Patent Publication Number: US-2023135482-A1

Title: Electrical connector and connector device

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation of and claims benefit under 35 U.S.C. § 120 to U.S. application Ser. No. 17/209,335, filed Mar. 23, 2021, which is a continuation of and claims benefit under 35 U.S.C. § 120 to U.S. application Ser. No. 16/720,967, filed Dec. 19, 2019, which is based upon and claims the benefit of priority under 35 U.S.C. § 119 from Japanese Patent Application No. 2018-248235, filed Dec. 28, 2018, the entire contents of each of which are herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     A disclosed embodiment relates to an electrical connector and a connector device. 
     2. Description of the Related Art 
     Conventionally, a connector device for electrically connecting a signal transmission medium such as a coaxial cable, a flexible printed circuit (FPC), or a flexible flat cable (FFC) to a wiring substrate has been widely used in an electronic instrument. Such a connector device includes a first connector that is connected to a terminal of a signal transmission medium and a second connector that is connected to a wiring substrate. In an electronic instrument where such a type of connector device is used therein, electromagnetic interference that is caused by radiation of an electromagnetic wave or the like may be problematic, so that a shield function may be provided to a connector device. 
     For example, Japanese Patent Application Publication No. 2008-097849 discloses a connector device that covers a housing where a plurality of signal contacts are arrayed thereon with a shell with a conductive property that is provided on a first connector and a shell with a conductive property that is provided on a second connector. Such a connector device has a configuration for causing a ground member with a conductive property on a first connector to contact a shell with a conducive property on a second connector, and a shield function thereof is improved by such a configuration. 
     However, further improvement of a shield function in a connector device is desired with a frequency increase of a signal that is transmitted or received, an increase of an operation frequency, or the like, in an electronic instrument where such a connector device is used therein. 
     SUMMARY OF THE INVENTION 
     An electrical connector according to an aspect of an embodiment is an electrical connector that is attached to a wiring substrate and mated with a counterpart connector that is connected to a terminal of a signal transmission medium, and that includes a housing that has an insulation property, a plurality of contacts with a conductive property that are arrayed on the housing, and a shell with a conductive property. The shell with a conductive property has a pair of wall parts that are opposed to one another via the plurality of contacts in a direction along a principal surface of the wiring substrate where the direction is orthogonal to an array direction of the plurality of contacts and contact a ground member with a conductive property on the counterpart connector. Among the pair of wall parts, one wall part that is provided at a position that is distant from the signal transmission medium includes a first side plate that is provided with one end that is attached to a ground conductive path of the wiring substrate and extends in a direction away from the wiring substrate from the one end toward another end, a joining part that is provided with one end that is joined to another end of the first side plate, and a second side plate that is provided with one end that is joined to another end of the joining part and extends in a direction closer to the wiring substrate from the one end toward another end where the other end is a free end. The second side plate has a contact piece that extends in a direction away from the wiring substrate and elastically contacts the ground member of the counterpart connector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING(S) 
         FIG.  1    is a diagram illustrating an example of a plug connector and a receptacle connector in a connector device according to an embodiment. 
         FIG.  2    is a diagram illustrating a state where a plug connector and a receptacle connector according to an embodiment are mated therewith. 
         FIG.  3    is an appearance perspective view of a plug connector according to an embodiment. 
         FIG.  4    is an appearance perspective view of a plug connector according to an embodiment. 
         FIG.  5    is a plan view of a plug connector according to an embodiment. 
         FIG.  6    is a cross-sectional view along line VI-VI as illustrated in  FIG.  5   . 
         FIG.  7    is a cross-sectional view along line VII-VII as illustrated in  FIG.  5   . 
         FIG.  8    is an appearance perspective view of a receptacle connector according to an embodiment. 
         FIG.  9    is an appearance perspective view of a receptacle connector according to an embodiment. 
         FIG.  10    is a plan view of a receptacle connector according to an embodiment. 
         FIG.  11    is a cross-sectional view along line XI-XI as illustrated in  FIG.  10   . 
         FIG.  12    is a cross-sectional view along line XII-XII as illustrated in  FIG.  10   . 
         FIG.  13    is a plan view of a connector device in a state where a plug connector and a receptacle connector according to an embodiment are mated therewith. 
         FIG.  14    is a cross-sectional view along line XIV-XIV as illustrated in  FIG.  13   . 
         FIG.  15    is a cross-sectional view along line XV-XV as illustrated in  FIG.  13   . 
