Patent Publication Number: US-11031740-B2

Title: Coaxial cable electrical connector

Description:
RELATED APPLICATION 
     This application claims priority to Japanese Application Serial No. 2019-081892, filed on Apr. 23, 2019, which is incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a connector. 
     BACKGROUND ART 
     In the past, in an electronic device or an electric device, when connecting a coaxial cable that transmits a high-frequency signal to a substrate such as a printed circuit board, the coaxial cable is connected to a coaxial multi-pole connector that includes a signal terminal connected to a signal wire of a coaxial cable and a shield terminal that surrounds the signal terminal and is connected to a shield of the coaxial cable, and is mounted on a substrate (see e.g., Patent Document 1). 
       FIG. 7  is a schematic plan view showing a state in which a coaxial cable is connected to a known connector. 
     In the figure, a plurality of terminals  813  housed in a housing of the connector is arrayed to be aligned in a vertical direction in the figure. Each terminal  813  is an elongated member formed by performing processing such as die-cutting and bending on a conductive metal plate, and is extended in a left-right direction in the figure. Note that the terminal  813  includes a signal terminal  813   a  and a shield terminal  813   b.    
     Additionally, a shield bar  814  is an elongated member formed by performing processing such as die-cutting and bending on a conductive metal plate, and is extended in the vertical direction in the figure. A leg portion  814   a  of the shield bar  814  is soldered to the shield terminal  813   b  by a solder connecting portion w 3 . 
     Furthermore, a coaxial cable  891  used for high-speed transmission includes a core wire  892  made of a conductive metal; an insulating body (not shown) that surrounds an outer periphery of the core wire  892 ; a shield  893  made of a conductive net that surrounds an outer periphery of the insulating body; and an outer covering  894  having an insulating property that surrounds an outer periphery of the shield  893 . The core wire  892  is soldered to the signal terminal  813   a  by the solder connecting portion w 2 , and the shield  893  is soldered to the shield bar  814  by the solder connecting portion w 1 . Thus, the ground potential of all of the shield terminals  813   b  and the shield  893  can be shared. 
     In the example shown in the figure, a low-speed transmission signal wire  896  is connected to the signal terminal  813   a,  and a low-speed transmission shield wire  897  is connected to the leg portion  814   a  of the shield bar  814 , however, description on the low-speed transmission signal wire  896  and the low-speed transmission shield wire  897  is omitted. 
     Patent Document 1: Japanese Unexamined Patent Publication No. 2012-049035 
     SUMMARY 
     However, in the known connector, the solder connecting portion w 2  in the adjacent signal terminal  813   a  and the solder connecting portion w 3  in the shield terminal  813   b  are in close proximity to each other, so that during the soldering work, the molten solder of the solder connecting portion w 2  and the solder connecting portion w 3  may fuse, causing the adjacent signal terminals  813   a  or the signal terminals  813   a  and the shield terminal  813   b  to short circuit. In particular, in recent years, miniaturization of connectors is advancing with advancement in miniaturization of electric devices, electronic devices, and the like, and thus the spacing between adjacent terminals  813  is becoming narrower, which increases the possibility of the molten solder fusing and the adjacent terminals  813  short circuiting, and makes the soldering work difficult. 
     An object of the present disclosure is to solve the problems of the known connector, and to provide a highly reliable connector in which number of components can be reduced and the cost can be reduced, noise can be suppressed thus stabilizing the signal quality, and the soldering work can be carried out easily and surely. 
     To this end, a connector includes at least one signal terminal extending in a front-rear direction; at least two ground terminals extending in the front-rear direction disposed on both sides in a width direction of the signal terminal; and a housing that holds the signal terminal and the ground terminal; wherein: all of the ground terminals are integrally formed with one ground coupling member extending in the width direction; the housing is integrally formed with the signal terminal, the ground terminal, and the ground coupling member by insert molding; the signal terminal has a contact portion that comes into contact with a counterpart signal terminal and a tail portion soldered to a core wire of a coaxial cable exposed from the housing; the ground coupling member includes a shield connecting portion that is exposed from the housing on a rear side of the tail portion of the signal terminal and soldered to a shield of the coaxial cable; and the ground terminal has a portion other than a contact portion that comes into contact with a counterpart ground terminal embedded in the housing. 
     In another connector, the signal terminal is provided as a plurality, a number of the ground terminals is a number only one larger than a number of the signal terminals, and the signal terminals and the ground terminals are arranged to be alternately aligned in one row in the width direction. 
     Furthermore, in yet another connector, the contact portion of the ground terminal is located at a same height as the contact portion of the signal terminal, and the shield connecting portion of the ground coupling member is located at a position lower than the tail portion of the signal terminal. 
