Abstract:
A circuit board includes a plate-shaped conductive core and an insulative section covering the core. An electrical component is disposed on the insulative section. A heat radiating member is disposed on the insulative section and connected to the core. A casing houses the circuit board, the electrical component and the heat generating member.

Description:
BACKGROUND 
       [0001]    The present invention relates to an electrical connection box for housing a circuit board on which electrical circuits such as power supply circuits are mounted. 
         [0002]    In general, circuit boards including electrical circuits such as power supply circuits are installed in the vehicles with boxes housing the circuit boards. In a case where the circuit board includes a large-current electrical circuit such as a power supply circuit generating large amount of heat, the radiation performance of the box should be enough large. 
         [0003]    As a countermeasure for radiating the heat produced from the electrical circuits, the electrical connection box having a cooling structure is well known in the art (for example, see Japanese Patent Publication No. 2001-19838A). 
         [0004]    As shown in  FIG. 6 , in such an electrical connection box, a plurality of print boards  2  having a metal core is contained within the chassis made up of a plurality of casings  1 . In addition, such electrical connection box has a structure that heat pipes  6  are connected to a body panel of vehicle to radiate heat from the chassis, in which while heat-conductive insulating sheets  3  and metal spacers  4  are interposed, a radiation fin  5  is attached to the print board  2 , and while the heat-conductive insulating sheet  3  is interposed, the heat pipes  6  are attached to the print board  2 . 
         [0005]    However, the above electrical connection box, in order to radiate heat to the exterior of the chassis, it is necessary to connect the heat pipe  6  to the body panel, and therefore the attaching position in the vehicle is limited. 
         [0006]    Further, since the heat-conductive insulating sheet  31  the radiation fin  5  having a complex shape, and the heat pipes  6  are needed for the radiation structure, it becomes large. Hence, it leads to large electrical connection box with higher cost. 
         [0007]    Furthermore, when the electrical connection box is dismantled, the heat-conductive insulating sheets  3 , the radiation fin  5 , and the heat pipes  6  should be detached from the boards  2 . As a result it requires a much effort for the dismantling. 
       SUMMARY 
       [0008]    It is therefore one advantageous aspect of the invention to provide, at low cost, an electrical connection box having not only superior soaking and radiation performance but also superior recycling efficiency, and capable of reducing in size and weight without limiting the attaching position. 
         [0009]    According to one aspect of the invention, there is provided an electrical connection box, comprising: 
         [0010]    a circuit board, including a plate-shaped conductive core and an insulative section covering the core; 
         [0011]    an electrical component, disposed on the insulative section; 
         [0012]    a heat radiating member, disposed on the insulative section and connected to the core; and 
         [0013]    a casing, housing the circuit board, the electrical component and the heat generating member. 
         [0014]    With this configuration, heat transferred from the electrical component to the metal core can be effectively radiated from the heat radiating member. As a result, because the heat-conductive insulating sheet, the radiation fin or the heat pipe are not necessary, it allows supplying large current into the circuit board without using bus bar. Further, due to the simplification of the structure, it allows reduction in size and weight, and cost-saving. It also permits easy dismantlement, without limiting the attaching position. Therefore, the soaking and radiation performance can be much improved. 
         [0015]    The heat radiating member may be disposed in the vicinity of the electrical component. 
         [0016]    In this case, the heat of the electrical component can be smoothly radiated. 
         [0017]    The heat radiating member may abut against an inner face of the casing. 
         [0018]    In this case, since the heat radiating member can serve as a member that supports the circuit board with respect to the casing the number of the component can be much reduced and thus simpler structure can be obtained, as compared to a case where a supporting member is separately provided. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a perspective view of an electrical connection box according to a first embodiment of the invention, showing a disassembled state. 
           [0020]      FIG. 2  is an enlarged section view of a part of a circuit board in the electrical connection box of  FIG. 1 . 
           [0021]      FIG. 3  is a perspective view of an electrical connection box according to a second embodiment of the invention, showing a disassembled state. 
           [0022]      FIG. 4  is a perspective view of a circuit board and radiation pins in the electrical connection box of  FIG. 3 . 
           [0023]      FIG. 5  is an enlarged section view of a part of the circuit board of  FIG. 4 . 
           [0024]      FIG. 6  is a perspective view of a conventional electrical connection box, showing a disassembled state. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0025]    Exemplary embodiments of the invention will be described below in detail with reference to the accompanying drawings. 
         [0026]    As shown in  FIG. 1 , an electrical connection box  11  according to a first embodiment of the invention has an upper casing  12  and a lower casing  13 . The circuit board  14  is disposed between the upper casing  12  and the lower casing  13 . The circuit board  14  Is covered with the upper casing  12  and, the lower casing  13 . The wiring pattern (not shown) is formed on the both sides of the circuit board  14 . For example, the electrical components (not shown), such as relays, fuses, electronic control units are mounted on the circuit board  14 . 
         [0027]    The upper casing  12  and the lower casing  13  are formed by, for example, polypropylene that the glass fiber is incorporated into. The upper casing  12  and the lower casing  13  are combined, in a state that the circuit board  14  is sandwiched therebetween. 
         [0028]    The electrical connection box  11  has a plurality of socket  15  adapted to be connected with connectors of the wiring harness. 
         [0029]    The socket  15  has an engaging concave portion  18  formed in the upper casing  12 . The connection terminal is arranged within the engaging concave portion  18 , which is uprightly formed so as to electrically connect to the wiring pattern of the circuit board  14 . In addition, in the socket  15 , the connector of the wiring harness is engaged with the engaging concave portion  18 , and then the terminal of the connector is electrically connected to the connection terminal of the socket  15 . 
         [0030]    Additionally, the electrical connection box  11  has a plurality of sockets  16  capable of attaching the electrical component, such as an external relay. 
