Abstract:
In a flexible connector having a fitting portion for connection, with a counterpart connector. A plurality of flexible conductive wires ( 31 ) are arranged on a plane in parallel with each other and extend to have end portions. The flexible conductive wires are held by an insulator ( 8 ) which makes the fitting portion cooperate with the end portions of the flexible conductive wires. A flexible reinforcing member ( 6 ) is placed at one side of the plane to reinforce the flexible conductive wires and mechanically couples to the insulator.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a flexible connector for connecting two connection objects such as printed circuit boards to each other and, in particular, to a flexible connector having a flexible portion or part between the connection objects. 
     Various flexible connections have been disclosed in Japanese Utility Model Registration (JP-Y2) No. 2511926 and Japanese Unexamined Utility Model Publication (JP-U) No. H05-65066. 
     With reference to FIG. 1A at first, an example of the flexible connections will be described. To provide flexible connection between a first printed circuit board  21  and a second printed circuit board  22 , a flexible printed circuit (hereinafter referred to as “FPC”) member  23  is interposed between the printed circuit boards  21  and  22 . At this point, FPC connectors  24  and  25  are mounted on the printed circuit boards  21 ,  22 , respectively. One end of the FPC  23  is connected to the FPC connector  24  and the other end of the FPC  23  is connected to the FPC connector  25 . 
     In the flexible connector, when the FPC connectors  24 ,  25  are of zero-insertion-force type (hereinafter referred to as “ZIF type”), members such as sliders for the fitting/removing operation of the connectors are required and the operation of such members such as sliders is complex. When the FPC connectors  24 ,  25  are of Non-ZIF type, such members such as sliders and its operation are not required, but the fitting portions of the FPC  23  with the FPC connectors  24 ,  25  are easy,to be broken during the fitting/removing operation. Further, the FPC  23  should be manufactured as a separate part, thus increasing the cost. Moreover, since the FPC  23  and the FPC connectors  24 ,  25  are normally manufactured by different manufacturers, it is difficult to provide assurance for the electrical performance (for example, impedance matching). 
     With reference to FIG. 1B, another example of such a flexible connector will be described. To provide flexible connection between a first printed circuit board  21  and a second printed circuit board  22 , a FPC  23  and two FPC relay connectors  26 ,  27  are interposed between the printed circuits  21  and  22 . At this point, plug or receptacle connectors  28 ,  29  are mounted on the printed do circuit boards  21 ,  22 , respectively. One end of the FPC  23  is connected to the plug connectors or receptacle connector  28  via the FPC relay connector  26  and the other end of the FPC  23  is connected to the plug or receptacle connector  29  via the FPC relay connector  27 . 
     With the flexible connector, since the number of contact points is large, the possibility of malfunction and deterioration of transmission characteristics is high. The number of parts is large, thus increasing the cost. The FPC  23  should be manufactured as a separate part, thus further increasing the cost. Moreover, since the FPC  23 , the FPC relay connectors  26 ,  27 , and the plug or receptacle connectors  28 ,  29  are normally manufactured by different manufacturers, it is difficult to provide assurance for the electrical performance. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a flexible connector integrally having a transmission line, which has a reduced number of parts, does not require complex operation, and has reduced cost, and easily allows assurance for the electrical performance. 
     Other objects of the present invention will become clear as the description proceeds. 