     Moreover, in yet another connector, the housing includes a cable accommodating groove that extends in the front-rear direction formed in the upper surface, and the tail portion of the signal terminal and the shield connecting portion of the ground coupling plate are exposed at the bottom surface of the cable accommodating groove. 
     Furthermore, in yet another connector, the housing includes a rib portion that extends in the front-rear direction formed on both sides of the cable accommodating groove, and a majority of the portion of the ground terminal embedded within the housing is located below the rib portion. 
     In yet another further connector, the signal terminal includes a main body portion connected to a rear end of the contact portion; the tail portion is wider than the contact portion and the main body portion and is connected to a rear end of the main body portion; the ground terminal includes a main body portion connected to a rear end of the contact portion and a coupling portion connected to a rear end of the main body portion; and the coupling portion has a narrower width than the contact portion and the main body portion. 
     Furthermore, in still another connector, the coupling portion includes a stepped portion, and a rear end is integrally connected to the ground coupling member. 
     In still another connector, the housing includes holes opened to an upper surface and a lower surface at positions corresponding to the main body portion of the signal terminal and the main body portion of the ground terminal. 
     In still another connector, a shell in which at least a part of the housing is accommodated is further provided, and the ground terminal is electrically separated from the shell. 
     According to the present disclosure, the connector can reduce the number of parts and reduce the cost, can suppress noise, thus stabilizing signal quality, can perform soldering easily and surely, and can improve reliability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a state before fitting of a cable connector and a substrate connector according to the present embodiment. 
         FIG. 2  is an exploded view of the cable connector according to the present embodiment. 
         FIG. 3  is a perspective view showing a state in which the distal end of the coaxial cable is connected to the inner housing according to the present embodiment. 
         FIG. 4  is a perspective view showing a state in which the distal end of the coaxial cable is connected to the signal terminal and the ground terminal according to the present embodiment. 
         FIGS. 5A and 5B  are two-sided views showing the signal terminal and the ground terminal according to the present embodiment, where  FIG. 5A  is a plan view and  FIG. 5B  is a perspective view. 
         FIGS. 6A-6C  are three-sided views showing a state in which the distal end of the coaxial cable is connected to the inner housing according to the present embodiment, where  FIG. 6A  is a plan view,  FIG. 6B  is a cross-sectional view taken along line A-A in  FIG. 6A , and  FIG. 6C  is a cross-sectional view taken along line B-B in  FIG. 6A . 
         FIG. 7  is a schematic plan view showing a state in which a coaxial cable is connected to a known connector. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     An embodiment will be described in detail below with reference to the drawings. 
       FIG. 1  is a perspective view showing a state before fitting of a cable connector and a substrate connector according to the present embodiment, and  FIG. 2  is an exploded view of the cable connector according to the present embodiment. 
     In the figures, reference number  1  denotes a cable connector serving as a connector according to the present embodiment, and is specifically, a coaxial multi-pole connector connected to a distal end of a coaxial cable  91  serving as a cable. In the example shown in the figure, ten coaxial cables  91  are arranged in one row in the width direction (Y-axis direction), at least one coaxial cable  91  merely needs to be provided and the number of coaxial cables can be appropriately changed. Furthermore, as shown in  FIG. 1 , the cable connector  1  is fitted with a substrate connector  101  serving as a counterpart connector mounted on a surface of the substrate  191 , and is connected to the substrate  191  by being fitted with the substrate connector  101 . 
     The substrate  191  may be, for example, a printed circuit board used in electronic devices such as computers, smart phones, tablets, and the like, electric devices such as household appliances, and the like; a flat plate shaped cable or the like referred to as a flexible circuit board (FPC), flexible flat cable (FFC), and the like, and may be any type of cable, but here, description will be made as being a printed circuit board used in electronic devices in which high-frequency signals are used such as smartphones and the like. 
     The coaxial cable  91  may be of any type, but is, for example, a coaxial cable having a small diameter suitable for transmitting high-frequency signals for wireless communication. Each coaxial cable  91  includes a conductive core wire  92  serving as a signal line made of a conductive metal arranged at the center, a substantially cylindrical dielectric  95  arranged to surround an outer periphery of the core wire  92 , a shield  93  serving as a ground line made of a substantially cylindrical conductive metal arranged to surround an outer periphery of the dielectric  95 , and an outer covering  94  having an insulating property arranged to surround an outer periphery of the shield  93 . 
     It should be noted that in the present embodiment, expressions indicating directions such as up, down, left, right, front, and rear, which are used to explain the configurations and operations of the respective parts included in the cable connector  1 , the substrate connector  101  and other members are not absolute but relative, and are appropriate when the respective parts included in the cable connector  1 , the substrate connector  101  and the other members are in the orientation shown in the figure but should be interpreted with changes according to the change in orientation when the orientations of the respective parts included in the cable connector  1 , the substrate connector  101  and the other members are changed. 
