Patent Publication Number: US-2013243995-A1

Title: Carrier For Manufacturing Substrate and Method Of Manufacturing Substrate Using The Same

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 12/787,300, filed on May 25, 2010, entitled “Carrier For Manufacturing Substrate and Method Of Manufacturing Substrate Using The Same&#39; which claims the benefit of Korean Patent Application No. 10-2009-0133970, filed Dec. 30, 2009, entitled “A carrier member for manufacturing a substrate and a method of manufacturing a substrate using the same”, both of which are hereby incorporated by reference in their entirety into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a carrier for manufacturing a substrate and a method of manufacturing a substrate using the same. 
     2. Description of the Related Art 
     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. 
     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. 
     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 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. Hereinafter, a conventional method of manufacturing a coreless substrate will be described with reference to  FIGS. 1A to 1E . 
       FIGS. 1A to 1E  are sectional views sequentially showing a conventional method of manufacturing a substrate using a carrier, and  FIG. 2  is an enlarged view showing an essential part of a first metal layer and a second metal layer shown in  FIG. 1 . Problems of conventional technologies will be described with reference to  FIGS. 1A to 1E . 
     First, as shown in  FIG. 1A , a carrier  10  is provided. The carrier  10  is fabricated by sequentially forming adhesive films  12 , first metal layers  13  and second metal layers  14  on both sides of a copper clad laminate (CCL)  11 . In this case, the carrier is heated and pressed by a press, and thus the copper clad laminate  11  and the second metal layer  14  attach to each other at a periphery thereof by means of the adhesive film  12 . Meanwhile, in order to stably attach the copper clad laminate  11  and the second metal layer  14  to each other, the contact face therebetween must have a thickness of 10 mm, and the first metal layer  13  and the second metal layer  14  are vacuum-adsorbed. 
     Subsequently, as shown in  FIG. 1B , build up layers  15  are formed on both sides of the carrier  10 . Here, each of the build up layers  15  is formed in a general manner, and is additionally provided with a third metal layer  16  for preventing the warpage of the build up layer  15  at the outermost layer thereof. 
     Subsequently, as shown in  FIG. 1C , the build up layers  15  are separated from the carrier  10 . Here, the build up layers  15  are separated from the carrier  10  by removing the edge of the adhesive film through which the copper clad laminate  11  and the second metal layer  14  are attached to each other by a routing process. 
     Subsequently, as shown in  FIG. 1D , the second metal layer  14  and the third metal layer  15  formed at the outermost layers of the build up layer  15  are removed by etching. 
     Subsequently, as shown in  FIG. 1E , 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 . 
     In the above-mentioned conventional method of manufacturing a substrate, copper foil is used as the first metal layer  13  and the second metal foil  14 . However, the copper foil includes a matte surface (M surface) having high surface roughness and a shiny surface (S surface) having low surface roughness. Therefore, as shown in  FIG. 2 , small space (S) is formed between the first metal layer  13  and the second metal layer  14  due to the matte surface (M surface), and thus it is difficult to completely maintain a vacuum. Consequently, there is a problem in that wrinkles occur when the build up layer  15  is formed on the second metal layer  14 . 
     Further, even when pin-holes are formed in the first metal layer  13  or the second metal layer  14 , there is a problem in that a vacuum is not maintained between the first metal layer  13  and the second metal layer  14 , and thus it is difficult to continue a process. 
     Furthermore, when the build up layers  15  are separated from the carrier  10  by removing the edge of the adhesive film  12  through a routing process, the build up layers  15  warp in an extreme manner due to the difference in material properties between the second metal layer  13  and the insulating material of the carrier  10 . Therefore, there are problems in that process automation cannot be realized and in that subsequent processes must be manually performed. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made to solve the above-mentioned problems, and the present invention provides a carrier for manufacturing a substrate, which can completely maintain a vacuum by attaching an auxiliary adhesive layer to a metal layer, and which can prevent the warpage of a build up layer by maintaining the adhesion between the auxiliary adhesive layer and the metal layer for a predetermined time using the adhesivity of the auxiliary adhesive layer even after a routing process, and a method of manufacturing a substrate using the same. 
