Abstract:
In order to improve durability, a display apparatus includes a substrate; an encapsulation substrate facing the substrate; a display unit disposed between the substrate and the encapsulation substrate; a sealing unit disposed between the substrate and the encapsulation substrate so as to bond the substrate and the encapsulation substrate and spaced from the display unit; and a protective member formed over at least one surface among surfaces of the substrate and the encapsulation substrate, except surfaces facing the display unit. The protective member includes a base, a plurality of capsules comprising monomers, and a catalyst inducing polymerization of the monomers.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2010-0128618, filed on Dec. 15, 2010, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The present disclosure relates to a display apparatus and a method of manufacturing the display apparatus, and more particularly, to a display apparatus and a method of manufacturing the display apparatus having improved durability. 
         [0004]    2. Description of the Related Art 
         [0005]    Recently, display apparatuses have been replaced with portable thin flat panel display apparatuses. In particular, thin flat panel display apparatuses including an organic light emitting display apparatus and a liquid crystal display (LCD) apparatus have been highlighted for their excellent image qualities. 
         [0006]    In general, a flat panel display apparatus has a structure in which a display unit is disposed between a substrate and an encapsulation substrate, and the substrate and the encapsulation substrate are bonded by using a sealing unit. 
         [0007]    The substrate and the encapsulation substrate may be damaged by impact and have defects such as scratches, holes, cracks or the like during the manufacturing process or use of the flat panel display apparatus. Thus, there is limit in improving durability of a display apparatus. 
       SUMMARY 
       [0008]    One aspect of the present invention provides a display apparatus and a method of manufacturing the display apparatus so as to easily improve durability of the display apparatus. 
         [0009]    According to an aspect of the present invention, there is provided a display apparatus including a substrate; an encapsulation substrate facing the substrate; a display unit disposed between the substrate and the encapsulation substrate; a sealing unit disposed between the substrate and the encapsulation substrate so as to bond the substrate and the encapsulation substrate and spaced from the display unit; and a protective member formed over at least one surface among surfaces of the substrate and the encapsulation substrate except surfaces facing the display unit, and the protective member comprising a base, a plurality of capsules comprising monomers, and a catalyst inducing polymerization of the monomers. 
         [0010]    The protective member may be formed of a mixture of the base, the plurality of capsules, and the catalyst. 
         [0011]    The plurality of capsules may include coating layers covering surfaces of the monomers, respectively. 
         [0012]    Each of the coating layers may be formed of a polymer material. 
         [0013]    The base may include a resin. 
         [0014]    Each of the monomers may include a material selected from the group consisting of dicyclopentadiene, hydroxyl terminated polydimethylsiloxane, and polydiethylsiloxane. 
         [0015]    The catalyst may include a Grubbs catalyst. 
         [0016]    The protective member may include a region including epoxy resin which is formed by the polymerization of the monomers. 
         [0017]    The display unit may include an organic light emitting device or a liquid crystal device. 
         [0018]    According to another aspect of the present invention, there is provided a method of manufacturing a display apparatus, the method including the operations of disposing a display unit between a substrate and an encapsulation substrate facing the substrate, and bonding the substrate and the encapsulation substrate by using a sealing unit; and forming a protective member over at least one surface among surfaces of the substrate and the encapsulation substrate except surfaces facing the display unit, and the protective member comprising a base, a plurality of capsules comprising monomers, and a catalyst inducing polymerization of the monomers. 
         [0019]    The protective member may be formed by mixing the base, the plurality of capsules, and the catalyst. 
         [0020]    The plurality of capsules may include coating layers covering surfaces of the monomers, respectively. 
         [0021]    Each of the coating layers may be formed of a polymer material. 
         [0022]    The base may include a resin. 
         [0023]    Each of the monomers may include a material selected from the group consisting of dicyclopentadiene, hydroxyl terminated polydimethylsiloxane, and polydiethylsiloxane. 
         [0024]    The catalyst may include a Grubbs catalyst. 
         [0025]    The protective member may include a region including epoxy resin, which is formed by the polymerization of the monomers. 
         [0026]    The display unit may include an organic light emitting device or a liquid crystal device. 
         [0027]    The protective member may be formed over a predetermined area of at least one side surface among side surfaces of the substrate and side surfaces of the encapsulation substrate. 
