Abstract:
A reduced height wire to board connector assembly includes mating plug and receptacle connectors. The receptacle connector has an internal recess which opens vertically and receives a plug connector therein. Wires are terminated to terminals of the plug connector and they extend out through a wire insertion portion in one of the sidewalls of the receptacle connector. The receptacle connector has a conductive member supported thereby and this fixing member provides a ground connection and a retaining function to the receptacle connector. The plug connector has insulation displacement type terminals and two wire clamps to retain the wires terminated thereto in place.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
       [0001]    The present invention relates to a connector device, and more particularly to an improved wire to board connector of reduced height and improved reliability. 
         [0002]    In communications equipment for transferring large volumes of information, such as portable telephones, personal computers and the like, coaxial cables are used for transferring high-frequency signals. A cable-attached plug connector is formed by arranging a large number of such coaxial cables in parallel into a flat shape and attaching a plug connector to an end of the coaxial cables. These cables are terminated, by way of the plug connector, to electronic components mounted on a substrate, such as a circuit board, for processing signals transiting the cables. 
         [0003]    There has been a trend toward the miniaturization of communications equipment such as portable telephones, personal computers, and the like. In order to realize miniaturization, there has been an increasingly stringent demand for reduced height, size, and weight of a connector as a component of those equipment. This reduced size may lead to a deterioration in workability. To avoid this, a technique for improving the workability is required. 
         [0004]      FIG. 11  shows a known cable plug-style connector I in a condition prior to connection to to a mating connector, taking the form of a receptacle connector  302  which mates with the plug connector  300 . In order to connect the two connectors  300 ,  302  together, the plug connector  300  is moved towards the receptacle connector  302  in parallel to a mounting substrate P. This is commonly referred to as a horizontal type connector device. The coaxial cables C are respectively connected to terminals of the plug connector  300  (the terminals of the plug connector are referred to as plug-side terminals). When the plug connector  300  and the receptacle connector  302  are connected with each other, terminals of the receptacle connector  302  (“receptacle-side terminals”) come into contact with the plug-side terminals, allowing electrical signals from the coaxial cables C to flow into electric components (not shown) on the substrate P, on which the receptacle connector  302  is provided. 
         [0005]      FIG. 12  is a longitudinal sectional view showing the plug connector  300  as connected to the receptacle connector  302 . As shown in  FIG. 12 , the two connectors are connected with each other while being in close proximity to the substrate P. A blade portion of the plug style connector  300  is received in the receptacle of the receptacle connector  302 . 
         [0006]    As opposed to the horizontal type connector device as described above, as shown in  FIGS. 13 and 14 , a connector device of a type in which a plug connector  400  is moved from above towards a receptacle connector  402  mounted on the substrate P to thereby connect the two connectors is referred to as a vertical type connector device. In this vertical type connector device, the plug connector  400  is placed on top of the receptacle connector  402  (it should be noted that the words “upper (top)” and “lower (bottom)” as used herein are taken to mean respectively, the top and bottom sides of the connector as viewed in the drawings. 
         [0007]    In the known horizontal-type connector device, the receptacle connector  302  is connected to the plug connector  300 , which is flat on the substrate P, while being in close proximity to the substrate P. Accordingly, the horizontal type connector device can be reduced in height as compared with the vertical type connector device in which the plug connector is placed on the receptacle connector. However, the fingers of the operator may touch the substrate P while inserting the plug connector into the receptacle connector, thus hindering the operation or damaging the wiring. 
         [0008]    In contrast, in the case of the vertical type connector device, the plug connector  400  is connected from above the receptacle connector  402 , so the substrate P does not interfere with the connection and hence good workability is ensured. However, the plug connector  400  is stacked on top of the receptacle connector  402 , with the result that the height dimension of the connector device upon connecting the two connectors becomes large, which poses a problem in terms of height reduction. 
         [0009]    In view of this, there has been proposed a vertical type connector which not only excels in workability but also enables height reduction. Such a structure is shown in  FIGS. 15 and 16 .  FIG. 15  shows aa plug connector  500  ready for mating to a receptacle connector  502 , and  FIG. 16  shows the receptacle connector  502  and the plug connector  500  mated together. Formed in the receptacle connector  502  is an upwardly open fitting recess  503  into which the plug connector  500  is fitted from above. Since the plug connector  500  is thus fitted into the receptacle connector  502 , it is possible to achieve height reduction while maintaining the advantage of the vertical type connector device, that is, while ensuring good workability in connecting the plug connector and the receptacle connector with each other. 