     An aspect of the present invention provides a carrier for manufacturing a substrate, including: a base plate; adhesive layers formed on one side or both sides of the base plate; auxiliary adhesive layers, each of which is buried in one side of each of the adhesive layers, has a smaller area than each of the adhesive layers and has lower adhesivity than each of the adhesive layers; and metal layers, each of which is formed on one side of each of the auxiliary adhesive layers, whose edges are attached to the adhesive layers, and whose other portions excluding the edges are attached to the auxiliary adhesive layers. 
     Here, the adhesive layer may be prepreg, an ajinomoto build up film (ABF) or an epoxy film. 
     Further, the auxiliary adhesive layer may be a polymer film. 
     Further, the auxiliary adhesive layer may have an adhesivity of 0.01˜0.2 KN/m. 
     Further, the adhesivity of one side of the auxiliary adhesive layer may be lower than that of the other side of the auxiliary adhesive layer. 
     Another aspect of the present invention provides a method of manufacturing a substrate using a carrier, including: forming an adhesive layer on one side or both sides of a base plate; forming an auxiliary adhesive layer on the adhesive layer, the auxiliary adhesive layer having lower adhesivity and a smaller area than the adhesive layer; applying a metal layer onto one side of the auxiliary adhesive layer and then heating and pressing the metal layer to bury the auxiliary adhesive layer in one side of the adhesive layer, and then attaching the edge of the metal layer to the adhesive layer and attaching the other portion of the metal layer, excluding the edge thereof, to the auxiliary adhesive layer to provide a carrier for manufacturing a substrate; and forming a build up layer on one side of the metal layer and then removing the edge of the metal layer attached to the adhesive layer to separate the metal layer from the auxiliary adhesive layer. 
     Here, in the separating of the metal layer from the auxiliary adhesive layer, the adhesion between the metal layer and the auxiliary adhesive layer may be maintained for a predetermined time due to the adhesivity of the auxiliary adhesive layer after the edge of the metal layer has been removed. 
     Further, in the separating of the metal layer from the auxiliary adhesive layer, the metal layer may be separated from the auxiliary adhesive layer by warping the metal layer after the edge of the metal layer has been removed. 
     Further, in the forming of the adhesive layer, the adhesive layer may be prepreg, an ajinomoto build up film (ABF) or an epoxy film. 
     Further, in the forming of the auxiliary adhesive layer, the auxiliary adhesive layer may be a polymer film. 
     Further, in the forming of the auxiliary adhesive layer, the auxiliary adhesive layer may have an adhesivity of 0.01˜0.2 KN/m. 
     Further, in the applying of the metal layer onto the auxiliary adhesive layer, the adhesivity of one side of the auxiliary adhesive layer may be lower than that of the other side of the auxiliary adhesive layer. 
     Various objects, advantages and features of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings. 
     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 
       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: 
         FIGS. 1A to 1E  are sectional views sequentially showing a conventional method of manufacturing a substrate using a carrier; 
         FIG. 2  is an enlarged view showing an essential part of a first metal layer and a second metal layer shown in  FIG. 1 ; 
         FIG. 3  is a sectional view showing a carrier for manufacturing a substrate according to an embodiment of the present invention; and 
         FIGS. 4 to 11  are sectional views sequentially showing a method of manufacturing a substrate using the carrier according to an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     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 “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. 
     Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. 
       FIG. 3  is a sectional view showing a carrier for manufacturing a substrate according to an embodiment of the present invention. 
     As shown in  FIG. 3 , the carrier  100  for manufacturing a substrate according to this embodiment includes: a base plate  110 ; adhesive layers  120  formed on one side or both sides of the base plate  110 ; auxiliary adhesive layers  130 , each of which is buried in one side of each of the adhesive layers  120 , has a smaller area than each of the adhesive layers  120  and has lower adhesivity than each of the adhesive layers  120 ; and metal layers  140 , each of which is formed on one side of each of the auxiliary adhesive layers  130 , whose edges are attached to the adhesive layers  120 , and whose other portions excluding the edges are attached to the auxiliary adhesive layers  130 . 