     The substrate connector  101  includes a counterpart shell  171  formed by performing processing such as die-cutting and bending on a conductive metal plate, a counterpart housing (not shown) made from an insulating material such as synthetic resin disposed in the counterpart shell  171 , and a counterpart signal terminal  161  and a counterpart ground terminal  151  made from a conductive metal attached to the counterpart housing. The counterpart shell  171  has a flat, substantially rectangular parallelepiped shape so as to extend in the width direction (Y-axis direction), and is interiorly formed with an accommodating recess  113  to which at least a front end (X-axis positive direction end) of the cable connector  1  is inserted and accommodated. As shown in  FIG. 1 , the accommodating recess  113  is a space in which the side to be fitted with the cable connector  1  is open, and inside thereof, the counterpart signal terminal  161  and the counterpart ground terminal  151  are arranged and accommodated in one row in the width direction and so as to be alternately aligned. In the example shown in the figure, ten counterpart signal terminals  161  and eleven counterpart ground terminals  151  are provided, however, the number may be appropriately changed. 
     A soldering portion (not shown) of each counterpart signal terminal  161  and each counterpart ground terminal  151  is connected and fixed by soldering to a terminal connection pad (not shown) formed to be exposed on the surface of the substrate  191 . As a result, the substrate connector  101  is fixed to the surface of the substrate  191 , and each counterpart signal terminal  161  and each counterpart ground terminal  151  are conducted with a substrate side signal line and a substrate side ground line (not shown) formed on the substrate  191  so as to be connected to the corresponding terminal connection pad. Furthermore, the lower surface of a connection tail  172  of the counterpart shell  171  is connected and fixed by soldering to a shell connection pad  192  formed to be exposed on the surface of the substrate  191 . As a result, the substrate connector  101  is fixed to the surface of the substrate  191 , and the counterpart shell  171  is conducted with a substrate side ground line (not shown) formed on the substrate  191  so as to be connected to the shell connection pad  192 . 
     As shown in  FIG. 2 , the cable connector  1  includes a housing  11  formed of an insulating material such as synthetic resin, and a shell  71  formed by performing processing such as die-cutting and bending on the conductive metal plate. The housing  11  includes an inner housing  12  serving as a housing for holding a terminal, and an outer housing  13 , and the shell  71  includes a lower shell  72  and an upper shell  73 . 
     It is to be noted that the inner housing  12  and the outer housing  13  are members integrated with another member by over-molding (insert molding) and do not exist alone in a state separated from the other members, however, they are depicted as existing alone in  FIG. 2  for the sake of convenience of explanation. 
     The signal terminal  61  and the ground terminal  51  made of conductive metal are integrally attached to the inner housing  12  by over-molding (insert molding) The signal terminal  61  and the ground terminal  51  are arranged in one row in the width direction and so as to be alternately aligned, and are integrated with the inner housing  12 . Furthermore, the core wire  92  of the coaxial cable  91  is connected to the signal terminal  61 , and the shield  93  of the coaxial cable  91  is connected to the ground terminal  51 . In the example shown in the figure, ten signal terminals  61  and eleven ground terminals  51  are provided, however, the number may be appropriately changed, for example, according to the number of coaxial cables  91 . Note that, in a predetermined length range from the front end, that is, the distal end (X-axis positive direction end) of each coaxial cable  91 , as shown in  FIG. 2 , the outer covering  94 , the shield  93 , and the dielectric  95  are removed, and the core wire  92 , the dielectric  95 , and the shield  93  are sequentially exposed from the distal end. Thus, the core wire  92  and the shield  93  are connected to the signal terminal  61  and the ground terminal  51 , and the distal end of the coaxial cable  91  can be connected to the inner housing  12  by soldering. 
     The inner housing  12  to which the distal end of the coaxial cable  91  is connected is accommodated in the lower shell  72 . As shown in  FIG. 2 , the lower shell  72  is a square tube shaped member having an outer shape of a flat, substantially rectangular parallelepiped shape so as to extend in the width direction (Y-axis direction), and includes a flat plate shaped bottom plate portion  72   b  extending along an X-Y plane, a flat plate shaped top plate portion  72   a  parallel to the bottom plate portion  72   b,  and a pair of left and right side plate portions  72   c  that extend along an X-Z plane and couple both end edges in the width direction of the bottom plate portion  72   b  and the top plate portion  72   a.    
     Note that the top plate portion  72   a  is present in a first predetermined length range from the front end  72   f  of the lower shell  72  toward the rear side but is not present in a second predetermined length range from the rear end  72   r  of the lower shell  72  toward the front side, and the second predetermined length range becomes a top plate defective portion  74 . In the example shown in the figure, first predetermined length&lt;second predetermined length is satisfied. In the top plate defective portion  74 , the height (dimension in the Z-axis direction) of the left and right side plate portions  72   c  is approximately half, but an engagement opening  75   b  is formed in the side plate portion  72   c.    
