Abstract:
A device is provided for coupling (i) a PCB sheet, which includes a first PCB and a space formed after removing a defective PCB from the PCB sheet, with (ii) a replacement second PCB received in the space and has a connecting part spaced from a periphery of the space by a channel. The device includes a PCB securing plate adapted to support the PCB sheet. PCB securing pins project from an upper surface of the PCB securing plate to be inserted into pin receiving holes of the first and second PCBs for positioning the PCBs. PCB securing tapes are integrally attached on the PCB securing plate for securing the PCB sheet and the second PCB to the PCB securing plate. An adhesive is adapted to be filled into the channel to couple, when cured, the PCB sheet and the second PCB together.

Description:
RELATED APPLICATIONS 
   The present application is a division of and claims priority from application Ser. No. 10/177,664, filed Jun. 24, 2002, now U.S. Pat. No. 7,017,248, which is a divisional of application Ser. No. 09/510,298 filed Feb. 22, 2000, now U.S. Pat. No. 6,574,862 issued Jun. 10, 2003, the disclosure of which is hereby incorporated by reference herein in its entirety. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a method and a device for coupling a printed circuit board (to be called PCB below) sheet, in which a plurality of PCBs are continuously arranged on a sheet when manufacturing the PCBs, and if a defective PCB is found after the manufacture, then the defective PCB sheet portion is removed to replace it with a new PCB sheet portion. Particularly, the present invention relates to a method and a device for coupling a PCB sheet, in which in a continuously printed PCBs on a sheet, a defective portion is removed, a first PCB sheet formed by the removal is located by a position locating means to be filled with a second PCB sheet of a good quality circuit pattern, and an adhesive material is spread on a space area between the first PCB sheet and a second PCB sheet, thereby making the arrangement of the PCBs continuous. Thus the defective PCB is removed, and a good quality PCB is replaced into the place in an easy manner, so that the defective PCB can be turned to a good quality portion. 
   2. Description of the Prior Art 
   Generally, as shown in  FIG. 1 , in the conventional PCB sheet structure, a plurality of circuit patterns  51 ,  51 ′ and  51 ″ are arranged and continuously printed upon a PCB sheet  52 . 
   In this conventional PCB sheet  52 , the plurality of the circuit patterns  51 ,  51 ′ and  51 ″ are printed, and then, the quality of the total of the circuit patterns is checked by using a jig and a fixture. Then the acceptable PCB sheets  52  are used as the final product. However, if anyone of the plurality of the circuit patterns is defective, then the whole PCB sheet on which the plurality of the circuit patterns  51 ,  51 ′ and  51 ″ are printed has to be discarded. 
   That is, if any one of the plurality of the circuit patterns is found to be defective upon inspecting them, even the good circuit patterns have to be discarded. 
   As a result, the material loss is high because of the discarding of the total sheet, and the workability and productivity are aggravated, as well as increasing the production cost. 
   SUMMARY OF THE INVENTION 
   The present invention is intended to overcome the above described disadvantages of the conventional technique. 
   Therefore it is an object of the present invention to provide a device for coupling a PCB sheet, in which defective circuit pattern portions are removed from a continuously arranged circuit pattern sheet to replace with new ones, so that a whole circuit pattern sheet can be saved without being discarded, thereby increasing the product yield, and curtailing the production cost. 
   It is another object of the present invention to provide a method for coupling a PCB sheet, in which defective circuit pattern portions are cut away from a continuously arranged circuit pattern sheet, and the cut space is filled with new ones by using a position locating means, the filling being carried out in a simple manner by using a heat resistant tape and an adhesive means containing a hardening agent, thereby improving the workability and the productivity. 
   In achieving the above objects, the device for coupling a PCB sheet according to the present invention includes: a position locating means disposed upon a PCB securing plate, for locating the position of a second PCB sheet of a good quality circuit pattern to fill a space after removing a PCB sheet of a defective circuit pattern from a continuously arranged circuit patterns of a first PCB sheet; a PCB securing means attached on the PCB securing plate, for preventing loose movements of the first and second PCB sheets; a space for putting an adhesive means into between the first and second PCB sheets (which are secured on the PCB securing plate); and the adhesive means being filled into the space between the first and second PCB sheets to be cured so as to couple the first and second PCB sheets together. 