     The adhesive layers  120 , which serve to attach and fix the metal layers  140 , are formed on both sides of the base plate  110 . In the drawings, the adhesive layers  120  are formed on both sides of the base plate  110 , but the present invention is not limited thereto, and the adhesive layer  120  may be formed on one side of the base plate  110 . Further, since the adhesive layer  120  must be attached to the metal layer  140 , it may be formed of prepreg, an ajinomoto build up film (ABF), an epoxy film or the like, which has at least a predetermined adhesivity. 
     Meanwhile, the kind of the base plate  110  is not particularly limited. A copper clad laminate (CCL), a prepreg coated on both sides thereof with copper foil or the like may be used as the base plate  110 . 
     The auxiliary adhesive layer  130 , which serves to maintain the adhesion between the adhesive layer  120  and the metal layer  140  even after the adhesive layer  120  and the metal layer  140  are detached from each other by removing the edge of the adhesive layer  120 , is buried in the one side of the adhesive layer  120 . The auxiliary adhesive layer  130  must not be buried in the entire region of the adhesive layer  120 . The auxiliary adhesive layer  130  must be formed such that it has a larger area than the adhesive layer  120 , and must be buried in the partial region of the adhesive layer  120  such that the edge of the adhesive layer  120  is brought into contact with the edge of the metal layer  140 . Since the auxiliary adhesive layer  130  is attached to the metal layer  140  by its adhesivity, the present invention, differently from conventional technologies, does not employ vacuum adsorption. However, since the metal layer  140  must be finally detached from the auxiliary adhesive layer  130 , the auxiliary adhesive layer  130  must have lower adhesivity than the adhesive layer  120 , and the metal layer  140  must be separated from the auxiliary adhesive layer  130  by performing an additional separation process or warping the metal layer  140  (refer to  FIGS. 8 to 9 ). Therefore, the auxiliary adhesive layer  130  may have an adhesivity of 0.01˜0.2 KN/m, but the present invention is not limited thereto. 
     Further, in order to finally separate the metal layer  140  from the auxiliary adhesive layer  130 , the bonding force between the auxiliary adhesive layer  130  and the metal layer  140  must be weaker than the bonding force between the auxiliary adhesive layer  130  and the adhesive layer  120 . Therefore, it is preferred that the adhesivity of one side of the auxiliary adhesive layer  130  (the one side thereof is brought into contact with the metal layer  140 ) be lower than the adhesivity of the other side of the auxiliary adhesive layer  130  (the other side thereof is brought into contact with the adhesive layer  120 ). 
     Considering the ease of the control of the bonding force and the realization of the difference in adhesivity between one side and the other side of the auxiliary adhesive layer  130 , it is preferred that a polymer film be employed as the auxiliary adhesive layer  130 . 
     The metal layer  140 , which serves as a release layer for separating a build up layer  150  from the adhesive layer  120  and the auxiliary adhesive layer  130 , is formed on one side of the auxiliary adhesive layer  130 . As described above, since the auxiliary adhesive layer  130  is formed such that it has a larger area than the adhesive layer  120 , the edge of the adhesive layer  120  is exposed. Therefore, when the metal layer  140  is formed on the auxiliary adhesive layer  130  and then heated and pressed, the edge of the metal layer  140  is attached to the edge of the adhesive layer  120 , and the other portion of the metal layer, excluding the edge thereof, is attached to the auxiliary adhesive layer  130 . Meanwhile, the metal layer  140  may be made of copper (Cu), nickel (Ni) or aluminum (A), which can be easily etched, because the metal layer  140  must be separated from a carrier  100  together with a build up layer  150  and then removed from the build up layer  150  (refer to  FIG. 10 ). For example, copper foil may be used as the metal layer  140 . 
