Abstract:
Disclosed herein is a printed circuit board including: a substrate; one or more elastic electrode formed on the substrate and made of an elastic material; and one or more metal electrode formed on the elastic electrode.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2012-0080655, filed on Jul. 24, 2012, entitled “Printed Circuit Board and Method for Manufacturing of Printed Circuit Board”, which is hereby incorporated by reference in its entirety into this application. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field The present invention relates to a printed circuit board and a method for manufacturing the same. 
         [0003]    2. Description of the Related Art 
         [0004]    A printed circuit board is a board that electrically connects a plurality of components to an electrical or electronic device to enable the components electrically connected to each other to exchange power or electrical signals with each other. The printed circuit board has been widely used throughout electrical and electronic devices, such as mobile phones, laptop computers, display devices, or the like. 
         [0005]    The printed circuit board may be divided into a rigid substrate, a flexible substrate, or a rigid and flexible substrate. Here, the flexible substrate may be bent. 
         [0006]    At the time of forming the printed circuit board, the printed circuit board is subjected to various high temperature processes, such that a deformation such as warpage, or the like, may be generated in the printed circuit board. In addition, the flexible substrate may be mounted with the electronics components in the state in which it is bent. In this case, in order to electrically connect the printed circuit board to an external electronic component, an electrode may be formed on the printed circuit board. In general, the electrode may be formed on the printed circuit board in a length or width direction (U.S. Pat. No. 7,593,085). As described above, in the case in which the printed circuit board is excessively deformed, damage such as disconnection, or the like, of the electrodes formed on the printed circuit board may be generated. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention has been made in an effort to provide a printed circuit board having high durability against a deformation thereof; and a method for manufacturing the same. 
         [0008]    Further, the present invention has been made in an effort to provide a printed circuit board having improved reliability, and a method for manufacturing the same. 
         [0009]    Further, the present invention has been made in an effort to provide a printed circuit board capable of being implemented in a micro thin thickness, and a method for manufacturing the same. 
         [0010]    According to a preferred embodiment of the present invention, there is provided a printed circuit board including: a substrate; one or more elastic electrode formed on the substrate and made of an elastic material; and one or more metal electrode formed on the elastic electrode. 
         [0011]    The elastic electrode may be made of graphene or graphene oxide. 
         [0012]    The metal electrode may be made of a conductive metal. 
         [0013]    The printed circuit board may further include a seed layer formed between the metal electrode and the elastic electrode. 
         [0014]    The metal electrodes may be formed on both sides of the elastic electrodes. 
         [0015]    According to another preferred embodiment of the present invention, there is provided a method for manufacturing a printed circuit board, the method including: preparing a carrier member having metal layers formed over the entire upper surface thereof; primarily patterning the metal layers; forming elastic metal layers on the primarily patterned metal layers and the carrier member; forming a substrate on the elastic metal layers; forming elastic electrodes by removing the carrier member; and forming metal electrodes by secondarily patterning the primarily patterned metal layer. 
         [0016]    The forming of the primarily patterned metal layers may be performed by patterning the metal layers in a form corresponding to the elastic electrodes. 
         [0017]    In the forming of the metal electrodes, the secondary patterning may be performed on the primarily patterned metal layers so that one or more metal electrodes are formed on the elastic electrodes. 
         [0018]    In the forming of the metal electrodes, the secondary patterning may be performed on the primarily patterned metal layers so that the metal electrodes are formed on both sides of the elastic electrodes. 
         [0019]    The metal electrodes may be made of a conductive metal. 
         [0020]    In the forming of the elastic metal layers, the elastic metal layers may be formed by an oxidation and reduction method. 
         [0021]    The elastic metal layers may be made of graphene or graphene oxide. 
         [0022]    According to another preferred embodiment of the present invention, there is provided a method for manufacturing a printed circuit board, the method including: preparing a carrier member having metal layers formed over the entire upper surface thereof; primarily patterning the metal layers; forming elastic electrodes on the primarily patterned metal layers; forming a substrate on the elastic electrodes; removing the carrier member; and forming metal electrodes by secondarily patterning the primarily patterned metal layers. 
         [0023]    The forming of the primarily patterned metal layers may be performed by patterning the metal layers in a form corresponding to the elastic electrodes 
         [0024]    In the forming of the elastic electrodes, the elastic electrodes may be formed by a chemical vapor deposition (CVD). 
         [0025]    The method may further include, after the forming of the primarily patterned metal layers, forming seed layers on the primarily patterned metal layers. 
         [0026]    In the forming of the metal electrodes, the secondary patterning may be performed on the primarily patterned metal layers so that one or more metal layers are formed on the elastic electrodes. 
         [0027]    In the forming of the metal electrodes, the secondary patterning may be performed on the primarily patterned metal layers so that the metal electrodes are formed on both sides of the elastic electrodes. 