   In another aspect of the present invention, the method for coupling a PCB sheet according to the present invention includes the steps of: cutting a defective PCB sheet of a defective circuit pattern to remove it from a continuously arranged circuit patterns of a first PCB sheet (defective circuit pattern removing step); filling a vacant place of the removed defective PCB sheet with a second PCB sheet of a good quality circuit pattern by utilizing a position locating means (PCB sheet position locating step); placing the first and second PCB sheets on a PCB securing plate by using a PCB securing means to prevent any loose movements of them, and filling an adhesive (with a volatile component being removed) into a space between the first and second PCB sheets to cure the adhesive at a temperature of 120-200° C. within a drying furnace (adhesive injecting and curing step); and removing the position locating means to separate the PCB securing plate from the PCB sheet after a curing of the adhesive (PCB securing plate separating step). 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects and other advantages of the present invention will become more apparent by describing in detail the preferred embodiment of the present invention with reference to the attached drawings in which: 
       FIG. 1  is a perspective view of the general PCB sheet in which circuit patterns are continuously printed on a sheet; 
       FIG. 2  is an exploded perspective view showing the coupling of the first and second PCB sheets, the sheets being fixed on the PCB securing plate according to the present invention; 
       FIG. 3  is a schematic view showing the coupled state of the first and second PCB sheets according to the present invention; 
       FIG. 4  illustrates in detail the coupling portion of the first and second PCB sheets according to the present invention; 
       FIG. 5  is a frontal sectional view showing the coupled state of the first and second PCB sheets according to the present invention; 
       FIG. 6  illustrates a state in which the second PCB sheet is inserted into the first PCB sheet, and the two sheets are fixed onto the PCB securing plate, in a second embodiment of the present invention; 
       FIG. 7  is a schematic perspective view showing the coupled state of the first and second PCB sheets in the second embodiment of the present invention; 
       FIG. 8  illustrates in detail the coupling portion of the first and second PCB sheets according to the present invention; 
       FIG. 9  is a frontal sectional view showing the coupled state of the first and second PCB sheets of  FIG. 8 ; 
       FIG. 10  illustrates a state in which a good quality PCB sheet is inserted into the whole PCB sheet, and the two sheets are fixed onto the PCB securing plate, in a third embodiment of the present invention; 
       FIG. 11  illustrates a state in which a good quality PCB sheet is coupled into a space formed by the removal of the defective PCB sheet in the third embodiment of the present invention; 
       FIGS. 12A and 12B  are plan views showing the coupling of a new good quality PCB sheet to the whole PCB sheet in the third embodiment of the present invention; 
       FIG. 13  is a frontal sectional view showing the whole PCB sheet and a new good quality PCB sheet; 
       FIG. 14  illustrates a state in which a good quality PCB sheet is inserted into the whole PCB sheet, and the two sheets are fixed onto the PCB securing plate by using a securing jig, in a fourth embodiment of the present invention; 
       FIG. 15  is a schematic perspective view showing the coupling of a new good quality PCB sheet to the whole PCB sheet in the fourth embodiment of the present invention; 
       FIG. 16  is a plan view showing the coupling of a new good quality PCB sheet to the whole PCB sheet of  FIG. 15 ; and 
       FIG. 17  is a frontal sectional view showing the whole PCB sheet and a new good quality PCB sheet of  FIG. 15 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The preferred embodiments of the present invention will be described referring to the attached drawings. 
     FIG. 2  is an exploded perspective view showing the coupling of the first and second PCB sheets, the sheets being fixed on the PCB securing plate according to the present invention.  FIG. 3  is a schematic view showing the coupled state of the first and second PCB sheets according to the present invention. 
   A first PCB sheet  4   a  on which a plurality of circuit pattern parts  2  are printed is disposed on a PCB securing plate  1 . A second PCB sheet  4   b  on which a good quality circuit pattern part  2  is printed is put to a place where a defective circuit pattern part  2 ′ of a first PCB sheet  4   a  has been removed. The second PCB sheet  4   b  is placed by being located by a PCB securing means  11 . 