         [0010]    Further, in the receptacle connector  502 , there is formed a release hole  510  in the form of a cutout that communicates with the fitting recess  503  so as not to prevent the coaxial cables C from projecting outwards upon connecting the plug connector  500  and the receptacle connector  502  with each other (see  FIGS. 15 &amp; 16 ). The fitting recess  503  is thus open at the top and at the rear. It should be noted that for the sake of convenience, the portion of the receptacle connector  502  in which the release hole  510  is formed is referred to as a cable insertion portion and denoted by reference symbol  502   b.    
         [0011]    In order to ensure reliable connection between the receptacle-side terminals  505  and the plug-side terminals  506 , the receptacle-side terminal  505  is shaped so as to generate a contact pressure between the receptacle-side terminal  505  and the plug-side terminal  506  upon abutting against the plug-side terminal  506 . The contact pressure also acts as a force for retaining the connection between the plug connector  500  and the receptacle connector  502  (hereinafter refereed to as the connector connection retaining force). 
         [0012]    The connector connection retaining force acts to press the plug connector  500  towards the cable insertion portion  502   b  of the receptacle connector  502  upon fitting the plug connector  500  into the fitting recess  503  of the receptacle connector  502 . In this regard, the receptacle connector  502  has, at the cable insertion portion  502   b , the release hole  510  open at the rear as described above. Since the release hole  510  communicates with the fitting recess  503  of the receptacle connector  502 , the receptacle connector  502  has the fitting recess  503  that is open at the top and at the rear, so the mechanical strength of the receptacle connector  502  is accordingly weak. 
         [0013]    Upon connecting the plug connector  500  and the receptacle connector  502  together, stress concentration resulting from the contact pressure will occur, in particular, at a location of the cable insertion portion  502   b  where the release hole  510  in the form of a cutout is formed and in the vicinity of the location, causing distortion. As a result, there is a fear of the receptacle connector  502  undergoing damaging deformation. 
         [0014]    Further, when the coaxial cables C are pried upwards so a force for releasing the connection between the plug connector  500  and the receptacle connector  502  acts on the plug connector  500  and the receptacle connector  502  that have been connected together, the plug connector  500  is detached from the receptacle connector  502 , which may hinder the electrical connection of the connector device. 
         [0015]    The present invention is directed to a reduced height wire to board connector of the plug style which avoids the shortcomings of the prior art described above. 
       SUMMARY OF THE INVENTION 
       [0016]    It is accordingly, a general object of the present invention to provide a novel structure for a plug connector and a receptacle connector, which reduces deformation of the receptacle connector due to forces exerted during mating and unmating of the plug and receptacle connector. 
         [0017]    Another object of the present invention is to provide an improved wire to board connector assembly using a plug connector and a receptacle connector, wherein the receptacle connector includes a receptacle that opens to the top and the plug connector is inserted into the receptacle vertically, without enlarging the height of the connector assembly. 
         [0018]    Yet another object of the present invention is to provide a plug connector for use in wire to board connection applications, the plug connector including an insulative housing with a wire-receiving open area into which the ends of a set of wires are positioned, the housing including a first wire clamp formed of insulative material which exerts a termination pressure onto the free ends of the wires to terminate the wires to individual insulation displacement terminals, a second wire clamp formed of conductive material, the second wire clamp engaging the wires and contacting conductive shields thereof so as to common the internal grounds of the wires together, and the plug connector further including an outer, conductive shell that holds the first and second wire clamps in place with the housing and which contacts the second wire clamp and conductive faces of a mating receptacle connector, the outer shell having openings through which conductive portions of terminals of the plug connector extend for mating with an opposing mating connector. 
         [0019]    Still another object of the present invention is to provide a receptacle connector for use in wire to board applications, the receptacle connector including an insulative housing with a flat base for attaching to a substrate such as a printed circuit board, the housing including a plurality of terminals the terminals having tail portions for attachment to the circuit board and contact portions that extend along a face of a receptacle defined within the housing, thereby defining a plurality of contact faces for mating with an opposing connector inserted therein, the housing further including a shell that partially covers portions of the housing, the receptacle shell including contact portions for mating with ground contact points on an opposing mating connector. 
         [0020]    The present invention accomplishes this and other objects due to its structure. The present invention relates to a connector device including: a connector having a housing provided with a cable and a terminal connected to one end of the cable; and a mating connector to which the connector is connected, the connector device being characterized in that the mating connector includes a mating housing; a mating terminal provided in the mating housing and brought into contact with the terminal of the connector when the mating connector is connected with the receptacle connector, the mating terminal being fixed onto a substrate. A cable insertion portion is formed in the mating connector housing in opposition to a location where the mating terminal is disposed, the cable insertion portion being a portion through which the cable is inserted; and means for fixing the cable insertion portion to a substrate. 
