Abstract:
A battery including a battery cell provided with an electrode terminal protruding from a side, a circuit board attached along sides of the battery cell, and a resin mould section which partially covers the circuit board and the battery cell, thereby integrating them. The circuit board includes rigid base sections for mounting components, and a flexible base section which connects between the rigid base sections and can bend flexibly. The rigid base section is provided with a pierced aperture, which pierces the rigid base section in the thickness direction, and into which an electrode terminal is fitted, and an electrically conductive material which is electrically connected to the wiring of the rigid base section, and electrically connected to the electrode terminal provided in the pierced aperture. The circuit board may be easily positioned in relation to the battery cell.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims all rights of priority to Japanese Patent Application No. 2002-050431 filed on Feb. 26, 2002, (pending). 
   BACKGROUND OF THE INVENTION 
   The present invention relates to batteries of a form where a circuit board is integrated with a battery cell by a resin mould section. 
   As shown in  FIG. 9 , battery  51  is a conventional battery for use in portable terminals such as cell phones, simple portable telephones and the like. 
   This battery  51  comprises a rectangular tabular battery cell  52 , a circuit board  53  positioned along a side  52   a  of the battery cell  52 , a resin mould section  54  fixed to sides  52   a ,  52   b , and  52   c  of the battery cell  52 , a cable  55  leading from the resin mould section  54 , and a connection terminal  56  provided on the end of the cable  55 . 
   The battery cell  52  is formed by enclosing an electrolyte together with a laminate of several layers of positive film and negative film separated by a separator, inside a container made by deep drawing aluminum or aluminum alloy. Also, as shown in  FIG. 10 , a negative electrode terminal  52   d  is positioned so as to protrude from the center of the side  52   b  of the battery cell  52 , and the other surfaces of battery cell  52  form the positive electrode terminal. 
   The circuit board  53  is provided with electronic components  70  for charge control of the battery cell  52 , and is attached to the side  52   a  of the battery cell  52 . Furthermore, the circuit board  53  is connected to the positive electrode terminal and to the negative electrode terminal  52   d  of the battery cell  52  by metal connection plates  57  and  58 . 
   These connection plates  57  and  58  are made of metal plate bent into an L-shape, and the circuit board  53  and the battery cell  52  are electrically connected by soldering their distal ends  57   a  and  58   a  to a rear face  53   b  of ends  53   c  and  53   d  of the circuit board  53 , and soldering the other ends  57   b  and  58   b  to the negative electrode terminal  52   d  and the positive electrode terminal respectively. 
   Here, because the other end  57   b  of the connection plate  57  is positioned along the sides  52   a  and  52   b  of the battery cell, an insulation sheet  59  is provided between the battery cell  52  and the connection plate  57 , so that the connection plate  57  does not contact and short with the sides  52   a  and  52   b  which constitute the positive electrode terminal. 
   These connection plates  57  and  58  are positioned so as to hold the battery cell  52 , so that the circuit board  53  is fixed to the battery cell  52 . Next, the circuit board  53  and connection plates  57  and  58  which are fixed to the battery cell  52 , are enveloped by a resin mould section  54 , and thus formed integral with the battery cell  52 , as shown in  FIG. 9 . 
   The connection terminal  56  is for supplying power from the battery cell  52  to a portable terminal (not shown in the figure), by connecting to a connection terminal of the portable terminal, and is connected to the cable  55 . The cable  55  is soldered to the front face  53   a  side of the end  53   c  of the circuit board  53 , as shown in  FIG. 10 . 
   However, in the above mentioned battery  51 , the positioning of the circuit board  53  in relation to the battery cell  52  is problematic, due to the circuit board  53  being connected by soldering to the side  52   a  of the battery cell  52  through the connection plates  57  and  58 . 
   Furthermore, with regard to the recent demand for miniaturization of portable terminals, the existence of the cable  55  limits the extent to which miniaturization of the battery is possible. 
   Moreover, because the terminals of the battery cell  52  are connected to the portable terminal through the cable  55 , this introduces an extra impedance between the battery cell  52  and the portable terminal, with the problem of a drop in power supply efficiency of the battery cell  52 . 