     The inner housing  12  to which the distal end of the coaxial cable  91  is connected is introduced into the lower shell  72  from the top plate defective portion  74  and accommodated therein. At this time, a lower engagement protrusion  12   b  formed on the left and right side surfaces of the inner housing  12  enters and engages with the engagement opening  75   b.  The inner housing  12  is thereby held at a predetermined position in the lower shell  72 . 
     When the inner housing  12  is accommodated and held at a predetermined position in the lower shell  72 , the upper shell  73  is attached. The upper shell  73  is a member in which a shape seen from the front-rear direction (X-axis direction) is substantially a gate shape, and includes a flat plate shaped main body portion  73   a  extending along the X-Y plane, and a pair of left and right half-side plate portions  73   c  extending along the X-Z plane and extending downward (Z-axis negative direction) from both end edges in the width direction of the main body portion  73   a.  The upper shell  73  has a length (dimension in the X-axis direction) that is equivalent to the second predetermined length so as to close the entire top plate defective portion  74 . Furthermore, the engagement opening  75   a  is formed in the half-side plate portion  73   c.  Therefore, when the upper shell  73  is attached, the upper engagement protrusion  12   a  formed on the left and right side surfaces of the inner housing  12  held in the lower shell  72  enters and engages the engagement opening  75   a,  whereby the upper shell  73  is held at a predetermined position to cover the upper side of the inner housing  12  and close the entire top plate defective portion  74 . 
     Then, the inner housing  12  to which the distal end of the coaxial cable  91  is connected is accommodated in the lower shell  72 , and furthermore, after the entire top plate defective portion  74  is closed by the upper shell  73 , the outer housing  13  is formed to be integrated with the shell  71 , the signal terminals  61 , and the inner housing  12  by over-molding (insert molding). Thus, the cable connector  1  as shown in  FIG. 1  can be obtained. The resin forming the outer housing  13  is formed to enter a space between the lower shell  72  and the upper shell  73  from the rear end  72   r  of the lower shell  72  and cover the outer peripheries of the lower shell  72  and the upper shell  73  corresponding to a majority of the top plate defective portion  74 . The engagement protrusion  76  formed on the upper surface of the main body portion  73   a  of the upper shell  73  enters and engages with the engagement opening  13   a  formed at a position corresponding to the top plate of the outer housing  13 . Furthermore, a cable passage hole  13   b  through which the coaxial cable  91  passes is formed in the rear plate of the outer housing  13 . 
     Next, a connection structure between the distal end of the coaxial cable  91  and the inner housing  12  will be described in detail. 
       FIG. 3  is a perspective view showing a state in which the distal end of the coaxial cable is connected to the inner housing according to the present embodiment;  FIG. 4  is a perspective view showing a state in which the distal end of the coaxial cable is connected to the signal terminal and the ground terminal according to the present embodiment;  FIGS. 5A and 5B  are two-sided views showing the signal terminal and the ground terminal according to the present embodiment; and  FIGS. 6A-6C  are three-sided views showing a state in which the distal end of the coaxial cable is connected to the inner housing according to the present embodiment. In  FIGS. 5A and 5B ,  FIG. 5A  is a plan view and  FIG. 5B  is a perspective view; and in  FIGS. 6A-6C ,  FIG. 6A  is a plan view,  FIG. 6B  is a cross-sectional view taken along line A-A in  FIG. 6A , and  FIG. 6C  is a cross-sectional view taken along line B-B in  FIG. 6A . 
     In the present embodiment, each signal terminal  61  is a member formed by performing die-cutting, bending and the like on a conductive metal plate, and as shown in  FIGS. 5A and 5B , is a member having an elongated band-like shape extending in the front-rear direction and a planar shape along the X-Y plane. Furthermore, each signal terminal  61  includes a main body portion  63 , a contact portion  62  extending from a front end of the main body portion  63  toward the front side, and a tail portion  64  serving as a soldering portion extending from the rear end of the main body portion  63  toward the rear side. Note that the width (dimension in the Y-axis direction) of the contact portion  62  and the main body portion  63  is the same, however, the width of the tail portion  64  is wider than the width of the contact portion  62  and the main body portion  63 . 
     Furthermore, the main body portion  63  is a portion that is embedded in the main body portion  15  of the inner housing  12  and held by the main body portion  15 . Furthermore, the contact portion  62  is a portion in which at least the upper surface is exposed on the upper surface  14   a  of a tongue  14  of the inner housing  12  and brought into contact with the counterpart signal terminal  161  when the cable connector  1  is fitted with the substrate connector  101 . Furthermore, the tail portion  64  is a portion in which at least the upper surface is exposed in a cable accommodating groove  16  formed in the main body portion  15  of the inner housing  12  and connected to the core wire  92  of the coaxial cable  91  by soldering. 
