Abstract:
Provided is a thin printed circuit board (PCB) for manufacturing a chip scale package (CSP). The thin printed circuit board includes a plurality of unit printed circuit boards, each of which is comprised of a circuit pattern, to which a semiconductor chip is adhered, and a substrate surrounding the circuit pattern. The unit printed boards are arranged in a row and includes a support molding, which is spaced a predetermined interval apart from the circuit pattern of each unit printed circuit board on the substrate of each unit printed circuit board and formed in a ring shape along the edge of the thin printed circuit board.

Description:
This application claims the priority to Korean Patent Application No. 2003-48652, filed on Jul. 16, 2003, in the Korean Intellectual Property Office, the contents of which are incorporated herein by reference in its entirety. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a printed circuit board (PCB) for manufacturing a semiconductor package, and more particularly, to a thin PCB for manufacturing a chip scale package (CSP). 
   2. Description of the Related Art 
   In recent years, as most electronic products including various portable data communication devices, such as personal computers, cellular phones, and personal data terminals, have been scaled down and become more light-weight and efficient, their data processing capacities have increased. Thus, using a chip scale package (CSP) technique, a semiconductor chip can be assembled in a semiconductor package having a size similar to or slightly larger than the chip size. CSP techniques vary according to manufacturing methods, for example, a thin PCB method of manufacturing a CSP. In this method, semiconductor packages comprise a semiconductor chip manufactured with a thin PCB. However, the thickness (e.g., 0.17 mm or less) of a conventional thin PCB for manufacturing a CSP is typically smaller than that (e.g., 3 mm) of a conventional PCB for manufacturing a typical semiconductor package. 
     FIGS. 1 through 3  are diagrams illustrating problems of a conventional thin PCB. As shown in  FIG. 1 , in a conventional thin PCB  10 , a plurality of unit PCBs  10   a ,  10   b , and  10   c  are connected in a row. Although only three exemplary unit PCBs  10   a ,  10   b , and  10   c  are illustrated in  FIG. 1 , the thin PCB  10  can include a greater number of unit PCBs. Circuit patterns  11   a ,  11   b , and  11   c  are disposed in the unit PCBs  10   a ,  10   b , and  10   c , respectively. A plurality of holes (not shown) are formed in each of the circuit patterns  11   a ,  11   b , and  11   c . A plurality of holes or slots  12  are vertically arranged at interfaces between adjacent unit PCBs, for example, between the unit PCBs  10   a  and  10   b  or  10   b  and  10   c . These holes or slots  12  suppress distortion of the PCB  10 . A plurality of holes  13  are formed in an upper portion of the thin PCB  10 , and a plurality of holes  14  are formed in a lower portion thereof. These holes  13  and  14  are used as recognition marks for a package manufacturing apparatus and may be used for alignment of the thin PCB  10  when the thin PCB  10  is transferred. 
   As described above, the thin PCB  10  has a relatively small thickness. Thus, the thin PCB  10  is flexible and makes it difficult to manufacture semiconductor packages. Thus, one solution shown in  FIG. 2  was proposed. That is, semiconductor packages are manufactured using a carrier  20  supporting a thin PCB  10 . In this method, since the thin PCB  10  is supported by the carrier  20 , it is inflexible during package manufacturing processes. The carrier  20  can be formed of an inflexible material, for example, a sus material. A vacant space  23  is located in the center of the carrier  20  so as to expose the rear surface of the thin PCB  10 . The carrier  20  is a kind of frame that surrounds the vacant space  23 . Holes  21  are formed on both lateral surfaces of the carrier  20 , and a mark  22  is formed on an edge thereof. The holes  21  and the mark  22  are used as recognition marks and may be used for alignment of the carrier  20  when the carrier  20  is transferred. 
   As shown in  FIG. 3 , in order to adhere the thin PCB  10  to the carrier  20 , the thin PCB  10  is first mounted on the carrier  20 . Only the upper and lower portions of the thin PCB  10  overlap upper and lower portions of the carrier  20  and are supported by the carrier  20 , and the remaining portion of the thin PCB  10  do not overlap the carrier  20 . Next, the thin PCB  10  is secured to the carrier  20  by an adhesive  31 . The adhesive  31  is applied to the upper and lower portions of the thin PCB  10  and the upper and lower portions of the carrier  20 . 
