Abstract:
A connecting unit includes a wiring board and a connector. The wiring board has a main face and a side face substantially perpendicular to the main face, and includes a soaking plate and a first terminal. The connector has a through hole for passing the first terminal therethrough. The first terminal is disposed in an intermediate layer of the wiring board and is projected outwardly from the side face. When the connector is connected to the wiring board, the first terminal passes through the through hole.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to a wiring board having a soaking plate (heat dissipation plate), and more particularly to a connecting unit for connecting a connector to the wiring board. 
       BACKGROUND ART 
       [0002]    With respect to wiring boards, for example, for mounting on a vehicle, there have been extensively used the type of wiring boards in which a connector is connected to a side edge portion of the wiring board, and the wiring board is connected to a wire harness through this connector (see, for example, PTL  1 ).  FIG. 6  is a perspective view showing a connector connecting structure of a related wiring board,  FIG. 7A  is a plan view thereof,  FIG. 7B  is a front-elevational view thereof (a cross-sectional view taken along the line B-B′), and  FIG. 7C  is a side-elevational view thereof. As shown in  FIG. 7A , a large-current circuit pattern  102   a  and a small-current circuit pattern  102   b  are formed on a face of the wiring board  101 . In the wiring board  101 , left and right areas (in the drawings) serve as terminal connecting areas  101   a , respectively, and a central area serves as a parts-mounting area  101   b.    
         [0003]    A plurality of through holes  103  ( 103   a  to  103   c ) are formed through the terminal connecting area  101   a,  and are arranged in three rows. L-shaped terminals  104  ( 104   a  to  104   c ) are connected to the through holes  103 , respectively. In this case, as shown in  FIG. 7B , the L-shaped terminal  104   c  connected respectively to the through holes  103   c  disposed in the first row counting from an end of the wiring board are bent perpendicularly (that is, at right angles) at a height h 1 , and the L-shaped terminals  104   b  connected respectively to the through holes  103   b  disposed in the second row are bent perpendicularly at a height h 2  (&gt;h 1 ), and the L-shaped terminals  104   a  connected respectively to the through holes  103   a  disposed in the third row are bent perpendicularly at a height h 3  (&gt;h 2 ). 
         [0004]    As shown in  FIG. 7C , through holes  106  ( 106   a  to  106   c ) of a three-tier structure arranged in first, second and third tiers are formed through an end wall of a connector  105 , and the L-shaped terminals  104   a  to  104   c  extend respectively through the corresponding through holes  106   a  to  106   c  and project into the interior of the connector  105 . The connector  105  is fixed to the wiring board  101 . Therefore, the wiring board can be connected to a wire harness (not shown), using the connector  105 . 
         [0005]    The through holes  103   a  disposed in the third row are used for a large-current circuit, and the large-current circuit patterns  102   a  are connected to these through holes  103   a.  The through holes  103   c  and  103   b  disposed in the first and second rows are used for a small-current circuit, and the small-current circuit pattern  102   b  is connected to the through holes  103   c  and  103   b.    
         [0006]    Electronic parts (not shown) of various kinds such as a relay and so on are mounted on the parts-mounting area  101   b,  and these electronic parts are connected to the corresponding through holes  103   a  to  103   c  via the circuit patterns  102   a  and  102   b.    
         [0007]    In this related wiring board  101 , the terminal connecting areas  101   a  need to be provided adjacent respectively to the side edge portions thereof to which the connectors  105  are connected, respectively. Furthermore, in order that the L-shaped terminals  104  can be connected respectively to many through holes  103 , the L-shaped terminals  104  ( 104   a  to  104   c ) of different heights (h 1  to h 3 ) are arranged at the terminal connecting area  101   a,  and therefore are densely disposed, and therefore a sufficient space for forming the circuit patterns  102  can not be secured at the terminal connecting area  101   a.    