         FIG.  16    is a front elevation view of a connector device in a state where a plug connector and a receptacle connector according to an embodiment are mated therewith. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     Hereinafter, an embodiment(s) of an electrical connector and a connector device as disclosed in the present application will be explained in detail, with reference to the accompanying drawing(s). Additionally, this invention is not limited by an embodiment(s) as illustrated below. 
     1. Configuration of Connector Device 
     First, a connector device that includes a plug connector and a receptacle connector according to an embodiment will be explained with reference to  FIG.  1    and  FIG.  2   . 
     As illustrated in  FIG.  1   , a connector device  1  according to an embodiment includes a plug connector  10  that is connected to terminals of a plurality of coaxial cables  2  and a receptacle connector  20  that is attached to a wiring substrate  3 . The plurality of coaxial cables  2  are an example of a signal transmission medium. Additionally, the plug connector  10  may be a configuration to be connected to a terminal of a signal transmission medium such as a flexible printed circuit (FPC) or a flexible flat cable (FFC), instead of the plurality of coaxial cables  2 . The wiring substrate  3  is, for example, an electrical circuit substrate such as a printed wiring substrate. 
     The plug connector  10  is an example of a counterpart connector and a first connector and the receptacle connector  20  is an example of an electrical connector and a second connector. Additionally, only a part of the coaxial cables  2  is conveniently illustrated in the drawing(s) and a boundary with a remaining part thereof is illustrated as a cross section thereof. 
     Furthermore, hereinafter, a direction where the plug connector  10  is inserted into the receptacle connector  20  therein (a negative direction of a Z-axis) is a “downward direction” and a removal direction (a positive direction of the Z-axis) that is an opposite direction thereof is an “upward direction”, for explanatory convenience. Furthermore, longitudinal directions of the plug connector  10  and the receptacle connector  20  (positive and negative directions of an X-axis) are “leftward and rightward directions”. Furthermore, transverse directions of the plug connector  10  and the receptacle connector  20  (positive and negative directions of a Y-axis) are “frontward and backward directions”. 
     In the connector device  1 , a plurality of contacts  12  with a conductive property as described later (see  FIG.  4   ) on the plug connector  10  are electrically connected to a plurality of contacts  22  with a conductive property that are arrayed on a housing  21  of the receptacle connector  20 , by mating between the plug connector  10  and the receptacle connector  20 . Thereby, a center conductor  2   a  as described later (see  FIG.  6   ) of such a coaxial cable  2  and a non-illustrated signal conductive path that is formed on a principal surface M of the wiring substrate  3  are electrically connected thereto via the contacts  12 ,  22 . 
     As the plug connector  10  is mated with the receptacle connector  20 , the plurality of contacts  12  and the plurality of contacts  22  as described above are covered by a shell  14  with a conductive property on the plug connector  10  and a shell  23  with a conductive property on the receptacle connector  20 . The shells  14 ,  23  are ground members that are connected to ground and it is possible to provide the connector device  1  with a shield function by such shells  14 ,  23 . 
     Furthermore, the shell  23  of the receptacle connector  20  has a front wall part  24  and a back wall part  25  that are opposed to one another via the plurality of contacts  22  in frontward and backward directions that are directions along the principal surface M of the wiring substrate  3  where the directions are orthogonal to an array direction of the plurality of contacts  22 . Each of such a front wall part  24  and a back wall part  25  contacts a ground member of the plug connector  10 . 
     Specifically, the back wall part  25  contacts a conductive member  13  (see  FIG.  6   ) of the plug connector  10  and the front wall part  24  contacts the shell  14  of the plug connector  10 . Thereby, it is possible to further improve a shield function in the connector device  1 . Additionally, the shell  14  and the conductive member  13  are an example of a ground member. Although the shell  14  and the conductive member  13  are separate bodies, the shell  14  and the conductive member  13  may be formed integrally. 
     2. Configuration of Plug Connector  10   
     Next, a configuration of the plug connector  10  according to an embodiment will be explained with reference to  FIG.  3    to  FIG.  7   . As illustrated in  FIG.  3   , the plug connector  10  is connected to terminals of the plurality of coaxial cables  2 . As illustrated in  FIG.  6    and  FIG.  7   , the coaxial cable  2  is formed by laminating a dielectric body  2   b , an outside conductor (a shield line)  2   c  (an example of a first ground conductive path), and an outer circumference covering material  2   d  on an outer circumferential side of a center conductor (a signal line)  2   a  (an example of a first signal conductive path) in order. 