         [0028]    The metal electrodes may be made of a conductive metal. 
         [0029]    The elastic metal layer may be made of graphene or graphene oxide. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0031]      FIG. 1  is a view showing a printed circuit board according to a preferred embodiment of the present invention; 
           [0032]      FIGS. 2 to 7  are views showing a method for manufacturing a printed circuit board according to a preferred embodiment of the present invention; and 
           [0033]      FIGS. 8 to 14  are views showing a method for manufacturing a printed circuit board according to another preferred embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    The objects, features and advantages of the present invention will be more clearly understood from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant descriptions thereof are omitted. Further, in the following description, the terms “first”, “second”, “one side”, “the other side” 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, when it is determined that the detailed description of the related art would obscure the gist of the present invention, the description thereof will be omitted. 
         [0035]    Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. 
         [0036]      FIG. 1  is a view showing a printed circuit board according to a preferred embodiment of the present invention. 
         [0037]    Referring to  FIG. 1 , a printed circuit board  100  may be configured to include a substrate  130 , an elastic electrode  121 , a metal electrode  111 , and a seed layer  140 . 
         [0038]    In order to assist in understanding the present invention, a plan view of the printed circuit board  100  according to the preferred embodiment of the present invention, and a front view (A-A′) and a side view of the printed circuit board  100  based on the plan view are shown in  FIG. 1 , respectively. 
         [0039]    The substrate  130  may be at least one of a flexible substrate, a rigid substrate, and a rigid and flexible substrate. For example, in the case in which the substrate  130  is the flexible substrate, the substrate  130  may be formed of a polymer film, such as a poly imide (PT) film, a polyethyleneterephthalate (PET) film, or the like. 
         [0040]    The elastic electrode  121  may be formed on the substrate  130 . The elastic electrode  121  may be made of graphene or graphene oxide. The graphene may be made of carbon atoms and be a thin film having a thickness of one carbon atom. The graphene may have electric conductivity about 100 times or more higher than that of copper. In addition, the graphene may be a substance capable of moving an electron at a speed about 100 times or more faster than that of single crystal silicon mainly used in a semiconductor. In addition, the graphene may have strength 200 times or more stronger than that of steel and have thermal conductivity two times or more higher than that of diamond. In addition, the graphene may be a substance that has excellent elasticity to maintain an electric property thereof even in the case of being strained or bent. 
         [0041]    The metal electrode  111  may be formed on the elastic electrode  121 . For example, the metal electrodes  111  may be formed on both sides of the elastic electrode  121 . The metal electrodes  111  may be formed on a region in which occurrence of deformation of the substrate  130  is less. In the case in which the substrate  130  is bent, the largest deformation is generated at a central region of the substrate  130  and less deformation is generated at regions of both sides thereof as compared to the central region. Therefore, the metal electrodes  111  may be formed on both sides of the elastic electrode  121  formed on the substrate  130 . The metal electrode  111  may be made of a conductive metal. 
         [0042]    The seed layer  140  may be formed between the elastic electrode  121  and the metal electrode  111 . The seed layer  140  may serve as a lead line when the elastic electrode  121  is formed. The seed layer  140  may be made of a conductive metal. For example, the seed layer  140  may be made of the same conductive metal as that of the metal electrode  111 . Although the preferred embodiment of the present invention shows the case in which the printed circuit board  100  includes the seed layer  140 , the present invention is not limited thereto. That is, the metal electrode  111  serves as the lead line for forming the elastic electrode  121 , such that the seed layer  140  may be omitted. 
         [0043]    According to the preferred embodiment of the present invention, the metal electrodes  111  may be formed on both sides of the substrate  130  so as to be spaced apart from each other. The metal electrodes  111  formed so as to be spaced apart from each other as described above may be electrically connected to each other by the elastic electrode  121 . Since the elastic electrode  121  is made of the graphene to have excellent elasticity, even though deformation is generated in the substrate  130 , the possibility that a defect such as electrode disconnection, or the like will be generated is low. That is, according to the preferred embodiment of the present invention, the metal electrodes  111  are formed on both sides of the substrate  130  in which the deformation is hardly generated and are connected to each other by the elastic electrode  121  having the high elasticity, thereby making it possible to improve durability and reliability of the printed circuit board  100 . 
         [0044]      FIGS. 2 to 7  are views showing a method for manufacturing a printed circuit board according to a preferred embodiment of the present invention. 
         [0045]    In order to assist in understanding the method for manufacturing a printed circuit board according the preferred embodiment of the present invention, a plan view of the printed circuit board, and a front view (A-A′) and a side view (B-B′) of the printed circuit board based on the plan view are shown in  FIGS. 2 to 7 , respectively. 
