Abstract:
Disclosed herein is a carrier for manufacturing a printed circuit board, including: a magnetic sheet; and a metal layer attached to at least one side of the magnetic sheet by magnetic properties of the magnetic sheet. The carrier is advantageous in that its structure can be simplified without performing a vacuum or releasing process at the time of the attachment and separation of the carrier, thus reducing process cost and process time and maintaining the size of a printed circuit board.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2009-0125592, filed Dec. 16, 2009, entitled “A carrier for manufacturing a printed circuit board and a method of manufacturing the same and a method of manufacturing a printed circuit board using the same”, which is hereby incorporated by reference in its entirety into this application. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a carrier for manufacturing a printed circuit board, a method of manufacturing the same and a method of manufacturing a printed circuit board using the same. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, printed circuit boards (PCBs) are manufactured by patterning one or both sides of a substrate, composed of various thermosetting resins, using copper foil, and disposing and fixing ICs or electronic parts on the substrate to form an electric circuit and then coating the substrate with an insulator. 
         [0006]    Recently, with the advancement of the electronics industry, electronic parts are increasingly required to be highly functionalized, light, thin, short and small. Thus, printed circuit boards loaded with such electronic parts are also required to be highly densified and thin. 
         [0007]    In particular, in order to keep up with the thinning of printed circuit boards, a coreless substrate which can decrease thickness by removing a core and can shorten a signal processing time is attracting considerable attention. However, a coreless substrate needs a carrier serving as a support during a process because it does not have a core. 
         [0008]      FIGS. 1 to 5  show a conventional method of manufacturing a printed circuit board using a carrier. Hereinafter, the conventional method of manufacturing a printed circuit board using a carrier will be described with reference to  FIGS. 1 to 5 . 
         [0009]    First, as shown in  FIG. 1 , a carrier  10  is provided. Specifically, the carrier  10  is fabricated by sequentially forming adhesive layers  12 , first metal layers  13  and second metal layers  14  on both sides of a copper clad laminate (CCL)  11  including an insulation layer and copper foil layers formed on both sides of the insulation layer. In this case, the carrier  10  is heated and pressed by a high-temperature and high-pressure press, and thus both ends of the adhesive layers  12  are attached to the copper clad laminate  11  and the second metal layer  14 . Meanwhile, the first metal layer  13  is not attached to the second metal layer  14 , but is only brought into contact with the second metal layer  14 . 
         [0010]    Subsequently, as shown in  FIG. 2 , build up layers  15  are formed on both sides of the carrier  10 , and third metal layers  16  are formed on the outermost insulation layers of the build up layers  15 . Here, the build up layers  15  are formed in a general manner, and may be additionally provided with vias for connecting build up circuit layers. Further, the third metal layers  16  are formed in order to prevent the warpage of the build up layers  15 . 
         [0011]    Subsequently, as shown in  FIG. 3 , the build up layers  15  are separated from the carrier  10 . In this case, the build up layers  15  are separated from the carrier  10  by removing both ends of the adhesive layer  12 , through which the copper clad laminate  11  and the second metal layer  14  are attached to each other, by a routing process. The first metal layer  13 , which serves as a release layer, is easily separated from the second metal layer  14  when the adhesive layer  12  is removed, because the first metal layer  13  is not attached to the second metal layer  14 . 
         [0012]    Subsequently, as shown in  FIG. 4 , the second metal layer  14  and third metal layer  16  formed on the build up layer  15  are remove by etching. 
         [0013]    Subsequently, as shown in  FIG. 5 , openings  17  for exposing pads  19  are formed in the outermost insulation layers of the build up layer  15 , and then solder balls  18  are formed on the pads  19 . 
         [0014]    However, the conventional method of manufacturing a printed circuit board using a carrier is problematic in that both ends of a printed circuit board are removed by a to routing process, thus decreasing the size of a printed circuit board. 
         [0015]    Further, the conventional method of manufacturing a printed circuit board using a carrier is problematic in that process cost and process time are increased because a vacuum method is used in order to strengthen the conjunction of the carrier  10  or a release layer is additionally formed in order to easily separate the build up layers  15  from the carrier  10 . 
       SUMMARY OF THE INVENTION 
       [0016]    Accordingly, the present invention has been made to solve the above-mentioned problems, and the present invention provides a carrier for manufacturing a printed circuit board, by which the size of a printed circuit board is maintained even when the carrier is separated from the printed circuit board, a method of manufacturing the carrier, and a method of manufacturing a printed circuit board using the carrier. 
