Patent Publication Number: US-6984137-B2

Title: Electrical connector and electrical connector assembly

Description:
FIELD OF THE INVENTION 
   The present invention relates to an electrical connector assembly that is constituted by a first connector and a second connector, each of the first and second connectors having signal contacts disposed in two rows, a grounding member disposed between the rows of signal contacts and a housing that holds the signal contacts and the grounding member and being engaged with each other, and an electrical connector that constitutes the electrical connector assembly. 
   BACKGROUND 
   In recent years, the speed of signals has become more and more high and electrical connectors also have been required to provide structures suited to the transmission of higher speed signals. 
   In performing high-speed signal transmission, grounding plays an important role and what grounding parts should be disposed in what places is important. The reliability of connection is also important, for example, when grounding parts are connected to a substrate. 
     FIG. 8  is a sectional view of an electrical connector assembly disclosed in the Japanese Patent Laid-Open No. 5-135826. 
   An electrical connector assembly  80  shown in this  FIG. 8  is constituted by a first electrical connector  81  and a second electrical connector  82  that are engaged with each other. The first electrical connector  81  has signal contacts  811  disposed in two rows, a grounding member  812  disposed between the rows of the signal contacts  811 , and a housing  813  that holds the signal contacts  811  and the grounding member  812 . The signal contacts  811  and the grounding member  812  have what is called dip type leg sections  811   a,    812   a  that pierce through a substrate (not shown). 
   Similarly, the second electrical connector  82  also has signal contacts  821  disposed in two rows, a grounding member  822  disposed between the rows of the signal contacts  821 , and a housing  823  that holds the signal contacts  821  and the grounding member  822 . The signal contacts  821  and the grounding member  822  have what is called dip type leg sections  821   a,    822   a  that pierce through a substrate (not shown). 
     FIG. 9  is an appearance perspective view of an electrical connector assembly disclosed in the National Publication of International Patent Application No. 2000-516028, and  FIG. 10  is a drawing that shows the arrangement of contacts that constitute the electrical connector the appearance of which is shown in  FIG. 9 . 
   This electrical connector  90  has four rows of contacts  91 ,  92 , and a housing  93  that holds these four rows of contacts  91 ,  92 . In this housing  93 , between the inner two rows of contacts  92  among these four rows of contacts  91 ,  92  there is formed an opening  931  to which leg sections  92   a  of these inner two rows of contacts  92  are exposed. 
   In the case of the electrical connector assembly  80  of  FIG. 8  disclosed in the Japanese Patent Laid-Open No. 5-135826, the grounding members  812 ,  822  are disposed between the rows of signal contacts  811 ,  821  of the electrical connectors  81 ,  82 , and therefore, in this respect, crosstalks of the signal contacts  811 ,  821  are reduced, providing a structure suitable for high-speed signal transmission. However, in the case of the electrical connector assembly  80  shown in this  FIG. 8 , both the signal contacts  821  and the grounding member  822  have the dip type leg sections  821   a,    822   a  that pierce through the substrate and, therefore, this poses the problems that (1) the solder connection cannot be visually checked from the top surface side of the substrate and (2) because the leg sections  822   a  of the grounding member  822  are spaced from each other, it is difficult to minimize the length of a grounding path. 
   On the other hand, in the case of the electrical connector disclosed in the National Publication of International Patent Application No. 2000-516028 shown in  FIGS. 9 and 10 , the contacts  92  of the inner two rows are not grounding contacts and hence are not suitable for high-speed signal transmission. Furthermore, each of the contacts  92  is independent, posing the problem that the number of component parts becomes very large. 
   SUMMARY 
   In view of the above circumstances, the invention provides an electrical connector and an electrical connector assembly that has increased reliability of grounding paths and a small number of component parts and are suitable for high-speed signal transmission. 
   The electrical connector of the present invention includes: signal contacts disposed in two rows; a grounding member disposed between the rows of the signal contacts; and a housing that holds the signal contacts and the grounding member, wherein the grounding member comprises a first grounding plate disposed in the immediate vicinity of one signal contact row, a second grounding plate disposed in the immediate vicinity of the other signal contact row, and a connection section that connects the first and second grounding plates together and is surface mounted on a substrate on which the electrical connector is mounted, the grounding member being in the form of the letter Π as viewed from the side, and wherein the housing has a through opening between the first and second grounding plates so that the connection section can be visually checked. 