   SUMMARY OF THE INVENTION 
   The present invention was conceived to solve the problems of the prior art described above and its object is to provide a battery in which the positioning of the circuit board in relation to the battery cell can be easily performed. 
   In order to solve the above problem, a first aspect of the invention proposes a battery comprising a battery cell provided with an electrode terminal protruding from at least one side, a circuit board attached along at least two sides of the battery cell, and a resin mould section which at least partially covers this circuit board and battery cell, thereby integrating them. The circuit board comprises at least two rigid base sections for mounting components, and a flexible base section which is connected between the two rigid base sections. The rigid base section is provided with a pierced aperture, which pierces the rigid base section in the thickness direction, and into which the electrode terminal is fitted, and an electrically conductive material which is electrically connected to wiring of the rigid base section, and which is electrically connected to the electrode terminal provided in the pierced aperture. 
   According to this aspect, when one rigid base section is positioned on one side of a battery cell, it is possible to position the other rigid base section along the other side, by bending the flexible base section. 
   Furthermore, because the rigid base section is fixed to the side of the battery cell by fitting the protruding electrode terminal into the pierced aperture in the rigid base section, it is possible to accurately and easily position the rigid base section in relation to the side of the battery cell. 
   Then, by positioning the electrically conductive material in this pierced aperture and electrically connecting the protruding electrode terminal and the circuit board, power is supplied from the battery cell to each component on the circuit board. 
   Furthermore, a second aspect of the invention proposes for the battery according to the first aspect wherein the components include a connection terminal exposed to the outside and which is fixed to the rigid base section provided with the pierced aperture. 
   According to this aspect, because the connection terminal together with the circuit board are integrated into the battery cell by the resin mould section, it is possible to achieve miniaturization of the battery. Furthermore, because the connection terminal is fixed directly to the circuit board without connecting through a cable, it is possible to achieve a reduced impedance when supplying power to the load of a portable terminal or other terminal. 
   Moreover, because the connection terminal is fixed to the rigid base section provided with the pierced aperture, accurate positioning of the connection terminal in relation to the battery cell is favorably obtained. 
   Furthermore, a third aspect of the invention proposes a mounting structure for a circuit board, which mounts a circuit board on a battery cell provided with an electrode terminal protruding from at least one side. The circuit board comprises at least two rigid base sections for mounting components, and a flexible base section connected between the two rigid base sections. The rigid base section is provided with a pierced aperture, which pierces the rigid base section in the thickness direction, and into which the electrode terminal is fitted. An electrically conductive material is positioned on the pierced aperture and electrically connected to wiring of the rigid base section. The electrically conductive material and an electrode terminal fitted into the pierced aperture are electrically connected. 
   According to this aspect, when one rigid base section is positioned on one side of the battery cell, it is possible to position the other rigid base section along an other side by bending the flexible base section. 
   Furthermore, because the rigid base section is fixed to the side of the battery cell by fitting the protruding electrode terminal into the pierced aperture in the rigid base section, it is possible to accurately and easily position the rigid base section in relation to the side of the battery cell. 
   Then, by positioning the electrically conductive material in this pierced aperture and electrically connecting the protruding electrode terminal and the circuit board, power is supplied from the battery cell to each component on the circuit board. 
   Furthermore, a fourth aspect of the invention proposes for the mounting structure for a circuit board according to the third aspect wherein the electrically conductive material and the electrode terminal are connected by welding. 
   According to this aspect, the battery cell and the circuit board are electrically connected, by welding the electrically conductive material positioned in the pierced aperture to the electrode terminal fitted into the pierced aperture. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
       FIG. 1  is a perspective view showing a battery according to a first embodiment of the present invention; 
       FIG. 2  is a perspective view showing a battery cell used in the battery of  FIG. 1 . 
       FIG. 3  is a perspective view showing a circuit board used in the battery of  FIG. 1 . 
       FIG. 4  is a perspective view showing the state of the battery in  FIG. 1 , before formation of a resin mould section. 