         [0028]    The protective member may be formed over a predetermined area of surfaces opposite the surfaces of the substrate and the encapsulation substrate which face the display unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    The above and other features and advantages of the present invention will become more apparent by describing in detail embodiments thereof with reference to the attached drawings in which: 
           [0030]      FIG. 1  is a cross-sectional view of a display apparatus according to an embodiment of the present invention; 
           [0031]      FIG. 2  is a magnified view of a portion A in the display apparatus of  FIG. 1 ; 
           [0032]      FIG. 3  is a magnified view of a portion X in the display apparatus of  FIG. 1 ; 
           [0033]      FIG. 4  is a cross-sectional view of a display apparatus according to another embodiment of the present invention; and 
           [0034]      FIGS. 5A through 5G  shows steps of a method of manufacturing a display apparatus according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0035]    Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. 
         [0036]      FIG. 1  is a cross-sectional view of a display apparatus  100  according to an embodiment of the present invention.  FIG. 2  is a magnified view of a portion A in the display apparatus  100  of  FIG. 1 .  FIG. 3  is a magnified view of a portion X in the display apparatus  100  of  FIG. 1 . 
         [0037]    Referring to  FIG. 1 , the display apparatus  100  includes a substrate  101 , a display unit  110 , an encapsulation substrate  170 , a sealing unit  150 , and a protective member  180 . Hereinafter, the aforementioned members will be described in detail. 
         [0038]    The substrate  101  may be formed of transparent glass containing SiO 2  as a main component, but is not limited thereto. In another example, the substrate  101  may also be formed of a transparent plastic material that may be an insulating organic material selected from the group consisting of polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethyelene napthalate (PEN), polyethyelene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), triacetate cellulose (TAC), and cellulose acetate propionate (CAP). 
         [0039]    The display unit  110  is disposed on the substrate  101 . The type of the display unit  110  may vary. According to the present embodiment, the display unit  110  includes an organic light emitting device, but the display unit  110  is not limited thereto. In another embodiment, the display unit may include a liquid crystal device. 
         [0040]    The encapsulation substrate  170  is disposed to face the display unit  110 . The substrate  101  and the encapsulation substrate  170  are bonded by using the sealing unit  150 . The sealing unit  150  is formed around the display unit  110  without contacting the display unit  110 . 
         [0041]    The encapsulation substrate  170  protects the display unit  110  from external moisture or oxygen. The encapsulation substrate  170  may be formed by using various materials, and in particular, may be formed of a glass material or a plastic material. 
         [0042]    The protective member  180  is disposed on side surfaces of the substrate  101  and the encapsulation substrate  170 . The protective member  180 , as a self-repairing structure, includes a base  185 , a plurality of capsules  183 , and a catalyst  184 . Each of the capsules  183  has one or more monomers  181  and a coating layer  182  covering the one or more monomers  181 . 
         [0043]    Each monomer  181  includes a material which becomes an epoxy-based resin by polymerization. In more detail, the monomer  181  includes a material selected from the group consisting of dicyclopentadiene, hydroxyl terminated polydimethylsiloxane, and polydiethylsiloxane. 
         [0044]    The coating layer  182  covering the monomer  181  is formed of a polymer material. In particular, the coating layer  182  may include a thermosetting polymer material. The coating layer  182  is formed to have an appropriate thickness and appropriate strength so as to burst under a pressure equal to or greater than a predetermined level. 
         [0045]    The catalyst  184  is included in the protective member  180  so as to facilitate polymerization of the monomers  181 , and in particular, the catalyst  184  includes a Grubbs catalyst. 
         [0046]    An example of the catalyst  184  may include benzylidene-bis(tricyclohexylphosphine)dichlororuthenium. 
         [0047]    The base  185  may include a resin. In particular, the base  185  may include an epoxy resin. 
         [0048]    When a shock or impact is applied to a side surface of the display apparatus  100 , the shock is first delivered to the protective member  180 . Also, a shock equal to or greater than a predetermined level is applied to a side surface of the display apparatus  100 , small cracks, holes, or scratches are incurred on the side surface of the display apparatus  100  or on a side surface of the encapsulation substrate  170 . 
         [0049]    Due to the shock applied to the display apparatus  100 , the coating layer  182  of each capsule  183  of the protective member  180  bursts. Also, when defects such as cracks, holes, or scratches on a surface of the substrate  101  or a surface of the encapsulation substrate  170  caused by the shock applied to the display apparatus  100  contact the capsule  183 , the coating layer  182  may burst. 