         [0021]    The portion of the mating housing where the cable insertion portion is formed exhibits poor strength as compared with other portions thereof where no such insertion portion is formed. For this reason, upon connecting the connector to the mating connector, stress concentration resulting from a contact pressure due to the connection occurs at the location of the mating connector corresponding to the above portion. In this regard, however, the cable insertion portion is fixed to the substrate by the fixing means, thereby achieving enhanced strength. 
         [0022]    Further, the fixing means may be characterized by including a support portion that is abutted against or embedded in the cable insertion portion to support the cable insertion portion, and a firmly fixing portion formed integrally with the support portion and soldered onto the substrate. The cable insertion portion is supported by the support portion and thus enhanced in its strength. In addition, the cable insertion portion thus enhanced in strength is soldered onto the substrate by means of the firmly fixing portion, whereby the cable insertion portion is further enhanced in its strength. 
         [0023]    At least one of the connector and the mating connector may have a latching portion that is latched onto the other connector upon connecting the two connectors. The connector and the mating connector are locked to each other by the latching portion, thereby making it possible to prevent detachment of the two connectors from each other. 
         [0024]    Further, it is preferable that the latching portion be elastic in strength for latching onto the connector or the mating connector, and an opening into which the elastic member is fitted is formed in either the mating connector or the connector. The latching of the elastic member onto the connector or the mating connector makes the connection between the connector and the mating connector secure. Further, the force with which the elastic member is latched onto the connector or the mating connector increases due to the elasticity of the elastic member. Further, with the opening being thus formed, the elastic member is fitted into the opening, whereby the degree of latching is enhanced to achieve secure locking. 
         [0025]    Further, it is preferable that the fixing means be formed of a metal member for causing noise flowing in the cable upon connecting the connector to the mating connector to flow to the ground. The mating housing may also include a metal plate for causing electrical noise flowing in the cable to flow directly to a ground, rather than a signal connection with the fixing means being formed on the metal plate. In addition, it is also conceivable to form the latching portion in a part of the metal plate. 
         [0026]    According to the present invention, the cable insertion portion corresponds to a location of the mating connector where, upon connecting the connector to the mating connector, stress concentration occurs due to the connection, and is fixed onto the substrate by the fixing means, whereby the strength of the cable insertion portion can be enhanced. As a result, even when stress develops in the mating connector due to contact pressure between the terminals when the connector and mating connector are mated together, it is possible to effectively prevent the cable insertion portion and, by extension, the housing from undergoing deformation. 
         [0027]    Further, the connector and the mating connector are locked to each other by the latching portion to thereby prevent detachment of the two connectors from each other. Accordingly, even when, after connecting the connector and the mating connector with each other, a force for releasing this connection acts on the two connectors, it is possible to prevent detachment of the connector and the mating connector from each other. 
         [0028]    Further, by forming the fixing means as a metal plate so as to allow the noise flowing in the cable to flow to the ground, the applicability of the fixing means can be increased. 
         [0029]    These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    In the course of this detailed description, the reference will be frequently made to the attached drawings in which: 
           [0031]      FIG. 1  is an exploded perspective view, as seen from front and diagonally above, of a vertical type connector device constructed in accordance with the principles of the and shown in a state prior to connection between a receptacle connector and a plug connector; 
           [0032]      FIG. 2  is an exploded perspective view, as seen from rear and diagonally above, of the connector device according to the present invention in the state prior to the connection between the receptacle connector and the plug connector is made; 
           [0033]      FIG. 3  is a perspective view showing a state in which the receptacle connector and the plug connector in the state as shown in  FIG. 2  have been connected with each other; 
           [0034]      FIG. 4  is a sectional view taken along a line A-A of  FIG. 1 ; 
           [0035]      FIG. 5  is a sectional view taken along a line B-B of  FIG. 3 ; 
           [0036]      FIG. 6  is a perspective view showing a state prior to covering a housing of the plug connector with an upper shell; 
           [0037]      FIG. 7  is a perspective view of a metal plate as seen from rear and diagonally above; 
           [0038]      FIG. 8  is a sectional view taken along a line C-C of  FIG. 1 ; 
           [0039]      FIG. 9  is a sectional view taken along a line D-D of  FIG. 3 ; 
           [0040]      FIG. 10  is an enlarged main-portion view of  FIG. 9 ; 
           [0041]      FIG. 11  is a perspective view of a known prior art horizontal-type connector device in a state prior to connecting a plug connector to a receptacle connector; 
           [0042]      FIG. 12  is a longitudinal sectional view showing a state in which the receptacle connector and the plug connector in the state as shown in  FIG. 11  have been assembled together; 
           [0043]      FIG. 13  is a longitudinal sectional view of a known prior art vertical-type connector device in a state prior to connecting a plug connector to a receptacle connector; 
           [0044]      FIG. 14  is a longitudinal sectional view showing a state in which the receptacle connector and the plug connector as shown in  FIG. 13  have been assembled together; 
           [0045]      FIG. 15  is a perspective view, illustrating another known prior art vertical-type connector device in a state prior to connecting a plug connector to a receptacle connector; and, 
           [0046]      FIG. 16  is a longitudinal sectional view showing a state in which the receptacle connector and the plug connector as shown in  FIG. 15  have been assembled together. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0047]      FIGS. 1-3  illustrate a vertical type connector device  1 , in which the connection is effected by fitting a plug connector  100  of a cable-attached plug connector I to a receptacle connector  202  attached onto a substrate P. 