       CITATION LIST 
     Patent Literature 
       [0008]    [PTL  1 ] JP-A- 2006 - 333583   
       SUMMARY OF INVENTION 
     Technical Problem 
       [0009]    As described above, in the related wiring board, the L-shaped terminals  104   a  to  104   c  of three different heights are connected respectively to the corresponding through holes  103   a  to  103   c  formed in the terminal connecting area  101   a  of the wiring board  101 , and therefore a relatively-large space is required for the connection of the L-shaped terminals  104   a  to  104   c , and therefore there has been encountered a problem that the sufficient parts-mounting area can not be secured. 
         [0010]    This invention has been made in order to solve the above problem of the related structure, and an object of the invention is to provide a connector connecting structure of a wiring board in which a larger parts-mounting area can be secured. 
         [0011]    In order to achieve the above object, according to the present invention, there is provided a connecting unit, comprising: 
         [0012]    a wiring board that has a main face and a side face substantially perpendicular to the main face, and includes a soaking plate and a first terminal; and 
         [0013]    a connector that has a through hole for passing the first terminal therethrough, 
         [0014]    wherein the first terminal is disposed in an intermediate layer of the wiring board and is projected outwardly from the side face; and 
         [0015]    wherein when the connector is connected to the wiring board, the first terminal passes through the through hole. 
         [0016]    Preferably, a second terminal, having a flat plate shape, is provided on the main face of the wiring board, the connector includes an electric wire for connecting to the second terminal, and when the connector is connected to the wiring board, the electric wire is connected to the second terminal. 
         [0017]    Preferably, the second terminal and other second terminals having flat plate shapes are provided on the main face along an extending direction of the side face, and the electric wire and other electric wires for connecting to the other second terminals are provided in the connector along a direction perpendicular to an passing though direction of the through hole, and are arranged so as to be staggered in a direction normal to the main face of the wiring board when the connector is connected to the wiring board. 
         [0018]    Preferably, the wiring board has a large-current circuit and a small-current circuit, the first terminal is connected to the large-current circuit, and the electric wire for connecting to the second terminal is connected to the small-current circuit. 
         [0019]    Preferably, both of the soaking plate and the first terminal are disposed in the intermediate layer of the wiring board. 
       ADVANTAGEOUS EFFECTS OF INVENTION 
       [0020]    By the above configuration, the connector is connected to the wiring board in such a manner that the projecting-type terminals disposed in the intermediate layer of the wiring board pass through the respective through holes formed in the connector. Therefore, the number of connecting wires connected at the face of the wiring board can be reduced, and the area of the wiring board at which the terminals are connected can be reduced. Therefore, the whole of the wiring board can be formed into a compact design, and therefore a space required for installing the wiring board can be reduced, and also the cost can be reduced. 
         [0021]    By the above configuration, the connecting wire provided at the connector projects outwardly from the connector, and a distal end portion of this connecting wire is bent downwardly, and is connected to the flat plate-type terminal formed on the face of the wiring board, and a through hole is not used. With this construction, the area of the wiring board at which the terminals are connected can be further reduced. 
         [0022]    By the above configuration, the plurality of connecting wires provided at the connector are alternately arranged (that is, arranged in a staggered manner) in the direction normal to the wiring board, and therefore the plurality of connecting wires can be connected to the flat plate-type terminals without overcrowding. 
         [0023]    By the above configuration, the projecting-type terminals provided in the wiring board are used as the terminals for large-current circuit connecting purposes, and the connecting wire connected to the flat plate-type terminal is used as the terminal for small-current circuit connecting purposes. Therefore, the circuit patterns can be formed in the wiring board while easily separating the large-current circuit and the small-current circuit from each other. 
         [0024]    By the above configuration, the soaking plate and the projecting-type terminals are disposed in the same layer within the wiring board, and with this construction the soaking plate and the projecting-type terminals can be formed at the same step of the manufacturing process, and the time and labor required for the manufacture can be reduced. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0025]      FIG. 1  is a perspective view showing a connector connecting structure of a wiring board according to an embodiment of the present invention. 