         [0017]    Further, the present invention provides a carrier for manufacturing a printed circuit board, by which process cost and process time can be decreased by simplifying the structure of the carrier without using a vacuum method or inserting a release layer, a method of manufacturing the carrier, and a method of manufacturing a printed circuit board using the carrier. 
         [0018]    An aspect of the present invention is to provide a carrier for manufacturing a printed circuit board, including: a magnetic sheet; and a metal layer attached to at least one side of the magnetic sheet by magnetic properties of the magnetic sheet. 
         [0019]    Here, the magnetic sheet may contain glass fiber. 
         [0020]    Further, the magnetic sheet may contain magnetic fillers having magnetic properties. 
         [0021]    Further, the metal layer may be made of nickel (Ni), cobalt (Co), chromium (Cr), iron (Fe), or manganese (Mn). 
         [0022]    Further, the magnetic sheet may include a sheet, and a magnetic metal layer formed on at least one side of the sheet. 
         [0023]    Another aspect of the present invention provides a method of manufacturing a carrier for manufacturing a printed circuit board, including: providing a magnetic sheet; and attaching a metal layer to at least one side of the magnetic sheet by magnetic properties of the magnetic sheet. 
         [0024]    Here, in the providing of the magnetic sheet, the magnetic sheet may contain glass fiber. 
         [0025]    Further, in the providing of the magnetic sheet, the magnetic sheet may contain magnetic fillers having magnetic properties. 
         [0026]    Further, in the attaching of the metal layer, the metal layer may be made of nickel (Ni), cobalt (Co), chromium (Cr), iron (Fe), or manganese (Mn). 
         [0027]    Further, the providing of the magnetic sheet may include: providing a sheet; and forming a magnetic metal layer having magnetic properties on at least one side of the sheet. 
         [0028]    Still another aspect of the present invention provides a method of manufacturing a printed circuit board using a carrier, including: attaching a metal layer to at least one side of a magnetic sheet by the magnetic properties of the magnetic sheet to provide a carrier; sequentially forming a first protective layer, a build up layer and a second protective layer on the metal layer; and separating the metal layer from the magnetic sheet and then removing the metal layer. 
         [0029]    Here, in the providing of the carrier, the metal layer may be made of nickel (Ni), cobalt (Co), chromium (Cr), iron (Fe), or manganese (Mn). 
         [0030]    Further, in the providing of the carrier, the magnetic sheet may contain glass fiber. 
         [0031]    Further, in the providing of the carrier, the magnetic sheet may contain magnetic fillers having magnetic properties. 
         [0032]    Further, the providing of the carrier may include: forming a magnetic metal layer having magnetic properties on at least one side of a sheet to provide a magnetic sheet; and attaching a metal layer to the magnetic metal layer by the magnetic properties of the magnetic metal layer. 
         [0033]    Further, the separating the metal layer from the magnetic sheet may include: separating the metal layer from the magnetic sheet; removing the metal layer by etching; and forming openings for exposing pads of outermost circuit layers of the build up layer in the exposed first protective layer and second protective layer. 
         [0034]    Still another aspect of the present invention provides a method of manufacturing a printed circuit board using a carrier, including: attaching a metal layer to at least one side of a magnetic sheet by the magnetic properties of the magnetic sheet to provide a carrier; sequentially forming a circuit layer and a build up layer on the metal layer; and separating the metal layer from the magnetic sheet and then removing the metal layer. 
         [0035]    Here, the separating of the metal layer from the magnetic sheet may include: separating the metal layer from the magnetic sheet; removing the metal layer by etching; forming protective layers on both sides of the exposed build up layer; and forming openings for exposing pads of the circuit layer and outermost circuit layers of the build up layer in the protective layers. 
         [0036]    Further, the circuit layer may be made of a metal different from the metal layer. 
         [0037]    Various objects, advantages and features of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings. 
         [0038]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]    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: 
           [0040]      FIGS. 1 to 5  are sectional views sequentially showing a conventional method of manufacturing a printed circuit board using a carrier; 
           [0041]      FIG. 6  is a sectional view showing a carrier for manufacturing a printed circuit board according to a first embodiment of the present invention; 
           [0042]      FIG. 7  is a sectional view showing a carrier for manufacturing a printed circuit board according to a second embodiment of the present invention; 
           [0043]      FIGS. 8 and 9  are sectional views sequentially showing a method of manufacturing the carrier shown in  FIG. 6 ; 
           [0044]      FIGS. 10 to 12  are sectional views sequentially showing a method of manufacturing the carrier shown in  FIG. 7 ; 
           [0045]      FIGS. 13 to 17  are sectional views sequentially showing a method of manufacturing a printed circuit board using a carrier according to a first embodiment of the present invention; and 
           [0046]      FIGS. 18 to 22  are sectional views sequentially showing a method of manufacturing a printed circuit board using a carrier according to a second embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0047]    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. 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” 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. 