         [0046]    Referring to  FIG. 2 , a carrier member  200  having a metal layer  110  formed thereon may be provided. Here, the metal layer  110  may be formed over the entire upper surface of the carrier member  200 . According to the preferred embodiment of the present invention, the carrier member  200  may have a film form such as a metal foil, a polymer film, or the like. 
         [0047]    The metal layer  110  may be later patterned to become a metal electrode  111 . The metal layer  110  may be made of a conductive metal. 
         [0048]    Referring to  FIG. 3 , the metal layer  110  may be primarily patterned. The primary patterning may be performed so that the metal layer  110  remains only on a portion on which the metal electrode  111  is to be formed. That is, remaining regions of the metal layer  100  except for the region on which the metal electrode  111  is to be formed may be etched. Here, the primary patterning may be performed using any one of general etching methods such as wet etching, dry etching such as reactive ion etching (RIE), and the like. 
         [0049]    Referring to  FIG. 4 , an elastic metal layer  120  may be formed. The elastic metal layer  120  may be formed on the primarily patterned metal layer  100  and the carrier member  200  exposed by the patterning of the metal layer  110 . The elastic metal layer  120  may be made of graphene or graphene oxide. The graphene may be made of carbon atoms and be a thin film having a thickness of one carbon atom. The graphene may have electric conductivity of about 100 times or more higher than that of copper. In addition, the graphene may be a substance capable of moving an electron at a speed about 100 times or more faster than that of a single crystal silicon mainly used in a semiconductor. In addition, the graphene may have strength 200 times or more stronger than that of steel and have thermal conductivity two times or more higher than that of diamond. In addition, the graphene may be a substance that has excellent elasticity to maintain electric property thereof even in the case of being strained or bent. 
         [0050]    The elastic metal layer  120  may be formed using a reduction method. In addition, an elastic electrode  121  may be formed using a well-known non-selective forming method as well as the reduction method. 
         [0051]    Referring to  FIG. 5 , a substrate  130  may be formed on the elastic metal layer  120 . The substrate  130  may be at least one of a flexible substrate, a rigid substrate, and a rigid and flexible substrate. For example, in the case in which the substrate  130  is the flexible substrate, the substrate  130  may be formed of a polymer film such as a poly imide (P 1 ) film, a poly ethylene terephthalate (PET) film, or the like. The substrate  130  may be formed on the elastic electrode  121  by a method such as a spray coating method, a lamination method, or the like. 
         [0052]    Referring to  FIG. 6 , the carrier member  200  may be removed. Since the carrier member  200  is attached in a film form to the metal layer  100 , it may be easily removed from the primarily patterned metal layer  110 . When the carrier member  200  is removed, the elastic metal layer  120  formed on the carrier member  200  may also simultaneously removed. Here, as the carrier member  200  is removed, the elastic metal layer  120  may be patterned so as to remain only on the primarily patterned metal layer  110 . That is, the elastic metal layer  120  may be patterned in a form of the elastic electrode  121 . 
         [0053]    Referring to  FIG. 7 , one or more metal electrodes  111  may be formed. As the carrier member  200  is removed, the primarily patterned metal layer  110  may be exposed to the outside. The exposed primarily patterned metal layer  110  may be secondarily patterned to form the metal electrode  111 . By the secondary patterning, one or more metal electrodes  111  may be formed on the elastic electrodes  121 . Here, according to the preferred embodiment of the present invention, the metal electrodes  111  may be formed on both sides of the elastic electrodes  121  corresponding to positions at which deformation is hardly generated, by the secondary patterning. The secondary patterning may be performed using any one of wet etching, dry etching such as reactive ion etching (RIE), and the like. 
         [0054]    That is, according to the preferred embodiment of the present invention, the printed circuit board  100  including the metal electrodes  111  formed on both sides of the substrate  130  and the elastic electrode  121  electrically connecting the metal electrodes  111  to each other may be formed. 
         [0055]      FIGS. 8 to 14  are views showing a method for manufacturing a printed circuit board according to another preferred embodiment of the present invention. 
         [0056]    In order to assist in understanding the method for manufacturing the printed circuit board according to another preferred embodiment of the present invention, a plan view of the printed circuit board, and a front view (A-A′) and a side view (B-B′) of the printed circuit board based on the plan view are shown in  FIGS. 8 to 14 , respectively. 
         [0057]    Referring to  FIG. 8 , a carrier member  200  having a metal layer  110  formed thereon may be provided. Here, the metal layer  110  may be formed over the entire upper surface of the carrier member  200 . According to the preferred embodiment of the present invention, the carrier member  200  may have a film form such as a metal foil, a polymer film, or the like. 
         [0058]    The metal layer  110  may be then patterned and become a metal electrode  111 . The metal layer  110  may be made of a conductive metal. 