         [0048]    As can be seen from, for example,  FIGS. 1 ,  4 ,  6 , and the like, the plug connector  100  has a plug housing  107 , and an upper shell  112  that covers portions of the plug housing  107  to hold components inside the housing. The upper shell  112  also serves as a shield to cause electrical noise flowing in the coaxial cables C to flow to a ground, and is formed of a conductive material such as metal. The plug housing  107  is formed of synthetic resin or other such insulating material. Further, as can be seen from  FIG. 1 , a plurality of plug-side terminals  121  that are connected with the coaxial cables C are arranged side-by-side along the front edge portion of the plug housing  107 . 
         [0049]    As shown best in  FIGS. 4 and 5 , each plug-side terminal  121  has an upwardly open rectangular shape when seen from the side. The plug-side terminals  121  are insulation displacement terminals and are partially exposed on the front edge of the plug housing  107  so that they come into contact with the receptacle-side terminals  221  of the receptacle connector  202  when the plug connector  100  and the receptacle connector  202  are mated together. 
         [0050]    As shown in  FIG. 4 , each coaxial cable C is composed of a signal line C 6  composed of a centrally located inner conductor C 2  covered with an inner insulator C 4 , an outer conductor C 8  composed of a number of metal wires longitudinally aligned, spirally wound, or braided and provided so as to cover the signal line C 6 , and an outer insulator C 10  covering the outer conductor C 8 . A distal end portion Ca of the coaxial cables C connected to the plug-side terminals  121  is composed of a section where the outer insulator C 10  and the outer conductor C 8  are both stripped off to leave the signal line C 6  exposed, a sheath-remaining portion C 10   a  situated immediately rear of this section and where the outer insulator C 10  remains, and a section situated immediately rear of the sheath-remaining portion C 10   a  and where only the outer insulator C 10  is stripped off to leave the outer conductor C 8  exposed. 
         [0051]    The plug housing  107  includes a recess  116  that is open at the top and at the rear (see  FIGS. 4 &amp; 5 ). Fitted into the recess  116  are a first cable holder, or clamp  108 , and a second cable holder, or clamp  110 , which hold the distal end portions Ca of the plurality of coaxial cables C while transversely crossing the same. The first cable holder  108  is a plate-like member attached to a forward portion of the recess  116  ( FIGS. 4-6 ). When attached to the plug housing  107 , the first cable holder  108  holds the inner insulator C 4  of the signal line C 6  of each coaxial cable C while pressing it down from above. In holding the signal line C 6  by the first cable holder  108 , when the first cable holder  108  is attached onto the recess  116 , due to the pressing force acting at this time, the inner insulator C 4  of the coaxial cable C is torn off as it is pressure-welded onto the plug-side terminal  121 , leaving the inner conductor C 2  exposed, and the thus exposed inner conductor C 2  and the plug-side terminal  121  are electrically connected with each other. 
         [0052]    The second cable holder  110 , which is shaped like a hollow bar with an inverted U-shaped cross section and is formed from a conductive material, preferably metal, is located rear of the first cable holder  108 . Further, when the second holder  110  is attached onto the recess  116 , due to the pressing force acting at this time, the outer conductor C 8  and the outer insulator C 10 , which is located immediately rear of the outer conductor C 8 , at the distal end portion Ca of each coaxial cable C, are sandwiched from above and below between the second cable holder  110  and the plug housing  107 . ( FIGS. 4-6 .) 