           [0026]      FIGS. 2A ,  2 B and  2 C are a plan view, a front-elevational view (a cross-sectional view taken along the line A-A′) and a side-elevational view of the connector connecting structure of the wiring board according to the embodiment of the invention, respectively. 
           [0027]      FIG. 3  is an explanatory view showing the step of forming a metal plate and projecting-type terminals in the connector connecting structure of the wiring board of the invention. 
           [0028]      FIG. 4  is an explanatory view showing the process of providing a prepreg in the connector connecting structure of the wiring board according to the embodiment of the invention. 
           [0029]      FIG. 5  is an explanatory view showing the process of forming circuit patterns in the connector connecting structure of the wiring board according to the embodiment of the invention. 
           [0030]      FIG. 6  is a perspective view showing a connector connecting structure of a related wiring board. 
           [0031]      FIGS. 7A ,  7 B and  7 C are a plan view, a front-elevational view (a cross-sectional view taken along the line B-B′) and a side-elevational view of the connector connecting structure of the related wiring board, respectively. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0032]    A preferred embodiment of the present invention will now be described with reference to the drawings.  FIG. 1  is a perspective view showing a connector connecting structure of a wiring board provided in accordance with one preferred embodiment of the invention, and  FIGS. 2A ,  2 B and  2 C are a plan view, a front-elevational view (a cross-sectional view taken along the line A-A′) and a side-elevational view of the connector connecting structure of the wiring board, respectively. 
         [0033]    As shown in the drawings, the wiring board  10  of this embodiment has a generally rectangular shape as a whole, and each of right and left ends (in the drawings) of the wiring board  10  is notched to form a recess, and an inner side (edge) of the notched portion (that is, a bottom of the recess) is formed as a side edge P of a straight shape. As shown in  FIG. 1 , electronic parts  20  of various kinds are mounted on a face of the wiring board  10 . 
         [0034]    As shown in  FIG. 2A , right and left areas of the wiring board  10  serve as terminal connecting areas  10   a,  respectively, and a central area thereof serves as a parts-mounting area  10   b.  Each terminal connecting area  10   a  serves mainly as the area to which connector-connecting wires are connected, and the parts-mounting area serves as the area on which the electronic parts  20  of various kinds are mounted. 
         [0035]    A metal plate (soaking plate)  11  is provided in an inner layer of the wiring board  10  (see  FIG. 2B ), and further a plurality of projecting-type terminals  12  of a rectangular shape are provided in the same layer as the metal plate  11 . 
         [0036]    More specifically, five projecting-type terminals  12  (see  FIG. 2A ) are provided in each of the terminal connecting areas  10   a,  and are disposed at substantially equal intervals. The projecting-type terminals  12  are made of the same material as the metal plate  11 . Part of each projecting-type terminal  12  projects outwardly from the side edge P of the wiring board. A through hole  13  is formed through at least one of the projecting-type terminals  12  (In the illustrated embodiment, a plurality of through holes  13  are formed through the corresponding projecting-type terminals  12 , respectively.). The through holes  13  are connected to a circuit pattern  14  for large-current circuit-connecting purposes which is formed on the face of the wiring board  10 . This circuit pattern  14  is connected to the electronic parts for a large-current circuit which are provided at the parts-mounting area  10   b.    
         [0037]    A plurality of pads (flat plate-type terminals)  15  are formed on each terminal connecting area  10   a,  and are disposed at substantially equal intervals along the side edge P. The pads  15  are connected to a circuit pattern  16  for small-current circuit-connecting purposes. The circuit pattern  16  is connected to the electronic parts for a small-current circuit which are provided at the parts-mounting area  10   b.    
         [0038]    A connector  17  substantially equal in length to the side edge P is attached to the side edge P, and the wiring board  10  is connected to a wire harness (not shown) via this connector  17 . 