     Moreover, each ground terminal  51  is a member formed by performing die-cutting, bending and the like a conductive metal plate, and as shown in  FIGS. 5A and 5B , is a member having an elongated band shape extending in the front-rear direction. Each ground terminal  51  includes a main body portion  53 , a contact portion  52  extending from a front end of the main body portion  53  toward the front side, and a coupling portion  54  extending from a rear end of the main body portion  53  toward the rear side. The contact portion  52  and the main body portion  53  extend within the same plane along the X-Y plane, however, the coupling portion  54  includes a stepped portion  54   a  in the middle, where a portion on the front side of the stepped portion  54   a  extends within the same plane as the contact portion  52  and the main body portion  53  and a portion on the rear side of the stepped portion  54   a  extends within a plane lower (located in the Z-axis negative direction) than the contact portion  52  and the main body portion  53 . In addition, the width (dimension in the Y-axis direction) of the contact portion  52  and the main body portion  53  is the same, but the width of the coupling portion  54  is narrower than the width of the contact portion  52  and the main body portion  53 . 
     Furthermore, the main body portion  53  is a portion that is embedded in the main body portion  15  of the inner housing  12  and held by the main body portion  15 . Furthermore, the contact portion  52  is a portion in which at least the upper surface is exposed on the upper surface  14   a  of the tongue  14  of the inner housing  12  and brought into contact with the counterpart ground terminal  151  when the cable connector  1  is fitted with the substrate connector  101 . Furthermore, the rear ends of the coupling portions  54  of all of the ground terminals  51  are connected to a ground coupling plate  55  serving as a single ground coupling member extending in the width direction. The ground coupling plate  55  extends within the same plane as the portion of the coupling portion  54  on the rear side of the stepped portion  54   a.  As shown in  FIG. 5A , a plurality of ground terminals  51  (11 in the example shown in the figure) extending in the front-rear direction are arranged in a width direction so as to create a space between each other in plan view, and the rear ends of each of the coupling portions  54  are connected to a single ground coupling plate  55  extending in the width direction, and thus it can be also said that the arrangement is similar to that of a comb tooth. 
     Furthermore, one signal terminal  61  extending in the front-rear direction is disposed in each of the spaces between the adjacent ground terminals  51 . In the example shown in the figure, the interval between the ground terminal  51  and the signal terminal  61 , that is, the pitch, is all constant. Moreover, the positions of the front end of the ground terminal  51  and the front end of the signal terminal  61  in the front-rear direction are the same, and the length (dimension in the X-axis direction) of the signal terminal  61  is shorter than the length of the ground terminal  51 , and thus the rear end of the signal terminal  61  does not come into contact with the ground coupling plate  55 . The contact portion  62  and the main body portion  63  of the signal terminal  61  extend within the same plane as the contact portion  52  and the main body portion  53  of the ground terminal  51 , and have the same length. As described above, the tail portion  64  of the signal terminal  61  has a wider width than the contact portion  62  and the main body portion  63 , however, the coupling portion  54  of the ground terminal  51  has a narrower width than the contact portion  52  and the main body portion  53 , so that the interval between the tail portion  64  in the signal terminal  61  and the coupling portion  54  in the ground terminal  51  adjacent to each other is substantially the same as the interval between the contact portion  62  and the main body portion  63  in the signal terminal  61  and the contact portion  52  and the main body portion  53  in the ground terminal  51 . Therefore, when connecting the tail portion  64  of the signal terminal  61  and the core wire  92  of the coaxial cable  91  by soldering, the soldering area is enlarged by the wide tail portion  64 , and the soldering properties are improved. Furthermore, since the width of the coupling portion  54  is narrow, the coupling portion  54  adjacent to the tail portion  64  is reliably covered by a rib portion  17  described below, and the molten solder can be prevented from adhering to the coupling portion  54  of the ground terminal  51 . Therefore, the possibility of a short circuit between the signal terminal  61  and the ground terminal  51  is extremely low due to soldering, whereby the soldering workability improves. 
     In the ground coupling plate  55 , an intermediate portion between the areas where the coupling portions  54  are connected in the adjacent ground terminals  51  functions as a shield connecting portion  55   a  connected by soldering to the shield  93  of the coaxial cable  91 . The position in the width direction of the shield connecting portion  55   a  is the same as the position of the tail portion  64  of the signal terminal  61 . Note that in the example shown in the figure, a connection enlarged portion  55   b  projecting rearward from each shield connecting portion  55   a  is formed in the ground coupling plate  55 , however, the connection enlarged portion  55   b  may be omitted. 