   Also, an electrical connector assembly of the present invention includes: a first connector and a second connector, each of the first and second connectors having signal contacts disposed in two rows, a grounding member disposed between the rows of signal contacts and a housing that holds the signal contacts and grounding member and being engaged with each other, wherein each of the grounding components comprises a first grounding plate disposed in the immediate vicinity of one signal contact row, a second grounding plate disposed in the immediate vicinity of the other signal contact row, and a connection section that connects the first and second grounding plates together and is surface mounted on a substrate on which the electrical connector is mounted, the grounding members being in the form of the letter Π as viewed from the side, and wherein each of the housings has a through opening between the first and second grounding plates so that the connection section can be visually checked. 
   It is preferred that in the above electrical connector assembly of the invention, the grounding plate of the first connector be positioned inward compared to the grounding plate of the second connector and has relatively large rigidity. 
   According to the above electrical connector or electrical connector assembly of the invention, because the first and second grounding plates that constitute the grounding member are disposed each in the immediate vicinity of each row of signal contacts that are disposed in two rows, the electrical connector or electrical connector assembly is suitable for high-speed signal transmission. Also, because the housing has a through opening and the connection section that constitutes the grounding member can be visually checked, the condition of the solder joining of the connection section can be visually checked and the reliability of a grounding path is improved. Furthermore, the grounding member may be a one-piece member that is in the form of the letter Π as viewed from the side, which reduces the number of component parts. 
   When the grounding plate of the first connector is positioned inward compared to the grounding plate of the second connector and has relatively large rigidity, a housing wall is unnecessary on the inner side of the grounding plate of the first connector, with the result that it is possible to maintain the size of the electrical connector assembly in the width direction without impairing the ease of visual check of the connection section. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a plug connector that constitutes an electrical connector assembly in an embodiment of the invention; 
       FIG. 2  is a perspective view of a receptacle connector that constitutes an electrical connector assembly in an embodiment of the invention; 
       FIG. 3  is a schematic sectional view of a connection section of a grounding member soldered to a substrate; 
       FIG. 4  is a sectional view that shows the fitting condition of the plug connector shown in  FIG. 1  and the receptacle connector shown in  FIG. 2 ; 
       FIG. 5  is a sectional view that shows the fitting condition of the plug connector shown in  FIG. 1  and the receptacle connector shown in  FIG. 2 ; 
       FIG. 6  is a perspective view that shows signal contacts of a plug connector and a receptacle connector; 
       FIG. 7  is an explanatory drawing of a method of forming convexities of a signal contact; 
       FIG. 8  is a sectional view of an electrical connector assembly disclosed in the Japanese Patent Laid-Open No. 5-135826; 
       FIG. 9  is an appearance perspective view of an electrical connector assembly disclosed in the National Publication of International Patent Application No. 2000-516028; and 
       FIG. 10  is a drawing that shows the arrangement of contacts that constitute the electrical connector the appearance of which is shown in  FIG. 9 . 
   

   DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
   Embodiments of the invention will be described below. 
     FIGS. 1 and 2  are perspective views of a plug connector and a receptacle connector, respectively, that constitute an electrical connector assembly in an embodiment of the invention. The plug connector and the receptacle connector are each an embodiment of an electrical connector of the invention. 
   A plug connector  10  shown in  FIG. 1  is constituted by signal contacts  11  disposed in two rows, a grounding member  12  that is in the form of the letter Π as viewed from the side, and a housing  13  that holds the signal contacts  11  and the grounding member  12 . 
   The housing  13  has an outer wall  131  that covers the outer circumference of the housing and an inner wall  132  provided in a standing manner on the inner side of the outer wall along the outer wall, and on the inner side of the inner wall  132  a large through opening  133  is formed. 
   Each of the signal contacts  11  has, as parts shown in  FIG. 1 , a contact section  111  that comes into contact with the contact of the mating connector, the contact section rising along the outer side of the inner wall  132  of the housing  13 , and a terminal section  114  connected to a substrate (not shown), the terminal section extending laterally from the bottom of the housing  13  and projecting from the housing  13 . The detailed structure of the signal contacts  11  will be described later. 