         [0039]    A plurality of (five in the illustrated embodiment) through holes  21  of a rectangular shape are formed through an end wall of the connector  17  as shown in  FIG. 2C , and a plurality of (twelve in the illustrated embodiment) metallic connecting wires  22  are provided at the connector  17 . These connecting wires  22  project outwardly from a left (in the drawings) end face of the connector  17  as shown in  FIG. 2A , and distal end portions of the metallic connecting wires  22  are bent downwardly as shown in  FIG. 2B . The connecting wires  22  are arranged in a staggered manner as shown in  FIG. 2C . Namely, the connecting wires  22  are staggered (that is, arranged alternately) in a direction normal to the wiring board  10 . The distal end portions of the connecting wires  22  are connected to the corresponding pads  15  as described later. 
         [0040]    A pair of brackets  18  each having a fixing hole  23  are formed at opposite side faces of the connector  17 , respectively. The connector  17  is attached to the wiring board  10  in such a manner that the projecting-type terminals  12  provided at the wiring board  10  pass respectively through the through holes  21  formed in the connector  17 . Further, the connector  17  is fixed to the wiring board  10  by screws  19  each passing through the corresponding fixing hole  23  in the bracket  18  and a corresponding fixing hole  24  formed through the wiring board  10 . As a result, the projecting-type terminals  12  projecting through the respective through holes  21  into the interior of the connector  17  can be used as the terminals for connection to the wire harness (not shown) through the connector  17 . 
         [0041]    The projecting-type terminals  12  are connected via the respective through holes  13  to the large-current circuit-connecting circuit pattern  14  formed on the face of the wiring board  10 . Therefore, the connection to the large-current circuit can be made, using the projecting-type terminals  12 . 
         [0042]    The distal end portions of the connecting wires  22  are arranged on the corresponding pads  15  in contacted relation thereto, and are fixed to the corresponding pads  15  by soldering. Therefore, the connecting wires  22  provided at the connector  17  can be used as terminals for connection to the wire harness through the connector  17 . The pads  15  are connected to the small-current circuit-connecting circuit pattern  16 , and therefore the connection to the small-current circuit can be made, using the pads  15 . 
         [0043]    Next, the procedure of manufacturing the above wiring board will be described with reference to  FIGS. 3 to 5 . First, a metallic plate  25  which is a material for forming the metal plate  11  and the projecting-type terminals  12  is processed or formed into a shape shown in  FIG. 3  by etching or a pressing process. More specifically, the metal plate (soaking plate)  11  of a generally H-shape and five projecting-type terminals  12  of a rectangular shape disposed at each of right and left sides of the metal plate  11  are formed. In the example shown in  FIG. 3 , although the projecting-type terminals  12  are severed from the metal plate,  11 , at least one of the projecting-type terminals  12  can be integrally connected with the metal plate  11  as described later according to a required use. 
         [0044]    Then, as shown in  FIG. 4 , a prepreg  31  having a metallic foil is laminated on one side (face) of the metallic plate  25 , or prepregs  31  are laminated on both sides (faces) of the metallic plate  25 , respectively. Then, the prepreg  31  is hot pressed, thereby forming an outer shape of the wiring board  10 . Further, the through holes  13  and the fixing holes  24  are formed, and thereafter ribs  26  extending from the metal plate  11  and the projecting-type terminals  12  are cut off by pressing, a rooter or other means. 
         [0045]    Then, masking is applied to a surface of the prepreg  31  so as to form the circuit patterns, and etching is applied to the surface of the prepreg  31 , thereby forming the desired circuit. As a result, the wiring board  10  having the circuit patterns  14  and  16 , the through holes  13  and the pads  15  is formed as shown in  FIG. 5 . 
         [0046]    As described above, in the connector connecting structure of the wiring board of this embodiment, the connector  17  is connected to the wiring board  10  so that the projecting-type terminals  21  provided in the intermediate layer of the wiring board  10  and partially projecting outwardly therefrom pass through the respective through holes  21  formed in the connector  17 . Therefore, it is not necessary that large-current circuit connecting wires (corresponding to the L-shaped terminals  104   a  shown in  FIGS. 7A and 7B ) be connected to the large-current circuit-connecting circuit pattern at the face of the wiring board  10  as in the related structure. Therefore, a space required for the connection of the large-current circuit connecting wires can be saved, and the terminal connecting area  10   a  can be made small. 
