Abstract:
Provided herein is a method of manufacturing an organic electroluminescence display device, including the steps of: forming a getter layer on a unit sealing substrate using a dry method; providing a device substrate including a device array formed thereon, the device array including a plurality of unit organic electroluminescence devices; attaching the device substrate to the unit sealing substrate such that the getter layer faces the device array, thus forming a module; and imparting fluidity to the getter layer such that the getter layer covers upper and lateral sides of the device array. The method is advantageous in that fluidity is imparted to the getter layer, so that the upper and lateral sides of the device array is covered by the getter layer, thereby greatly improving the moisture resistance of the organic electroluminescence device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of PCT International Patent Application No. PCT/KR2010/002840, filed May 4, 2010, and Korean Patent Application No. 10-2009-0046850, filed May 28, 2009, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a method of manufacturing an organic electroluminescence display device, and, more particularly, to a method of manufacturing an organic electroluminescence display device having a getter layer. 
         [0004]    2. Description of the Related Art 
         [0005]    An organic electroluminescence device is a device including an anode and a cathode with an organic function film disposed therebetween. The organic function film includes an organic light-emitting layer. The recombination in the organic light-emitting layer of holes injected through the anode and electrons injected through the cathode causes the emission of light. Since such an organic electroluminescence device, unlike a liquid crystal display device, is a device that emits its own light, it has the advantage of not requiring a backlight. Further, since such an organic electroluminescence device, unlike a plasma display device, has a very low driving voltage, there is the advantage of low power consumption. 
         [0006]    However, the organic function film is problematic in that it can be easily deteriorated by moisture. In order to solve this problem, a getter layer may be disposed in an encapsulating substrate which encapsulates the organic electroluminescence device. 
       SUMMARY OF THE INVENTION 
       [0007]    Accordingly, the present invention has been devised to solve the above problem, and an object of the present invention is to provide a method of manufacturing an organic electroluminescence display device having improved moisture resistance. 
         [0008]    Objects of the present invention are not limited to the above-mentioned object, and other objects of the present invention that are not mentioned will be clearly understood by those skilled in the art from the following descriptions. 
         [0009]    In order to accomplish the above object, an aspect of the present invention provides a method of manufacturing an organic electroluminescence display device. The method includes the steps of: forming a getter layer on a unit sealing substrate using a dry method; providing a device substrate including a device array formed thereon, the device array including a plurality of unit organic electroluminescence devices; attaching the device substrate to the unit sealing substrate such that the getter layer faces the device array, thus forming a module; and imparting fluidity to the getter layer such that the getter layer covers upper and lateral sides of the device array. 
         [0010]    Here, the module may be heat-treated to impart fluidity to the getter layer. The getter layer may be a film containing porous nanoparticles and a polymer binder, and the heat treatment of the module may be conducted at a temperature equal to or above a glass transition temperature of the polymer binder. The heat treatment of the module may be conducted using a hot plate, a chamber or an air knife. 
         [0011]    The forming of the getter layer may be conducted by pressing a getter film onto the unit sealing substrate or by an evaporation method. A protective film provided on at least one side of the getter film may be removed before pressing the getter film onto the unit sealing substrate. In the evaporation method, the getter layer may be formed by evaporating porous nanoparticles and monomers to deposit the evaporated porous nanoparticles and monomers on the unit sealing substrate. 
         [0012]    The getter layer may be heat-treated before forming the module. The heat treatment of the getter layer may be conducted using a hot plate, a chamber or an air knife. 
         [0013]    The getter layer may be an optically-transparent getter layer. 
         [0014]    According to the present invention, the upper side and lateral side of the device array is covered with the getter layer by imparting fluidity to the getter layer, thus greatly improving the moisture resistance of the organic electroluminescence device. 
         [0015]    Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0017]      FIGS. 1 to 5  are schematic views sequentially showing a method of manufacturing an organic electroluminescence display device according to an embodiment of the present invention; 
           [0018]      FIG. 6  is a schematic view showing a method of manufacturing an organic electroluminescence display device according to another embodiment of the present invention; and 
           [0019]      FIG. 7  is a schematic view showing a method of manufacturing an organic electroluminescence display device according to still another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0020]    Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures. 
