Patent Publication Number: US-8535065-B2

Title: Connector assembly for interconnecting electrical connectors having different orientations

Description:
BACKGROUND OF THE INVENTION 
     The subject matter described and/or illustrated herein relates generally to an electrical connector assembly that is configured to interconnect connectors that have different orientations with respect to each other. 
     Some communication systems, such as a blade server system, include a large backplane (or midplane) circuit board, which is generally referred to as a backplane. The system also includes a plurality of card modules (e.g., line cards, server blade cards, switch cards, I/O cards). Some of the card modules may be coupled to a front side of the backplane, and other card modules can be coupled to a back side of the backplane. The card modules coupled to the front side extend parallel to each other, but orthogonal to the card modules coupled to the back side of the backplane. For example, the card modules along the front side may extend vertically, and the card modules along the back side may extend horizontally. The front side card modules and the back side card modules are communicatively coupled to one another through the backplane. 
     In some systems, a pair of header connectors are mounted to the backplane and oppose each other with the backplane between the header connectors. Each header connector has a mating interface that faces away from the backplane and board contacts that are electrically connected to the backplane. Each of the header connectors is configured to engage one of the card modules at the mating interface. For those systems having an orthogonal architecture, the board contacts of each header connector are rotated and/or shaped before engaging the backplane. For example, each differential pair of board contacts may be rotated about 45° before the board contacts connect to the backplane. However, the rotated and/or shaped board contacts may present challenges to signal integrity and electrical performance of the overall system. These challenges become even more difficult when the transmission speed and/or density of the board contacts increases. 
     Accordingly, there is a need for an electrical connector assembly that interconnects connectors having different orientations relative to each other and that can address at least one of the above challenges. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, an electrical connector assembly is provided that includes an electrical connector having a connector body with mating and interior sides facing in opposite directions. The electrical connector also includes electrical contacts that are held by the connector body. The connector assembly also includes an interposer having a connector side, an opposite board side, and plated vias that extend into the interposer from at least one of the connector or board sides. The connector side engages the interior side of the electrical connector. The electrical contacts of the electrical connector are electrically coupled to corresponding vias. The connector assembly also includes board contacts that extend from the board side of the interposer and are electrically coupled to corresponding vias. The electrical contacts are configured to engage a module connector along the mating side, and the board contacts are configured to engage an electrical component along the board side. The board contacts are communicatively coupled to the electrical contacts through the interposer. 
     In some embodiments, the vias include first vias that extend into the interposer from the connector side and second vias that extend into the interposer from the board side. The interposer also has conductive traces that extend along and electrically couple associated first and second vias. The first vias are electrically coupled to the electrical contacts and the second vias are electrically coupled to the board contacts. 
     Optionally, the electrical contacts include first signal pairs of electrical contacts, and the board contacts include second signal pairs of board contacts. The first signal pairs are in a first configuration along the mating side, and the second signal pairs are in a second configuration along the board side. The first and second configurations are different. 
     In another embodiment, an electrical connector assembly is provided that includes an interposer having plated vias and conductive traces that communicatively couple associated vias. The connector assembly also includes a connector body and a contact organizer having the interposer located therebetween. The connector body has a mating side and the contact organizer has a mounting side. The mating and mounting sides face away from the interposer in opposite directions along a mating axis. The connector assembly also includes electrical contacts that are positioned along the mating side of the connector body and that are communicatively coupled to the interposer. The connector assembly also includes board contacts that are positioned along the mounting side of the contact organizer and that are communicatively coupled to the interposer. The board contacts are communicatively coupled to associated electrical contacts through the interposer. 
     In a further embodiment, a communication system is provided that includes a circuit board having opposite first and second board surfaces. The system also includes first and second electrical connector assemblies that are mounted to the first and second board surfaces, respectively. At least one of the first or second connector assemblies includes an electrical connector and an interposer that is located between the electrical connector and the circuit board. The first and second connector assemblies have mating interfaces with electrical contacts. The mating interfaces of the first and second connector assemblies are configured to engage corresponding module connectors that have an orthogonal relationship with respect to each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of a portion of a communication system having electrical connector assemblies formed in accordance with one embodiment. 