   The grounding member  12  comprises a first grounding plate  121  disposed in the immediate vicinity of one signal contact row  11   a  among the signal contacts  11  disposed in two rows, a second grounding plate  122  disposed in the immediate vicinity of the other signal contact row  11   b,  and a connection section  123  that connects the first grounding plate  121  and the second grounding plate  122  together and is surface mounted on a substrate (not shown here, refer to  FIG. 3 ) on which the plug connector  10  is mounted. Grounding contacts  124  formed by blanking and bending are arranged in the first grounding plate  121  and second grounding plate  122  of this grounding member  12 . In the connection section  123  of this grounding member  12  there are provided many slit-like openings  125  that pierce through the rear surface of this plug connector  10 . This grounding member  12  is held by the housing  13  in such a manner that the connection section  123  of the grounding member is disposed in the through opening  133  of the housing  13  and that the first grounding plate  121  and second grounding plate  222  are held on the inner side of the inner wall  132  of the housing  13 . 
   A receptacle connector  20  shown in  FIG. 2  is constituted by signal contacts  21  disposed in two rows, a grounding member  22  that is in the form of the letter Π as viewed from the side, and a housing  23  that holds the signal contacts  21  and the grounding member  22 . 
   In the housing  23 , an outer wall  231  that covers the outer circumference of the housing is formed and in the middle of a region enclosed by the outer wall  231  there is formed a through opening  232  that extends in the longitudinal direction. 
   Each of the signal contacts  21  of this receptacle connector  20  has, as parts shown in  FIG. 2 , a contact section  211  that comes into contact with the contact of the mating connector, the contact section rising along the inner side of the outer wall  231  of the housing  23 , and a terminal section  214  connected to a substrate (not shown), the terminal section extending laterally from the bottom of the housing  23  and projecting from the housing  23 . The contact section  211  of this signal contact  21  has the same shape as the contact section  111  of the signal contact  11  of the plug connector  10  shown in  FIG. 1 . The detailed structure of the signal contact  21  will be described later along with the description of the detailed structure of the signal contact  11  of the plug connector  10  shown in  FIG. 1 . 
   The grounding member  22  comprises a first grounding plate  221  disposed in the immediate vicinity of one signal contact row  21   a  among the signal contacts  21  disposed in two rows, a second grounding plate  222  disposed in the immediate vicinity of the other signal contact row  21   b,  and a connection section  223  that connects the first grounding plate  221  and the second grounding plate  222  together and is surface mounted on a substrate (not shown here, refer to  FIG. 3 ) on which this receptacle connector  20  is mounted. 
   The first grounding plate  121  and second grounding plate  122  that constitute the grounding member  12  of the plug connector  10  shown in  FIG. 1  are supported by the inner wall  132  of the housing  13  and, therefore, the grounding member  12  of this plug connector  10  is formed from a thin plate material, whereas the first grounding plate  221  and second grounding plate  222  that constitute the grounding member  22  of the receptacle connector  20  shown in  FIG. 2  are provided in a standing manner by the rigidity of the grounding plates themselves. Therefore, the grounding member  22  of this receptacle connector  20  is formed from a thick plate material compared to the grounding member  12  of the plug connector  10  shown in  FIG. 1  and has relatively large rigidity. 
   Thus, because the grounding member  22  of this receptacle connector  20  has rigidity large enough to enable the grounding member  22  to stand itself, it is unnecessary to form a wall to support the first grounding plate  221  and second grounding plate  222  that constitute the grounding member  22  in the housing  23  of this receptacle connector  20 . As a result of this, it is possible to minimize the size of the electrical connector assembly constituted by this receptacle connector  20  and the plug connector  10  in the width direction and to keep the visibility of the connection sections  123 ,  223  in a good condition. 
   In the connection section  223  of the grounding member  22  that constitutes the receptacle connector  20  shown in  FIG. 2  there are formed many slit-like openings  224  that pierce through the rear surface of this receptacle connector  20 . This grounding member  22  is held by the housing  23 , with the connection section  223  of the grounding member being disposed in the through opening  232  of the housing  23 . 
     FIG. 3  is a schematic sectional view of a connection section of a grounding member soldered to a substrate. 
   Both of the connectors  10 ,  20  of  FIGS. 1 and 2  have grounding members  12 ,  22 , and slit-like openings  125 ,  224  that pierce through the rear surface are formed in the connection sections  123 ,  223  of these grounding members  12 ,  22 . 