     As shown in  FIG. 4 , the coaxial cable  91  is desirably soldered to the signal terminal  61  and the ground coupling plate  55  using a solder preform  81 . The solder preform  81  is a member formed into a plate shape of a predetermined size and shape by pre-processing the solder, and in the present embodiment, includes an elongated band-shaped core wire preform  81   a  mounted on the tail portion  64  of the signal terminal  61 , and a shield preform  81   b  mounted on the shield connecting portion  55   a  of the ground coupling plate  55 . When a distal end portion of the coaxial cable  91  is disposed at a predetermined position with respect to the inner housing  12 , as shown in  FIG. 4 , the core wire preform  81   a  is interposed between the exposed core wire  92  and the tail portion  64  of the signal terminal  61 , and the shield preform  81   b  is interposed between the exposed shield  93  and the shield connecting portion  55   a  of the ground coupling plate  55 . Note that, in  FIG. 4 , for the sake of convenience of explanation, only two coaxial cables  91  are drawn, and other coaxial cables  91  are omitted. 
     When the solder preform  81  is heated in this state, the solder melts, thus soldering the core wire  92  and tail portion  64  and soldering the shield  93  and the shield connecting portion  55   a.  Note that the soldering work can be performed by applying molten solder between the core wire  92  and the tail portion  64  and between the shield  93  and the shield connecting portion  55   a  without using the solder preforms  81 . 
     As described above, since the position in the width direction of the shield connecting portion  55   a  is the same as the position of the tail portion  64  of the signal terminal  61 , and the ground coupling plate  55  connected to the rear end of the coupling portion  54  of the ground terminal  51  is lower (located in the Z-axis negative direction) than the tail portion  64  of the signal terminal  61 , as shown in  FIG. 6 , the coaxial cable  91 , in which the core wire  92  and the shield  93  are soldered to the tail portion  64  and the shield connecting portion  55   a  can maintain a substantially straight line even in side view. 
     As illustrated in  FIG. 3 , the inner housing  12  includes a substantially rectangular parallelepiped main body portion  15  having a rectangular shape in plan view, and a rectangular parallelepiped tongue  14  thinner than the main body portion  15  extending from the front end of the main body portion  15  toward the front side. The upper surface  14   a  of the tongue  14  is a flat surface, and the upper surface of the contact portion  62  of the signal terminal  61  and the upper surface of the contact portion  52  of the ground terminal  51  are exposed on the upper surface  14   a.    
     Furthermore, a peak portion  15   c  that projects out upward and extends in the width direction is formed at the front end of the main body portion  15 , so that the upper surface  14   a  of the tongue  14  and the upper surface  15   a  of the main body portion  15  are distinguished by the peak portion  15   c.  Since the upper surface  15   a  of the main body portion  15  is higher (located in the Z-axis positive direction) than the upper surface  14   a  of the tongue  14 , the main body portion  63  of the signal terminal  61  and the main body portion  53  of the ground terminal  51  are embedded in the main body portion  15  and are not exposed to the upper surface  15   a  of the main body portion  15 . 
     A plurality of upper pin marking holes  18   a  is opened at positions proximate to the peak portion  15   c  in the upper surface  15   a,  and lower pin marking holes  18   b  are opened at positions corresponding to each of the upper pin marking holes  18   a  in the lower surface  15   b  of the main body portion  15 . When integrally molding the inner housing  12  with the signal terminal  61  and the ground terminal  51  by over-molding (insert molding), each upper pin marking hole  18   a  and the lower pin marking hole  18   b  act as marks of an upper die pin and a lower die pin for holding down terminals used to sandwich each signal terminal  61  and each ground terminal  51  from above and below to hold them at predetermined positions in the molding die, and are formed at positions corresponding to the main body portion  63  of each signal terminal  61  and the main body portion  53  of each ground terminal  51 . As shown in  FIGS. 6A-6C , the upper pin marking hole  18   a  and the lower pin marking hole  18   b  are holes that reach from the upper surface  15   a  and the lower surface  15   b  of the main body portion  15  to the main body portion  63  of the signal terminal  61  and the main body portion  53  of each ground terminal  51  embedded in the main body portion  15 . Note that the lower surface  15   b  of the main body portion  15  is a flat surface flush with the lower surface  14   b  of the tongue  14 . 