         [0050]    When the coating layer  182  bursts, the monomer  181  flows therefrom. The flown monomers  181  form a region including polymer. In particular, the flown monomers  181  form a portion of epoxy resin (not shown) by polymerization. Also, the catalyst  184  disposed around the monomers  181  facilitates the monomers  181  such that a portion of epoxy resin is formed by inducing the polymerization of the monomers  181  in a room temperature. 
         [0051]    The epoxy resin formed by the polymerization of the monomers  181  fills the defects such as cracks, holes, or scratches that are incurred on the side surface of the substrate  101  or the side surface of the encapsulation substrate  170 . Thus, it is possible to repair the defects incurred on a surface of the display apparatus  100  without any additional process. 
         [0052]    In one or more embodiments, the display unit  110  may vary. In the present embodiment, an organic light emitting device may be formed as the display unit  110 . 
         [0053]    Referring to  FIG. 3 , a buffer layer  111  is formed on the substrate  101 . The buffer layer  111  provides a flat surface on the substrate  101 , and prevents moisture and foreign substances from entering toward the substrate  101 . 
         [0054]    An active layer  112  having a predetermined pattern is formed on the buffer layer  111 . The active layer  112  may be formed of an inorganic semiconductor such as amorphous silicon or poly silicon, or formed of an organic semiconductor, and may include a source region, a drain region, and a channel region. 
         [0055]    The source and drain regions may be formed by doping the active layer  112  that is formed of amorphous silicon or poly silicon with impurities. By being doped with boron (B) that is a group III element, a p-type semiconductor may be formed, and by being doped with nitrogen (N) that is a group V element, an n-type semiconductor may be formed. 
         [0056]    A gate insulating layer  113  is formed on the active layer  112 , and a gate electrode  114  is formed on a predetermined region of the gate insulating layer  113 . The gate insulating layer  113  functions to insulate the active layer  112  from the gate electrode  114 , and may be formed of an organic material or an inorganic material including SiNx or SiO 2 . The gate electrode  114  may be formed of a metal selected from the group consisting of Au, Ag, Cu, Ni, Pt, Pd, Al, and Mo. In another embodiment, the gate electrode  114  may be formed of a metal alloy such as Al—Nd alloy, Mo—W alloy, and the like but is not limited thereto. In other embodiments, the gate electrode  114  may be formed by using various materials in consideration of adhesion, planarization, electrical resistance, formability, or the like. The gate electrode  114  is connected to a gate line (not shown) for applying an electrical signal. 
         [0057]    An interlayer insulating layer  115  is formed on the gate electrode  114 . The interlayer insulating layer  115  and the gate insulating layer  113  are formed in such a manner that the source and drain regions of the active layer  112  are exposed, and a source electrode  116  and a drain electrode  117  contact the exposed source and drain regions of the active layer  112 . 
         [0058]    The source and drain electrodes  116  and  117  may be formed of a metal selected from the group consisting of Au, Pd, Pt, Ni, Rh, Ru, Ir and Os. In another embodiment, the source and drain electrodes  116  and  117  may be formed of a metal alloy containing at least two metals from the group consisting of Al, Mo, Al—Nd alloy, and Mo—W alloy but is not limited thereto. 
         [0059]    A passivation layer  118  is formed to cover the source electrode  116  and the drain electrode  117 . For the passivation layer  118 , an inorganic insulating layer and/or an organic insulating layer may be used. The inorganic insulating layer may include SiO 2 , SiNx, SiON, Al 2 O 3 , TiO 2 , Ta 2 O 5 , HfO 2 , ZrO 2 , BST, or PZT, and the organic insulating layer may include polymer derivatives having commercial polymers (PMMA and PS) and a phenol group, an acryl-based polymer, an imide-based polymer, an allyl ether-based polymer, an amide-based polymer, a fluorine-based polymer, a p-xylene-based polymer, a vinylalcohol-based polymer, or a combination thereof. The passivation layer  118  may be formed as a multi-stack including the inorganic insulating layer and the organic insulating layer. 
         [0060]    The passivation layer  118  is formed to expose the drain electrode  117 , and an organic light emitting device  120  is formed to be connected to the exposed drain electrode  117 . The organic light emitting device  120  includes a first electrode  121 , a second electrode  122 , and an intermediate layer  123 . In more detail, the first electrode  121  and the drain electrode  117  contact each other. 