   By using the grounding member  12  of the plug connector  10  shown in  FIG. 1  as a representative,  FIG. 3  shows one of the many openings  125  formed in the connection section  123  of the grounding member  12  and the portions on both sides of the opening  125  in the connection section  123  of the grounding member  12 . 
   The connection section  123  of this grounding member  12  is soldered to a substrate  30  with a solder  31  and surface mounted on the substrate. At this time, as shown in  FIG. 3 , the peripheral edge parts of the opening  125  are soldered to the substrate  30  with the solder  31 . 
   Because in this manner many openings  125 ,  224  are provided in the grounding member  12  (the same applies to the grounding member  22  of the receptacle connector  20  shown in  FIG. 2 ), the edges of these many openings  125 ,  224  are soldered and soldering is performed strongly and securely as a whole. Also, because the openings  125 ,  224  are through ones and are provided in the through openings  133 ,  232  provided in the housings  13 ,  23 , it is possible to visually check the condition of soldering of the connection sections  123 ,  223  of the grounding members  12 ,  22  and hence the reliability of soldering can be increased. 
     FIGS. 4 and 5  are each a sectional view that shows the fitting condition of the plug connector  10  shown in  FIG. 1  and the receptacle connector  20  shown in  FIG. 2 .  FIG. 4  shows the receptacle connector  20  of  FIG. 2  sectioned along the arrow X—X and the plug connector  10  of  FIG. 1  sectioned in the corresponding place, and  FIG. 5  shows the receptacle connector  20  of  FIG. 2  sectioned along the arrow Y—Y and the plug connector  10  of  FIG. 1  sectioned in the corresponding place. 
   Incidentally, in  FIG. 4 , the contact section  111  of the signal contact  11  of the plug connector  10  and the contact section  211  of the signal contact  21  of the receptacle connector  20  are drawn in such a manner that they bite into the mating contact. However, this shows the positions of the contact sections  111 ,  211  of the signal contacts  11 ,  21  of the plug connector  10  and receptacle connector  20  before engagement. In reality, however, these contact sections interfere with the mating contact upon engagement and become deflected, with the result that the contact sections come into contact with the mating contact with a prescribed contact pressure and are kept in an electrically conducting state. 
   Also, in  FIG. 4 , a grounding contact  124  of the grounding member  12  of the plug connector  10  is drawn in such a manner that part of the grounding contact  124  are hidden behind the first grounding plate  221  and second grounding plate  222  of the grounding member  22  of the receptacle contact  20  and in  FIG. 5 , the grounding contact  124  bites into the first grounding plate  221  and second grounding plate  222 . However, this is also for the same reason as why the contact sections  111 ,  211  of the above signal contacts are drawn so as to bite into the mating contact. In actuality, however, upon engagement the grounding contact  124  interferes with the first grounding plate  221  and the second grounding plate  222  and is elastically deformed, with the result that the grounding contact  124  comes into contact with the first grounding plate  221  and the second grounding plate  222 , with a prescribed contact pressure kept, and that the glands of the plug connector  10  and receptacle connector  20  become connected to each other. 
   As is apparent from  FIGS. 4 and 5 , a gland wall constituted by the first grounding plate  121 ,  221  is formed in a position close to one signal contact row  11   a,    21   a  and a gland wall constituted by the second grounding plate  122 ,  222  is formed in a position close to the other signal contact row  11   b,    21   b.  As a result of this, crosstalks are suppressed, providing a structure suitable for high-speed signal transmission. 
   The description related to  FIGS. 4 and 5  is stopped here temporarily and the structure of the signal contacts  11 ,  21  themselves will be described. 
     FIG. 6  is a perspective view that shows signal contacts of a plug connector and a receptacle connector. 
   As shown in  FIG. 6 , in the signal contacts  11 ,  21  are formed the contact sections  111 ,  211 , convexities  112 ,  212 , press fitted sections  113 ,  213  and terminal sections  114 ,  214 . 
   When the plug connector  10  (refer to  FIGS. 1 ,  4  and  5 ) and the receptacle connector  20  (refer to  FIGS. 2 ,  4  and  5 ) become engaged with each other, the contact sections  111 ,  211  interfere with the mating connector, are elastically deformed, come into contact with the mating contact with a prescribed contact pressure, and are electrically connected with the mating contact. The surface of the contact section  111 ,  211  that comes into contact with the mating contact is formed from a surface of a flat metal plate (what is called a roll surface). This surface is a smooth surface, which contributes to a decrease in an insertion/removing force and high contact reliability. 
