Abstract:
A display apparatus includes: a substrate; a display panel on the substrate; and a sealing substrate opposite to the display panel. The display apparatus includes further includes a heat dissipating layer which is between the display panel and the sealing substrate and dissipates heat generated from the display panel; and a sealing portion which is between the substrate and the sealing substrate and surrounds the display panel.

Description:
This application claims priority to Korean Patent Application No. 10-2013-0077371 filed on Jul. 2, 2013, and all the benefits accruing therefrom under 35 U.S.C. §119, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     (a) Field 
     The disclosure relates to a display apparatus. 
     (b) Description of the Related Art 
     As popular display apparatuses, there is a liquid crystal display (“LCD”), a plasma display panel (“PDP”), an organic light emitting display (“OLED”), a field effect display (“FED”), and an electrophoretic display (“EPD”). 
     Particularly, the OLED display includes two electrodes, and an organic emission layer disposed therebetween. Electrons from one electrode and holes from the other electrode are combined in the organic emission layer to thereby generate excitons, which release energy to emit light. 
     SUMMARY 
     The invention provides a display apparatus including a display panel such as an organic light emitting diode (“OLED”) display, having advantages of reducing or effectively preventing deterioration of an organic emission layer of the OLED display, by efficiently dissipating heat generated in the OLED display to the outside of the display apparatus. 
     An exemplary embodiment of the invention provides a display apparatus including: a substrate; a display panel on the substrate; a sealing substrate opposite to the display panel; a heat dissipating layer which is between the display panel and the sealing substrate and is configured to dissipate heat generated from the display panel; and a sealing portion which is between the substrate and the sealing substrate and surrounds the display panel. 
     The display apparatus may further include a first adhesion layer which is between the heat dissipating layer and the display panel and couples the heat dissipating layer and the display panel to each other. 
     The display apparatus may further include a second adhesion layer which is between the heat dissipating layer and the sealing substrate and couples the heat dissipating layer and the sealing substrate to each other. 
     Each of the first and second adhesion layers may include one of epoxy, acrylate and silicone. 
     The heat dissipating layer may include a thermally conductive material. 
     The thermally conductive material may include one of graphite, alumina, silver, copper and aluminum, and a combination thereof. 
     The sealing substrate may include one of glass, metal and plastic. 
     The display apparatus may further include a getter layer which is between the display panel and the sealing portion and surrounds the display panel. 
     One or more exemplary embodiment of the display apparatus in accordance with the invention can dissipate the heat generated in OLED display as the display panel to thereby reduce or effectively prevent deterioration of the organic emission layer, by the heat dissipating layer between the sealing substrate and the display panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of this disclosure will become more apparent by describing in further detail exemplary embodiments thereof with reference to the accompanying drawings, in which: 
         FIG. 1  is a cross-sectional view of an exemplary embodiment of a display apparatus in accordance with the invention. 
         FIG. 2  to  FIG. 7  show an exemplary embodiment of a manufacturing process of a display apparatus in accordance with the invention. 
         FIG. 8  is an enlarged view of an exemplary embodiment of a region P shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the invention. In the drawings and this specification, parts or elements that are not related to the description hereof are omitted in order to clearly describe the invention, and the same or like elements are designated by the same reference numerals throughout the specification. 
     In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for better understanding and ease of description, but the invention is not limited thereto. 
     In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, for better understanding and ease of description, the thickness of some layers and areas is exaggerated. Throughout this specification, when a first part of a layer, a film, a plate, or the like is described as being arranged “on” a second part, this indicates the first part is arranged on the second part directly or with a third part therebetween. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, throughout this specification, when a part is described as “comprising (or including)” elements, this indicates that the part may further include other elements unless particularly otherwise defined. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Furthermore, when the first part is described as being arranged “on” the second part, this indicates that the first part is arranged at an upper side or a lower side of the second part without the limitation to the upper side thereof on the basis of the gravity direction. 
     Embodiments of the invention are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     All methods described herein can be performed in a suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”), is intended merely to better illustrate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention as used herein. 
     An inner temperature of a display apparatus including a display panel such as an organic light emitting diode (“OLED”) display is increased by the heat generated from driving of the OLED. As the inner temperature of the display apparatus is increased, an inner layer of the display panel such as an organic emission layer of the OLED which is vulnerable to heat may be deteriorated. Once the organic emission layer is deteriorated, the life-span of the OLED, the OLED display and/or the display apparatus including the OLED display is reduced and image quality thereof is deteriorated. 