         [0061]    The intermediate layer  123  includes an organic light emitting layer (not shown), and emits visible light when a voltage is applied thereto via the first electrode  121  and the second electrode  122 . 
         [0062]    A pixel defining layer (PDL)  119  that is formed of an insulating material is arranged on the first electrode  121 . 
         [0063]    A predetermined opening is formed on the PDL  119  so as to expose the first electrode  121 . The intermediate layer  123  is formed on the exposed first electrode  121 . Afterward, the second electrode  122  is formed to be connected to the intermediate layer  123 . 
         [0064]    The first electrode  121  and the second electrode  122  have polarities of an anode electrode and a cathode electrode, respectively. In an alternative embodiment, the polarities of the first electrode  121  and the second electrode  122  may be reversed. 
         [0065]    The encapsulation substrate  170  is disposed on the second electrode  122 . 
         [0066]    The display apparatus  100  according to the present embodiment includes the protective member  180 . The protective member  180  includes the monomers  181  covered by the coating layers  182 . When an external shock is applied to the display apparatus  100 , defects such as cracks, holes, or scratches may be incurred on the side surface of the substrate  101  or the side surface of the encapsulation substrate  170 , and the epoxy resin portion is formed by the polymerization of the monomers  181  and fills the defects. 
         [0067]    By doing so, defects incurred during the use of the display apparatus  100  can be immediately and naturally repaired without any additional efforts. Also, when the display apparatus  100  is transported, stored and inspected during the manufacture of the display apparatus  100 , defects such as cracks, holes, or scratches may be incurred on the side surface of the substrate  101  or the side surface of the encapsulation substrate  170 . In this case, the region including epoxy resin is formed by the polymerization of the monomers  181  and fills the defects so that the defects may be immediately and naturally repaired. 
         [0068]    As a result, the display apparatus  100  having significantly improved durability may be easily embodied. 
         [0069]      FIG. 4  is a cross-sectional view of a display apparatus  200  according to another embodiment of the present invention. For convenience of description, differences between the present embodiment and the previous embodiment will be described. 
         [0070]    Referring to  FIG. 4 , the display apparatus  200  includes a substrate  201 , a display unit  210 , an encapsulation substrate  270 , a sealing unit  250 , and a protective member  280 . The protective member  280  includes a first part  281  and a second part  282 . 
         [0071]    The display unit  210  is disposed on the substrate  201 . The encapsulation substrate  270  is disposed to face the display unit  210 . The substrate  201  and the encapsulation substrate  270  are bonded by using the sealing unit  250 . The sealing unit  250  is formed around the display unit  210  without contacting the display unit  210 . 
         [0072]    The first part  281  of the protective member  280  is disposed on side surfaces of the substrate  201  and the encapsulation substrate  270 . The second part  282  of the protective member  280  is disposed on a bottom surface of the substrate  201  and a top surface of the encapsulation substrate  270 , wherein the bottom surface is the opposite surface of a surface whereon the display unit  210  is formed, and the top surface is the opposite surface of a surface facing the display unit  210 . 
         [0073]    The first part  281  and second part  282  of the protective member  280  are formed of the same material and have the same structure as the protective member  180  of the previous embodiment. Thus, detailed descriptions thereof are omitted here. 
         [0074]    The display apparatus  200  according to the present embodiment includes the protective member  280 . The protective member  280  includes monomers (not shown) covered by coating layers (not shown). When an external shock is applied to the display apparatus  200 , defects such as cracks, holes, or scratches may be incurred on an exterior surface of the substrate  201  or an exterior surface of the encapsulation substrate  270 , and then, a region including epoxy resin is formed by polymerization of the monomers and fills the defects. 
         [0075]    By doing so, defects incurred during the use of the display apparatus  200  can be immediately and naturally repaired without any additional efforts. Also, when the display apparatus  200  is transported, stored and inspected during the manufacture of the display apparatus  200 , defects such as cracks, holes, or scratches may be incurred on the exterior surface of the substrate  201  or the exterior surface of the encapsulation substrate  270 . In this case, the region including epoxy resin is formed by the polymerization of the monomers and fills the defects so that the defects may be immediately and naturally repaired. 
         [0076]    As a result, the display apparatus  200  having significantly improved durability may be easily embodied. 