     As illustrated in  FIG.  6    and  FIG.  7   , one terminal of the coaxial cable  2  sequentially exposes the center conductor  2   a , the dielectric body  2   b , and the outside conductor  2   c  from a distal end side thereof. The outside conductor  2   c  among such exposed parts is sandwiched by a pair of ground bars  4  that are composed of thin plates with a conductive property, so that the plurality of coaxial cables  2  are attached to the ground bars  4 . 
     As illustrated in  FIG.  4   , the plug connector  10  includes a housing  11  with an insulation property (an example of a first housing), the plurality of contacts  12  with a conductive property (an example of a first contact) that are arrayed on the housing  11 , the conductive member  13  that contacts a lower ground bar  4  among the pair of ground bars  4 , and the shell  14  with a conductive property that covers an outer surface of the housing  11  where the plurality of contacts  12  are arrayed thereon and contacts an upper ground bar  4  among the pair of ground bars. 
     Each of a space between the contacts  12 , a space between such a contact  12  and the conductive member  13 , and a space between the contact  12  and the shell  14  is insulated by the housing  11 . Each of the contacts  12 , the conductive member  13 , and the shell  14  is formed by, for example, applying a punching process or a folding process to a single metal plate. 
     As illustrated in  FIG.  4   , the housing  11  includes a base part  111  with longitudinal directions that are positive and negative directions of an X-axis (leftward and rightward directions), a protrusion part  112  that protrudes from the base part  111  in a positive direction of the X-axis, a protrusion part  113  that protrudes from the base part  111  in a negative direction of the X-axis, and protrusion parts  114 ,  115  with an approximately U-shaped cross section where each thereof protrudes downward from the base part  111  and extends in the positive and negative directions of an X-axis (the leftward and rightward directions). As illustrated in  FIG.  6   , the protrusion parts  114 ,  115  are arranged so as to be spaced apart from one another in frontward and backward directions. 
     As illustrated in  FIG.  4   , the plurality of contacts  12  are arrayed so as to be spaced apart in leftward and rightward directions and fixed on the housing  11  by, for example, insert molding. As illustrated in  FIG.  6   , such a plurality of contacts  12  are arranged from the base part  111  to the protrusion part  114  of the housing  11 . Each contact  12  exposes a proximal end part  121  thereof from an upper surface of the base part  111  in the housing  11  and such a proximal end part  121  is connected to the center conductor  2   a  of the coaxial cable  2  by soldering or the like. Furthermore, each contact  12  exposes a distal end part  122  thereof from the protrusion part  114 . 
     As illustrated in  FIG.  4   , the conductive member  13  is arranged on the housing  11  so as to cover a back part of the protrusion part  115 . Such a conductive member  13  is fixed on the housing  11  by, for example, insert molding. As illustrated in  FIG.  6   , the conductive member  13  includes a base part  131  that is provided with longitudinal directions that are leftward and rightward directions and contacts such a ground bar  4  and a J-shaped protrusion part  132  that extends downward from the base part  131 . Such a protrusion part  132  is arranged on the protrusion part  115  of the housing  11 . 
     The shell  14  has a cover upper part  141  that covers an upper part of the housing  11  in a state where one terminal of the coaxial cable  2  is arranged on the plug connector  10  and a cover front part  142  that covers a front part of the housing  11  in a state where the one terminal of the coaxial cable  2  is arranged on the plug connector  10 . As illustrated in  FIG.  3   , a plurality of openings  141   a  are formed on the cover upper part  141 . Tongue pieces are formed on edges of such a plurality of openings  141   a  and such a tongue piece and the ground bar  4  are connected by a solder  15 . Additionally,  FIG.  3    does not illustrate the solder  15 . 
     Furthermore, as illustrated in  FIG.  3   , the shell  14  has a side protrusion part  143  that protrudes outward from a terminal of the cover upper part  141  in a positive direction of an X-axis and a side protrusion part  144  that protrudes outward from a terminal of the cover upper part  141  in a negative direction of the X-axis. As illustrated in  FIG.  4   , a distal end part  143   a  of the side protrusion part  143  is engaged with an engagement recess  112   a  that is formed on the protrusion part  112  of the housing  11  so as to be fixed on the housing  11 . As illustrated in  FIG.  3   , a distal end part  144   a  of the side protrusion part  144  is engaged with an engagement recess  113   a  that is formed on the protrusion part  113  of the housing  11  so as to be fixed on the housing  11 . 