         [0021]    The objects, features and advantages of the present invention will be more clearly understood from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In the present specification, the terms “have”, “include”, “comprise” and the like are used to differentiate a certain component from other components, but the configuration of such components should not be construed to be limited by the terms. Further, in the description of the present invention, in cases where it was determined that the detailed description of the related art would obscure the gist of the present invention, the description thereof has been omitted. 
         [0022]    The terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept of the term to describe the best method he or she knows for carrying out the invention. 
         [0023]      FIGS. 1 to 5  are schematic views sequentially showing a method of manufacturing an organic electroluminescence display device according to an embodiment of the present invention. Concretely,  FIG. 2  is a sectional view taken along the line A-A′of  FIG. 1 . 
         [0024]    Referring to  FIGS. 1 and 2 , a sealing substrate  10  is provided. The sealing substrate  10  includes a plurality of unit sealing substrates  10   u  defined by scribing lines  10   a . The unit sealing substrates  10   u  are described so as to distinguish them from the sealing substrate  10 . The sealing substrate  10  may be an optically-transparent insulation substrate, such as a glass substrate or a plastic substrate or the like. 
         [0025]    A getter layer G is formed on each of the unit sealing substrates  10   u  by a dry method. The dry method is suitably used when the sealing substrate  10  is large, and can form various shapes of getter layers (G). 
         [0026]    As an example of the dry method, the getter layer (G) can be formed by pressing a getter film (GF) onto the unit sealing substrate  10   u.    
         [0027]    The getter film (GF) may be provided on at least one side thereof with a protective film. In this case, the protective film can be removed before pressing the getter film (GF) onto the unit sealing substrate  10   u.    
         [0028]    Specifically, the getter film (GF), the upper side and lower side of which are respectively provided with an upper protective film and a lower protective film, is cut to a predetermined size, the upper side of the getter film (GF) is attached using a vacuum suction machine  50 , and then the lower protective film provided on the lower side of the getter film (GF) is removed. The lower side of the getter film (GF) may be heat-treated to improve the state of the surface thereof. Thereafter, the getter film (GF) is pressed onto the unit sealing substrate  10   u , thus forming the getter layer (G). In this case, the unit sealing substrate  10   u  or the vacuum suction machine  50  is heated to 40˜100          to improve the adhesion between the getter layer (G) and the unit sealing substrate  10   u . Subsequently, the unit sealing substrate  10   u  is cooled to room temperature or lower, and then the upper protective film provided on the upper side of the getter layer (G) can also be removed. 
         [0029]    A plural number of the vacuum suction machines  50  may be used in accordance with the rows of the unit sealing substrates  10   u . Meanwhile, the getter layers (G) may be selectively formed on a part of the unit sealing substrates  10   u , not all of the unit sealing substrates  10   u.    
         [0030]    The getter film (GF) or the getter layer (G) may be an optically-transparent getter, and may be provided with porous nanoparticles and a polymer binder. Examples of the porous nanoparticles may include metal oxides, such as alumina, silica, calcium oxide (CaO), selenium oxide (SeO) and barium oxide (BaO), and carbon compounds. When alumina, silica or a carbon compound is used as the porous nanoparticles, it exists with it chemically bonded with a polymer binder. Further, when calcium oxide (CaO), selenium oxide (SeO) or barium oxide (BaO) is used as the porous nanoparticles, acrylic resin may be employed as the polymer binde. 
         [0031]    Subsequently, the getter layer (G) may be heat-treated. The heat-treatment of the getter layer (G) may be conducted using a hot plate, a chamber or an air knife. As a result, the moisture and solvent included in the getter layer (G) can be removed, and, moreover, the state of the surface of the getter layer (G) can be improved. 
         [0032]    Thereafter, the getter layer (G) is cooled to solidify. 