   As described above, since the conventional thin PCB  10  has a very small thickness, it should be adhered to a supporting portion such as the carrier  10  and used in package manufacturing processes. Thus, prior to the package manufacturing processes, additional processes of aligning and adhering the thin PCB  10  to the carrier  20  should be performed. Also, after a semiconductor package is completed, a process of removing the adhesive  31  from the carrier  20  should be further performed to reuse the carrier  20 . 
   SUMMARY OF THE INVENTION 
   The present invention provides a thin printed circuit board (PCB) that is inflexible during package manufacturing processes, despite its very small thickness. 
   According to an aspect of the present invention, there is provided a thin printed circuit board for manufacturing a chip scale package. The thin printed circuit board comprises a plurality of unit printed circuit boards which each adhere to a semiconductor chip, and a substrate surrounding the circuit pattern. Each unit printed circuit board comprises a circuit pattern. The unit printed boards are arranged in a row. The thin printed circuit board comprises a support molding, which is spaced a predetermined interval apart from the circuit pattern of each unit printed circuit board on the substrate of each unit printed circuit board and formed in a ring shape along the edge of the thin printed circuit board. 
   The support molding may comprise epoxy molding compound or resin. 
   The support molding can be formed using a metal pattern. 
   One or more holes or slots can be vertically arranged at interfaces between adjacent unit printed circuit boards to prevent distortion of the thin printed circuit board. 
   According to another aspect of the present invention, there is provided a thin printed circuit board for manufacturing a chip scale package. The thin printed circuit board comprises a plurality of unit printed circuit boards, each of which comprises a circuit pattern, to which a semiconductor chip is adhered, and a substrate surrounding the circuit pattern. The unit printed boards may be arranged in a row. The thin printed circuit board comprises one or more slots, which are vertically arranged at interfaces between the unit printed circuit boards; and support moldings, which are spaced apart from the circuit patterns of the unit printed circuit boards above and below the interfaces between the unit printed circuit boards and formed perpendicular to the direction in which the slots are formed. 
   The support moldings can be formed of one of an epoxy molding compound and a resin. 
   The support moldings can be formed using a metal pattern. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
       FIGS. 1 through 3  are diagrams illustrating a conventional thin PCB; 
       FIG. 4  is a diagram illustrating a thin PCB according to an embodiment of the present invention; and 
       FIG. 5  is a diagram illustrating a thin PCB according to another embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. 
     FIG. 4  is a diagram illustrating a thin PCB according to an embodiment of the present invention. 
   Referring to  FIG. 4 , a thin PCB  400  of the present embodiment comprises a plurality of unit PCBs  400   a ,  400   b , and  400   c , which are connected in a row. Although only three exemplary unit PCBs  400   a ,  400   b , and  400   c  are illustrated in  FIG. 4 , the thin PCB  400  can include a greater number of unit PCBs. Circuit patterns  410   a ,  410   b , and  410   c  are formed in the unit PCBs  400   a ,  400   b , and  400   c , respectively. A plurality of holes (not shown) are formed in each of the circuit patterns  410   a ,  410   b , and  410   c . A semiconductor chip is adhered to each of the circuit patterns  410   a ,  410   b , and  410   e  in a subsequent process, and a signal is transmitted from the semiconductor chip through the holes formed in the circuit pattern  410   a ,  410   b , or  410   c  out of the package. A plurality of holes or slots  420  are vertically arranged at interfaces between adjacent unit PCBs, for example, between the unit PCBs  400   a  and  400   b  or  400   b  and  400   c . These holes or slots  420  suppress distortion of the thin PCB  400 . A plurality of holes  430  are formed in an upper portion of the thin PCB  400 , and a plurality of holes  440  are formed in a lower portion thereof. These holes  430  and  440  are used as recognition marks for a package manufacturing apparatus and may be used for alignment of the thin PCB  400  during thin PCB  400  transfer. 
