Abstract:
A method for manufacturing a metal encapsulation member is disclosed. The method comprises: preparing a substrate on one side of which an adhesive material is applied; adhering a metal member onto the one side of the substrate; attaching an adhesive member onto the metal member; and removing predetermined portions of the metal member and the adhesive member.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a method for manufacturing a metal encapsulation member. More particularly, the present invention relates to a method for manufacturing a metal encapsulation member, which may facilitate formation of a metal encapsulation member for protecting an organic electroluminescent device. 
     BACKGROUND OF THE INVENTION 
     Electroluminescent devices are actively researched among the other flat panel display devices because they may emit various colors of light, may be easily patterned and made into thin films, and have low direct current driving voltage and high luminous efficiency. 
     In particular, organic electroluminescent devices (OLEDs) do not require a separate light source unlike a conventional thin film transistor liquid crystal display devices (TFT-LCDs), thereby reducing the volume and weight of the devices, and may be driven with a low voltage compared to a plasma display panel. Due to those advantages, organic electroluminescent devices are expected to be widely used in the future. 
     Since an organic electroluminescent device is made of a plurality of organic thin films, it may react with moisture, oxygen and the like so that the lifespan of the device may be shortened. For this reason, a cap for protecting the organic electroluminescent device is covered thereon in various manners so as to prevent the organic electroluminescent device from being exposed to the outside, and such a process is referred to as an encapsulation process. Conventionally, inorganic materials such as glass and ceramic have been mainly used for an encapsulation film of the organic electroluminescent device. 
     An encapsulation film made of an inorganic material such as glass or ceramic does not have problems such as thermal deformation and the like. However, the glass material has a low thermal conductivity, and thus heat generated during the use of the organic electroluminescent device is not released smoothly, causing degradation of electroluminescent layers and reduction in lifespan of the organic electroluminescent device. 
     Accordingly, metallic encapsulation films, particularly made of Invar, have been recently used in some cases in order to solve the problems caused by the encapsulation films made of inorganic materials. Invar is a nickel-iron alloy and so named because it is invariant to temperature changes, i.e. the thermal expansion coefficient thereof is about one millionth at a temperature below 100° C. and nearly zero at room temperature. In general, Invar alloy is used as a material for components of a machine such as a precision machine, optical machine and watch, wherein the change in dimensions of such components due to temperature variation may cause errors. 
     Meanwhile, in order to perform a process of encapsulating an organic electroluminescent device using an encapsulation film made of Invar, a technique for facilitating the encapsulating process is required. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a method for manufacturing a metal encapsulation member, which may facilitate a process for encapsulating an organic electroluminescent device. 
     According to one aspect of the invention to achieve the above-described object, there is provided a method for manufacturing a metal encapsulation member, comprising: preparing a substrate on one side of which an adhesive material is applied; adhering a metal member onto the one side of the substrate; attaching an adhesive member onto the metal member; and removing predetermined portions of the metal member and the adhesive member. 
     In addition, there may be further provided other configurations to implement the present invention. 
     According to the present invention, there is provided a method for manufacturing a metal encapsulation member, which may facilitate a process for encapsulating an organic electroluminescent device. In addition, there is provided a method for manufacturing a metal encapsulation member, which may advantageously reduce costs by simplifying the manufacturing process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 to 7  illustrate a method for manufacturing a metal encapsulation member according to one embodiment of the present invention; and 
         FIGS. 8 and 9  illustrate a method for encapsulating an organic electroluminescent device using a metal encapsulation member according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following detailed description of the present invention, references are made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to carry out the invention. It is to be understood that the various embodiments of the invention, although different from each other, are not necessarily mutually exclusive. For example, specific shapes, structures and characteristics described herein may be implemented as modified from one embodiment to another without departing from the spirit and scope of the invention. Further, it shall be understood that the locations or arrangements of individual elements within each of the embodiments described herein may also be modified without departing from the spirit and scope of the invention. Accordingly, the following detailed description is not to be taken in a limiting sense, and the scope of the invention is to be taken as encompassing the scope of the appended claims and all equivalents thereof, as long as properly described. In the drawings, like reference numerals refer to the same or similar functions throughout the several views, and certain features such as length, area, thickness and shape may be exaggerated for convenience. 
     Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings to enable those skilled in the art to easily carry out the invention. 
       FIGS. 1 to 7  illustrate a method for manufacturing a metal encapsulation member according to one embodiment of the present invention. 
     Referring to  FIG. 1 , a substrate  100 , on one side of which an adhesive material  110  is applied, may be provided and a metal member  200  may be adhered onto the one side where the adhesive material  110  is applied. 
     The substrate  100  is preferably flexible to allow the substrate  100  to be easily removed, because the substrate  100  is removed when an encapsulation process for an organic electroluminescent device is performed later using a metal encapsulation member manufactured according to one embodiment of the present invention. Accordingly, the substrate  100  is preferably made of a material such as PET. 