   The first and second PCB sheets  4   a  and  4   b  are fixed to the PCB securing plate  1  by means of PCB securing tapes  5  which are the constituents of the PCB securing means  11 . Thus any loose movements of the first and second PCB sheets  4   a  and  4   b  are prevented. 
   A plurality of PCB securing pins  6  upstand on the PCB securing plate  1 , while the first and second PCB sheets  4   a  and  4   b  are provided with a plurality of pin receiving holes  7  correspondingly with the PCB securing pins  6 . Thus the PCB securing pins  6  of the PCB securing plate  1  are inserted into the pin receiving holes  7  to support the PCB sheets  4   a  and  4   b.    
   A space  13  is formed between the first and second PCB sheets  4   a  and  4   b , so that an adhesive  8  of an adhesive means  14  can be injected into a channel  9  of the space  13 . A tape  5 ′ is put to the bottom, front and rear of the channel  9  of the space  13 , so that the adhesive can be prevented from being leaked. 
   A cover  10  covers the first and second PCB sheets  4   a  and  4   b  to protect the circuit patterns of the first and second PCB sheets  4   a  and  4   b . The adhesive  8  which has been injected into the channel  9  is cured to couple the first and second PCB sheets  4   a  and  4   b  together. 
   Now the method for the PCB sheet according to the present invention will be described. 
   As shown in  FIGS. 2 to 5 , if any one of the circuit pattern parts  2  which constitute a PCB sheet  3  is found to be defective upon testing by a tester (not illustrated), then the defective sheet part  4 ′ of the defective circuit pattern part  2 ′ is cut off by using a router or another cutter. Then a second PCB sheet  4   b  on which a good quality circuit pattern part  2  is printed is prepared and is disposed to the cut space to be coupled with the first PCB sheet  4   a.    
   Then the first PCB sheet  4   a  which is coupled with the second PCB sheet  4   b  is secured to the PCB securing plate  1 . Under this condition, the plurality of the PCB securing pins  6  are inserted into the plurality of the pin receiving holes  7 , with the result that the first and second PCB sheets  4   a  and  4   b  are supported on the PCB securing plate  1 , with the sheets  4   a  and  4   b  being separated by a certain distance. 
   Then the first and second PCB sheets  4   a  and  4   b  are fixed to the PCB securing plate  1  by using a PCB securing tape  5  which is a both-face tape, so that any loose movements of the first and second PCB sheets  4   a  and  4   b  can be prevented. Under this condition, it is made sure that the PCB securing tape  5  should be only minimally affected by the thermal deformation. That is, a heat resistant tape is used, so that the tape can be easily removed upon completion of the coupling of the first and second PCB sheets  4   a  and  4   b.    
   Meanwhile, between the first and second PCB sheets  4   a  and  4   b  which are disposed on the PCB securing plate  1 , there is provided a separation distance L of about 1-5 mm. Thus there is formed a space  13  which forms a channel  9 . Then a heat resistant tape  5 ′ is put to the bottom, front and rear of the channel  9 , so that the injected adhesive can be prevented from being leaked. 
   If the separation distance L between the first and second PCB sheets  4   a  and  4   b  is less than 1 mm, then the first and second PCB sheets  4   a  and  4   b  cannot be sufficiently strongly coupled together. On the other hand, if the separation distance L is more than 5 mm, although the first and second PCB sheets  4   a  and  4   b  can be sufficiently strongly coupled together, the expensive adhesive is too much consumed, and therefore, the economy is aggravated. Preferably, the separation distance should be about 2 mm, and the volume of the injected adhesive  8  should be slightly smaller than or equal to the volume of the channel  9 . 
   Thus the first and second PCB sheets  4   a  and  4   b  are secured by using the PCB securing tape  5  and the tape  5 ′, the latter surrounding the channel  9  of the space  13 . Then the adhesive  8  is injected into the channel  9  of the space  13  which is formed between the first and second PCB sheets  4   a  and  4   b . Then the whole structure is transferred to a drying furnace to make the adhesive  8  cured at a temperature of 120-200° C. Under this condition, the volatile component of the adhesive  8  has been removed in advance, and therefore, the thermal deformations such as the thermal expansion and the thermal contraction are made to be minimal. Further, a hardening agent such as a highly heat resistant epoxy resin is added to the adhesive, and the proportion of the hardening agent is 1-5 wt % as against 99-95 wt % of the adhesive. 