     In order to prevent such problems, in the display apparatus, a heat dissipation sheet is generally attached to an upper portion of a sealing substrate by using a double-sided adhesive tape or the like to thereby dissipate the heat from the display panel such as the OLED display. This, however, causes the overall thickness of the display apparatus and/or the OLED display to be undesirably increased and/or makes efficiently dissipating the heat between the sealing substrate and the OLED display to the outside difficult due to the double-sided adhesive tape or the like. Therefore, there remains a need for an improved display apparatus and/or display panel having a reduced thickness and which has improved heat dissipation. 
     Hereinafter, the invention will be described in detail with reference to the accompanying drawings. 
     Referring to  FIG. 1 , in an exemplary embodiment of a display apparatus in accordance with the invention, a heat dissipating layer  400  can be disposed between a sealing substrate  600  and a display panel  200  to thereby efficiently dissipate heat generated from the display panel  200  to the outside of the display apparatus. 
     The display apparatus in accordance with the illustrated exemplary embodiment may include a substrate  100 , the display panel  200 , the heat dissipating layer  400 , the sealing substrate  600  and a sealing portion  800 . 
     Referring to  FIG. 1 , the substrate  100  corresponds to a base layer on which a display panel and the like are disposed in a general display apparatus. 
     The substrate  100  may be an insulating substrate including glass, quartz, ceramic, plastic, or the like, but is not limited thereto. In one exemplary embodiment, for example, the substrate  100  may be a metal substrate including stainless steel or the like. 
     In accordance with the illustrated exemplary embodiment, the display panel  200  can display an image. In the illustrated exemplary embodiment, the display panel  200  includes a light emitting layer such as an organic emission layer, which will be described in detail later. 
     In the illustrated exemplary embodiment, the light emitting layer of the display panel  200  includes the organic emission layer employed in an OLED display. However, the display apparatus in accordance with the illustrated exemplary embodiment may be applied to a liquid crystal display (“LCD”), a field effect display (“FED”), and an electrophoretic display (“EPD”) without being limited to the OLED display. 
     The sealing substrate  600  is disposed on the display panel  200  to seal display panel  200 . The sealing substrate  600  serves to protect the display panel  200  from external moisture or oxygen. Particularly, the sealing substrate  600  may reduce or effectively prevent deterioration of the light emitting layer, such as the organic emission layer, of the display panel  200  from by moisture or oxygen. 
     The sealing substrate  600  may include various materials, such as one of a glass material, a metal material and a plastic material. 
     Referring to  FIG. 1 , the sealing portion  800  is disposed between the sealing substrate  600  and the substrate  100 . In addition, the sealing portion  800  is disposed around the display panel  200  to surround the display panel  200 , such as in a plan view of the display apparatus. 
     Where the sealing portion  800  is disposed between the sealing substrate  600  and the substrate  100 , the sealing portion  800  is coupled to the sealing substrate  600  and the substrate  100 . The sealing portion  800  may include a material including frit. However, the sealing portion  800  may include any of a number of various materials by which the sealing substrate  600  and the substrate  100  are coupled to each other without being limited thereto. 
     In accordance with the illustrated exemplary embodiment, the heat dissipating layer  400  is disposed between the sealing substrate  600  and the display panel  200 . The heat dissipating layer  400  is configured to dissipate the heat generated in the display panel  200  to the outside the display panel  200  and/or the display apparatus. 
     Particularly, the OLED display including an organic emission layer may be deteriorated by moisture or heat. Accordingly, where dissipating the heat generated in the display panel  200  including an organic emission layer to the outside is difficult, the temperature of the display panel  200  is increased so that the organic emission layer and/or the display panel  200 , may be deteriorated. 
     In accordance with the illustrated exemplary embodiment, the heat dissipating layer  400  is disposed between the sealing substrate  600  and the display panel  200  in order to reduce or effectively prevent deterioration of the display panel  200 . 
     The heat dissipating layer  400  may include a thermally conductive material. Where the heat dissipating layer  400  includes the thermally conductive material, rapid dissipation of the heat generated in the display panel  200  to the outside is possible. 
     A thermally conductive material of the heat dissipating layer  400  may include one of graphite, alumina, silver, copper and aluminum. In other words, the heat dissipating layer  400  may include one of the aforementioned materials or a combination of two or more of the aforementioned materials. 
     In an exemplary embodiment of manufacturing a display apparatus, the heat dissipating layer  400  may be formed by processing a material in a discrete bead or discrete pellet pattern. 