         [0033]    Referring to  FIG. 3 , the sealing substrate  10  is cut along scribing lines  10   a  to be separated into the unit sealing substrates  10   u.    
         [0034]    Referring to  FIG. 4 , there is provided a device substrate  20   u  on which a device array (ELa) including a plurality of unit organic electroluminescence devices  23  is formed. 
         [0035]    The unit organic electroluminescence device includes a lower electrode  23   a , an upper electrode  23   c  and an organic function film  23   b  disposed between these electrodes  23   a  and  23   c.    
         [0036]    The organic function film  23   b  may include at least one organic light-emitting layer, the lower electrode  23   a  may be an anode, and the upper electrode  23   c  may be a cathode. In this case, the organic function film  23   b  may further include a hole injecting layer and/or a hole transport layer between the lower electrode  23   a  and the organic light-emitting layer, and may further include an electron injecting layer and/or an electron transport layer between the organic light-emitting layer and the upper electrode  23   c.    
         [0037]    Of these electrodes  23   a  and  23   c , the upper electrode  23   c  may be at least an optically-transparent electrode. When the upper electrode  23   c  is a cathode, it may be a Mg—Ag film or an ITO film having a thickness through which light can be transmitted. Considering the difference in the work function between the lower electrode  23   a  and the upper electrode  23   c , when the upper electrode  23   c , which is the cathode, is an Mg—Ag film, the lower electrode  23   a , which is the anode, may be an ITO film. Further, when the upper electrode  23   c , which is the cathode, is an ITO film, the lower electrode  23   a , which is the anode, may be a gold (Au) film or a platinum (Pt) film. 
         [0038]    The process of forming the device array (ELa) on the device substrate  20   u  is described in detail as follows. First, the lower electrode  23   a  extending in a first direction may be formed on the device substrate  20   u . A pixel defining film  25  may be formed on the lower electrode  23   a . A separation pattern  27  extending in a second direction crossing the first direction may be formed on the pixel defining film  25 . The organic function film  23   b  and the upper electrode  23   c  may be sequentially formed on the lower electrode  23   a . In this case, another organic function film  23   b  and another upper electrode  23   c  may also be sequentially formed on the separation pattern  27 . 
         [0039]    Subsequently, a sealant  30  is applied on the periphery of the device array (ELa). The unit sealing substrate  10   u  is disposed over the device substrate  20   u  coated with the sealant  30  such that the getter layer G formed on the unit sealing substrate  10   u  faces the device substrate  20   u . The unit sealing substrate  10   u  and the device substrate  20   u  are attached to each other by pressing in a vacuum to form a unit module (M). The inside of the unit module (M), that is, the space between the unit sealing substrate  10   u  and the device substrate  20   u  may be made vacuous. 
         [0040]    Referring to  FIG. 5 , the upper side and lateral side of the device array (ELa) is covered with the getter layer (G) by imparting fluidity to the getter layer (G). The process of imparting fluidity to the getter layer (G) may be conducted at a normal pressure that is greater than that of a vacuum. In this case, the external pressure is higher than the pressure in the unit module (M), the inside of which is under a vacuum. Therefore, when fluidity is imparted to the getter layer (G), the distance between the unit sealing substrate  10   u  and the device substrate  20   u  decreases, and thus the getter layer (G) can cover the upper side and lateral side of the device array (ELa). 
         [0041]    In this case, since externally-penetrated pollutants, such as moisture, etc., reach the organic function film  23   b  only when they pass through the getter layer (G), the getter layer (G) can sufficiently protect the organic function film  23   b  from the pollutants, such as moisture, etc. Consequently, the moisture resistance of the organic electroluminescence device  23  can be greatly improved. Moreover, the space among the device substrate  20   u , the unit sealing substrate  10   u  and the sealant  30  can be filled with the getter layer (G). 