     3. Configuration of Receptacle Connector  20   
     Next, a configuration of the receptacle connector  20  according to an embodiment will be explained with reference to  FIG.  8    to  FIG.  12   . As illustrated in  FIG.  8   , the receptacle connector  20  includes a housing  21  with an insulation property (an example of a second housing), a plurality of contacts  22  with a conductive property (an example of a second contact), and a shell  23  with a conductive property that is attached to the housing  21 . Each of the contacts  22  and the shell  23  is formed by, for example, applying a punching process or a folding process to a single metal plate. 
     As illustrated in  FIG.  8    and  FIG.  12   , the housing  21  includes a base part  211 , a front wall part  212 , a back wall part  213 , a center wall part  214 , and side wall parts  215 ,  216 . The front wall part  212 , the back wall part  213 , the center wall part  214 , the side wall part  215 , and the side wall part  216  protrude upward from the base part  211 . 
     Each of the front wall part  212 , the back wall part  213 , and the center wall part  214  extends in leftward and rightward directions and are arranged so as to be spaced apart from one another in frontward and backward directions. As illustrated in  FIG.  8   , the plurality of contacts  22  are arrayed on the center wall part  214  so as to be spaced apart in leftward and rightward directions. As illustrated in  FIG.  11   , the plurality of contacts  22  are arranged on the center wall part  214  by press fitting. 
     As illustrated in  FIG.  11    and  FIG.  12   , a housing recess  28  where the protrusion part  114  (see  FIG.  6   ) of the plug connector  10  is housed therein is formed between the front wall part  212  and the center wall part  214 . Furthermore, a housing recess  29  where the protrusion part  115  (see  FIG.  6   ) of the plug connector  10  is housed therein is formed between the center wall part  214  and the back wall part  213 . 
     As illustrated in  FIG.  11   , such a contact  22  is provided with an intermediate part  222  that is supported by the front wall part  212  of the housing  21  and one terminal  221  that is a free end and is capable of being elastically deformed. The one terminal  221  of the contact  22  is arranged on the center wall part  214  and a contact part  221   a  that contacts the contact  12  of the plug connector  10  is formed on such one terminal  221 . In a state as illustrated in  FIG.  11   , the contact part  221   a  protrudes frontward from the center wall part  214  and is arranged on the housing recess  28 . Furthermore, another terminal  223  of the contact  22  is arranged below the front wall part  212  and electrically connected to a non-illustrated signal conductive path (an example of a second signal conductive path) that is formed on the wiring substrate  3  (see  FIG.  1   ) by soldering or the like. 
     As illustrated in  FIG.  8   ,  FIG.  9   , and  FIG.  11   , the shell  23  includes a front wall part  24  that is arranged so as to be spaced apart from the front wall part  212  in front of the front wall part  212  on the housing  21  and a back wall part  25  that is attached to the back wall part  213  of the housing  21  and covers the back wall part  213 . Furthermore, the shell  23  includes a side wall part  26  that is attached to the side wall part  215  of the housing  21  and covers the side wall part  215  and a side wall part  27  that is attached to the side wall part  216  of the housing  21  and covers the side wall part  216 . 
     As illustrated in  FIG.  9    and  FIG.  11   , the front wall part  24  of the shell  23  has a first side plate  31 , a plurality of joining parts  32 , and a second side plate  33 . The first side plate  31  is provided with one end that is attached to a non-illustrated ground conductive path on the wiring substrate  3  and extends in a (upward) direction away from the wiring substrate  3  from the one end toward another end. The plurality of joining parts  32  are provided with ends that are joined to another end of the first side plate  31  and other ends that are joined to one end of the second side plate  33 . The second side plate  33  extends in a (downward) direction closer to the wiring substrate  3  from one end toward another end where the other end is a free end. 
     As illustrated in  FIG.  8   , the first side plate  31  has a ground connection part  311  that is attached to a non-illustrated ground conductive path (an example of a second ground conductive path) on the wiring substrate  3 , an extension part  312  that is continuous with the ground connection part  311  and extends in a (upward) direction away from the wiring substrate  3 , a recess  313  that is a backward dent in a direction toward the back wall part  25  at a position close to one end of the joining part  32 , and a cut part  314 . 
     As illustrated in  FIG.  9    and  FIG.  11   , the second side plate  33  has an extension part  331  that is provided with one end that is joined to another side of the joining part  32  and extends in a (downward) direction closer to the wiring substrate  3  from the one end toward another end where the other end is a free end. In an example as illustrated in  FIG.  11   , the extension part  331  extends backward and obliquely downward. Additionally, one end of the extension part  331  is one end of the second side plate  33  as described above and another end of the extension part  331  is also another end of the second side plate  33  as described above. 