     The carrier  100  according to this embodiment, differently from conventional carriers, is advantageous in that the metal layer  140  and the auxiliary adhesive layer  130  are attached to each other by the adhesivity of the auxiliary adhesive layer  130 , so that it is not required to use vacuum adsorption, with the result that a process of manufacturing a substrate can be more stably performed. 
     Further, the carrier  100  according to this embodiment is advantageous in that the warpage of the build up layer  150  can be prevented by maintaining the adhesion between the auxiliary adhesive layer  130  and the metal layer  140  using the adhesivity of the auxiliary adhesive layer  130  even after a routing process for the adhesive layer  120 , thus realizing process automation. 
       FIGS. 4 to 11  are sectional views sequentially showing a method of manufacturing a substrate using the carrier according to an embodiment of the present invention. 
     As shown in  FIGS. 4 to 11 , the method of manufacturing a substrate using the carrier  100  according to this embodiment includes: forming an adhesive layer  120  on one side or both sides of a base plate  110 ; forming an auxiliary adhesive layer  130  on the adhesive layer  120 , the auxiliary adhesive layer  130  having lower adhesivity and a smaller area than the adhesive layer  120 ; applying a metal layer  140  onto one side of the auxiliary adhesive layer  130  and then heating and pressing the metal layer  140  to bury the auxiliary adhesive layer  130  in one side of the adhesive layer  120 , and then attaching the edge of the metal layer  140  to the adhesive layer  120  and attaching the other portion of the metal layer  140 , excluding the edge thereof, to the auxiliary adhesive layer  130  to provide a carrier  100  for manufacturing a substrate; and forming a build up layer  150  on one side of the metal layer  140  and then removing the edge of the metal layer  140  attached to the adhesive layer  120  to separate the metal layer  140  from the auxiliary adhesive layer  130 . 
     First, as shown in  FIG. 4 , an adhesive layer  120  is formed on a base plate  110 . Here, since the adhesive layer  120  serves to attach and fix a metal layer  140  in subsequent processes, it may be formed of prepreg, an ajinomoto build up film (ABF), an epoxy film or the like, which has predetermined adhesivity or more. In the drawings, the adhesive layers  120  are formed on both sides of the base plate  110 , but the present invention is not limited thereto, and the adhesive layer  120  may be formed on one side of the base plate  110 . When the adhesive layer  120  is formed only on one side of the base plate  110 , an auxiliary adhesive layer  130 , a metal layer  140  and a build up layer are also sequentially formed only on one side of the base plate  110 . 
     Subsequently, as shown in  FIG. 5 , an auxiliary adhesive layer  130  is formed on one side of the adhesive layer  120 . Here, the auxiliary adhesive layer  130  serves to maintain the adhesion between the adhesive layer  120  and the metal layer  140  even after the edge of the adhesive layer  120  has been removed in subsequent processes. Further, the auxiliary adhesive layer  130  may have a smaller area than the adhesive layer  120  such that the edge of the adhesive layer  120  is brought into contact with the edge of the metal layer  140 . Meanwhile, the auxiliary adhesive layer  130  must have lower adhesivity than the adhesive layer  120  because it must be finally detached from the metal layer  140 . Therefore, the auxiliary adhesive layer  130  may have an adhesivity of 0.01˜0.2 KN/m, but the present invention is not limited thereto. 
     Further, in order to finally separate the auxiliary adhesive layer  130  and the metal layer  140  from each other, the bonding force between the auxiliary adhesive layer  130  and the metal layer  140  must be weaker than the bonding force between the auxiliary adhesive layer  130  and the adhesive layer  120 . Therefore, it is preferred that the adhesivity of one side of the auxiliary adhesive layer  130  (the one side thereof is brought into contact with the metal layer  140 ) be lower than the adhesivity of the other side of the auxiliary adhesive layer  130  (the other side thereof is brought into contact with the adhesive layer  120 ). 