       FIG. 5  is an enlarged view showing the state of the battery in  FIG. 1 , with the resin mould section removed from the battery, and disassembled into a battery cell, rigid base sections, a connection terminal and an electrically conductive material. 
       FIG. 6  is an enlarged cross-sectional view showing the state of the battery in  FIG. 1 , with a negative electrode terminal and an electrically conductive material fitted into a pierced aperture in the rigid base section. 
       FIG. 7  is an enlarged view showing the state of the battery in  FIG. 1 , with the resin mould section removed from the battery, and disassembled into a battery cell, rigid base sections, and an electrically conductive material. 
       FIG. 8  is an enlarged cross-sectional view showing the state of the battery in  FIG. 1 , with the electrically conductive material fitted into a pierced aperture in the rigid base section. 
       FIG. 9  is a perspective view showing an example of a conventional battery. 
       FIG. 10  is a perspective view showing the state of the battery in  FIG. 9 , with a resin mould section removed from the battery, and disassembled into a battery cell, a circuit board and a connection board. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   This invention solves the problems of prior art by providing a battery in which the positioning of the circuit board in relation to the battery cell can be easily performed. 
     FIGS. 1 to 7  demonstrate a first embodiment according to the present invention. As shown in  FIG. 1 , a battery  1  comprises a rectangular tabular battery cell  2 , a circuit board  3  positioned along narrow sides  2   a ,  2   b , and  2   c  of the battery cell  2 , and a resin mould section  4  enveloping the circuit board  3  and secured to the sides  2   a ,  2   b , and  2   c  of the battery cell  2 . 
   The battery cell  2  is of the same configuration as mentioned above, with the separator, electrodes, and electrolyte enclosed inside a rectangular tabular container formed of aluminum alloy or other material. As shown in  FIG. 2 , a negative electrode terminal  2   d  is formed protruding from the center of the side  2   b , and the surfaces of the battery cell  2  excluding the negative electrode terminal  2   d  are formed as the positive electrode terminal. Therefore, the protruding negative electrode terminal  2   d  is electrically insulated from the side  2   b.    
   As shown in  FIG. 3 , the circuit board  3  is of a narrow shape in order to be positioned along the side of the battery cell, and comprises rigid base sections  3   a ,  3   b , and  3   c , and flexible base sections  3   d  and  3   e . These rigid base sections  3   a ,  3   b , and  3   c , and flexible base sections  3   d  and  3   e  are formed integrally. 
   The rigid base sections  3   a ,  3   b , and  3   c  are a laminate of several layers of synthetic resin wiring sheets. These wiring sheets are ones where wiring conductors are formed by a photolithography technique on the surface. By laminating several layers of these wiring sheets, it is possible to provide a large number of wires in the narrow rigid base sections  3   a ,  3   b , and  3   c . Here, because these rigid base sections  3   a ,  3   b , and  3   c  are laminates of the same number of wiring sheets, they have equal thickness. 
   A plurality of electronic components  5  for battery cell charge control and over-current protection are provided on the front face of rigid base section  3   a . A connection terminal  6  for electrically connecting to a portable terminal (not shown in the figure), an electrically conductive material  7  for electrically connecting to the negative electrode terminal of a battery cell, are provided on the front face of the rigid base section  3   b . Also, as shown in  FIG. 5 , a pierced aperture  3   f  is formed in this rigid base section  3   b , for fitting the negative electrode terminal  2   d  of the battery cell  2 . 
   As shown in  FIG. 6 , the electrically conductive material  7  is formed with a protruding section  7   b  which protrudes from a surface  7   a  thereof. The protruding section  7   b  is shaped so as to fit in the pierced aperture  3   f . When the negative electrode terminal  2   d  is fitted into the pierced aperture  3   f , this electrically conductive material  7  abuts with the negative electrode terminal  2   d . Then, by spot welding the negative electrode terminal  2   d  to the electrically conductive material  7 , the negative electrode terminal  2   d  of battery cell  2  and the rigid base section  3   b  are electrically connected. 