     A flexible connector to which the present invention is applicable has a fitting portion for being connected with a counterpart connector. The flexible connector comprises a plurality of flexible conductive wires arranged on a plane in parallel to each other and extending in a predetermined direction to have end portions, a flexible reinforcing member placed at one side of the plane to reinforce the flexible conductive wires, an insulator holding the flexible conductive wires to make the fitting portion in cooperation with the end portions of the flexible conductive wires, and coupling means connected to the insulator and the flexible reinforcing member for mechanically coupling the insulator to the flexible reinforcing member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a perspective view showing an example of conventional flexible connector together with printed circuit boards; 
     FIG. 1B is a perspective view showing another example of conventional flexible connector together with printed circuit boards; 
     FIG. 2A is a perspective view of a flexible connector according to an embodiment of the present invention, showing its front; 
     FIG. 2B is a perspective view of the flexible connector of FIG. 2A, showing its back; 
     FIG. 3A is a perspective view showing the flexible connector shown in FIGS. 2A and 2B in the preassembled state; 
     FIG. 3B is an enlarged perspective view showing the engaging structure between a metallic plate and an insulator shown in FIG. 3A; 
     FIG. 4A is a perspective view showing a conductor and first and second insulating sheets before attachment in a first manufacturing process of the flexible connector of FIGS. 2A and 2B; 
     FIG. 4B is a perspective view of the conductor and the first and second insulating sheets after the attachment; 
     FIG. 4C is a perspective view of a conductor with a different designed pattern for the flexible connector; 
     FIG. 5A is a perspective view illustrating a state before the insulator is attached to the lamination of the conductor and the first and second insulating sheets in a second manufacturing process of the flexible connector of FIGS. 2A and 2B; 
     FIG. 5B is a perspective view illustrating a state after the insulator is attached to the sub-assembly; 
     FIG. 6A is a perspective view illustrating a state before the metallic plate is attached to the second insulating sheet and a third insulating sheet is attached to the metallic plate in a third manufacturing process of the flexible connector of FIGS. 2A and 2B; 
     FIG. 6B is a perspective view showing a portion of the flexible connector of FIGS. 2A and 2B in the completed state; 
     FIG. 7A is a sectional view showing main parts of the flexible connector of FIGS. 2A and 2B; 
     FIG. 7B is a sectional view showing the main parts of the flexible connector of FIGS. 2A and 2B in the fitted state with a relative connector; and 
     FIGS. 8A,  8 B, and  8 C are perspective views showing examples of usage of the flexible connector of FIGS. 2A and 2B, respectively. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     With reference to FIGS. 2A through 8C, description will be made as regards a flexible connector according to an embodiment of the present invention. 
     In FIGS. 2A and 2B, the flexible connector is designated by numeral “ 1 ” and includes a flexible high-speed transmission line  2  and insulators  8  attached to the both ends of the length of the high-speed transmission line  2  by integral molding or insertion. 
     In FIG. 3A, the high-speed transmission line  2  includes a conductor  3  manufactured by pressing or etching, an upper insulating sheet  4  attached to the front surface of the conductor  3 , a middle insulating sheet  5  attached to the rear surface of the conductor  3 , a thin metallic plate  6  attached as a flexible reinforcing member to the rear surface of the second insulating sheet  5 , and a lower insulating sheet  7  attached to the rear surface of the metallic plate  6 . The metallic plate  6  is formed with contact portions  61  at both ends in a predetermined or longitudinal direction thereof. Each of the contact portions  61  includes engaging portions  62  formed by bending both ends in a width or cross direction thereof. Each of the engaging portions  62  has a pair of L-like holes  63  formed therein. The middle insulating sheet  5  will be referred to as a first insulating sheet. The upper insulating sheet  4  will be referred to as a second insulating sheet. The lower insulating sheet  7  will be referred to as a third insulating sheet. 
     Each of the insulators  8  is formed with a pair of claws or pawls  83  as a first engaging portion on both ends of the width thereof. When the high-speed transmission line  2  and the insulators  8  are assembled, the L-like holes  63  of the engaging portions  62  are engaged with the claws  83  of the insulators  8  as shown in FIG.  3 B. Herein, the engaging portions  62  serve as a second engaging portion. A combination of the claws  83  and the engaging portion  62  is referred to as a coupling arrangement. 
     Referring to FIG. 4A, the conductor  3  is previously formed with a plurality of flexible conductive wires or patterns  31  equal in width spaced at equal intervals. Each of the patterns  31  extends in the predetermined direction to have end portions  31   a.  Then, the first insulating sheet  4  and the second insulating sheet  5  are attached to the front surface and the rear surface of the conductor  3 , respectively, is shown in FIG.  4 B. It should be noted that carriers  35  are connected integrally to both ends of the conductor  3  in the longitudinal direction. For the current capacity for a power source, the impedance, and the like, one of the flexible conductive wires  31  may have different width selected according to the pin assignment. 
     As shown in FIG. 4C, the conductor  3  may be previously formed with a first wire group comprising a plurality of flexible conductive wires or patterns  32  of small width, a second wire group comprising a plurality of flexible conductive wires  33  of middle width, and a third wire group comprising a plurality of flexible conductive wires  34  of large width. In other words, the flexible conductive wires are grouped into a plurality of wire groups between which the flexible conductive wires have different widths. 