         [0053]    Further, the plug housing  107  has a conductive insert  119  ( FIGS. 4-5 ) arranged at a location within the recess  116 , opposed to the second cable clamp  110 . The insert  119 , which is made of a material having excellent conductivity such as metal, is integrated into the plug housing  107  and is electrically connected with the outer conductor (ground shield) C 8  of every coaxial cable C. In this manner, the outer ground shields of the coaxial cables are all commoned together, and as explained in detail below, they are connected to the conductive shell  112  of the plug connector. 
         [0054]    As shown in  FIGS. 4 and 5 , when the plug connector  100  is connected to the receptacle connector  202 , the insert  119  is brought into contact with a rear edge surface  213 R of a metal plate  209  of the receptacle connector  202 . It should be noted that the insert  119  may not necessarily be formed integrally with the plug housing  107  such as by insert or over molding, but may be located in its position by press-fitting or adhesion. 
         [0055]    As shown in  FIG. 6 , the upper shell  112  that covers the plug housing  107  has a rectangular upper wall  112 U, and left and right side walls  112 L,  112 R bent in a L-shaped configuration with respect to the upper wall  112 U. The upper, side, and lower surfaces of the plug housing  107  are partially held by the upper wall  112 U and the side walls  112 L,  112 R. 
         [0056]    An engagement window, or slot h 2 , is formed in each of the side walls  112 L,  112 R ( FIGS. 1 ,  2 , &amp;  6 ) of the plug connector  100 . Upon covering the plug connector housing  107  with the upper shell  112 , the engagement window h 2  engages a lug or protruding engaging member h 1  on the side edges of the plug housing  107 . The engagement of the engagement window h 2  with the engaging member h 1  prevents detachment of the upper shell  112  from the plug housing  107 . A pair of bent members  112   a  are bent inwards and are formed in the upper wall  112 U. The bent members  112   a  contact with the second cable clamp  110  when the plug housing  107  is covered with the upper shell  112  ( FIG. 5 ), thereby causing any electrical noise flowing in the outer ground conductor C 8  of each coaxial cable C to flow through the upper shell  112  eventually to a ground via the second cable clamp  110 . The route for removing the noise will be described in detail later in the section on operational effects. 
         [0057]    A folded portion  112   e  that has an L-shaped configuration is formed in each of the left and right end portions along the rear edge of the upper wall  112 U ( FIG. 6 ). The folded portion  112   e  also has an opening  114  that is formed in its rear surface. ( FIGS. 6 &amp; 8 .) A pair of downwardly extending members  112   f , are formed in the portion of the rear edge of the upper wall  112 U of the upper shell  112  between the folded portions  112   e  and are folded downwards to be somewhat shorter than the folded portion  112   e . By forming the downwardly extending members  112   f , a cutout portion  113  is formed at the central portion of the rear edge of the upper wall  112 U of the upper shell  112  in approximately the middle of rear edge of the housing. 
         [0058]    It should be noted that in attaching each coaxial cable C to the plug connector  100 , the outer sheath at the distal end portion Ca of the coaxial cable C is stripped off in advance to leave the signal line C 6  and the outer conductor C 8  exposed. ( FIGS. 4 &amp; 5 .) The outer sheath of the signal line C 6  is composed of the outer conductor C 8  and the outer insulator C 10 , and the outer sheath of the outer conductor C 8  is composed of the outer insulator C 10 . 
         [0059]    Next, the receptacle connector  202  of the present invention will be described with reference to  FIGS. 1-5  and the like. The receptacle connector  202  has a receptacle housing  207  having a flat rectangular-parallelepiped configuration as a whole, and a metal plate  209  is provided as part of the receptacle housing  207 . The receptacle housing  207  is formed of synthetic resin or other such insulative material. Further, the receptacle housing  207  has in its central portion a recess  203  in which the plug connector  100  is received to mate the two connector components together. 
         [0060]    The recess, or receptacle  203 , is formed in the housing and is surrounded by a walls, including front edge wall  204 F and rear edge wall  204 R which are respectively located in the front and rear. A left edge wall  205 L and a right edge wall  205 R which connect to the front and rear edge walls  204 F and  204 R define the other two sides of the recess, while a bottom plate, or floor  206 , complete the recess  203 . A release hole  232  is formed at the central portion of the rear long edge wall  204 R and communicates with the recess  203  and is preferably formed as a rectangular cutout. Therefore, the fitting recess  203  is open at the top of the receptacle housing and along the rear edge thereof. ( FIG. 2 .) 