     As shown in  FIG. 3 , a plurality of (ten in the example shown in the figure) cable accommodating grooves  16  extending in the front-rear direction is formed side by side in the width direction on the upper surface  15   a  of the main body portion  15 . Each cable accommodating groove  16  is a groove formed to be recessed from the upper surface  15   a  of the main body portion  15  at a position corresponding to each signal terminal  61  in the width direction so as to accommodate a lower portion near the distal end of the corresponding coaxial cable  91 , and extends from the rear side of the upper pin marking hole  18   a  to the rear end (X-axis negative direction end) of the main body portion  15 . Furthermore, each cable accommodating groove  16  includes a front half portion  16   a,  which has a depth (dimension in the Z-axis direction) that is relatively shallow to mainly accommodate the core wire  92 , and a rear half portion  16   b,  which has a depth that is deeper than the front half portion  16   a  to mainly accommodate the shield  93 . Note that, in  FIG. 3 , for the sake of convenience of explanation, only two coaxial cables  91  are drawn, and other coaxial cables  91  are omitted. 
     Furthermore, at least the upper surface of the tail portion  64  of the corresponding signal terminal  61  is exposed at the bottom surface of the front half portion  16   a,  and at least the upper surface of the shield connecting portion  55   a  corresponding to the signal terminal  61  in the ground coupling plate  55  is exposed at the bottom surface of the rear half portion  16   b.    
     Moreover, a plurality (eleven in the example shown in the figure) of rib portions  17  extending in the front-rear direction is formed side by side in the width direction at a portion corresponding to the upper side of the ground terminal  51  in the upper surface  15   a  of the main body portion  15 . The rib portion  17  is a portion that also functions as a wall for defining both left and right sides of each cable accommodating groove  16 , and extends from the rear side of the upper pin marking hole  18   a  to the rear end of the main body portion  15 . Furthermore, each rib portion  17  includes a front portion  17   a,  which upper surface is flush with the upper surface  15   a  of the main body portion  15 , an intermediate portion  17   b  connected to the rear end of the front portion  17   a  and projected upward so as to have a height higher than the front portion  17   a,  and a rear portion  17   c  connected to the rear end of the intermediate portion  17   b  and which upper surface is substantially flush with the upper surface of the front portion  17   a.  It is desirable that the height of the upper surface of the intermediate portion  17   b  is higher than the upper end of the shield  93  exposed in the coaxial cable  91  in a state the distal end is connected to the inner housing  12 , as shown in  FIGS. 6A-6C . The shield  93  thus can be prevented from coming into contact with the main body portion  73   a  of the upper shell  73 . 
     As described above, since the left and right sides of each cable accommodating groove  16  are defined by the rib portion  17 , workability of the work of mounting the core wire preform  81   a  and the shield preform  81   b  on the tail portion  64  of the signal terminal  61  and the shield connecting portion  55   a  of the ground coupling plate  55  exposed at the bottom surface of each cable accommodating groove  16  is improved. Furthermore, since each ground terminal  51  is covered by the corresponding rib portion  17 , the holding thereof is ensured. 
     Moreover, normally, when forming the signal terminal  61  by performing processing such as die-cutting, bending, or the like on the conductive metal plate, the rear ends of the plurality of tail portions  64  are commonly connected to a metal plate, which is referred to as a carrier (not shown), but the ground coupling plate  55  connected to the coupling portion  54  of each ground terminal  51  extends within a plane lower than the tail portion  64  of each signal terminal  61  disposed between the adjacent ground terminals  51  due to the presence of the stepped portion  54   a,  and thus when arranging the signal terminal  61  and the ground terminal  51  in combination as shown in  FIGS. 5A and 5B , the plurality of signal terminals  61  can be disposed between the adjacent ground terminals  51  all at once by gripping the carrier, which improves the workability. Note that the carrier is removed from the tail portion  64  after the signal terminal  61  is disposed in a predetermined position. 
     Thus, in the present embodiment, the cable connector  1  includes at least one signal terminal  61  extending in the front-rear direction, at least two ground terminals  51  extending in the front-rear direction disposed on both sides in the width direction of the signal terminal  61 , and an inner housing  12  that holds the signal terminal  61  and the ground terminal  51 ; where all the ground terminals  51  are integrally formed with one ground coupling plate  55  extending in the width direction; the inner housing  12  is integrally formed with the signal terminal  61 , the ground terminal  51 , and the ground coupling plate  55  by insert molding; the signal terminal  61  has the contact portion  62  that comes into contact with the counterpart signal terminal  161  and the tail portion  64  that is soldered to the core wire  92  of the coaxial cable  91  exposed from the inner housing  12 ; the ground coupling plate  55  includes the shield connecting portion  55   a  that is exposed from the inner housing  12  at the rear side of the tail portion  64  of the signal terminal  61  and soldered to the shield  93  of the coaxial cable  91 ; and the ground terminal  51  has a portion other than the contact portion  52  that comes into contact with the counterpart ground terminal  151  embedded in the inner housing  12 . 