     As shown in FIG. 5A, each insulator  8  is attached to the pattern of wires. The attached state is shown in FIG.  5 B. 
     Referring to FIG. 6A, two elongated holes  64  are previously formed in the metallic plate  6  to extend along the length of the metallic plate  6 . The width of each elongated hole  64  is slightly larger than the width of each slit  41  formed in the upper, the middle, and the lower insulating sheets  4 ,  5 , and  7  as described later. In the state shown in FIG. 6A, the front surface of the metallic plate  6  is attached to the rear surface of the middle insulating sheet  5  and the pairs of L-like holes  63  of the metallic plate  6  are engaged with the pairs of pawls  83  of the respective insulators  8 . Further, the lower insulating sheet  7  is attached to the rear surface of the metallic plate  6 . The carriers  35  and parts of the pattern  31  near the carriers  35  of the conductor  3  are cut and removed. After that, two slits  41  are cut or formed in the lamination of the upper insulating sheet  4 , the conductor  3 , the middle insulating sheet  5 , the metallic plate  6 , and the lower insulating sheet  7  by a cutter. At this point, the edge of the cutter is placed to a portion between one wire of the pattern  31  and the adjacent one of the pattern  31  and in the each elongated hole  64  of the metallic plate  6 . As a result of this, the process of manufacturing the connector  1  is accomplished. This state of the connector  1  is shown in FIG.  68 . The slits  41  are formed in the upper, the middle, and the lower insulating sheets  4 ,  5 , and  7  and improve the flexibility of the high-speed transmission line  2 . 
     With reference to FIG. 7A, the description will be continued. The conductor  3 , the A upper insulating sheet  4 , and the middle insulating sheet  5  are held and secured to a body  81  of each insulator  8 . Further, the end portions  31   a  of the patterns  31  of the conductor  3  is held and secured to each insulator  8 . Thus, each insulator  8  is cooperated with the end portions  31   a  of the patterns  31  and with a contact portion  61  of the metallic plate  6  to make a fitting portion  82  for being connected with a counterpart connector or a relative connector  11  illustrated in FIG.  7 B. Each engaging portion  62  of the metallic plate  6  is engaged with each insulator  8  so that the metallic plate  6  and the insulators  8  are integrated. The metallic plate  6  is provided at its ends with the contact portions  61  (see FIG. 3A) which serve as ground parts and come in contact with a plurality of ground contacts of a counterpart connector. 
     As shown in FIG. 7B, the relative connector  11  includes an insulator  12 , a plurality of signal contacts  13  and ground contacts  14  aligned on the insulator  12  for press engaging, and a shell  15  covering the insulator  12  and held by the insulator  12 . In the state shown in FIG. 7B, the pattern  31  at the end of the contact  3  of the flexible connector  1  is in contact with the respective signal contacts  13  of the relative connector  11  and the contact portion  61  of the metallic plate  6  is in contact with the respective ground contacts  14  of the relative connector  11 . 
     FIG. 8A shows a case that the first printed circuit board  21  and the second printed circuit board  22  are at the same level. FIG. 8B shows a case that the both circuit boards  21  and  22  are at different levels and are disposed such that the respective rear surfaces of the circuit boards  21  and  22  face to each other. FIG. 8C shows a case that the both circuit boards  21  and  22  are at different levels and are disposed such that the rear surface of the first printed circuit board  21  faces to the front surface of the second printed circuit board  22 . 
     As apparent from the above description, the aforementioned flexible connector  1  exhibits the following effects: 
     1. The insulators having fitting portions and the transmission line are integrated, thereby enabling the process production and thus easily allowing the assurance for the electrical performance (for example, impedance matching). 
     2. The removal between the connector and the transmission line is prevented, thereby eliminating the possibility of malfunction due to the removal. No stubbing effect is occurred, thereby facilitating the matching of impedance. The ground portions can have improved air tightness and improved function. The flexible connector can have improved resistance against load produced by wrenching or the like. 
     3. The number of parts is reduced and the number of steps in the manufacturing process is also reduced, thereby reducing the cost. 
     4. When the flexible connector is structured to have the same fitting portions and the conductor with different patterns, the flexible connector can provide connection of different modes even with the same relative connector.