     Further, the heat dissipating layer  400  is located over the display panel  200  to cover the display panel  200 . The heat dissipating layer  400  may be disposed to cover a whole of the display panel  200  in order for the heat dissipating layer  400  to efficiently dissipate the heat generated in the display panel  200 . The heat dissipating layer  400  may overlap an entire of the display panel  200  in the plan view. However, the heat dissipating layer  400  may be disposed to cover a part of a top surface of the display panel  200  such that a portion of the display panel  200  is exposed by the heat dissipating layer  400 , without being limited thereto. 
     In accordance with the illustrated exemplary embodiment, a first adhesion layer  300  may be included between the display panel  200  and the heat dissipating layer  400  such that the heat dissipating layer  400  is adhered to the display panel  200  via the first adhesion layer  300 . 
     Where the adhesion layer  300  may be included between the display panel  200  and the heat dissipating layer  400 , the first adhesion layer  300  can efficiently transfer the heat generated in the display panel  200  to the heat dissipating layer  400  by adhering the heat dissipating layer  400  to the top surface of the display panel  200 . 
     Further, the first adhesion layer  300  includes a material through which the heat dissipating layer  400  and the display panel  200  are coupled to each other. In one exemplary embodiment, for example, the first adhesion layer  300  may include one of epoxy, acrylate and silicone, and a combination thereof. 
     The first adhesion layer  300  may be attached to the top surface of the display panel  200  in a film pattern, that is, as a substantially flat and uniform thickness member which may be separately provided and subsequently attached to the display panel  200 . Alternatively, in an exemplary embodiment of manufacturing a display apparatus, the first adhesion layer  300  may be formed by coating a liquid material on the top surface of the first adhesion layer  300 . The first adhesion layer  300  may also be formed by coating the liquid material and then hardening the liquid material with a heat curing method or an ultraviolet (“UV”) curing method. 
     In addition, a second adhesion layer  500  may be disposed between the heat dissipating layer  400  and the sealing substrate  600 . The second adhesion layer  500  facilitates coupling between the heat dissipating layer  400  and the sealing substrate  600 . 
     As the heat dissipating layer  400  and the sealing substrate  600  are adhered to each other by the second adhesion layer  500 , the heat generated in the display panel  200  can be easily dissipated to the outside of the sealing substrate  600  via the heat dissipating layer  400 . 
     The second adhesion layer  500  may include one of epoxy, acrylate and silicone, and a combination thereof, similarly to the first adhesion layer  300 . 
     The second adhesion layer  500  may also be disposed on the top surface of the heat dissipating layer  400  in the film pattern or by such a liquid coating method, similarly to the first adhesion layer  300 . 
     Further, referring to  FIG. 1 , an absorption layer  700 , which may be otherwise referred to as a getter layer may be disposed between the display panel  200  and the sealing portion  800 , in the plan view. The getter layer  700  is disposed to surround the display panel  200 , similarly to the sealing portion  800 . 
     The getter layer  700  can remove moisture or oxygen absorbed into the display panel  200 . The getter layer  700  may include a material which can absorb moisture or oxygen. In one exemplary embodiment, for example, the getter layer  700  may include one of barium oxide, calcium oxide, magnesium oxide, lithium oxide, sodium oxide, potassium oxide, lithium sulfate, sodium sulfate, calcium sulfate, magnesium sulfate, potassium sulfate, potassium chlorate, magnesium chloride, calcium bromide, cesium bromide, vanadium bromide and calcium nitride, and a combination thereof. 
     Hereinafter, an exemplary embodiment of a manufacturing process of a display apparatus in accordance with the invention will be described in brief with reference to  FIG. 2  to  FIG. 7 . 
     First, the display panel  200  is formed (e.g., provided) on the substrate (see  FIG. 2 ). Herein, the display panel  200  is briefly shown in  FIG. 2 , but the display panel  200  may include a plurality of layers as will be described later. 
     The first adhesion layer  300  is formed on the top surface of the display panel  200 . The first adhesion layer  300  may be formed to cover not only the top surface of the display panel  200  but also side surfaces thereof. As described above, the first adhesion layer  300  may be formed on the top surface of the display panel  200  in the film pattern or with the liquid coating method. 
     Successively, the heat dissipating layer  400  may be formed on the top surface of the display panel  200  (see  FIG. 4 ). As described above, the heat generated in the display panel  200  can be transferred to the heat dissipating layer  400  by attaching the heat dissipating layer  400  to the top surface of the display panel  200 . The heat dissipating layer  400  may be formed on the top surface of the display panel  200 , but also may be formed to cover not only the top surface of the display panel  200  but also side surfaces thereof. 