         [0031]    These sockets  16  have an engaging concave portion  21  formed in the upper casing  12 . The connecting terminal  22  is arranged within the engaging concave portion  21 , which is uprightly formed so as to electrically connect to the wiring pattern of the circuit board  14 . In addition, in the socket  16 , the electrical component is engaged with the engaging concave portion  21 , and then the connection terminal of the electrical component is electrically connected to the connection terminal  22  of the socket  16 . 
         [0032]    As shown in  FIG. 2 , the circuit board  14  has the plate-shaped metal core  24  and the insulative section  25  formed so as to cover the surface of the metal core  24 . The circuit board  14  is fabricated by laminating the metal core  24  and the insulative section  25  one on another. 
         [0033]    The metal core  24  is for example, a plate made of copper. The insulative section  25  is formed by molding glass epoxy resin, etc, having nonconductive property and low heat conductivity. In addition, instead of the copper, aluminum that specific gravity is about one third of copper may be employed as the material of the metal core  24 . 
         [0034]    On the circuit board  14  made of the metal core board, the conductive circuit pattern (not shown) made of copper foil is formed in the insulative section  25 . 
         [0035]    Further, the electrical component  23  such as relays is mounted on the circuit board  14 , and then the terminal section  23   a  of the electrical component  23  is soldered to the circuit pattern to electrically connect with each other. 
         [0036]    Furthermore, the radiation plate (heat radiation member)  31  is provided to the circuit board  14 . The radiation plate  31  is formed by any suitable metallic material having a superior thermal conductivity, such as copper or aluminum. The radiation plate  31  is an U-shaped member in which side sections  31   b  are provided at both ends of a top section  31   a.    
         [0037]    The radiation plate  31  is disposed in the vicinity of the electrical component  23  facing the circuit board  14  so as to span the attaching position. Then, the radiation plate  31  is attached to the circuit board  14  in a such manner that leg section  31   c  formed in the attachment plate section  31   b  is inserted and penetrated, and attached by soldering to the exposed portion of the metal core  24  that the insulating section  25  around the edge of the through hole  32  is eliminated. 
         [0038]    With the above configuration, heat transferred from the electrical component  23  mounted on the circuit board  14  is transferred to the metal core  24  of the circuit board  14  and then radiated from the radiation plate  31  attached to the metal core  24 . 
         [0039]    Thus, since the radiation plate  31  is connected to the metal core  24  of the circuit board  14 , the heat of the electrical component  23  transferred to the metal core  24  can be surely radiated from the radiation plate  31 . As a result, because the heat-conductive insulating sheet, the radiation fin or the heat pipe are not necessary, it allows supplying large current into the circuit board without using bus bar. Further, due to the simplification of the structure, it allows reduction in size and weight, and cost-saving. It also permits easy dismantlement, without limiting the attaching position. Therefore, the soaking and radiation performance, and a recycling efficiency can be much improved. 
         [0040]    In particular, since the radiation plate  31  is provided in the vicinity of the electrical component  23 , the radiation of the electrical component  23  mounted on the circuit board  14  can be effectively performed. 
         [0041]    Next, a second embodiment of the invention will be described. Components similar to those in the first embodiment will be designated by the same reference numerals. The repetitive explanations for those will be omitted. 
         [0042]    As shown in  FIG. 3 , an electrical connection box  41  has a plurality of sockets  15 . The connector of the wiring harness side is engaged with engaging concave portion  18  of the socket  15 , and then the terminal of the connector is electrically connected to the connection terminal  19  of the circuit board  14  disposed within the engaging concave portion  18 . 
         [0043]    As shown in  FIG. 4 , in the electrical connection box  41 , the radiation pins  42  having columnar shapes are arranged and spaced with each other. 
         [0044]    The radiation pins  42  are formed with metallic material having a superior thermal conductivity, such as copper or aluminum. As shown in FIG.  5 , these radiation pins  42  are attached by soldering to the exposed portion of the metal core  24  that the insulating section  25  in the circuit board  14  is eliminated. 
         [0045]    In addition, these radiation pins  42  serve as a supporting member of the circuit board  14  with respect to the upper cover  12 . The radiation pins  42  are matched with the upper cover  12 , and thus the circuit board  14  is disposed in a predetermined position with respect to the upper cover  12 . 
         [0046]    In this embodiment, since the radiation pin  42  is connected to the metal core  24  of the circuit board  14 , the heat of the electrical component  23  transferred to the metal core  24  can be surely radiated from the radiation pins  42 . As a result, because the heat-conductive insulating sheet, the radiation fin or the heat pipe are not necessary, it allows supplying large current into the circuit board without using bus bar. Further, due to the simplification of the structure, it allows reduction in size and weight, and cost-saving. It also permits easy dismantlement, without limiting the attaching position. Therefore, the soaking and radiation performance, and a recycling efficiency can be much improved. 
         [0047]    In particular, since the radiation pin  42  serves as a supporting member that supports he circuit board  14  with respect to the upper casing  12 , as compared to a case where a separate supporting member, the number of the components can be reduced and then simpler structure can be accomplished. 
         [0048]    Alternatively, the circuit board  14  may be fixed to the upper cover  12  in such a manner that a screw hole is formed in the radiation pin  42 , a through-hole communicating with the screw hole is formed in the upper cover  12 , and a beads is inserted to the through-hole to screw onto the screw hole of the radiation pin  42 . 
         [0049]    Although only some exemplary embodiments of the invention have been described in detail above those skilled in the art will readily appreciated that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of the invention. Accordingly, all such modifications are intended to be included within the scope of the invention. 
         [0050]    The disclosure of Japanese Patent Application No. 2006-149982 filed May 30, 2006 including specification, drawings and claims is incorporated herein by reference in its entirety.