   As shown in  FIG. 7 , a pierced aperture  3   g  is provided in the rigid base section  3   c , pierced in thickness direction thereof, and an electrically conductive material  8  is able to be fitted into this pierced aperture  3   g.    
   That is, as shown in  FIG. 8 , the electrically conductive material  8  is formed with a protruding section  8   b  which protrudes from a surface  8   a  thereof. The protruding section  8   b  is shaped so as to fit in the pierced aperture  3   g . This electrically conductive material  8 , when fitted into the pierced aperture  3   g , abuts with the side  2   c  as well as the rigid base section  3   c . Then, by spot welding the electrically conductive material  8  to the side  2   c , the positive electrode terminal of battery cell  2  and the rigid base section  3   c  are electrically connected. 
   As shown in  FIG. 3 , the flexible base sections  3   d  and  3   e  are made by extending one part of the laminated wiring sheet of the rigid base section  3   a ,  3   b , and  3   c , and are thus flexible and able to be bent. Therefore, as shown in  FIG. 4 , the rigid base sections  3   a ,  3   b , and  3   c  can be respectively positioned on the sides  2   a ,  2   b , and  2   c  of the battery cell  2 , by bending these flexible base sections  3   d  and  3   e . Furthermore, by electrically connecting the negative electrode terminal of the battery cell  2  to the rigid base section  3   b , and the positive electrode terminal to the rigid base section  3   c , the battery cell  2  and the circuit board  3  are electrically connected, enabling power of the battery cell  2  to be supplied from the connection terminal  6  to a portable terminal. 
   In the above manner, the battery  1  is constructed by enveloping the circuit board  3  in resin with the circuit board  3  positioned on the sides  2   a ,  2   b , and  2   c  of battery cell  2 , and by forming the resin mould section  4  as shown in  FIG. 1 , the circuit board  3  is fixed to the battery cell  2 . 
   A production method for the battery  1  constructed in the above manner will now be explained. 
   Firstly, as shown in  FIG. 4 , the electronic components  5  are fixed to the rigid base section  3   a , and the connection terminal  6  and the electrically conductive material  7  are fixed to the rigid base section  3   b . Furthermore, the electrically conductive material  8  is fixed to the rigid base section  3   c . Afterwards, the negative electrode terminal  2   d  protruding from the side  2   b  is fitted into the pierced aperture  3   f , the rigid base section  3   b  is fixed along the side  2   b , and the electrically conductive material  7  and the negative electrode terminal  2   d  are abutted with each other, as shown in  FIG. 5 . Next, the flexible base sections  3   d  and  3   e  are bent, and the rigid base sections  3   a  and  3   c  are positioned along the sides  2   a  and  2   c  of the battery cell  2 , as shown in  FIG. 4 . Then the electrically conductive materials  7  and  8 , and the negative electrode terminal  2   d  and the positive electrode terminal are electrically connected by spot welding. Consequently, a battery unit  10  with the circuit board  3  and the battery cell  2  electrically connected is formed. 
   Next, this battery unit  10  is housed in a metallic mould (not shown in the figure). The metallic mould with the battery unit  10  housed thereinside, has a cavity for forming the resin mould section  4  shown in  FIG. 1 , and an inlet is provided facing this cavity for supplying resin. By supplying resin from this inlet, the resin mould section  4  enveloping the circuit board  3  is formed. 
   According to the battery  1  of the above embodiment, since the rigid base section  3   b  is fixed to the side  2   b  of the battery cell  2  by fitting the protruding negative electrode terminal  2   d  into the pierced aperture  3   f  of the rigid base section  3   b , positioning of the rigid base sections  3   a ,  3   b , and  3   c  in relation to, the sides  2   a ,  2   b , and  2   c  of the battery cell  2  can be performed accurately and easily. 
   Furthermore, since the electrically conductive materials  7  and  8  fitted into the pierced apertures  3   f  and  3   g , and the negative electrode terminal  2   d  and the positive electrode terminal fitted into the pierced aperture  3   f  can be simply welded, then electrical connection between the battery cell  2  and the circuit board  3  can be easily performed. 