     Furthermore, as illustrated in  FIG.  8    and  FIG.  12   , the second side plate  33  has a plurality of contact pieces  332  that are provided with proximal ends that are joined to the extension part  331  at a position close to another end of the extension part  331  and are cantilevered and supported by the extension part  331 . As illustrated in  FIG.  8   , each contact piece  332  is formed into an approximately L-shape and provided with a distal end part that protrudes frontward via the cut part  314 . Furthermore, as illustrated in  FIG.  9   , the plurality of contact pieces  332  are plurally formed on the second side plate  33  so as to be spaced apart. 
     As illustrated in  FIG.  12   , such a contact piece  332  has a contact piece extension part  332   a  with one end that is joined to a position close to another end of the extension part  331  on the extension part  331  and a contact part  332   b  that is joined to another end of the contact piece extension part  332   a  and contacts the shell  14  of the plug connector  10 . The contact piece extension part  332   a  extends in a (upward) direction away from the wiring substrate  3  from one end to another end. In an example as illustrated in  FIG.  12   , the contact piece extension part  332   a  has a flexural part for forming the contact part  332   b  at a position close to another end, and extends frontward and obliquely upward from a position close to another end of the extension part  331  and subsequently extends frontward and obliquely downward. 
     As illustrated in  FIG.  11   , the contact part  332   b  is arranged to be close to one end (or close to an upper end) of the joining part  32  on the contact piece  332  in upward and downward directions that are directions orthogonal to the principal surface M (see  FIG.  1   ) of the wiring substrate  3 . Furthermore, the contact part  332   b  is arranged at a position close to the first side plate  31  (or close to an outside) on the second side plate  33  in frontward and backward directions that are directions along the principal surface M of the wiring substrate  3  where the directions are orthogonal to an array direction of the contacts  22 . 
     As illustrated in  FIG.  11   , the back wall part  25  of the shell  23  has a first side plate  41 , a joining part  42 , a second side plate  43 , and a contact piece  44 . The first side plate  41  is provided with one end that is attached to a non-illustrated ground conductive path on the wiring substrate  3  and extends in a (upward) direction away from the wiring substrate  3  from the one end toward another end. The joining part  42  is provided with one end that is joined to another end of the first side plate  41  and another end that is joined to one end of the second side plate  43 . The second side plate  43  extends in a (downward) direction closer to the wiring substrate  3  from one end toward another end. 
     As illustrated in  FIG.  12   , the contact piece  44  is provided with one end that is joined to another end of the joining part  42  and extends in a (downward) direction closer to the wiring substrate  3  from one end toward another end. In an example as illustrated in  FIG.  12   , the contact piece  44  extends frontward and obliquely downward. Such a contact piece  44  is cantilevered and supported by the joining part  42  and another end thereof is a free end. For the contact piece  44 , as illustrated in  FIG.  12   , a contact part  44   a  that contacts the protrusion part  132  (see  FIG.  6   ) of the conductive member  13  is arranged on another end of the contact piece  44 . In a state as illustrated in  FIG.  11   , the contact piece  44  protrudes frontward from the back wall part  213  and is arranged in the housing recess  29 . 
     4. Mating State of Plug Connector  10  and Receptacle Connector  20   
     Next, a mating state of the plug connector  10  and the receptacle connector  20  will be explained specifically, with reference to  FIG.  6    and  FIG.  12    to  FIG.  15   . 
     The plug connector  10  is inserted into the receptacle connector  20 , so that the plug connector  10  and the receptacle connector  20  are provided in a mating state thereof. Insertion of the plug connector  10  into the receptacle connector  20  is executed by inserting the protrusion part  114  (see  FIG.  6   ) of the plug connector  10  into the housing recess  28  (see  FIG.  12   ) of the receptacle connector  20  and inserting the protrusion part  115  (see  FIG.  6   ) of the plug connector  10  into the housing recess  29  (see  FIG.  12   ) of the receptacle connector  20 . 
     In a case where the plug connector  10  and the receptacle connector  20  are provided in a mating state thereof, the plurality of contacts  12  with a conductive property on the plug connector  10  are electrically connected to the plurality of contacts  22  with a conductive property on the receptacle connector  20 . Specifically, the distal end part  122  of the contact  12  contacts the contact part  221   a  of the contact  22 , so that the contact  12  and the contact  22  are electrically connected. 