         [0061]    The release hole  232  is provided so as to permit the cables C to project out of the connector assembly when the plug connector  100  is mated with the receptacle connector  202 . The length dimension of the release hole  232  is formed to be slightly larger than the width of all of the cables C of the cable-attached plug connector I. The portion of the rear long edge wall  204 R where the release hole  232  is formed is herein referred to as a cable insertion portion. The planar configuration of the fitting recess  203  is also determined by the configuration of the metal plate  209  described below in detail. It should be noted that a stippling is present in the drawings as applied to the metal plate  209  for purposes of clearly indicating the metal plate  209 . 
         [0062]    As shown in  FIG. 7 , the metal plate  209  has an elongated square shape as seen in plan view, with a large opening being formed at the center thereof. A pair of opposing long sides of the metal plate  209  are folded so that the end face of the metal plate  209  is flat inverted-U shaped (it should be noted that the above-mentioned opening is denoted by reference symbol  211   a ). The metal plate  209  is composed of a principal surface  211  having the opening  211   a , a front edge surface  213 F, and a rear edge surface  213 R. The opening  211   a  may be formed by punching or stamping. Of the principal surface  211 , the other long edge and remaining short edges thereof excluding one long edge are regarded as remaining portions having a predetermined width, respectively renamed as a front remaining portion  211 F, a left remaining portion  211 L, and a right remaining portion  211 R. 
         [0063]    The front remaining portion  211 F has rectangular cutouts  212 L,  212 R formed near the opposite ends thereof, and the portion of the front remaining portion  211 F between the cutouts  212 L,  212 R constitutes a central portion  212 M. Further, inwardly dangling edge members  215  are respectively formed at opposing positions of substantially central portions of the left remaining portion  211 L and right remaining portion  211 R. The left and right edge members  215  are the portions that come into contact with the left and right side walls  112 L,  112 R of the upper shell  112  of the plug connector  100  when the receptacle connector  202  and the plug connector  100  are connected together. ( FIGS. 2 &amp; 3 .) The edge members  215  are elastic and return to their original position after any pressing pressure is released as when the connectors are unmated. 
         [0064]    In the rear edge surface  213 R of the metal plate  209 , a rectangular cutout  217  is formed by punching so that the central portion of the rear edge surface  213 R is upwardly open. An inwardly bent member  219  that is folded inwards is formed at either end portion of the rear edge surface  213 R. The size and configuration of the cutout  217  are determined in conformity with those of the release hole  232  in the rear long edge wall  204 R of the receptacle housing  207 . The rear edge surface  213 R serves to reinforce the rear long edge wall  204 R to enhance the strength of the same. 
         [0065]    As can be seen from  FIG. 8 , the inwardly bent member  219  is a cantilevered metal member which is inwardly folded and which is fixed at one end and free at the other end. Accordingly, the inwardly bent member  219  exhibits elasticity when an external force is applied onto its distal end side upon connecting the plug connector  100  to the receptacle connector  202 . The inwardly bent portion  219  is positioned such that it is opposed to the opening  114  formed in the folded portion  112   e  of the upper shell  112  upon connecting the plug connector  100  to the receptacle connector  302 . Therefore, upon connecting the plug connector  100  to the receptacle connector  302 , the inwardly bent member  219  is latched onto the opening  114  due to its above-mentioned elasticity. The inwardly bent member  219  is thus referred to as a latching portion. 
         [0066]    Further, at the lower edge of the rear edge surface  213 R of the metal plate  209 , a pair of outwardly bent members  222  that are folded outwards are integrally formed with the lower edge corresponding to the opposite end portions of the cutout  217 . As seen in the state as shown in  FIG. 4 , the portion of the rear edge surface  213 R including each outwardly bent member  222  has a horizontally flipped L-shaped configuration in cross section. 
         [0067]    The receptacle housing  207 , in which the metal plate  209  having the configuration as described above is to be disposed, is formed through integral molding involving sealing the metal plate  209  with synthetic resin and other insulating material such that the rear edge surface  213 R of the metal plate  209  is opposed to the inner surface of the rear long edge wall  204 R of the receptacle housing  207 , the front edge surface  213 F of the metal plate  209  is opposed to the front long edge wall  204 F of the receptacle housing  207 , and that the opposite ends of the metal plate  209  are respectively opposed to the left short edge wall  205 L and right short edge wall  205 R of the receptacle housing  207 . 
         [0068]    It should be noted that the metal plate  209  need not be held in the receptacle connector by insert or over molding, but it may be attached to the receptacle housing  207  by press-fitting or adhesion. Preferably, the receptacle housing  207  and the metal plate  209  abut each other. The rear edge surface  213 R abuts the outer surface of the rear long edge wall  204 R of the receptacle housing  207  or it may be embedded in the rear long edge wall  204 R. Further, in the rear long edge wall  204 R of the receptacle housing  207  in which the metal plate  209  is disposed, an opening  223  is formed in the portion of the rear long edge wall  204 R corresponding to the inwardly bent member  219  ( FIGS. 2 &amp; 3 ), and recesses  224  that are open at the bottom and at the rear are formed in the portion of the rear edge wall  204 R corresponding to the pair of outwardly bent portions  222 . 