     Subsequently, as shown in  FIG. 6 , a metal layer  140  is applied onto the auxiliary adhesive layer  130  to provide a carrier  100 . Concretely, the metal layer  140  is applied onto one side of the auxiliary adhesive layer  130  and then heated and pressed to bury the auxiliary adhesive layer  130  in one side of the adhesive layer  120 , and simultaneously the edge of the metal layer  140  is attached to the adhesive layer  120 , and the other portion of the metal layer  140 , excluding the edge thereof, is attached to the auxiliary adhesive layer  130 . In this process, the metal layer  140  and the auxiliary adhesive layer  130  are attached to each other not by vacuum adsorption but by the adhesivity of the auxiliary adhesive layer  130 , differently from conventional technologies. 
     Subsequently, as shown in  FIG. 7 , a build up layer  150  is formed on one side of the metal layer  140 . The build up layer  150  is formed by sequentially laminating a patterned circuit layer  153  and an insulating material  157  using plating or printing. Concretely, the build up layer  150  can be completed by applying an insulating material  151  onto the metal layer  140 , forming via holes in the insulating material  157  using a YAG or CO 2  laser and then forming a circuit layer  153  including vias  151  on the insulating material  151  through a Semi-Additive Process (SAP) or a Modified Semi-Additive Process (MSAP). Further, the build up layer  150  may be provided with a solder resist layer  155  at the outermost layer. Here, the solder resist layer  155  is made of a heat-resistant coating material, and serves to protect the circuit layer  153  such that solder is not applied on the circuit layer  153  during soldering. 
     Meanwhile, in the drawings, the build up layers  150  are formed on both sides of a carrier  100 , but the build up layer  150  may be formed only on one side of the carrier  100  by sequentially forming the adhesive layer  120 , the auxiliary adhesive layer  130  and the metal layer  140  only on one side of the base plate  110  in the previous process. 
     Subsequently, as shown in  FIGS. 8 to 9 , the edge of the metal layer  140  is removed to separate the metal layer  140  from the auxiliary adhesive layer  130 . When the edge of the metal layer  140  attached to the edge of the adhesive layer  120  is removed, the bonding force between the adhesive layer  120  and the metal layer  140  disappears. However, since the other portion of the metal layer  140 , excluding the edge thereof, is attached to the auxiliary adhesive layer  130 , the metal layer  140  is not separated from the auxiliary adhesive layer  130  the moment the edge of the metal layer  140  is removed (refer to  FIG. 8A ). However, since the adhesivity of the auxiliary adhesive layer  130  decreases with the passage of time, the metal layer  140  can be separated from the auxiliary adhesive layer  130  after the predetermined time. In addition, the metal layer  140  may be separated from the auxiliary adhesive layer  130  by warping the metal layer  140  (refer to  FIG. 8B ) or by performing an additional separation process. In this process, since the metal layer  140  is not immediately separated from the auxiliary adhesive layer  130  and the adhesion between the metal layer  140  and the auxiliary adhesive layer  130  is maintained for a predetermined time due to the adhesivity of the auxiliary adhesive layer  130 , the warpage of the build up layer  150  can be prevented, thus realizing process automation. 
     Subsequently, as shown in  FIGS. 10 to 11 , the metal layer  140  is removed from the build up layer  150 , and then holes  159  are formed in the solder resist layer  155 . Here, the metal layer  140  may be removed by etching, and the holes  159  are formed in the solder resist layer  155  in order to electrically connect the circuit layer  153  with external circuits. However, this process of forming the holes  159  in the solder resist layer  155  is not necessarily performed by an additional process. 
     As described above, according to the present invention, a metal layer and an auxiliary adhesive layer are attached to each other by the adhesivity of the auxiliary adhesive layer, so that it is not required to use vacuum adsorption, with the result that a process of manufacturing a substrate can be performed more stably. 
     Further, according to the present invention, the warpage of a build up layer can be prevented by maintaining the adhesion between the auxiliary adhesive layer and the metal layer using the adhesivity of the auxiliary adhesive layer even after a routing process for the adhesive layer, thus realizing process automation. 
     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. 
     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.