         [0077]      FIGS. 5A through 5G  are diagrams for describing a method of manufacturing a display apparatus  300 , according to an embodiment of the present invention. 
         [0078]    Referring to  FIG. 5A , a display unit  310  is formed on a substrate  301 . A material for forming the substrate  301  is described above in the foregoing embodiments and a detailed description thereof is omitted here. 
         [0079]    The display unit  310  is disposed on the substrate  301 . The display unit  310  may vary. In some embodiments, the display unit  310  may include an organic light emitting device or a liquid crystal device. 
         [0080]    Referring to  FIG. 5B , an encapsulation substrate  370  is disposed to face the display unit  310 . The substrate  301  and the encapsulation substrate  370  are bonded by using a sealing unit  350 . The sealing unit  350  is formed around the display unit  310  without contacting the display unit  310 . 
         [0081]    The encapsulation substrate  370  protects the display unit  310  from external moisture or oxygen. The encapsulation substrate  370  may be formed by using various materials, and in particular, may be formed of a glass material or a plastic material. 
         [0082]      FIG. 5C  is a magnified view of a portion A in  FIG. 5B . Referring to  FIG. 5C , a defect  371  such as a scratch is formed on an exterior surface of the encapsulation substrate  370 . The defect  371  may be incurred while processes of  FIGS. 5A and 5B  are performed, when an unfinished display apparatus is transported for processes of  FIGS. 5A and 5B , or when the unfinished display apparatus is transported, stored or inspected for subsequent processes after performing processes of  FIGS. 5A and 5B . 
         [0083]    Afterward, referring to  FIG. 5D , a protective member  380  is disposed on side surfaces of the substrate  301  and the encapsulation substrate  370 .  FIG. 5E  is a magnified view of a portion A in  FIG. 5D . 
         [0084]    The protective member  380 , as a self-repairing structure, includes a base  385 , a plurality of capsules  383 , and a catalyst  384 . Each of the capsules  383  has one or more monomers  381  and a coating layer  382  covering the one or more monomers  381 . 
         [0085]    Each monomer  381  includes a material which becomes an epoxy-based resin by polymerization. In more detail, the monomer  381  includes a material selected from the group consisting of dicyclopentadiene, hydroxyl terminated polydimethylsiloxane, and polydiethylsiloxane. 
         [0086]    The coating layer  382  covering the monomer  381  is formed of a polymer material. In particular, the coating layer  382  may include a thermosetting polymer material. The coating layer  382  has an appropriate thickness and appropriate strength so as to burst in response to a pressure equal to or greater than a predetermined level. 
         [0087]    The catalyst  384  includes a Grubbs catalyst. In more detail, the catalyst  384  may include benzylidene-bis(tricyclohexylphosphine)dichlororuthenium. 
         [0088]    The base  385  may include a resin, and in particular, the base  385  may include an epoxy resin. 
         [0089]      FIGS. 5F and 5G  illustrate a final product of the display apparatus  300 , defects of which are repaired by the protective member  380 .  FIG. 5G  is a magnified view of a portion A in  FIG. 5F . 
         [0090]    When the coating layer  382  bursts due to a contact between the capsule  383  and the defect  371  that is incurred on the encapsulation substrate  370 , the monomer  381  flows therefrom. The flown monomers  381  form a region including polymer, in particular, the flown monomers  381  form a region including epoxy resin  380 ′ by polymerization. Also, the catalyst  384  disposed around the monomers  381  facilitates the monomers  381  to form the region including epoxy resin  380 ′ by inducing the polymerization of the monomers  381  in a room temperature. 
         [0091]    The region including epoxy resin  380 ′ that is formed by the polymerization of the monomers  381  fills the defect  371  incurred on the exterior surface of the encapsulation substrate  370 . Thus, it is possible to repair the defect  371  incurred on a surface of the display apparatus  300  without any additional process. 
         [0092]    In the foregoing embodiment, the repair of defects formed before the protective member  380  is formed is discussed. But the invention is not limited thereto. That is, defects incurred after the protective member  380  is formed, e.g., defects that are incurred during use can be easily repaired by the protective member  380  so that durability of the display apparatus  300  is improved. 
         [0093]    The display apparatus and the method of manufacturing the display apparatus according to the one or more embodiments may easily improve durability of the display apparatus. 
         [0094]    While embodiments of the present invention has been particularly shown and described, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.