   After the injection of the adhesive  8 , the circuit patterns of the first and second PCB sheets  4   a  and  4   b  are covered with a flat cover part  10  to protect the first and second PCB sheets  4   a  and  4   b  from the heat. The adhesive  8  which has been injected into the channel  9  is exposed to the outside so as to be cured. Then the whole structure which consists of the first and second PCB sheets  4   a  and  4   b  and the PCB securing plate  1  is transferred to a drying furnace to make the adhesive  8  cured at a temperature of 120-200° C. 
   After the completion of the curing of the adhesive  8 , the tape  5 ′ is removed from around the channel  9 , and the PCB securing plate  1  is separated from the first and second PCB sheets  4   a  and  4   b , thereby completing the coupling of the first and second PCB sheets  4   a  and  4   b  together. 
     FIGS. 6 and 7  illustrate a state in which the second PCB sheet is inserted into the first PCB sheet, and the two sheets are fixed onto the PCB securing plate, in a second embodiment of the present invention.  FIG. 8  illustrates in detail the coupling portion of the first and second PCB sheets according to the present invention. 
   If any one of continuously printed circuit pattern parts  102  (printed on a first PCB sheet  104 ) is found to be a defective circuit pattern part  102 ′, then the rectangular portion of the defective circuit pattern part  102 ′ which is defined by a separation groove K is cut off by using a router or the like to form a blanked space S. Then a second PCB sheet  104 ′ with a new good quality circuit pattern  102  printed thereon is placed into the rectangular space S, and then, the first and second PCB sheets  104  and  104 ′ are located by using a PCB securing means  110 . 
   The first and second PCB sheets  104  and  104 ′ are installed on the PCB securing plate  101  by using a PCB securing tape  105  which is one of the elements of the PCB securing means  110 . 
   A plurality of PCB securing pins  106  upstand upon the PCB securing plate  101 , while the first and second PCB sheets  104  and  104 ′ are provided with a plurality of pin receiving holes  107  correspondingly with the PCB securing pins  106 . The PCB securing pins  106  and the pin receiving holes  107  constitute a PCB position locating means  120 . Thus the PCB securing pins  106  of the PCB securing plate  101  are inserted into the pin receiving holes  107  to support the PCB sheets  104  and  104 ′. 
   Further as shown in  FIG. 9 , between the first and second PCB sheets  104  and  104 ′, there is formed a space  130  to form a channel  109 , so that an adhesive  108  as an adhesive means  140  can be injected into the channel  109 . On the bottom of the channel  109 , there is put a PCB securing tape  105 ′ to prevent any leakage of the adhesive  108 . 
   A cover part  10  is put on the first and second PCB sheets  104  and  104 ′ which are secured on the PCB securing plate  101  like in the first embodiment. Thus the circuit pattern part  102  of the first and second PCB sheets  104  and  104 ′ are protected from the heat. The adhesive  108  is injected into the channel  109 , and the injected adhesive  108  is exposed to the outside so as to be cured. In this manner, the first and second PCB sheets  104  and  104 ′ are coupled together. 
   Accordingly, as shown in  FIGS. 6 to 9 , if any one of the circuit pattern parts  102  of the PCB sheet  103  is found be a defective circuit pattern part  102 ′, then the defective circuit pattern part  102 ′ is cut away along the groove K to form a blanked space S like in the first embodiment. Then a second PCB sheet  104 ′ on which a good quality circuit pattern part  102  is printed is placed into the blanked space S, and then, the second PCB sheet  104 ′ is coupled to the first PCB sheet  104 . 
   Under this condition, the reason why the blanked space S is formed in a rectangular shape is as follows. That is, when the finished PCB product is carried to a subsequent process to install chip components and other electronic components, the weakness of the coupling portion between the first and second PCB sheets  104  and  104 ′ is reinforced by providing a rectangular blanked space, because the rectangular space increases the coupling area. 