   As shown in  FIG. 4 , the convexities  112 ,  212  abut against the outer side of the inner wall  132  of the housing  13  of the plug connector  10  and the inner side of the outer wall  231  of the housing  23  of the receptacle connector  20  to thereby keep the contact sections  111 ,  211  from the inner wall  132  and the outer wall  231  in a spaced condition. 
   The contact sections  111 ,  211  are formed so as to come into contact with the vicinities of the convexities  212 ,  112  of the mating contact. This is because in the parts where the convexities  212 ,  112  are formed, the convexities  212 ,  112  abut against the housing and are fixed in position and the elastic parts that are the contact sections  111 ,  211  and the inelastic parts near the convexities  212 ,  112  are in contact with each other with a prescribed contact pressure, with the result that the contact between the two contacts is stable and a positive electrically conducting state is achieved. 
     FIG. 7  is an explanatory drawing of a method of forming convexities of a signal contact. Representatively, a description will be given here of the contact  21  of the receptacle connector  20 . 
   First, as shown in Part (A) of  FIG. 7 , projecting pieces  2121 ,  2122  that project in the width direction are formed by blanking a metal plate. After that, these projecting pieces  2121 ,  2122  that project in the width direction are bent in the arrow direction shown in Part (B) of  FIG. 7  and an inward force is applied, whereby the convexity  212  is formed. The same applies also to the convexity  112  of the contact  11  of the plug connector  10 . 
   The press fitted sections  113 ,  213  of the signal contacts  11 ,  21  shown in  FIG. 6  are parts that are press fitted into the housings  13 ,  23 . The press fitted sections  113 ,  213  spread in the width direction of the original metal plate, i.e., in the direction perpendicular to the drawing of  FIGS. 4 and 5  and are fixed by biting into a wall that faces the direction perpendicular to the drawing of  FIGS. 4 and 5  of the housings  13 ,  23 . 
   The terminal sections  114 ,  214  of the signal contacts  11 ,  21  shown in  FIG. 6  are to be mounted on a substrate. In the example shown here, the terminal sections  114 ,  214  have a shape suitable for surface mounting on a substrate. 
   Again with reference to  FIGS. 4 and 5 , in particular,  FIG. 4 , the description will be continued. 
   In the vicinity of the leading end of the inner wall  132  of the housing  13  of the plug connector  10 , i.e., leading end of the contact section  111  of the signal contact  11  of the plug connector  10 , there is formed a protective penthouse-like section  134  to protect the leading end of the contact section  111 . In the case of the structure of the housing  13  of this plug connector  10 , on the outer side of the inner wall  132  there is no projecting portion other than this protective penthouse-like section  134 , and it is possible to fabricate this housing  13  by use of a split mold capable of being divided in the vertical direction of  FIG. 4 . Because the signal contact  11  of this plug connector  10  is provided with the above convexity  112 , it is possible to keep the contact section  111  of the signal contact  11  in a condition spaced from the wall of the housing  13  and besides it is ensured that the contact from the contact section of the mating contact can be received in a stable manner by the portion where the convexity  112  of the signal contact  11  is formed. 
   The same applies also to the receptacle connector  20 . That is, in the vicinity of the leading end of the outer wall  231  of the housing  23  of the receptacle connector  20 , i.e., leading end of the contact section  211  of the signal contact  21  of the receptacle connector  20 , there is formed a protective penthouse-like section  233  to protect the leading end of the contact section  211 . In the case of the structure of the housing  23  of this receptacle connector  20 , on the inner side of the outer wall  231  there is no projecting portion other than this protective penthouse-like section  233 , and it is possible to fabricate this housing  23  by use of a split mold capable of being divided in the vertical direction of  FIG. 4 . Because the signal contact  21  of this receptacle connector  20  is provided with the above convexity  212 , it is possible to keep the contact section  211  of the signal contact  21  in a condition spaced from the wall of the housing  23  and besides it is ensured that the contact from the contact section of the mating contact can be received in a stable manner by the portion where the convexity  212  of the signal contact  21  is formed.