     The center conductor  2   a  of the coaxial cable  2  is connected to the proximal end part  121  of the contact  12  by soldering or the like, and the other terminal  223  of the contact  22  is connected to a non-illustrated signal conductive path that is formed on the wiring substrate  3 . Hence, in a case where the plug connector  10  and the receptacle connector  20  are provided in a mating state thereof, the center conductor  2   a  of the coaxial cable  2  and a signal conductive path of the wiring substrate  3  are electrically connected. 
     Furthermore, in a case where the plug connector  10  and the receptacle connector  20  are provided in a mating state thereof, the protrusion part  132  of the conductive member  13  on the plug connector  10  contacts the contact piece  44  of the back wall part  25  on the shell  23 , as illustrated in  FIG.  15   . The base part  131  of the conductive member  13  is connected to the outside conductor  2   c  of the coaxial cable  2  via the ground bar  4 , and one end of the first side plate  41  of the back wall part  25  is connected to a non-illustrated ground conductive path that is formed on the wiring substrate  3 , by soldering or the like. 
     Hence, the outside conductor  2   c  of the coaxial cable  2  is electrically connected to a non-illustrated ground conductive path that is formed on the wiring substrate  3 , via the ground bar  4  and the conductive member  13 . Furthermore, the outside conductor  2   c  of the coaxial cable  2  is electrically connected to the shell  14  of the plug connector  10  via the ground bar  4  and a non-illustrated solder. 
     Thus, the shell  14  and the shell  23  are electrically connected. The contacts  12 ,  22  are surrounded by the shells  14 ,  23  that are electrically connected and the conductive member  13 , and thereby, a shield function in the connector device  1  is realized. 
     Moreover, in a case where the plug connector  10  and the receptacle connector  20  are provided in a mating state thereof, the contact part  332   b  of the contact piece  332  on the second side plate  33  contacts the cover front part  142  of the shell  14 , as illustrated in  FIG.  15   . The second side plate  33  is joined to the first side plate  31  via the joining part  32  as illustrated in  FIG.  14    and one terminal of the first side plate  31  is connected to a non-illustrated ground conductive path that is formed on the wiring substrate  3 , by soldering or the like. 
     Hence, the cover front part  142  of the shell  14  is electrically connected to a non-illustrated ground conductive path that is formed on the wiring substrate  3 , via the front wall part  24  of the shell  23 . Thereby, as a conductive path to a non-illustrated ground conductive path that is formed on the wiring substrate  3 , a path that passes through the shell  14  and the front wall part  24  is added to the shell  14  in addition to a path that passes through the conductive member  13  and the back wall part  25 . Hence, it is possible for the connector device  1  to improve a shield function of the shell  14 , so that it is possible to attain further improvement of such a shield function, as compared with a case where the front wall part  24  is absent or a case where the front wall part  24  does not contact the shell  14 . 
     Furthermore, as illustrated in  FIG.  12   , the contact piece  332  is formed on the second side plate  33 , so that a spring length is readily ensured, for example, as compared with a case where it protrudes outward from the joining part  32 . Hence, it is possible to attain downsizing and height reduction of the connector device  1 . Furthermore, one end or a proximal end of the contact piece  332  is joined to a position close to another end (or close to a lower end) of the second side plate  33 , so that a spring length of the contact piece  332  is ensured more readily. 
     Furthermore, as illustrated in  FIG.  12   , the second side plate  33  is arranged between the first side plate  31  and the front wall part  212  of the housing  21 . Hence, as compared with a case where the second side plate  33  is positioned in front of the first side plate  31 , it is possible to reduce a length of the connector device  1  in frontward and backward directions, so that it is possible to attain downsizing of the connector device  1 . 
     Furthermore, as illustrated in  FIG.  15   , the contact piece  332  has the contact part  332   b  that contacts the shell  14  of the plug connector  10  at a position close to the first side plate  31  in frontward and backward directions. Also thereby, a spring length of the contact piece  332  is ensured more readily. 
     The contact part  332   b  is arranged to be close to one end (or close to an upper end) of the joining part  32  on the contact piece  332  in upward and downward directions. Thereby, as compared with a case where the contact part  332   b  is arranged to be close to another end (or close to a lower end) of the joining part  32  and the contact part  332   b  contacts the shell  14  at a position close to another end of the joining part  32 , a spring length of the contact piece  332  is ensured more readily. Moreover, as the contact part  332   b  is arranged to be close to one end (or close to an upper end) of the joining part  32  in upward and downward directions, it is also possible to increase a distance of sliding and mating of the contact part  332   b  and the shell  14  (the cover front part  142 ) (a so-called effective mating length) as the plug connector  10  and the receptacle connector  20  are mated. 