         [0042]    The process of imparting fluidity to the getter layer (G) can be realized by heat-treating the unit module (M). In the heat treatment of the unit module (M), the heat treatment temperature may be a temperature at which the getter layer (G) can be imparted with fluidity, for example, the glass transition temperature (Tg) or above of a polymer binder included in the getter layer (G). However, since the organic function film  23   b  can be damaged during the course of heat-treating the unit module (M), it is preferable that the heat treatment of the unit module (M) be conducted at low temperature, if possible. For example, the heat treatment temperature may be 40˜100         . The heat treatment of the unit module (M) may be conducted using a hot plate, a chamber or an air knife. 
         [0043]      FIG. 6  is a schematic view showing a method of manufacturing an organic electroluminescence display device according to another embodiment of the present invention. The method according to this embodiment is similar to the method described with reference to  FIGS. 1 to 5 , except for the following description. 
         [0044]    Referring to  FIG. 6 , a getter layer (G) can be formed by pressing a getter film (GF) onto the unit sealing substrate  10   u . Concretely, the getter film (GF) may be disposed beneath a base film  70 . The base film  70  can separate the getter layers (G) such that each of the getter layers (G) corresponds to each of the unit sealing substrates  10   u  because the base film  70  is provided with through-holes  70   a.    
         [0045]    A protective film may be provided on the lower side of the getter film (GF). In this case, the protective film can be removed before pressing the getter film (GF) onto the unit sealing substrate  10   u . The lower side of the getter film (GF) may be heat-treated to improve the state of the surface thereof. 
         [0046]    Thereafter, the upper side of the base film  70  is pressed using a pressing machine, for example, a roller  80 , thus forming the getter layer (G). In this case, the unit sealing substrate  10   u  or the roller  80  is heated to 40˜100          to improve adhesion between the getter layer (G) and the unit sealing substrate  10   u . Subsequently, the unit sealing substrate  10   u  is cooled to room temperature or lower, and then the base film  70  disposed on the upper side of the getter layer (G) can be removed. 
         [0047]    A plural number of the rollers  80  may be used in accordance with the rows of the unit sealing substrates  10   u . Meanwhile, the getter layers (G) may be selectively formed on a part of the unit sealing substrates  10   u , not all of the unit sealing substrates  10   u.    
         [0048]      FIG. 7  is a schematic view showing a method of manufacturing an organic electroluminescence display device according to still another embodiment of the present invention. The method according to this embodiment is similar to the method described with reference to  FIGS. 1 to 5 , except for the following description. 
         [0049]    Referring to  FIG. 7 , a getter layer (G) may be formed by an evaporation method, for example, vapor deposition polymerization or the like. Concretely, a crucible  95 , in which porous nanoparticles and monomers are stored, is heated to evaporate the porous nanoparticles and monomers, and thus the evaporated porous nanoparticles and monomers are deposited on the unit sealing substrate  10   u , thus forming the getter layer (G). In this case, each of the getter layers (G) can be formed on each of the unit sealing substrates  10   u  corresponding to each of the getter layers (G) using a shadow mask  90 . In this procedure, the monomers are polymerized into a polymer binder. If necessary, a polymerization initiator is stored in the crucible  95 , and thus the polymerization initiator can be evaporated together with the porous nanoparticles and the monomers. 
         [0050]    Examples of the porous nanoparticles may include metal oxides, such as alumina, silica, calcium oxide (CaO), selenium oxide (SeO) and barium oxide (BaO), and carbon compounds. When alumina, silica or a carbon compound is used for the porous nanoparticles, it is in a state of being chemically bonded with the monomers. Further, when calcium oxide (CaO), selenium oxide (SeO) or barium oxide (BaO) is used as the porous nanoparticles, metal oxides and monomers are charged in another crucible to co-evaporate the metal oxides and monomers, thus forming the getter layer (G). 
         [0051]    The difference in thickness of the getter layers (G) can be reduced by rotating the sealing substrate  10  in the course of forming the getter layers (G). 
         [0052]    Meanwhile, the getter layers (G) may be selectively formed on a part of the unit sealing substrates  10   u , not all of the unit sealing substrates  10   u . For this purpose, some of the through-holes  90   a  of the shadow mask  90  may be closed. 
         [0053]    Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.