Abstract:
An apparatus for transporting an FPCB strip includes a feeding spool, a collecting spool, and a buffer device between the feeding spool and the collecting spool. The feeding spool is configured for feeding an FPCB strip. The collecting spool is for collecting the FPCB strip from the buffer device. The buffer device includes a container, a redirection cylinder and an air pump. The redirection cylinder has a cavity defined therein, and a plurality of air exit holes defined in a side wall thereof. The air exit holes are in communication with the cavity. The air pump is in communication with the container and the cavity of the redirection cylinder for evacuating the air in the container so as to retain the bent portion in situ in the container and blowing air into the cavity, so as to form a cushion of air at the air exit holes.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to an apparatus for transporting a flexible printed circuit board (FPCB) strip. 
         [0003]    2. Description of Related Art 
         [0004]    Microphones, portable computers and other electronic products have achieved ever greater levels of miniaturization, thereby requiring thinner FPCBs having a plurality of fine electrical traces. 
         [0005]    At present, FPCBs are generally produced by a roll-to-roll processing method. The roll-to-roll processing method is a process carried out on flexible plastic or metal foil. The roll-to-roll processing method for producing FPCBs involves starting with a roll of unfinished FPCB strip and collecting the finished FPCB strip after etching, electroplating, electrolyzing, screen-printing or other processing steps. The finished FPCB strip is then cut into pieces to form a plurality of FPCBs. In the roll-to-roll processing method, a reverse wheel is used to change the direction of movement of the FPCB strip. The reverse wheel is rotated by a motor. The FPCBs contact the rotating reverse wheel, thus the FPCB strip is subjected to tension. In the processing steps of the FPCB strip, the motor may be frequently started and stopped. This may result in constantly changing the tension in the FPCB strip and too much friction occurring between the reverse wheel and the FPCB strip. In this case, the tension in the FPCB strip is difficult to control. Too much friction may cause damage to the FPCB strip, such as the breaking of conductive traces in the FPCB strip. 
         [0006]    Therefore, a method for an apparatus for transporting an FPCB strip is needed to overcome the above-described problems. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the different views. 
           [0008]      FIG. 1  is a schematic, isometric view of an apparatus for transporting a FPCB strip according to an exemplary embodiment, the apparatus comprising a reverse wheel. 
           [0009]      FIG. 2  is cross-sectional view of the apparatus of  FIG. 1  taken along line II-II, showing the structure of the reverse wheel. 
           [0010]      FIG. 3  is a schematic, side view of the apparatus of  FIG. 1  which is transporting an FPCB strip. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0011]    Referring to  FIGS. 1 and 2 , an apparatus  10  for the carriage of an flexible printed circuit board (FPCB) strip during the manufacturing process, according to an exemplary embodiment, includes a feeding spool  11 , a buffer device  12 , and a collecting spool  13 . The feeding spool  11  is cylindrical, and rotates. An FPCB roll (such as the FPCB roll  100  shown in  FIG. 3 ) is already wound on the feeding spool  11 . 
         [0012]    The buffer device  12  is arranged between the feeding spool  11  and the collecting spool  13 , and transports an FPCB strip (such as the FPCB strip  102  shown in  FIG. 3 ) from the FPCB roll on the feeding spool  11  onto the collecting spool  13 . The buffer device  12  includes a container  120 , a redirection cylinder  121  and an air suction member  122 . 
         [0013]    The container  120  is an open rectangular box. A recess  1200  is defined in a surface  1201  of the container  120 , and is blind. In this embodiment, the recess  1200  represents the hollow interior of the rectangular box, and is dimensioned to allow the FPCB strip to loop in and out. The container  120  has a side face  1202  adjacent to the surface  1201 . A first through hole  1203  is defined in the side face  1202 , in communication with the recess  1200 . The container  120  is positioned below the feeding spool  11 . 
         [0014]    The redirection cylinder  121  is cylindrical and hollow, and includes the cylindrical side wall  1210  and two end walls  1211 ,  1212  fixed to two opposite ends of the cylindrical side wall  1210 . The cylindrical side wall  1210  and the end walls  1211 ,  1212  cooperatively define a cylindrical cavity  1213 . A second through hole  1214  is defined through the end wall  1211 , and is in communication with the cavity  1213 . The side wall  1210  defines a number of air exit holes  1215  therein. The air exit holes  1215  are fine-gauge holes. Each of the air exit holes  1215  has a diameter smaller than 1 mm. 
         [0015]    The air exit holes  1215  are in a straight line, and one or more lines of holes  1215  is distributed at one quadrant of the side wall  1210 . In other words, referring to  FIG. 2 , in a sectional view of the side wall  1210 , all of the air exit holes  1215  are distributed in an arc range R of one quarter of the circumferential section of the side wall  1210 . In this embodiment, the air exit holes  1215  are arranged in a plurality of lines or rows along the circumferential direction of the side wall  1210 . Each row is parallel to the central axis of the side wall  1210 , and includes a number of air exit holes  1214 . The air exit holes  1214  may be divided into at least two lines, and each line includes at least twenty air exit holes  1214 . The redirection cylinder  121  is positioned above the container  120 , which stands below and between the feeding spool  11  and the redirection cylinder  121 . 
