 
     According to one embodiment of the present disclosure, the 3D pressurizing pad may further include a slit formed to be recessed from a middle portion of the pad body and connected to each of the first pressurizing portion and the second pressurizing portion. 
     According to one embodiment of the present disclosure, the first pressurizing portion may include a first convex surface configured to press the first edge adhesive surface of the display panel to the first curvature portion, and a first slope surface between the first convex surface and the slit. 
     According to one embodiment of the present disclosure, the second pressurizing portion may include a second convex surface configured to press the second edge adhesive surface of the display panel to the second curvature portion, and a second slope surface between the second convex surface and the slit. 
     According to one embodiment of the present disclosure, the first pressurizing portion may include a first convex surface configured to press the first edge adhesive surface of the display panel to the first curvature portion, a first hollow surface between one side end of the pad body and one end of the first convex surface, and a first slope surface between the other end of the first convex surface and the middle portion of the pad body. 
     According to one embodiment of the present disclosure, the second pressurizing portion may include a second convex surface configured to press the second edge adhesive surface of the display panel to the second curvature portion, a second hollow surface between the other side end of the pad body and one end of the second convex surface, and a second slope surface between the other end of the second convex surface and the middle portion of the pad body. 
     According to one embodiment of the present disclosure, the 3D pressurizing pad may further include a slit arranged on the middle portion of the pad body and formed between the first pressurizing portion and the second pressurizing portion, the first slope surface of the first pressurizing portion may be inclined between the other end of the first convex surface and one side of the slit, and the second slope surface of the second pressurizing portion may be inclined between the other end of the second convex surface and the other side of the slit. 
     According to one embodiment of the present disclosure, the first pressurizing portion may include a first convex surface configured to press the first edge adhesive surface of the display panel to the first curvature portion, a first inner slope surface between the first convex surface and a middle portion of the rear side of the pad body, and a first outer slope surface between an end of the middle portion of the rear side of the pad body and one end of the first convex surface. 
     According to one embodiment of the present disclosure, the second pressurizing portion may include a second convex surface configured to press the second edge adhesive surface of the display panel to the second curvature portion, a second inner slope surface between the second convex surface and a middle portion of a rear side of the pad body, and a second outer slope surface between the other end of the middle portion of the rear side of the pad body and one end of the second convex surface. 
     According to one embodiment of the present disclosure, the 3D pressurizing pad may further include a slit arranged on a middle portion of the pad body and formed between the first pressurizing portion and the second pressurizing portion, the first inner slope surface of the first pressurizing portion may be inclined between the other end of the first convex surface and one side of the slit, and the second inner slope surface of the second pressurizing portion may be inclined between the other end of the second convex surface and the other side of the slit. 
     According to one embodiment of the present disclosure, the 3D pressurizing pad may include an elastic material configured to be at least partially deformed when pressing the display panel. 
     According to one embodiment of the present disclosure, each of the first and second curvature portions may include a curved portion curved from the flat portion, and a sidewall extended from an end of the curved portion, and an angle between the flat portion and the sidewall may be 60° or more. 
     The manufacturing apparatus of a flexible display apparatus according to one embodiment of the present disclosure may further comprise a first transfer portion for loading each of the cover window and the display panel in the first attachment portion, a second transfer portion for taking the cover window to which the first adhesive surface of the display panel is attached, out of the first attachment portion and loading the cover window in the second attachment portion, a third transfer portion for taking the cover window to which the second adhesive surface of the display panel is attached, out of the second attachment portion and loading the cover window in the third attachment portion, and a fourth transfer portion for taking the cover window to which the display panel is attached, out of the third attachment portion. 
     The manufacturing apparatus of a flexible display apparatus according to one embodiment of the present disclosure may further comprise a hardening portion loaded with the curved window to which the display panel is attached, from the fourth transfer portion, hardening the adhesive surface between the display panel and the curved window. 
     A structure according to one embodiment of the present disclosure may comprise a cover window of which both edges have a shape of a specific angle or more, and at least one layer attached to an inner surface of the cover window without bubbles by an attachment process that does not use a diaphragm. 
     According to one embodiment of the present disclosure, the at least one layer may be attached to inner surfaces of the both edges by local pressurization of an elastic deformation pad that follows a shape of the both edges. 
     According to one embodiment of the present disclosure, the specific angle may be 60° or more. 
     According to one embodiment of the present disclosure, the cover window may have a height of 2.0 mm or more. 
     According to one embodiment of the present disclosure, the both edges may have a width of 3.0 mm or more. 
     A display apparatus according to one embodiment of the present disclosure may comprise a substrate having a pixel array portion, and a cover window covering the substrate, wherein both edges of the cover window have a shape of a specific angle or more, and at least one layer may be attached to an inner surface of the cover window. 
     According to one embodiment of the present disclosure, the at least one layer may be attached to inner surfaces of the both edges without bubbles by an attachment process that does not use a diaphragm. 
     According to one embodiment of the present disclosure, the specific angle may be 60° or more. 
     According to one embodiment of the present disclosure, the cover window may have a height of 2.0 mm or more. 
     According to one embodiment of the present disclosure, the both edges may have a width of 3.0 mm or more. 
     According to one embodiment of the present disclosure, the at least one layer may be attached to inner surfaces of the both edges by local pressurization of an elastic deformation pad that follows a shape of the both edges. 
     It will be apparent to those skilled in the art that the present disclosure described above is not limited by the above-described embodiments and the accompanying drawings and that various substitutions, modifications, and variations can be made in the present disclosure without departing from the spirit or scope of the disclosures. Consequently, the scope of the present disclosure is defined by the accompanying claims, and it is intended that all variations or modifications derived from the meaning, scope, and equivalent concept of the claims fall within the scope of the present disclosure.