   After completion of the blanking of the PCB sheet portion of the defective circuit pattern part  102 ′, a second PCB sheet  104 ′ on which a good quality circuit pattern is printed is placed into the blanked space S of the first PCB sheet  104 . The whole structure including the first and second PCB sheets  104  and  104 ′ is disposed on the PCB securing plate  101  to be secured on it. Under this condition, the PCB securing pins  106  of the PCB securing plate  101  are inserted into the pin receiving holes  107  to support the PCB sheets  104  and  104 ′, so that the first and second PCB sheets  104  and  104 ′ would be secured on the PCB securing plate  101 . 
   In order to prevent any loose movements of the first and second PCB sheets  104  and  104 ′, a PCB securing tape  105  which is a both-face tape is put to around the coupling portion between the first and second PCB sheets  104  and  104 ′ and on the bottom of the PCB sheet so as to be attached on the PCB securing plate  101 . 
   Further, between the first and second PCB sheets  104  and  104 ′ which are disposed on the PCB securing plate  101 , there is provided a separation distance of about 1-5 mm. Thus there is formed a space  130  which forms a channel  109 . Then a heat resistant tape  105 ′ is put to the bottom, front and rear of the channel  109 , so that the injected adhesive can be prevented from being leaked. 
   Thus the first and second PCB sheets  104  and  104 ′ are secured by using the PCB securing tape  105  and the tape  105 ′, the latter surrounding the channel  9  of the space  13 . Then the adhesive  108  is injected into the channel  109  of the space  130  which is formed between the first and second PCB sheets  104  and  104 ′. Then the whole structure is transferred to a drying furnace to make the adhesive  108  cured. Further, a hardening agent such as a highly heat resistant epoxy resin is added to the adhesive. After the injection of the adhesive  108 , the circuit patterns of the first and second PCB sheets  104  and  104 ′ are covered with a flat cover part  10  to protect the first and second PCB sheets  104  and  104 ′ from the heat like in the first embodiment. 
   Then the tape  105  which has been put to around the PCB sheet  104 ′ is removed, and the tape  105 ′ which has been put on the bottom of the channel  109  is also removed. Then, the PCB securing plate  101  is separated from the first and second PCB sheets  104  and  104 ′, thereby completing the coupling of the first and second PCB sheets  104  and  104 ′. 
     FIG. 10  illustrates a state in which a good quality PCB sheet is inserted into the whole PCB sheet, and the two sheets are fixed onto the PCB securing plate, in a third embodiment of the present invention.  FIG. 11  illustrates a state in which a good quality PCB sheet is coupled into a space formed by the removal of the defective PCB sheet in the third embodiment of the present invention. 
   A PCB sheet  204  on which a plurality of PCBs  202  are connectedly installed through a plurality of connecting parts  220  is disposed a PCB securing plate  201 . If a defective PCB  202 ′ is found among the plurality of the PCBs  202 , then the defective PCB  202 ′ is cut out along a PCB separating groove K. Then a good quality PCB  221  with connecting parts  220 ′ is fitted into the cut-out space  222  to be secured to the PCB sheet. 
   As shown in  FIGS. 12A and 12B , the removal of the defective PCB  202 ′ is carried out in the following manner. That is, either a cutting is carried out around the connecting parts  220  (as shown in  FIG. 2A ), or the plurality of the connecting parts  220  of the PCB  202  are cut off ( FIG. 2B ). The reason is as follows. That is, when carrying the PCB sheets to a subsequent process, the carrying posture becomes different depending on the circuit pattern arrangement direction on the PCB sheet. Therefore, when installing chip components or other electronic components into the PCB  202  of the PCB sheet  204 , the joining portion of the good quality PCB  221  has to be made to have a high strength. For this purpose, the joining portion is selectively made long or short. 
   As shown in  FIG. 13 , a PCB securing tape  205  which is a both-face tape is put around and on the bottom of the coupling portion of the good quality PCB  221  to prevent any loose movements of the PCB sheet  204  and the good quality PCB  221 . In this manner, the PCB sheet  204  and the good quality PCB  221  are fixed to the PCB securing plate  201 . 
   A plurality of PCB securing pins  206  upstand upon the PCB securing plate  201 , while the PCB sheet  204  and the good quality PCB  221  are provided with a plurality of pin receiving holes  207  correspondingly with the PCB securing pins  206 . These pins and holes are for locating each of the PCB sheets  204  at exact position and are for carrying the PCB sheets  204 . 