     The metal member  200  may serve to prevent oxygen, moisture, or other particles from permeating into the device from outer environments. The metal member  200  according to one embodiment of the present invention is preferably made of an iron-nickel (Fe—Ni) alloy including Invar. Invar refers to an iron-nickel alloy consisted of 36% nickel and 64% iron. Since the coefficient of thermal expansion (CTE) of Invar is very small, it may prevent the problem of reduction in reliability and lifespan of the organic electroluminescent device caused by deformation occurring when employing other metallic materials (e.g., thermal deformation occurring at a contact region between the substrate and the metal member due to repeated temperature increase and decrease resulting from the heat generated when driving the organic electroluminescent device). In addition, since the metal member  200  made of Invar has a high thermal conductivity, the heat generated in the organic electroluminescent device may be smoothly released, thereby preventing degradation of the organic electroluminescent device. Besides Invar, the metal member  200  according to one embodiment of the present invention may also employ an iron-nickel alloy consisted of 42% nickel and 58% iron. In order to ensure alignment between the substrate  100  and the metal member  200 , alignment keys  101  and  201  may be formed on the substrate  100  and the metal member  200 , respectively.  FIG. 2  illustrates that the metal member  200  is adhered onto the one side of the substrate  100  where the adhesive material  110  is applied. 
     Referring to  FIG. 3 , an adhesive member  300  may be attached onto the metal member  200 . The adhesive member  300  serves as a filler material and has an adhesive property so that it may also serve to improve the adhesive strength between the metal member  200  and the organic electroluminescent device. The adhesive member  300  may employ a resin, which is an organic substance. Further, the adhesive member  300  consisted of a thin plate made of a resin or the like may be stored in a rolled state before it is attached onto the metal member  200 , and a protective film  310  may be attached onto one side of the adhesive member  300  in order to facilitate the storage. Accordingly, the adhesive member  300  in a rolled state may be unwound to be placed on the metal member  200 , and a pressure may be applied to cause the adhesive member  300  and the metal member  200  to be attached to each other. 
     Referring to  FIG. 4 , predetermined portions of the metal member  200 , the adhesive member  300  and the protective film  310  may be removed. The portions indicated by dotted lines in  FIG. 4  represent where a press cutter is applied to remove the corresponding portions from the metal member  200 , the adhesive member  300  and the protective film  310 . That is, predetermined portions of the metal member  200 , the adhesive member  300  and the protective film  310  may be removed to conform to the size and shape of the organic electroluminescent device. To this end, an apparatus such as a press cutter may be used. Accordingly, as compared to the conventional method for manufacturing a metal encapsulation member, the method for manufacturing a metal encapsulation member according to the present invention has an advantage of manufacturing the metal encapsulation member through a simple process. 
       FIG. 5A  illustrates the metal member  200 ′, the adhesive member  300 ′ and the protective film  310 ′ after removing the predetermined portions of the metal member  200  and the adhesive member  300 , and  FIG. 5B  is a top view of  FIG. 5A . 
     Referring to  FIG. 6 , the protective film  310 ′ formed on the adhesive member  300 ′ may be removed. The protective film  310 ′ may not be an essential component in a metal encapsulation member  10  to be eventually formed, because it is attached to one side of the adhesive member  300 ,  300 ′ to facilitate the storage of the adhesive member  300 ,  300 ′ in a rolled state, as described above. Upon removing the protective film  310 ′, the remaining structure may be considered as the metal encapsulation member  10  for encapsulating the organic electroluminescent device. Meanwhile, in order to store the metal encapsulation member until it is used for encapsulating the organic electroluminescent device, the metal encapsulation member may be protected by a protective member  400  to be described below. 
     Referring to  FIG. 7 , the protective member  400  may be attached onto the substrate  100  to enclose the metal member  200 ′ and the adhesive member  300 ′ remaining after the predetermined portions thereof are removed. As described above, the protective member  400  is provided to prevent the metal encapsulation member  10  from being exposed to the outside and damaged while the metal encapsulation member  10  is stored until it is used for encapsulating the organic electroluminescent device. 
       FIGS. 8 and 9  illustrate a method for encapsulating an organic electroluminescent device using a metal encapsulation member according to one embodiment of the present invention. The method for encapsulating an organic electroluminescent device using a metal encapsulation member will be described below with reference to  FIGS. 8 and 9 . First, as illustrated in  FIG. 8 , the protective member  400  on the metal encapsulation member  10  is removed and the metal encapsulation member  10  may be turned over and disposed such that the adhesive member  300 ′ faces downward. In that state, the adhesive member  300 ′ is placed on the organic electroluminescent device  500  and  550 , and a pressure is applied to the organic electroluminescent device and the metal encapsulation member  10  such that the adhesive member  300 ′ may be attached to the organic electroluminescent device  500  and  550 . Then, as illustrated in  FIG. 9 , the substrate  100  and the adhesive material  110  may be removed when the adhesive member  300 ′ is attached to the organic electroluminescent device  500  and  550 . 
     Although the present invention has been illustrated and described as above in connection with the preferred embodiments, the invention is not limited to the above embodiments, and various modifications and changes may be made by those skilled in the art without departing from the spirit and scope of the invention. Such modifications and changes should be considered to fall within the scope of the present invention and the appended claims.