         [0048]    Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. 
         [0049]    A Carrier for Manufacturing a Printed Circuit Board 
         [0050]      FIG. 6  is a sectional view showing a carrier for manufacturing a printed circuit board according to a first embodiment of the present invention. Hereinafter, the carrier  100   a  for manufacturing a printed circuit board according to a first embodiment of the present invention will be described with reference to  FIG. 6 . 
         [0051]    As shown in  FIG. 6 , the carrier  100   a  for manufacturing a printed circuit board according to this embodiment includes a magnetic sheet  101   a  and a metal layer  104  formed on at least one side of the magnetic sheet  101   a.    
         [0052]    The magnetic sheet  101   a,  on one side or both sides of which the metal layers  104  are formed, includes a sheet  102  and magnetic fillers  103   a.    
         [0053]    Here, the sheet  102 , which serves to support a printed circuit board at the time of manufacturing the printed circuit board, is required to have high strength. For example, the strength of the sheet  102  can be increased by the addition of glass fiber. Further, the sheet may be made of a non-insulating material, such as a metal, or an insulating material, such as an epoxy resin. 
         [0054]    The magnetic fillers  103   a  are particles having magnetic properties, and the magnetic layers  104  are attached to the magnetic sheet  101   a  by the magnetic properties of the magnetic fillers  103   a.  The magnetic fillers  103  may be metal fillers such as nickel, iron or the like or may be ferrite fillers such as Ni—Cu—Zn ferrite, An—Zn ferrite or the like. Meanwhile, although it is shown in  FIG. 6  that the magnetic fillers  103   a  are distributed in the sheet  102 , the magnetic fillers  103   a  may be applied on the sheet  102 . 
         [0055]    The metal layers  104  are attached to one side or both sides of the magnetic sheet  101   a.    
         [0056]    Here, the metal layers  104  may be made of a material attaching to magnetic materials, such as nickel, cobalt, chromium, iron, manganese or the like. Meanwhile, the metal layers  104  may be made of a high-strength material because they constitute the carrier  100   a  together with the magnetic sheet  101   a.    
         [0057]    Further, although it is shown in  FIG. 6  that the metal layers  104  are formed on both sides of the magnetic sheet  101   a,  the metal layer  104  may be formed on one side of the magnetic sheet  101   a.    
         [0058]      FIG. 7  is a sectional view showing a carrier for manufacturing a printed circuit board according to a second embodiment of the present invention. Hereinafter, the carrier  100   b  for manufacturing a printed circuit board according to a second embodiment of the present invention will be described with reference to  FIG. 7 . Here, the same reference numerals are used to designate the same or similar components, and redundant descriptions of this embodiment overlapping the first embodiment are omitted. 
         [0059]    As shown in  FIG. 7 , the carrier  100   b  for manufacturing a printed circuit board according to this embodiment includes: a magnetic sheet  10  lb including a sheet  102  and magnetic metal layers  103   b  formed on both sides of the sheet  102 ; and metal layers  104  formed on both sides of the magnetic sheet  101   b.    
         [0060]    The magnetic metal layer  103   b  is formed on at least one side of the sheet  102 , and is made of a magnetic material. 
         [0061]    Here, the magnetic metal layer  103   b  may be made of a magnetic metal, such as nickel, cobalt, iron or an alloy thereof. Further, the magnetic metal layer  103   b  is not limited to metals, and may be a polymer magnet or an electromagnet. 
         [0062]    Meanwhile, the metal layers  104  are attached to the magnetic metal layers  103   b  by the magnetic properties of the magnetic metal layers  103   b.    
         [0063]    A Method of Manufacturing a Carrier for Manufacturing a Printed Circuit Board 
         [0064]      FIGS. 8 and 9  are sectional views sequentially showing a method of manufacturing a carrier for manufacturing a printed circuit board according to a first embodiment of the present invention. Hereinafter, the method of manufacturing a carrier  100   a  for manufacturing a printed circuit board according to a first embodiment of the present invention will be described with reference to  FIGS. 8 and 9 . 
         [0065]    First, as shown in  FIG. 8 , a magnetic sheet  101   a  is provided. 