     Furthermore, as illustrated in  FIG.  14   , the first side plate  31  has the recess  313  at a position close to one end of the joining part  32  in upward and downward directions where the position is opposed to the cover front part  142  of the shell  14  on the plug connector  10 . Such a recess  313  is a backward dent in a direction toward the back wall part  25 . 
     Hence, as illustrated in  FIG.  14   , it is possible to provide a position of the cover front part  142  in frontward and backward directions as a position that is substantially identical to a position of the extension part  312  of the front wall part  24 . Thereby, it is possible to reduce a length of the connector device  1  in frontward and backward directions, so that it is possible to attain downsizing of the connector device  1 . 
     Meanwhile, in a case where the first side plate  31  is conventionally cut to provide a contact piece, the first side plate  31  has to be cut long from a position close to one end of the first side plate  31  to another end thereof in order to ensure a spring length of such a contact piece. In such a case, a length of the first side plate  31  in upward and downward directions is increased, so that a length of the shell  23  in upward and downward directions is increased. Furthermore, a cut part on the first side plate  31  in upward and downward directions is long, so that an electromagnetic wave leaks from such a cut part and a shield function of the shell  23  is degraded. 
     The contact piece  332  in the connector device  1  according to the present embodiment is formed on the second side plate  33  that is joined to the first side plate  31  via the joining part  32 . Thereby, the cut part  314  of the first side plate  31  is sufficiently provided with a size not to contact the contact part  332   b  that is present at a position close to one end of the joining part  32  in upward and downward directions. 
     Hence, as compared with a case where a contact piece is conventionally provided on the first side plate  31 , it is possible to decrease a length of the cut part  314  of the first side plate  31  in upward and downward directions as illustrated in  FIG.  16   , so that it is possible to downsize a part of the cur part  314  that is not covered by the cover front part  142  of the shell  14 . Additionally, a size of a part of the cut part  314  that is not covered by the cover front part  142  of the shell  14  is a size not to pass an electromagnetic wave that has a frequency identical to a frequency of a signal that is transmitted by the contacts  12 ,  22 , and thereby, it is possible to reduce degradation of a shield function. 
     Additionally, although the cut part  314  is formed from a position that corresponds to the extension part  312  to a position that corresponds to the joining part  32  in upward and downward directions in an example as illustrated in  FIG.  8   , a configuration may be provided in such a manner that it is formed from a position that corresponds to the recess  313  to a position that corresponds to the joining part  32  in upward and downward directions. Thereby, it is possible to cover the cut part  314  with the cover front part  142  of the shell  14 . 
     Furthermore, as illustrated in  FIG.  15   , in a case where the plug connector  10  and the receptacle connector  20  are provided in a mating state thereof, the protrusion part  132  on the conductive member  13  is positioned in front of the back wall part  25  and the cover front part  142  on the shell  14  is positioned in front of the contact piece  332  on the front wall part  24 . In such a case, the contact piece  332  contacts the cover front part  142  while having a sufficient spring length. Hence, even in a case where a state where the plug connector  10  is tiled relative to the receptacle connector  20  is provided in a process to remove the plug connector  10  from the receptacle connector  20 , it is possible to prevent the contact piece  332  from being deformed plastically. 
     For example, in a case where the coaxial cable  2  that is connected to the plug connector  10  is gripped and lifted upward, the plug connector  10  is tiled in such a manner that a back part close to the protrusion part  115  is raised while a circumference of the cover front part  142  is a point of support. In such a case, the cover front part  142  of the shell  14  on the plug connector  10  is moved in a direction away from the contact part  332   b  of the contact piece  332 . Hence, it is possible to prevent a great force from acting on the contact piece  332  as compared with a case where the cover front part  142  is positioned in back of the contact piece  332 . 
     Furthermore, in a case where a front part of the plug connector  10  is lifted in a process to remove the plug connector  10  from the receptacle connector  20 , the plug connector  10  is tiled in such a manner that a front part close to the cover front part  142  is raised while a circumference of the protrusion part  115  is a point of support. In such a case, the cover front part  142  of the shell  14  on the plug connector  10  is moved in a direction away from the contact part  332   b  of the contact piece  332 . Hence, it is possible to prevent a great force from acting on the contact piece  332  as compared with a case where the cover front part  142  is positioned in back of the contact piece  332 . 