         [0047]    Furthermore, the distal end portions of the connecting wires  22  projecting from the end face of the connector  17  are bent downwardly and are contacted with the pads  15 , and are connected thereto by soldering. Therefore, it is not necessary to use through holes (through holes  103   a  to  103   c  in  FIGS. 7A and 7B ) as in the related structure, and therefore the terminal connecting area  10   a  can be further reduced. 
         [0048]    Therefore, the parts-mounting area  10   b  can be relatively made large, and a larger number of electronic parts can be mounted on the wiring board  10 . Furthermore, in the case where the electronic parts to be mounted on the wiring board are the same parts, the whole of the wiring board  10  can be formed into a compact design, and in the case where the wiring board  10  is to be received within an electric connection box (not shown), the whole of the electric connection box can be formed into a compact and low-cost design. 
         [0049]    Furthermore, the connecting wires  22  mounted on the connector  17  are arranged in a staggered manner as shown in  FIG. 2C , and therefore even when the number of the connecting wires  22  increases, the distal end portions of the connecting wires  22  can be orderly connected to the corresponding pads  15  without overcrowding. 
         [0050]    Furthermore, the metal plate  11  and the projecting-type terminals  12  are provided in the same layer within the wiring board  10 , and are formed from the common metallic plate  25  as shown in  FIG. 3 . Therefore, the metal plate  11  and the projecting-type terminals  12  can be formed at the same step of the manufacturing process, and thus a separate step of forming the projecting-type terminals  12  is not necessary, and therefore the time and labor required for the manufacturing process can be reduced. 
         [0051]    Furthermore, the projecting-type terminals  12  are connected to the large-current circuit, while the pads  15  are connected to the small-current circuit, and with this construction the large-current electronic parts and the small-current electronic parts can be mounted on the wiring board  10 , and also these electronic parts can be easily installed on the circuit pattern. 
         [0052]    Although the connector connecting structure of the wiring board of the present invention has been described with reference to the illustrated embodiment, the invention is not limited to this embodiment, and the constructions of the various portions can be replaced with suitable constructions having similar functions. 
         [0053]    For example, in the above embodiment, the projecting-type terminals  12  are separated from the metal plate  11 , and the metal plate  11  is used for thermal diffusion purposes, and the projecting-type terminals  12  are used as the large-current circuit-connecting terminals. However, the metal plate  11  can be connected to at least one of the projecting-type terminals  12  so that the metal plate  11  can be used as an electrode. 
         [0054]    Although the invention has been illustrated and described for the particular preferred embodiments, it is apparent to a person skilled in the art that various changes and modifications can be made on the basis of the teachings of the invention. It is apparent that such changes and modifications are within the spirit, scope, and intention of the invention as defined by the appended claims. 
         [0055]    The present application is based on Japanese Patent Application No. 2009-107727 filed on Apr. 27, 2009, the contents of which are incorporated herein by reference. 
       INDUSTRIAL APPLICABILITY 
       [0056]    The present invention is extremely useful in forming the wiring board with the metal plate into a compact design. 
       REFERENCE SIGNS LIST 
       [0000]    
       
         P side edge 
           10  wiring board 
           10   a  terminal connecting area 
           10  parts-mounting area 
           11  metal plate (soaking plate) 
           12  projecting-type terminal 
           13  through hole 
           14  circuit pattern (for large-current circuit connecting purposes) 
           15  pad 
           16  circuit pattern (for small-current circuit connecting purposes) 
           17  connector 
           18  bracket 
           19  screw 
           20  electronic parts 
           21  through hole 
           22  connecting wire 
           23 ,  24  fixing hole 
           25  metallic plate 
           26  ribs 
           31  prepreg 
           101   a  terminal connecting area 
           101   b  parts-mounting area 
           102   a,    102   b  circuit pattern 
           103   a  to  103   c  through hole 
           104   a  to  104   c  L-shaped terminal 
           105  connector 
           106   a  to  106   c  through hole