Abstract:
A fabrication method of battery pack device includes the steps of: preparing a plurality of protection circuit substrates disposed apart from each other in a space of a frame, and supported to the frame via a bridge member; attaching a connector component to a top face side of each of the protection circuit substrates; moving a leading end of a sealing material feeder towards the connector component from a bottom side of the protection circuit substrate and supplying a sealing material to a bottom end of the connector component; infiltrating the sealing material into a gap between the connector component and the protection circuit substrate, along a circumference at the bottom end of the connector component to seal the gap with the sealing material.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a fabrication method of a battery pack device including a plurality of protection circuit substrates arranged apart from each other in the space of a frame, a plurality of connector components, and a battery body, all integrated with mold resin. 
         [0003]    2. Description of the Background Art 
         [0004]    A connector device having a protection circuit substrate and connector component integrated with each other is conventionally employed for a battery pack in order to establish connection between the battery pack and, for example, the telephone unit of a cellular phone. A connector device is formed of a predetermined protection circuit substrate, and a connector component affixed to the protection circuit substrate. By inserting a terminal of the telephone unit to the connector component, the electric power of the battery pack is supplied to the cellular phone. One type of connector device is sealed with the battery pack body by mold resin to constitute an integral unit. 
         [0005]    A fabrication method of this type of connector device will be described hereinafter. As shown in  FIG. 11 , there are prepared a plurality of protection circuit substrates  10  spaced apart from each other in a space of a frame  110 , supported by frame  110  via a bridge member. A predetermined circuit pattern  1110   a  is formed at each of protection circuit substrates  10 . Circuit pattern  1110   a  includes a land  1120  connected to a connector component  20 . Solder paste is applied on circuit pattern  1110   a.  A connector component  20  (strips), an electronic component  1130 , and the like are mounted on circuit pattern  1110   a  with solder paste (not shown) therebetween. 
         [0006]    The top face of protection circuit substrate  10  where connector component  20 , electronic component  1130 , and the like are mounted (the face on which the connector component is disposed) is upturned. The protection circuit substrate  10  is passed through a reflow furnace being tilted for solder-bonding connector component  20 , electronic component  1130  and the like to the circuit pattern. 
         [0007]    As shown in  FIG. 12 , a width W 4  of connector component  20  is set smaller than a width W 3  of a battery pack body  50 . Taking into account variation in the dimension of protection circuit substrate  10  and the positioning accuracy of electronic component  1130  during the step of mounting connector component  20  on protection circuit substrate  10 , connector component  20  and protection circuit substrate  10  are disposed and solder-bonded such that an end face  118  of protection circuit substrate  10  protrudes outer than an end face  27  of connector component  20 . 
         [0008]    Then, as shown in  FIG. 13 , a sealing material  4  is supplied through a nozzle  71  of a sealing material feeder with the connector device protection circuit substrate  10  tilted to the shorter side direction of connector component  20  that is disposed on the top face of protection circuit substrate  10 . Accordingly, the gap between connector component  20  and protection circuit substrate  10  is sealed by sealing material  4 . Then, the bridge member is cut from frame  10 , as shown in  FIG. 11 , so that the region of protection circuit substrate  10  is divided. Thus, a connector device  26  (refer to  FIG. 17 ) having protection circuit substrate  10  and connector component  20  formed integrally is completed. 
         [0009]    Then, connector device  26  and battery pack body  50  are set integrally by mold resin  6  to complete a battery pack  17 , as shown in  FIG. 17 . A terminal (not shown) of the telephone set unit is inserted to a connection terminal  220  of connector component  20  exposed at the surface of battery pack  17 , whereby electric power is supplied. For example, Japanese Patent Laying-Open No. 2000-69137 is cited as a document disclosing a battery pack for a cellular phone or the like. 
         [0010]    The conventional fabrication method of connector device  26  had the following problems. In the case where the thickness W 5  of battery pack body  5  becomes so thin that the size of connector component  2  and the connection with protection circuit substrate  1  may have to be revised, supply of sealing material  4  from above connector component  2  (the top face side of protection circuit substrate  1 ) to the bottom end of connector component  2  will cause nozzle  71  of the sealing material feeder to collide against a second end face  23  that is the leading end face of projection  9  of connector component  2 , inducing the problem that sealing material  4  cannot be supplied. 