     Thus, the number of parts can be reduced, the cost of the cable connector  1  can be reduced, noise can be suppressed, thus stabilizing signal quality, the soldering work can be performed easily and surely, and the reliability of the connector can be improved. Furthermore, electrical properties can be stabilized because the potential levels of all of the ground terminals  51  can be matched and shared while allowing for soldering. 
     In addition, the signal terminal  61  is provided as a plurality, the number of ground terminals  51  is a number only one larger than the number of signal terminals  61 , and the signal terminals  61  and the ground terminals  51  are arranged so as to be alternately aligned in one row in the width direction. Thus, variations in signal characteristics can be suppressed. 
     Furthermore, the contact portion  52  of the ground terminal  51  is located at the same height as the contact portion  62  of the signal terminal  61 , and the shield connecting portion  55   a  of the ground coupling plate  55  is located at a position lower than the tail portion  64  of the signal terminal  61 . Therefore, the coaxial cable  91  in which the core wire  92  and shield  93  are soldered to the tail portion  64  and the shield connecting portion  55   a,  can maintain a substantially straight line. 
     Furthermore, the inner housing  12  includes the cable accommodating groove  16  that extends in the front-rear direction formed in the upper surface  15   a,  and the tail portion  64  of the signal terminal  61  and the shield connecting portion  55   a  of the ground coupling plate  55  are exposed at the bottom surface of the cable accommodating groove  16 . Thus, in a case where soldering is performed using the solder preform  81 , the solder preform  81  can be easily mounted at a predetermined position, the workability of soldering can be improved, and automation of soldering work can be enabled. 
     Moreover, the inner housing  12  includes the rib portion  17  that extends in the front-rear direction formed on both sides of the cable accommodating groove  16 , and a majority of the portion of the ground terminal  51  embedded within the inner housing  12  is located below the rib portion  17 . Thus, the ground terminal  51  is held at a position away from the upper surface  15   a  of the inner housing  12 . Furthermore, the ground terminal  51  is prevented from coming into contact with the upper shell  73 . 
     In addition, the signal terminal  61  includes the main body portion  63  connected to the rear end of the contact portion  62 ; the tail portion  64  is wider than the contact portion  62  and the main body portion  63  and is connected to the rear end of the main body portion  63 ; the ground terminal  51  includes the main body portion  53  connected to the rear end of the contact portion  52  and the coupling portion  54  connected to the rear end of the main body portion  53 ; and the coupling portion  54  has a narrower width than the contact portion  52  and the main body portion  53 . Accordingly, the tail portion  64  of the signal terminal  61  can be made wide to ensure soldering with the core wire  92 , and furthermore, as the distance with the coupling portion  54  of the adjacent ground terminal  51  does not become narrow even if the tail portion  64  of the signal terminal  61  is made wide, the impedance can be stably maintained. 
     Furthermore, the coupling portion  54  includes the stepped portion  54   a,  and the rear end is integrally connected to the ground coupling plate  55 . Thus, the shield connecting portion  55   a  of the ground coupling plate  55  can be located at a position lower than the tail portion  64  of the signal terminal  61 . 
     Furthermore, the inner housing  12  includes the upper pin marking hole  18   a  and the lower pin marking hole  18   b  opened to the upper surface  15   a  and the lower surface  15   b  at positions corresponding to the main body portion  63  of the signal terminal  61  and the main body portion  53  of the ground terminal  51 . When integrally molding the inner housing  12  with the signal terminal  61  and the ground terminal  51  by insert molding, the upper pin marking hole  18   a  and the lower pin marking hole  18   b  act as marks of an upper die pin and a lower die pin for holding down terminals used to sandwich each signal terminal  61  and each ground terminal  51  from above and below to hold them at predetermined positions in the molding die, so that the positions of each of the signal terminals  61  and each of the ground terminals  51  can be stably held by using the upper die pin and the lower die pin. 
     Furthermore, the cable connector  1  further includes the shell  71  in which at least a part of the inner housing  12  is accommodated, and the ground terminal  51  is electrically separated from the shell  71 . Thus, the shell  71  and the shield  93  of the coaxial cable  91  can be electrically separated, and the degree of freedom of noise suppression is improved. Furthermore, even when the potential of the shell  71 , which is the frame ground (FG), fluctuates, the noise can be suppressed and hence the signal quality can be stabilized as FG and the potential of the shield  93  and ground terminal  51 , which is the signal ground (SG), are separated. Moreover, as the shield  93  of the coaxial cable  91  is not connected to the shell  71 , the amount of heat required for soldering can be reduced, and workability is improved. 
     Note that the disclosure of the present specification describes characteristics related to a preferred and exemplary embodiment. Various other embodiments, modifications, and variations within the scope and spirit of the claims appended hereto could naturally be conceived of by persons skilled in the art by summarizing the disclosures of the present specification. 
     The present disclosure can be applied to connectors.