   Moreover, because the rigid base sections  3   a ,  3   b , and  3   c  have equal thickness, it is possible to fix the connection terminal  6  and the electrically conductive material  7  to the rigid base section  3   b , and fix the electrically conductive material  8  to the rigid base section  3   c , at the same time as fixing the electronic components  5  to the rigid base section  3   a.    
   Therefore, because of the above-mentioned structure it is possible to reduce the production time for the battery  1  and cut down on production costs. 
   Also, because the connection terminal  6  is fixed to the rigid base section  3   b , a cable for connecting the connection terminal to the circuit board is unnecessary. Therefore, it is possible to achieve a lower impedance when supplying power from the battery cell  2  to a portable terminal, and an improvement in power supply efficiency of the battery cell  2 . Also, it is possible to achieve miniaturization of the battery  1 , and miniaturization of a portable terminal in which this battery  1  is mounted. 
   Moreover, because the connection terminal  6  is fixed to the rigid base section  3   b  which is provided with the pierced aperture  3   f , it is possible to favorably obtain accurate positioning of the connection terminal  6  in relation to the battery cell  2 . Therefore, electrical connection with a portable terminal can be reliably performed. 
   In the above embodiment, the rigid base sections  3   a ,  3   b , and  3   c  are ones where the wiring sheets are laminated in several layers. However, its construction is not limited to this, and may be such that a board of synthetic resin having a predetermined thickness and provided with wiring in the interior for connection to the electronic components  5  and the like is provided on one or a number of wiring sheets. In this case, the part of the wiring sheets which is provided with the board of synthetic resin constitutes the rigid base sections  3   a ,  3   b , and  3   c , and the part with only the wiring sheets constitutes the flexible base sections  3   d  and  3   e.    
   Also, the electrically conductive material  7  having the protruding part  7   b  is fitted to the pierced aperture  3   f . However, an electrically conductive material with no protruding part may be positioned in the pierced aperture  3   f . However, in this case, it is necessary for the thickness of the negative electrode terminal  2   d  to be the same as the thickness of the rigid base section  3   a , so that the electrically conductive plate material and the negative electrode terminal  2   d  can abut with each other. 
   Moreover, the rigid base sections  3   a ,  3   b , and  3   c  have equal thickness to facilitate the connection terminal  6  and the electrically conductive material  7  to the rigid base section  3   b . However, in cases where shortening of the production time for the battery  1  is not taken into account, the rigid base sections need not be the same thickness. 
   Also, the rigid base sections  3   a ,  3   b  and  3   c  are attached along the three sides  2   a ,  2   b , and  2   c  of the battery cell  2 . However, it is sufficient if at least the rigid base sections  3   a  and  3   b  are attached along the sides  2   a  and  2   b . In this case, the pierced aperture is provided in the rigid base section  3   a  in the thickness direction thereof, and the positive electrode terminal of the battery cell  2  is electrically connected to the circuit board by fitting the electrically conductive material into this pierced aperture, and abutting this electrically conductive material against the side  2   a  of the battery cell  2 . 
   As described above, according to the first aspect of the invention, positioning of the rigid base sections in relation to the sides of the battery cell can be performed accurately and easily. Therefore, it is possible to shorten the production time and cut down on production costs. 
   Also, according to the second aspect of the invention, it is possible to miniaturize the battery. Therefore, it is also possible to miniaturize, for example, a portable terminal in which this battery is mounted. Also, because it is possible to lower the impedance when supplying power to the load of a portable terminal or other terminal, it is possible to improve the efficiency of power supply to the load of the portable terminal or other terminal. 
   Moreover, since it is possible to favorably obtain accurate positioning of the connection terminal in relation to the battery cell, electrical connection to the load of a portable terminal or other terminal can be reliably performed. 
   Furthermore, according to the third aspect of the invention, since positioning of the rigid base sections in relation to the sides of the battery cell can be performed accurately and easily, it is possible to shorten the production time and cut down on production costs. 
   Also, according to the fourth aspect of the invention, since electrical connection between the battery cell and the circuit board can be easily performed, it is possible to shorten the production time and cut down on production costs. 
   Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.