         [0011]    If there is only one protection circuit substrate  1 , sealing material  4  can be applied by increasing the tilt. However, in the case where protection circuit substrates  1  are arranged apart from each other as in  FIG. 16 , a large tilt will cause nozzle  71  of the sealing material feeder to collide against the closest connector unit  2 , leading to the problem that sealing material  4  cannot be supplied. Although collision of nozzle  71  of the sealing material feeder can be avoided if the distance between the plurality of connector components  2  (or protection circuit substrates  1 ) disposed apart from each other in  FIG. 1  is increased, the productivity will then be degraded to lead to increase of the cost. 
         [0012]    Even if collision of nozzle  71  against second end face  23  that is the leading end of projection  9  of connector component  2  is not initially encountered, this collision may eventually occur due to the attachment of sealing material  4  to the leading end of nozzle  71  during the repetitive usage of nozzle  71  of the sealing material feeder, i.e. the diameter of the leading end of nozzle  71  being increased. 
       SUMMARY OF THE INVENTION 
       [0013]    In view of the foregoing, an object of the present invention is to provide, with favorable productivity, a battery pack employing a connector device having reliable connection between the connector device and a main body such as a cellular phone. 
         [0014]    A fabrication method of a battery pack device according to the present invention includes the steps of: preparing a plurality of protection circuit substrates disposed apart from each other in a space of a frame, and supported to the frame via a bridge member; attaching a connector component to a top face side of each of the protection circuit substrates; moving a leading end of a sealing material feeder towards the connector component from a bottom side of the protection circuit substrate and supply a sealing material to a bottom end of the connector component; infiltrating the sealing material into a gap between the connector component and the protection circuit substrate, along a circumference at the bottom end of the connector component to seal the gap with the sealing material; cutting the bridge member to separate each of the protection circuit substrates from the frame; and attaching a battery pack body to the bottom side of the protection circuit substrate, and resin-molding the battery pack body, the protection circuit substrate and the connector component as a unitary element. 
         [0015]    Preferably, the protection circuit substrate and connector component constitute a strip. The connector component includes a first end face along one of longitudinal sides of the connector component, and a projection. The projection includes a second end face. The protection circuit substrate includes a first protection circuit substrate end face along one of longitudinal sides of the protection circuit substrate. The first protection circuit substrate end face is set flush with the first end face or protruding outer than the first end face. 
         [0016]    Preferably, the width between the second end face of the projection of the connector component and an end face of a housing, opposite to the second end face of the projection is equal to the thickness of the battery pack body. 
         [0017]    According to the configuration of the present invention set forth above, a sealing material is supplied and infiltrated to the bottom end of the connector component without the nozzle of a sealing material feeder colliding against the connector component, allowing the gap between the connector component and protection circuit substrate to be sealed. 
         [0018]    The presence of a projection at the connector component allows the resin not flowing into the gap between the connector unit and circuit body to be held back even if the sealing material is supplied from a face of the protection circuit substrate where the connector component is not connected. 
         [0019]    The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a perspective view of a connector device according to a first embodiment of the present invention. 
           [0021]      FIG. 2  is a perspective view of the connector device of the first embodiment viewed from the bottom side. 
           [0022]      FIG. 3  is a perspective view of the top surface of protection circuit substrates of the connector device of the first embodiment. 
           [0023]      FIG. 4  is a perspective view of the bottom of protection circuit substrates with components attached via solder paste in the connector device of the first embodiment. 
           [0024]      FIG. 5  is a perspective view of the connector device of the first embodiment, with the bottom of protection circuit substrates attached to a jig. 
           [0025]      FIG. 6  is a perspective view of the bottom of protection circuit substrates subsequent to component attachment by the passage of the connector device of the first embodiment through a reflow furnace. 
           [0026]      FIG. 7  is a perspective view of the surface of protection circuit substrates with the connector components attached according to the first embodiment. 
           [0027]      FIG. 8  is a sectional view of the connector component of  FIG. 7  taken along line VIII-VIII, represented in an inclined manner. 
           [0028]      FIGS. 9A and 9B  are perspective views representing the step of supplying sealing material to the connector component according to the first embodiment. 
           [0029]      FIG. 10  is a perspective view representing the step of attaching a connector device and a battery pack according to the first embodiment of the present invention. 
           [0030]      FIG. 11  is a perspective view representing the step of attaching a connector component to a protection circuit substrate according to prior art. 
           [0031]      FIG. 12  represents comparison in width between a connector component and battery pack body according to prior art. 
           [0032]      FIG. 13  represents the step of supplying sealing material to a connector component and protection circuit substrate according to a conventional method. 
           [0033]      FIG. 14  represents comparison in width between the connector component and battery pack body according to the first embodiment of the present invention. 