         [0066]    In this case, the magnetic sheet  101   a  may include a sheet  102  containing a reinforcing material, such as glass fiber, and magnetic fillers  103   a.  For example, when the sheet  102  is made of an insulating material such as an epoxy resin, the sheet  102  can be formed into the magnetic sheet  101   a  having excellent magnetic properties and high strength by impregnating glass fiber and magnetic fillers  103  into the sheet  102  and then curing the insulating material. Further, the magnetic fillers  103   a  may also be applied on the sheet  102  by a spray method. 
         [0067]    Subsequently, as shown in  FIG. 9 , metal layers  104  are formed on one or both sides of the magnetic sheet  101   a.    
         [0068]    In this case, the metal layers  104  can be attached to the magnetic sheet  101   a  by the magnetic properties of the magnetic sheet  101   a.  Meanwhile, the metal layers  104  and the magnetic sheet  101  a may be attached to each other to such a degree that foreign materials, such as an etchant and the like, do not infiltrate therebetween. 
         [0069]    Through the above processes, the carrier  100   a,  shown in  FIG. 9 , according to the first embodiment of the present invention is manufactured. 
         [0070]      FIGS. 10 to 12  are sectional views sequentially showing a method of manufacturing the carrier for manufacturing a printed circuit board according to the second embodiment of the present invention. Hereinafter, the method of manufacturing the carrier  100   b  for manufacturing a printed circuit board according to the second embodiment of the present invention will be described with reference to  FIGS. 10 to 12 . Here, the same reference numerals are used to designate the same or similar components, and redundant descriptions of this embodiment overlapping the first embodiment are omitted. 
         [0071]    First, as shown in  FIGS. 10 and 11 , a sheet  102  is provided, and then magnetic metal layers  103   b  are formed on one or both sides of the sheet  102  to form a magnetic sheet  101   b.    
         [0072]    In this case, the magnetic metal layers  103   b  may be formed on the sheet  102  by metal adhesion or sputtering. 
         [0073]    Subsequently, as shown in  FIG. 12 , metal layers  104  are attached to the magnetic sheet  101   b.    
         [0074]    In this case, the metal layers  104  can be attached to the magnetic metal layers  103   b  by the magnetic properties of the magnetic metal layers  103   b  of the magnetic sheet  101   b.    
         [0075]    Through the above processes, the carrier  100   b,  shown in  FIG. 12 , according to the second embodiment of the present invention is manufactured. 
         [0076]    A Method of Manufacturing a Printed Circuit Board Using a Carrier 
         [0077]      FIGS. 13 to 17  are sectional views sequentially showing a method of manufacturing a printed circuit board  200   a  using a carrier according to a first embodiment of the present invention. Hereinafter, the method of manufacturing a printed circuit board  200   a  using a carrier according to a first embodiment of the present invention will be described with reference to  FIGS. 13 to 17 . 
         [0078]    It is described in this embodiment that printed circuit boards  200   a  are formed on both sides of a carrier  100   a,  but, in the present invention, a printed circuit board  200   a  may be formed on one side of a carrier  100   a.  Further, it is described in this embodiment that the carrier  100   a  according to the first embodiment is used, but, in the present invention, the carrier  100   b  according to the second embodiment may be used. 
         [0079]    First, as shown in  FIG. 13 , metal layers  104  are attached to a magnetic sheet  101   a  containing magnetic fillers  103   a  to provide a carrier  100   a  for manufacturing a printed circuit board. 
         [0080]    In this case, when a printed circuit board  200   a  is formed on only one side of the carrier  100   a,  the metal layer  104  may be attached to only one side of the magnetic sheet  101   a.    
         [0081]    Subsequently, as shown in  FIG. 14 , a first protective layer  105 , a build up layer  106  and a second protective layer  107  are sequentially formed on each of the metal layers  104 . 
         [0082]    Specifically, a first protective layer  105  is formed on each of the metal layers  104  of the carrier  100   a.  Here, the first protective layer  105 , which serves to protect the outermost circuit layer of a build up layer  16 , may be formed of dry film type solder resist or liquid solder resist. 
         [0083]    Then, a build up layer  106  is formed on the first protective layer  105 . In  FIG. 15 , a three-layered build up layer is shown, but a single-layered or multi-layered build up layer may be formed. Meanwhile, the build up layer  106  may include a build up insulation layer and a build up circuit layer, and may be formed using a general method. For example, the build up circuit layer may be formed by a semi-additive process (SAP). 