         [0069]    Further, in the front edge wall  204 F of the receptacle housing  207 , the portion thereof corresponding to the central portion  212 M of the metal plate  209  is formed so as to allow the receptacle-side terminals  221 , which have a horizontally flipped S-shaped configuration in side view, to be arranged in parallel along the long edge of the receptacle housing  207  ( FIGS. 2 ,  4  &amp;  5 ). The above portion is referred to as a receptacle-side terminal placing portion and denoted by reference symbol  204 Fm. 
         [0070]    The number of the receptacle-side terminals  221  to be arranged in the receptacle-side terminal placing portion  204 Fm is the same as the number of the plug connector terminals  121 . Further, the length of the release hole  232  formed in the rear long edge wall  204 R of the receptacle housing  207  is set substantially in conformity with the length dimension (taken in the right-to-left direction) of the receptacle-side terminal placing portion  204 Fm in which the plurality of receptacle-side terminals  221  are arranged in parallel. 
         [0071]    Upon connecting the plug connector  100  and the receptacle connector  202  together, the receptacle-side terminals  221  and the plug-side terminals  121  are brought into pressure contact with each other, so the receptacle-side terminals  221  are compressed in the longitudinal direction by the pressurizing force from the plug-side terminals  121  (see  FIGS. 4 ,  5 ). Further, since the receptacle-side terminals  221  have an S-shaped configuration, they exhibit elasticity when compressed, thereby generating a contact pressure between them and the plug-side terminals  121 . The contact pressure acts as a connector connection retaining force to thereby retain the connection between the plug connector  100  and the receptacle connector  202 . 
         [0072]    Prior to the connection of the plug connector  100  and the receptacle connector  202  with each other, the receptacle connector  202  is first attached onto the substrate P. In effecting this attachment, the receptacle-side terminals  221  are soldered to appropriate pads or contacts on the substrate P and the pair of outwardly bent members  222  are soldered onto the substrate P and firmly fixed in place. Accordingly, electrical noise propagating through the outer conductor C 8  of each coaxial cable C when connecting the plug connector  100  and the receptacle connector  202  together, as well as the electrical noise generated from components connected to the substrate P are removed along a ground path from the outer conductor C 8 —the second cable holder  110 —the pair of bent members  112   a  of the upper shell  112 —the upper wall  112 U—the left and right side walls  112 L,  112 R—the left and right edge members  215  of the metal plate  209 —the left remaining portion  211 L (or the right remaining portion  211 R) of the metal plate  209 —the rear edge surface  213 R—the outwardly bent member  222 —and then to the substrate P. 
         [0073]    As shown in  FIG. 10 , upon connecting the plug connector  100  to the receptacle connector  202 , the inwardly bent member  219  comes into contact with the folded portion  112   e  of the upper shell  112 . Accordingly, electrical noise that propagates through the outer conductor C 8  of each coaxial cable C upon connecting the plug connector  100  to the receptacle connector  202  can be easily grounded to the substrate P also via the inwardly bent member  219 . The path used in this case is a path from the outer conductor C 8 —the second cable holder  110 —the pair of bent members  112   a  of the upper shell  112 —the folded portion  112   e  of the upper shell  112 —the inwardly bent member  219  of the metal plate  209 —the rear edge surface  213 R—the outwardly bent member  222 —the substrate P. 
         [0074]    An additional path for removing the electrical noise flowing in the outer conductor C 8  of each coaxial cable C is the route of a ground line from the outer conductor C 8 —the good conductor  119 —the pair of outwardly bent members  222 —the substrate P. The influence of noise on the signal can be made smaller as the distance between the outer conductor C 8  of each coaxial cable C and the outwardly bent members  222  becomes shorter. As a result, the influence of noise on the signal can be suppressed. In this regard, the last route is shorter than the two former routes. As described above, the upper shell  112 , the metal plate  209 , and the good conductor  119  serve to cause the noise flowing in each coaxial cable C to flow to the ground. 
         [0075]    Further, upon fitting the plug connector  100  into the fitting recess  203  of the receptacle connector  202 , the S-shaped receptacle-side terminals  221  undergo elastic deformation ( FIGS. 4 ,  5 ), so a contact pressure is generated between the plug-side terminals  121  and the receptacle-side terminals  221 . 