           [0034]      FIG. 15  is a diagram to describe supply of sealing material according to a conventional method. 
           [0035]      FIG. 16  is a diagram to describe the supply of sealing material being disabled according to a conventional method. 
           [0036]      FIG. 17  is a perspective view of the step of attaching a connector device and battery pack according to a conventional method. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
       [0037]    A connector device used in a battery pack of a cellular phone will be described hereinafter as a connector device  3  integrated with a protection circuit substrate  1  and a connector component  2  according to a first embodiment of the present invention. Referring to  FIGS. 1 and 2 , connector device  3  is configured to include protection circuit substrate  1  and connector component  2 . Connector component  2  includes a housing  21 , and a connection terminal  22  located in housing  21 . Connection terminal  22  is connected to a land  112  (refer to  FIG. 3 ) formed at protection circuit substrate  1 . 
         [0038]    A first protection circuit substrate end face  115  of protection circuit substrate  1  is set flush with or protruding outer than a first end face  24  of housing  21  in connector component  2 . 
         [0039]    Protection circuit substrate  1  also includes an end face  116 , opposite to first protection circuit substrate end face  115 . For the purpose of registration between connector component  2  and protection circuit substrate  1 , housing  21  includes an end face  25 , opposite to end face  116  of protection circuit substrate  1  (refer to  FIG. 8 ). 
         [0040]    Predetermined circuit patterns  114   a  and  114   b  are formed at a top face  11   a  of protection circuit substrate  1  (the face where connector component  2  is connected) and at a bottom  11   b  (the face where connector component  2  is not connected). A predetermined electronic component  113 , and Ni plates  117   a  and  117   b  are mounted at circuit patterns  114   a  and  114   b.    
         [0041]    In connector device  3 , a sealing material  4  is supplied for infiltration so as to seal the gap between connector component  2  and protection circuit substrate  1 . This infiltration of sealing material  4  between the gap prevents mold resin  6  from entering connector component  2  from the gap during the sealing of connector device  3  integrally with battery pack body  5  by mold resin  6 . Since connection terminal  22  furnished in connector component  2  is not covered with mold resin  6 , connector device  3  and the cellular phone main body can be rendered conductive reliably. 
         [0042]    An example of a fabrication method of a battery pack device employing connector device  3  will be described hereinafter. Referring to  FIGS. 3 and 4 , there is prepared a frame  111  whose relevant areas are equivalent to top face  11   a  and bottom face  11   b  of a plurality of protection circuit substrates  1  supported by frame  111  via a bridge member. Protection circuit substrates  1  are disposed apart from each other in the space of frame  111 . Circuit pattern  114   a  includes land  112  to which connector component  2  is connected. The plurality of protection circuit substrates  1  are cut off eventually from frame  111  to be individually separated as a protection circuit substrate. 
         [0043]    The step of connecting protection circuit substrate  1  with connector component  2  that includes connection terminal  22  electrically connected to a predetermined terminal of protection circuit substrate  1  and a housing  21  holding and covering connection terminal  22  will be described hereinafter. Referring to  FIG. 4 , lead (Pb)-free solder paste (not shown) is applied on circuit pattern  114   b  using a metal mask or the like (not shown). Predetermined electronic component  113  and Ni plates  117   a  and  117   b  are mounted with solder paste thereunder. 
         [0044]    Referring to  FIG. 5 , with circuit pattern  114   b  formed at bottom  11   b  of protection circuit substrate  1  facing upward, a jig  18  is attached such that frame  111  is tilted in the shorter side direction of protection circuit substrate  1 , followed by passage through a reflow furnace to solder-bond electronic component  113 , Ni plates  117   a  and  117   b,  or the like to protection circuit substrate  1 . Accordingly, electronic component  13 , and Ni plates  117   a  and  117   b  are solder-bonded, as shown in  FIG. 6 . In the reflow furnace, heat treatment of several ten seconds in duration is carried out at the temperature of approximately 230° C. to 250° C., for example. 
         [0045]    Referring to  FIG. 7 , lead (Pb)-free solder paste (not shown) is applied on circuit pattern  114   a  using a metal mask (not shown) or the like, and connector component  2  is mounted with solder paste thereunder at the region of land  112  relevant to connector component  2 , at the top face  11   a  side of protection circuit substrate  1 . 
         [0046]    Further, with circuit pattern  114   a  formed at top face  11   a  of protection circuit substrate  1  facing upward, a jig  18  is attached such that frame  111  is tilted in the shorter side direction of protection circuit substrate  1 , as in  FIG. 5 , followed by passage through a reflow furnace to solder-bond connector component  2  to protection circuit substrate  1 . In the reflow furnace, heat treatment is applied for the duration of several ten seconds at the temperature of approximately 230° C. to 250° C., for example. 