   Between the PCB sheet  204  and the good quality PCB  221 , there is formed a space  213  to form a channel  209 , so that an adhesive  208  as an adhesive means  214  can be injected into the channel  209 . On the bottom, front and rear of the channel  209 , there is put a PCB securing tape  205 ′ to prevent any leakage of the adhesive  208 . 
   Further, a cover  210  is covered on the good quality PCB  221  and the PCB  202  of the PCB sheet  204  which is secured on the PCB securing plate  201 . Thus the PCBs  202  of the PCB sheet  204  are protected from the ambient heat, and the adhesive  208  is injected into the channel  209  to be cured, thereby coupling a second PCB sheet  204 ′ (with the good quality PCB  221  printed thereon) to the first PCB sheet  204 . 
     FIGS. 14 and 15  illustrate a state in which a good quality PCB sheet is inserted into the whole PCB sheet, and the two sheets are fixed onto the PCB securing plate by using a securing jig, in a fourth embodiment of the present invention.  FIG. 16  is a plan view showing the coupling of a new good quality PCB sheet to the whole PCB sheet of  FIG. 15 . 
   A PCB  303  consists of a plurality of circuit pattern parts  302   a  which are connected to each other by connecting parts  301 . If a defective circuit pattern part is found among the plurality of the circuit pattern parts  302   a  upon carrying out a testing, then the defective circuit pattern part is removed by cutting a connecting part  301 ′. In the place of the removed defective circuit pattern part, there is placed a good quality circuit pattern part  302   b  by means of a PCB securing means  311  into a PCB securing jig  310  which has a plurality of separating walls  315 . 
   As shown in  FIG. 16 , the good quality circuit pattern part  302   b  has to be secured in the place of the removed defective circuit pattern part. For this purpose, a PCB securing tape  305  which is a both-face tape is put on the bottom of the coupling portion, so that any loose movements of the good quality circuit pattern part  302   b  can be prevented, thereby securing it to the PCB securing jig  310 . 
   A plurality of PCB securing pins  306  upstand upon the PCB securing jig  310 , while the PCB  303  and the good quality circuit pattern part  302   b  are provided with a plurality of pin receiving holes  307 . The plurality of the PCB securing pins  306  and the plurality of the pin receiving holes  307  constitute a PCB position locating means  312 . Thus the PCB securing pins  306  of the PCB securing jig  310  are inserted into the pin receiving holes  307  of the PCB  303  and the good quality circuit pattern part  302   b . Thus the good quality circuit pattern part  302   b  is secured at a side of the PCB  303  within the PCB securing jig  310 . 
   Between the PCB  303  and the good quality circuit pattern part  302   b , there is formed a space  313  which forms a channel. An adhesive  308  which is an adhesive means  314  is injected to the channel. 
   As shown in  FIG. 17 , a cover  309  covers the good quality circuit pattern part  302   b  and the PCB  303  on which a plurality of circuit patterns  302   a  are formed. In this manner, the good quality circuit pattern part  302   b  and the PCB  303  are protected from the ambient heat. Meanwhile, the adhesive  308  which has been injected into the channel of the space  313  is cured by being exposed to the external air, so that the good quality circuit pattern part  302   b  can be firmly coupled to the PCB  303 . 
   According to the present invention as described above, if a defective circuit pattern is found among the plurality of the circuit patterns, then the defective circuit pattern is removed to replace it with a good quality circuit pattern so as to secure it in place in an easy manner. By removing the defective circuit pattern, the whole PCB sheet which is otherwise to be discarded can be saved, thereby increasing the product yield and curtailing the production cost. That is, the PCB sheet on which a defective circuit pattern is printed is cut off, and the cut space is filled with a good quality circuit pattern sheet by means of a position locating means. Then a heat resistant tape and an adhesive means are used to secure the good quality circuit pattern sheet to the whole PCB sheet in an easy manner. Accordingly, in manufacturing the printed circuit board of the present invention, the workability and the productivity are drastically improved. 
   In the above, the present invention was described based on the specific embodiments and the attached drawings, but it should be apparent to those ordinarily skilled in the art that various changes and modification can be added without departing from the spirit and scope of the present invention which will be defined by the appended claims.