         [0084]    Then, a second protective layer  107  may be formed on the build up layer  16 . In this case, the second protective layer  107  may be made of the same material as the first protective layer  105 . 
         [0085]    Subsequently, as shown in  FIG. 15 , the metal layer  104  is separated from the magnetic sheet  101   a.    
         [0086]    In this case, since the metal layer  104  and the magnetic sheet  101   a  are attached to each other by their magnetic properties, they can be relatively easily separated from each other. Further, since an additional routing process is not required, the size of a printed circuit board can be maintained. 
         [0087]    Subsequently, as shown in  FIG. 16 , the metal layer  104  attached to the first protective layer  105  is removed. 
         [0088]    In this case, the metal layer  104  may be removed by an etching process. Further, it is preferable to prevent a build up circuit layer of the build up layer  16  from being unexpectedly etched by making the metal layer  140  using a metal different from the build up circuit layer. 
         [0089]    Subsequently, as shown in  FIG. 17 , openings  108  are formed in the first protective layer  105  and the second protective layer  107 . 
         [0090]    In this case, pads  109  of the outermost circuit layer of the build up layer  106  can be exposed through the openings  18 . Further, the openings may be formed by laser drilling or machine drilling 
         [0091]    Through the above processes, the printed circuit board  200   a,  shown in  FIG. 17 , according to the first embodiment of the present invention is manufactured. 
         [0092]      FIGS. 18 to 22  are sectional views sequentially showing a method of manufacturing a printed circuit board  200   b  using a carrier according to a second embodiment of the present invention. Hereinafter, the method of manufacturing a printed circuit board  200   b  using a carrier according to a second embodiment of the present invention will be described with reference to  FIGS. 18 to 22 . Here, the same reference numerals are used to designate the same or similar components, and redundant descriptions of this embodiment overlapping the first embodiment are omitted. 
         [0093]    Meanwhile, it is described in this embodiment that the carrier  100   b  according to the second embodiment is used, but, in the present invention, the carrier  100   a  according to the first embodiment may be used. 
         [0094]    First, as shown in  FIG. 18 , magnetic metal layers  103   b  are formed on both sides of a sheet  102  to form a magnetic sheet  101   b,  and then metal layers  104  are attached to the magnetic metal layers  103   b  to provide a carrier  100   b  for manufacturing a printed circuit board. 
         [0095]    In this case, when a printed circuit board  200   b  is formed on only one side of the carrier  100   b,  the magnetic metal layer  103   b  and the metal layer  104  may be sequentially formed on only one side of the sheet  102 . 
         [0096]    Subsequently, as shown in  FIG. 19 , a circuit layer  106   a  and a build up layer  106  are sequentially formed on each of the metal layers  104 . 
         [0097]    In this case, the circuit layer  106   a,  which becomes an outermost circuit layer of the build up layer  106  later, may be formed using a subtractive process, an additive process, a semi-additive process, a modified semi-additive process or the like. Further, the circuit layer  106   a  may be made of an electroconductive metal, such as gold, silver, copper, nickel or the like, and may be made of a metal different from the metal layer  104  which is to be removed later. 
         [0098]    Subsequently, as shown in  FIGS. 20 to 22 , the metal layer  104  is separated from the magnetic metal layer  103   b,  and then the metal layer  104  is removed from the build up layer  106 . Then, protective layers  110  are formed on the exposed outermost layers of the to build up layer  106 , and then openings  108  for exposing pads  109  are formed in the protective layers  110 . 
         [0099]    In this case, when the magnetic metal layer  103   b  is formed of an electromagnet, the attractive force between the magnetic metal layer  103   b  and the metal layer  104  can be removed by blocking the electric current flowing through the electromagnet. 
         [0100]    Through the above processes, the printed circuit board  200   b,  shown in  FIG. 22 , according to the second embodiment of the present invention is manufactured. 
         [0101]    As described above, according to the present invention, a carrier includes a magnetic sheet and metal layers attached to the magnetic sheet by magnetic properties, so that an additional cutting process is not required when a printed circuit board is separated from the carrier, thereby maintaining the size of a printed circuit board. 
         [0102]    Further, according to the present invention, the structure of a carrier can be simplified by using the magnetic properties of a magnetic sheet, thus reducing process cost and process time. 
         [0103]    Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, 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 as disclosed in the accompanying claims. 
         [0104]    Simple modifications, additions and substitutions of the present invention belong to the scope of the present invention, and the specific scope of the present invention will be clearly defined by the appended claims.