         [0047]    The relationship between connector component  2  and protection circuit substrate  1  will be described with reference to the sectional view of the connector component of  FIG. 7  taken along line VIII-VIII. The solder paste melts by the heat treatment in the reflow furnace. Accordingly, connector component  2  in a tilted posture slides (arrow  200 ), so that an end face  25  of connector component  2  approaches end face  116  of protection circuit substrate  1 . In the event of end face  25  brought into contact with a region of end face  116 , connector component  2  will not slide any further. Connector component  2  is registered at a predetermined position in self-alignment with respect to end face  116 . 
         [0048]    Although circuit pattern  114   b  formed at bottom  11   b  of protection circuit substrate  1  faces downwards, electronic component  113  and the like will not fall off from protection circuit substrate  1  even by passage through the reflow furnace by selecting appropriate conditions for the reflow furnace and by the event of electronic component  113  and the like being coupled to protection circuit substrate  1  with the solder paste once melting. 
         [0049]    There may still be a small gap W 1  between end face  25  of connector component  2  and end face  116  of protection circuit substrate  1 , as shown in  FIG. 8 . Furthermore, the melting of the solder paste will cause the solder to flow, so that connector component  2  settles downwards (arrow  201 ). Accordingly, the gap between the bottom end of connector component  2  and protection circuit substrate  1  becomes smaller. However, there may still be a small gap W 2  between the bottom end of connector component  2  and protection circuit substrate  1 , depending upon the initial thickness of the solder paste. 
         [0050]    In view of such a gap, the step of supplying sealing material  4  to fill the gap between connector component  2  and protection circuit substrate  1  includes the step set forth below, as shown in  FIGS. 9A and 9B . With protection circuit substrate  1  facing downwards and tilted in the shorter side direction of connector component  2 , a dispenser  8  and a syringe  7  that are sealing material supply devices are used to apply sealing material  4  from a nozzle  71  of syringe  7 . Here, silicone resin was used as sealing material  4 . At this stage, supply sealing material  4  may be supplied for infiltration with frame  111  placed on a jig identical to that passed through the reflow furnace. When sealing material  4  is supplied, the sealing material is infiltrated to seal the gap between the bottom end of connector component  2  and protection circuit substrate  1  by a capillary action, followed by drying sealing material  4  at ambient temperature. Thus, sealing material  4  is cured, and the gap filled. Sealing material  4  in the drawing runs from the top face of protection circuit substrate  1 . 
         [0051]    By setting bottom face  11   b  of protection circuit substrate  1  upwards, as shown in  FIG. 9B  when sealing material  4  is to be supplied, the productivity will not be degraded since collision of nozzle  71  against second end face  23  of projection  9  in housing  21  will not occur, and increasing the distance between protection circuit substrates  1  in frame  111  is not required. 
         [0052]    Even if sealing material  4  is supplied with the bottom of protection circuit substrate  1  facing upwards, the presence of projection  9  at housing  21  allows sealing material  4  that did not flow around connector component  2  to be held back. 
         [0053]    Then, the step of cutting protection circuit substrates  1  from frame  11  to separate each other is carried out. Thus, connector device  3  with connector component  2  attached to protection circuit substrate  1  is completed, as shown in  FIGS. 1 and 2 . 
         [0054]    The step of integrating battery pack body  5 , protection circuit substrates  1  and connector component  2  with mold resin  6  will be described hereinafter. Referring to  FIG. 10 , connector device  3  including protection circuit substrates  1  and connector component  2  is disposed at a predetermined position with respect to battery pack body  5  in which batteries are installed. Connector device  3  and battery pack body  5  are disposed in a predetermined mold (not shown). By introducing mold resin  6  into a metal casing, connector device  3  and battery pack body  5  are sealed integrally by mold resin  6 . Then, they are taken out from the mold. Thus, a battery pack  15  having connector device  3  and battery pack body  5  sealed by mold resin  6  is completed. A connection terminal  22  is exposed at connector component  2  of battery pack  15 . 
         [0055]    In connector device  3  set forth above, silicone resin was employed as sealing material  4  to seal the gap between connector component  2  and protection circuit substrate  1 . In the case where the gap is sealed taking advantage of a capillary phenomenon, another sealing material may be employed. 
         [0056]    Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being interpreted by the terms of the appended claims.