         [0076]    The contact pressure causes the plug connector  100  as a whole to move towards the rear long edge wall  204 R. The resulting pressurizing force acting at this time causes warpage of the rear long edge wall  204 R. Further, since the release hole  232  is formed in the rear long edge wall  204 R, stress concentration occurs in the rear long edge wall  204 R. 
         [0077]    In this regard, however, the rear edge surface  213 R of the metal plate  209 , which serves to reinforce the rear long edge wall  204 R to enhance the strength of the same, functions as the support portion for the rear long edge wall  204 R of the receptacle housing  207 . Accordingly, the strength of the rear long edge wall  204 R can be enhanced even though the release hole  232  is formed in the rear long edge wall  204 R. The pair of outwardly bent members  222  constituting a part of the rear edge surface  213 R are firmly fixed onto the substrate P by soldering. Accordingly, even when stress concentration occurs in the rear long edge wall  204 R of the receptacle housing  207  due to the contact pressure that acts between the plug-side terminals  121  and the receptacle-side terminals  221  upon connecting the plug connector  100  and the receptacle connector  202  together, the rear long edge wall  204 R can be fixed to the substrate P through the pair of outwardly bent members  222 , whereby the strength of the rear long edge wall  204 R can be enhanced irrespective of the presence/absence of the release hole  232 . 
         [0078]    As a result, it is possible to effectively prevent the rear long edge wall  204 R and, by extension, the receptacle housing  207  from deforming. In this sense, the rear edge surface  213 R including the outwardly bent members  222  can be referred to as fixing means for fixing the rear long edge wall  204 R to the substrate P. The pair of outwardly bent members  222  constitute a part of the metal plate  209 , and the metal plate  209  is disposed in the receptacle housing  207 . Accordingly, there is no need to separately prepare the pair of outwardly bent members  222  to enhance the strength of the rear long edge wall  204 R, thereby achieving improved workability and reduced number of components. 
         [0079]    Further, upon connecting the plug connector  100  to the receptacle connector  202 , the inwardly bent member  219  is latched onto the opening  114  formed in the folded portion  112   e  of the upper shell  112 , thereby making the locking between the plug connector  100  and the receptacle connector  202  secure. ( FIGS. 8 &amp; 9 .) Even when the coaxial cables C are pried so a force for releasing the connection between the plug connector  100  and the receptacle connector  202  acts on the plug connector  100  and the receptacle connector  202 , it is possible to prevent detachment of the plug connector  100  from the receptacle connector  202 . As a result, no trouble occurs in the electrical connection. Further, the provision of the opening  114  readily allows the inwardly bent member  219  to be deeply fitted into the plug connector  100 , thus making the locking together of the connectors secure. ( FIG. 10 .) 
         [0080]    In addition, it is needless to mention that the present invention is not limited to the above illustrated examples but may be subject to various modifications without departing from the gist of the present invention. For example, while in the above-described embodiment the inwardly bent member  219  is provided to the receptacle connector  202  and the opening  114  onto which the inwardly bent member  219  latches is provided in the plug connector  100 , the locations for disposing the inwardly bent member  219  and the opening  114  may be interchanged so that the inwardly bent member  219  is provided to the plug connector  100  and the opening  114  is provided in the receptacle connector  202 . 
         [0081]    Further, while in this embodiment each outwardly bent member  222  is formed as a part of the metal plate  209 , it is also possible to provide the outwardly bent member  222  as a metal member separate from the metal plate  209  and to use the outwardly bent member  222  as fixing means which allows the electrical noise flowing in each cable C to flow to the ground and which can be used alone for mounting the rear long edge wall  204 R to the substrate P. 
         [0082]    In addition, the rear edge surface  213 R having the outwardly bent members  222  may be provided not as a part of the metal plate  209  but as a separate metal member. A ground terminal that electrically connects to the substrate P may be provided to a part of the metal plate  209  that is electrically connected to the upper shell  112  to thereby remove the noise flowing in each cable C through the ground terminal. 
         [0083]    The present invention is applicable not only to a vertical type connector but also to a horizontal type connector device. In the case of such a horizontal type connector device as well, upon connecting the connector to the mating connector, stress concentration may occur at some location of the mating connector due to a contact pressure between the plug-side terminals and the receptacle-side terminals, which is generated due to the above connection. Therefore, by firmly fixing the above-mentioned location onto the substrate by the fixing means, the location where stress concentration occurs can be fixed onto the substrate, thereby achieving enhanced strength at that location. Therefore, it is possible to prevent deformation from occurring at the location where stress concentration occurs and in the vicinity thereof.