   A support molding  450  is formed along the edge of the thin PCB  400 . In the present embodiment the support molding  450  is formed of an epoxy molding compound (EMC) or a resin and formed using a metal pattern. The support molding  450  may be formed in a ring shape along the edge of the thin PCB  400  and spaced apart from the circuit patterns  410   a ,  410   b , and  410   c . That is, the support molding  450  may not contact the circuit patterns  410   a ,  410   b , and  410   c . The support molding  450  can support the circumference of the thin PCB  400 . Thus, the thin PCB  400  can be inflexible during package manufacturing processes despite its very small thickness. 
     FIG. 5  is a diagram illustrating a thin PCB according to another embodiment of the present invention. 
   Referring to  FIG. 5 , the thin PCB  500  of the present embodiment comprises a plurality of unit PCBs  500   a ,  500   b , and  500   c , which are connected in a row. Although only three exemplary unit PCBs  500   a ,  500   b , and  500   c  are illustrated in  FIG. 5 , the thin PCB  500  can include a greater number of unit PCBs. Circuit patterns  510   a ,  510   b , and  510   c  are formed in the unit PCBs  500   a ,  500   b , and  500   c , respectively. A plurality of holes (not shown) are formed in each of the circuit patterns  510   a ,  510   b , and  510   c . A semiconductor chip is adhered to each of the circuit patterns  510   a ,  510   b , and  510   c  in a subsequent process, and a signal is transmitted from the semiconductor chip through the holes formed in the circuit pattern  510   a ,  510   b , or  510   c  out of the package. A plurality of holes or slots  520  are vertically arranged at interfaces between adjacent unit PCBs, for example, between the unit PCBs  500   a  and  500   b  or  500   b  and  500   c . These holes or slots  520  suppress distortion of the thin PCB  500 . A plurality of holes  530  are formed in an upper portion of the thin PCB  500 , and a plurality of holes  540  are formed in a lower portion thereof. These holes  530  and  540  are used as recognition marks for a package manufacturing apparatus and may be used for alignment of the thin PCB  500  during thin PCB  500  transfer. 
   In the thin PCB  500 , portions where the slots  520  are formed are most vulnerable to external forces and pressure. Thus, support moldings  551  and  552  may be formed above and below the interface between adjacent unit PCBs  500   a ,  500   b , and  500   c , that is, above and below the portions where the slots  520  are formed. Although the slots  520  are formed vertically, the support moldings  551  and  552  may be formed horizontally, i.e., substantially perpendicular to the direction in which the slots  520  are arranged. As in the first embodiment, the support moldings  551  and  552  may not contact any of the circuit patterns  510   a ,  510   b , and  510   c . In the present embodiment the support moldings  551  and  552  are formed of an EMC or a resin and can be formed using a metal pattern. In the present embodiment, the support moldings  551  and  552  can support the interfaces between the unit PCBs  500   a ,  500   b , and  500   c , which are the most vulnerable portions of the thin PCB  500 . Thus, the thin PCB  500  can be inflexible during package manufacturing processes despite its very small thickness. 
   As explained thus far, a thin PCB for manufacturing a chip scale package (CSP) according to the present invention includes a support molding formed along the edge of the thin PCB, or includes a plurality of support moldings formed above and below the interfaces between unit PCBs, which are vulnerable to external forces. Thus, the thin PCB can be inflexible during package manufacturing processes despite its very thin thickness. Accordingly, the manufacture of semiconductor packages can be simple without using an additional supporting portion. 
   While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. For example, the present invention is not limited to thin PCBs. Of course, other various thin substrates for CSPs, for example, polyimide tape substrates, can be used and include support moldings in the same manner as the thin PCBs. 
   Although the exemplary embodiments of the present invention have been described in detail, it should be understood that many variations and/or modifications of the basic inventive concepts herein taught, which may appear to those skilled in the art, will still fall within the spirit and scope of the present invention as defined in the appended claims.