         [0016]    The air suction member  122  includes an air pump  1220 , a suction pipe  1221  and an exhaust pipe  1222 . The air pump  1220  has an air inlet  1223  and an air outlet (not shown). One end of the suction pipe  1221  is connected to the container  120  and in communication with the first through hole  1203 , and the opposite end of the suction pipe  1221  is connected to the air pump  1220  and in communication with the air inlet  1223 . One end of the exhaust pipe  1222  is connected to end wall  1211  of the redirection cylinder  121  and in communication with the second through hole  1214 , and the opposite end of the exhaust pipe  1222  is connected to the air pump  1220  and in communication with the air outlet. The air pump  1220  evacuates air from the recess  1200  of the container  120  via the suction pipe  1221 , and blows the evacuated gas into the cavity  1213  of the redirection cylinder  121  via the exhaust pipe  1222 . 
         [0017]    The collecting spool  13  includes a rotation driver  130  and two winding rollers  131  connected to the rotation driver  130 . The rotation driver  130  can be a motor, and includes a rotating axle  132 . The winding rollers  131  are connected with each other by a shaft  1310 , and are coaxially arranged with each other. The rotating axle  132  is coaxially connected to one of the winding rollers  131 . In this embodiment, a fixing hole  133  is defined in an end face of one of the winding rollers  131 . One end of the rotating axle  132  has an interference fit in the fixing hole  133 , thereby connecting the rotating axle  132  and the winding roller  131  with each other. In the present embodiment, the winding rollers  131  are cylindrical. The winding rollers  131  are driven by the rotation driver  130  to rotate. The rotation axes of the winding rollers  131  are parallel to the central axis of the side wall  1210  and the rotation axis of the feeding spool  11 . The winding rollers  131  can also be driven by a drive belt, a gear wheel or other driving mechanism, not being limited to the motor of the present embodiment. The number of the winding rollers  131  can also be one or more than two. 
         [0018]    Referring to  FIGS. 1-3 , a method for cutting an FPCB strip using the apparatus  10  is provided as follows. 
         [0019]    Firstly, an FPCB roll  100  is installed on the feeding spool  11 . A cutter  200  is positioned between the feeding spool  11  and the collecting spool  13 . The FPCB roll  100  has a free end  103 . 
         [0020]    The, the FPCB roll  100  is arranged between the feeding spool  11  and the collecting spool  13 . The cutter  200  is positioned after the redirection cylinder  121  and above the free end  103 , and must contact the free end  103  for cutting the free end  102  into different lengths and/or widths. 
         [0021]    In detail, the FPCB free end  103  is moved along a predetermined path between the feeding spool  11  and the collecting spool  13 . The predetermined path is described as follows. First, the free end  103  is moved downward into the recess  1200  of the container  120  from the feeding spool  11 , then bent upward to the redirection cylinder  121 , thus exiting from of the recess  1200 . Further then, the free end  103  is bent round the redirection cylinder  121  to the cutter  200 . In this embodiment, the redirection cylinder  121  changes the direction of movement by 90 degrees. In other words, the free end  103  and the strip of FPBC following is changed from vertical direction to horizontal direction by the redirection cylinder  121 . A quarter of the circumference of the roller  21  is in contact with the FPCB strip. Finally, the FPCB strip may either be cut across or may be cut longitudinally or both, to be wound onto one or more of the winding rollers  131 . Alternatively, the number of the cutter  200  can be more than one, thus the FPCB strip can be cut longitudinally into three or more pieces. Accordingly, the number of the winding rollers  131  may be three or more. 
         [0022]    Finally, the air pump  1220  is started, and the rotation driver  130  starts to drive the winding rollers  131  to rotate. The FPCB strip is continuously wound onto the winding rollers  131 , thus the FPCB strip is taken from the feeding spool  11  and gathered onto the collecting spool  13 . In this step, the air pump  122  evacuates the air in the recess  1200  of the container  120  via the suction pipe  1221 , and then blows the suctioned air into the cavity  1213  of the redirection cylinder  121  via the exhaust pipe  1222 . Therefore, a negative air pressure is formed in the recess  1200  of the container  120 , and a positive air pressure is formed in the cavity  1213 . The portion of the FPCB strip in the recess  1200  is evacuated further into the recess  1200  because of the negative air pressure, thereby preventing the loop of the FPCB strip from exiting out of the container  120 . 
         [0023]    The rotation of the winding rollers  131  pulls the FPCB strip out of the recess  1200 . The downward force below and the upward force above cooperate to flatten the FPCB strip. The air in the cavity  1213  exits from the exit holes  1215  because of the positive air pressure, thereby forming airstreams adjacent to the exit holes  1215 . The airstreams create a cushion of air which maintains a distance between the FPCB strip and the surface of the redirection cylinder  121 , thereby preventing the FPCB strip from being broken or damaged by any change of direction or rate of movement in the redirection cylinder  121 . The FPCB strip may be continuously cut by the cutter  200 , and the thinner strips are then wound onto the winding rollers  131 , thereby forming one or more FPCB rolls on the winding rollers  131 . 
         [0024]    It is understood that the apparatus  10  can also be used in other manufacturing processes, such as the formation and punching of electric traces, and is not limited to this exemplary embodiment. In this embodiment, the air being blown into the cavity  1213  is suctioned from the recess  1200  of the container  120 . There is no need to use compressed air in supplying the cavity  1213 , thereby reducing the cost. 
         [0025]    While certain embodiments have been described and exemplified above, various other embodiments will be apparent to those skilled in the art from the foregoing disclosure. The present disclosure is not limited to the particular embodiments described and exemplified but is capable of considerable variation and modification without departure from the scope of the appended claims.