     Furthermore, as illustrated in  FIG.  8   , the contact piece  332  is arranged so as to protrude frontward from the cut part  314 . Hence, even in a case where the cover front part  142  of the shell  14  is moved backward, the cover front part  142  contacts the recess  313 , so that it is possible to limit further movement thereof. Hence, also thereby, it is possible to prevent a great force from acting on the contact piece  332 . 
     As described above, the receptacle connector  20  according to an embodiment is an electrical connector that is attached to the wiring substrate  3  and is mated with the plug connector  10  that is connected to terminals of the plurality of coaxial cables  2 . The plurality of coaxial cables  2  are an example of a signal transmission medium and the plug connector  10  is an example of a counterpart connector. The receptacle connector  20  includes the housing  21  that has an insulation property, the plurality of contacts  22  with a conductive property that are arrayed on the housing  21 , and the shell  23  with a conductive property. The shell  23  has the front wall part  24  and the back wall part  25  that are opposed to one another via the plurality of contacts  22  in a direction along the principal surface M of the wiring substrate  3  where the direction is orthogonal to an array direction of the plurality of contacts  22 , and contact the conductive member  13  and the shell  14  that are provided with a conductive property on the plug connector  10 . The front wall part  24  and the back wall part  25  are an example of a pair of wall parts. The front wall part  24  is an example of one wall part. The conductive member  13  and the shell  14  are an example of a ground member. The front wall part  24  includes the first side plate  31  that is provided with one end that is attached to a ground conductive path of the wiring substrate  3  and extends in a direction away from the wiring substrate  3  from the one end toward another end, the joining part  32  that is provided with one end that is joined to another end of the first side plate  31 , and the second side plate  33  that is provided with one end that is joined to another end of the joining part  32  and extends in a direction closer to the wiring substrate  3  from the one end toward another end where the other end is a free end. Then, the second side plate  33  has the contact piece  332  that extends in a direction away from the wiring substrate  3  and elastically contacts the shell  14  of the plug connector  10 . Thereby, it is possible for the receptacle connector  20  according to an embodiment to attain further improvement of a shield function. 
     Furthermore, the second side plate  33  has the extension part  331  that is provided with one end that is joined to another end of the joining part  32  and extends in a direction closer to the wiring substrate  3  from the one end toward another end where the other end is a free end. The contact piece  332  is provided with one end that is joined to a position close to another end of the extension part  331  on the extension part  331  and extends in a direction away from the wiring substrate  3  from the one end toward another end. Thereby, it is possible to readily ensure a spring length, for example, as compared with a case where it protrudes from the joining part  32 . 
     Furthermore, the second side plate  33  is arranged between the first side plate  31  and the housing  21 . It is possible to reduce a length of the connector device  1  in frontward and backward directions as compared with a case where the second side plate  33  is positioned in front of the first side plate  31 , so that it is possible to attain downsizing of the connector device  1 . 
     Furthermore, the contact piece  332  has the contact part  332   b  that contacts the shell  14  of the plug connector  10  at a position close to the first side plate  31  in a direction along the principal surface M of the wiring substrate  3  where the direction is orthogonal to an array direction of the contacts  22 . Thereby, it is possible to ensure a spring length of the contact piece  332  more readily. 
     Furthermore, the contact part  332   b  is arranged to be close to one end of the joining part  32  on the contact piece  332  in a direction orthogonal to the principal surface M of the wiring substrate  3 . Thereby, a spring length of the contact piece  332  is ensured more readily. 
     Furthermore, the first side plate  31  has the recess  313  at a position close to one end of the joining part  32  in a direction orthogonal to the principal surface M of the wiring substrate  3  where the position is opposed to the cover front part  142  of the shell  14  of the plug connector  10 , and such a recess  313  is a dent in a direction toward the back wall part  25 . Thereby, it is possible to attain downsizing of the connector device  1 . The back wall part  25  is an example of another wall part. 
     According to an aspect of an embodiment, it is possible to provide an electrical connector and a connector device that are capable of attaining further improvement of a shield function thereof. 
     An additional effect or variation can readily be derived by a person(s) skilled in the art. Hence, a broader aspect of the present invention is not limited to a specific detail(s) and a representative embodiment(s) as illustrated and described above. Therefore, various modifications are allowed without departing from a spirit and a scope of a general inventive concept as defined by the appended claim(s) and an equivalent(s) thereof.