         [0059]    Referring to  FIG. 9 , the metal layer  110  may be primarily patterned. The primary patterning may be performed so that the metal layer  110  remains only on a portion on which the metal electrode  111  is to be formed. That is, remaining regions of the metal layer  100  except for the region on which the metal electrode  111  is to be formed may be etched. Here, the primary patterning may be performed using any one of general etching methods such as wet etching, dry etching such as reactive ion etching (RIE), and the like. 
         [0060]    Referring to  FIG. 10 , seed layers  140  may be formed. The seed layers  140  may be formed on the primarily patterned metal layers  110 . The seed layer  140  may be formed by an electroless plating method. The seed layer  140  may be made of a conductive metal. For example, the seed layer  140  may be made of the same metal as that of the metal layer  110 . 
         [0061]    Referring to  FIG. 11 , elastic electrodes  121  may be formed. The elastic electrode  121  may be formed on the seed layer  140 . The elastic electrode  121  may be made of graphene or graphene oxide. The graphene may be made of carbon atoms and be a thin film having a thickness of one carbon atom. The graphene may have electric conductivity about 100 times or more higher than that of copper. In addition, the graphene may be a substance capable of moving an electron at a speed about 100 times or more faster than that of single crystal silicon mainly used in a semiconductor. In addition, the graphene may have strength 200 times or more stronger than that of steel and have thermal conductivity two times or more higher than that of diamond. In addition, the graphene may be a substance that has excellent elasticity to maintain electric property thereof even in the case of being strained or bent. 
         [0062]    The elastic electrode  121  may be formed by a chemical vapor deposition (CVD) method. The elastic electrode  121  may be formed using any method in which it may be selectively formed, such as the CVD method. Although the preferred embodiment of the present invention shows the case in which the elastic electrode  121  is formed on the seed layer  140  by way of example, the present invention is not limited thereto. The elastic electrode  121  may be formed on the primarily patterned metal layer  110  using the primarily patterned metal layer  110  as the seed layer. That is, the process of forming the seed layer  140  may be omitted before forming the elastic electrode  121 . 
         [0063]    Referring to  FIG. 12 , a substrate  130  may be formed on the elastic electrode  121 . The substrate  130  may be at least one of a flexible substrate, a rigid substrate, and a rigid and flexible substrate. For example, in the case in which the substrate  130  is the flexible substrate, the substrate  130  may be formed of a polymer film such as a poly imide (P 1 ) film, a polyethyleneterephthalate (PET) film, or the like. The substrate  130  may be formed on the elastic electrode  121  by a method such as a spray coating method, a lamination method, or the like. 
         [0064]    Referring to  FIG. 13 , the carrier member  200  may be removed. Since the carrier member  200  is attached in a film form to the metal layer  100 , it may be easily removed from the primarily patterned metal layer  110 . 
         [0065]    Referring to  FIG. 14 , one or more metal electrodes  111  may be formed. AS the carrier member  200  is removed, the primarily patterned metal layer  110  may be exposed to the outside. The exposed primarily metal layer  110  may be secondarily patterned to form the metal electrode  111 . By the secondary patterning, one or more metal electrodes  111  may be formed on the elastic electrodes  121 . Here, according to the preferred embodiment of the present invention, the metal electrodes  111  may be formed on both sides of the elastic electrodes  121  corresponding to positions at which deformation is hardly generated, by the secondary patterning. The secondary patterning may be performed using any one of general etching methods such as wet etching, dry etching such as reactive ion etching (RIE), and the like. 
         [0066]    That is, according to the preferred embodiment of the present invention, the printed circuit board  100  including the metal electrodes  111  formed on both sides of the substrate  130  and the elastic electrode  121  electrically connecting the metal electrodes  111  to each other may be formed. 
         [0067]    With the printed circuit board and the method for manufacturing the same according to the preferred embodiments of the present invention, the metal electrodes are formed on both sides of the substrate and the metal electrodes formed on both sides of the substrate are connected to each other by the elastic electrodes made of the graphene, thereby making it possible to provide the printed circuit board having high durability against the deformation thereof. 
         [0068]    With the printed circuit board and the method for manufacturing the same according to the preferred embodiments of the present invention, the elastic electrodes are made of the grapheme, thereby making it possible to improve the durability and the reliability of the printed circuit board. 
         [0069]    With the printed circuit board and the method for manufacturing the same according to the preferred embodiments of the present invention, the elastic electrode has a very thin thickness, thereby making it possible to implement a micro thin printed circuit board. 
         [0070]    Although the embodiments of the present invention have been disclosed for illustrative purposes, it will be appreciated that the present invention is not limited thereto, and those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. 
         [0071]    Accordingly, any and all modifications, variations or equivalent arrangements should be considered to be within the scope of the invention, and the detailed scope of the invention will be disclosed by the accompanying claims.