     In  FIG. 4 , a cross-sectional thickness of the first adhesion layer  300  is shown to be similar to that of the heat dissipating layer  400 . However, the cross-sectional thickness of the first adhesion layer  300  may be smaller than that of the heat dissipating layer  400 . A cross-sectional thickness of the first adhesion layer  300  is sufficient if the first adhesion layer  300  adheres and secures the heat dissipating layer  400  to the top surface of the display panel  200 . 
     Referring to  FIG. 5 , the second adhesion layer  500  may be formed on the top surface of the heat dissipating layer  400 . As described above, the second adhesion layer  500  is formed in order to couple the heat dissipating layer  400  and the sealing substrate  600  to each other. Similarly to the first adhesion layer  300 , the second adhesion layer  500  may be formed on the top surface of the heat dissipating layer  400  in the film pattern or with the liquid coating method. 
     The getter layer  700  and the sealing portion  800  are sequentially formed to surround the display panel  200  (see  FIG. 6  and  FIG. 7 ). The getter layer  700  and the sealing portion  800  may be formed at a circumference of the display panel  200  by using a mask. 
     Referring again to  FIG. 1 , after the getter layer  700  and sealing portion  800  are formed, the sealing substrate  600  is located over the getter layer  700 , the sealing portion  800  and the second adhesion layer  500  to complete the sealing of the display panel  200  by the sealing substrate  600 . 
       FIG. 8  is an enlarged and detailed cross-sectional view of an exemplary embodiment of a region P shown in  FIG. 1 . 
     With reference to  FIG. 8 , a display apparatus, particularly including an OLED display, in accordance with the invention will be described in detail. 
     Referring to  FIG. 8 , a driving transistor Qd may be disposed above a display substrate  123  which may include transparent glass, plastic, or the like. Here, the display substrate  123  corresponds to the substrate  100  of  FIG. 1 . 
     A protective layer  122   b  is disposed on the driving transistor Qd. The protective layer  122   b  may include an inorganic material or an organic material. Where the protective layer  122   b  includes the organic material, a surface such as an upper surface thereof may be flat. 
     A via hole  122   a  may be defined in the protective layer  122   b  to expose a portion of the driving transistor Qd. 
     In addition, a first electrode  122   d  is disposed on the protective layer  122   b . The first electrode  122   d  may collectively include a reflective electrode, and a transparent electrode disposed on the reflective electrode. The reflective electrode may include metal having high reflectivity, such as silver (Ag) or aluminum (Al), or an alloy thereof. The transparent electrode may include a transparent conductive oxide, such as indium tin oxide (“ITO”) or indium zinc oxide (“IZO”). 
     A pixel defining layer  122   c  is disposed on the protective layer  122   b  while covering the periphery of the outer edge of the first electrode  122   d.    
     Referring to  FIG. 8 , an organic emission layer  122   e  is disposed on the first electrode  122   d . In addition, a second electrode  122   f  is disposed on the organic emission layer  122   e  and the pixel defining layer  122   c . The first electrode  122   d , the organic emission layer  122   d  and the second electrode  122   f  may collectively form a light emitting element LD. 
     The organic emission layer  122   e  may include a light emission layer (not shown) in which light emission actually occurs, and may further include organic layers (not shown) for effectively transferring carriers, such as holes or electrodes, to the light emission layer. The organic layers may include, but are not limited to, a hole injection layer and a hole transfer layer, which are disposed between the first electrode  122   d  and the light emission layer, and an electron injection layer and an electron transfer layer, which are disposed between the second electrode  122   f  and the light emission layer. 
     Further, a capping layer  125  may be disposed on the second electrode  122   f  to cover and protect the second electrode  122   f , and the capping layer  125  may include an organic layer. 
     In accordance with the illustrated exemplary embodiment, a sealing substrate  130  may be spaced apart from the capping layer  125  in a cross-sectional direction, but the invention is not limited thereto. Here, the sealing substrate  130  shown in  FIG. 8  corresponds to the sealing substrate  600  shown in  FIG. 1 . 
     In an exemplary embodiment, referring to  FIG. 1  and  FIG. 8 , the second adhesion layer  500 , the heat dissipating layer  400  and the first adhesion layer  300  may be sequentially stacked between the capping layer  125  and the sealing substrate  130 . 
     One or more exemplary embodiment of a display apparatus in accordance with the invention can dissipate the heat generated in the display panel thereof, to thereby reduce or effectively prevent deterioration of a light emitting layer such as including the organic emission layer of an OLED display, by disposing the heat dissipating layer between the sealing substrate and the display panel. 
     While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.