         FIG. 2  is a rear perspective view of the portion of the communication system shown in  FIG. 1 . 
         FIG. 3  is a front-perspective, exploded view of one of the connector assemblies formed in accordance with one embodiment. 
         FIG. 4  is a rear-perspective view of the connector assembly shown in  FIG. 3 . 
         FIG. 5  illustrates a portion of an interior side of an electrical connector that may be used with the connector assembly of  FIG. 3 . 
         FIG. 6  illustrates a portion of a connector side of an interposer that may be used with the connector assembly of  FIG. 3 . 
         FIG. 7  illustrates a board side of the interposer having board contacts coupled thereto. 
         FIG. 8  is a perspective view of an exemplary board contact. 
         FIG. 9  is a side view of the constructed connector assembly of  FIG. 3 . 
         FIG. 10  is a rear view of the constructed connector assembly of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 2  are front perspective and rear perspective views, respectively, of a portion of a communication system  100 . The system  100  is oriented with respect to mutually perpendicular axes  191 - 193  including a mating axis  191  and lateral axes  192 ,  193 . As shown, the system  100  includes a circuit board  102  having opposite first and second board surfaces  104  ( FIG. 1 ),  106  ( FIG. 2 ) that extend transverse to the mating axis  191  along a plane that is defined by the lateral axes  192 ,  193 . The board surfaces  104 ,  106  face in opposite directions along the mating axis  191 . The system  100  also includes a first electrical connector assembly  108  and a second electrical connector assembly  110  that are mounted to the first and second board surfaces  104 ,  106 , respectively. The connector assemblies  108 ,  110  are communicatively coupled to each other through the circuit board  102 . 
     In an exemplary embodiment, the system  100  is a blade server system in which front card modules (not shown), such as removable line cards or server blade cards, are configured to engage the connector assembly  108  and rear card modules (not shown), such as removable switch cards or I/O cards, are configured to engage the connector assembly  110 . In such embodiments, the circuit board  102  may be characterized as a backplane or midplane circuit board. However, a blade server system is only one example and embodiments described may be used in other communication systems or environments. For example, the connector assemblies  108 ,  110 , which are described in greater detail below, may be used to connect an electrical connector directly to a circuit board that is not a midplane or backplane circuit board or to another electrical component. Accordingly, embodiments described herein are not limited to blade server systems. 
     In the illustrated embodiment, the connector assemblies  108 ,  110  are aligned and directly oppose each other with the circuit board  102  therebetween. However, in other embodiments, the connector assemblies  108 ,  110  may not be aligned and may have different positions along the board surfaces  104 ,  106 . It is noted that only a portion of the system  100  is shown in  FIGS. 1 and 2 , which illustrate only one pair of connector assemblies  108 ,  110 . In an exemplary embodiment, the system  100  includes multiple pairs of connector assemblies similar to the connector assemblies  108 ,  110  that are coupled to the circuit board  102 . Such connector assemblies may be arranged in rows and columns along each of the board surfaces  104 ,  106 . 
     The connector assemblies  108 ,  110  are configured to engage module connectors (not shown) during loading operations in which the module connectors are advanced in a mating direction along the mating axis  191  and engaged to the connector assemblies  108 ,  110 . Such module connectors may be part of the aforementioned card modules (e.g., removable line cards, server blade cards, and the like) or the module connectors may be other types of connectors, such as a cable connector. 
     As shown in  FIG. 1 , the connector assembly  108  includes a mating interface  112  ( FIG. 1 ) having an array of electrical contacts  114 . The electrical contacts  114  include signal contacts  116  and ground contacts (or shields)  118 . In an exemplary embodiment, the signal contacts  116  are arranged in signal pairs  117  and are configured to transmit differential signals. The ground contacts  118  can be C-shaped shields that are shaped to at least partially surround one of the signal pairs  117 . The C-shaped shields open in a direction along the lateral axis  193 . However, in other embodiments, the ground contacts  118  may be other types of conductive elements that facilitate shielding the signal contacts  116 . For example, the ground contacts  118  may be pin contacts in which a plurality of the pin contacts are arranged around and proximate to each signal contact  116 . 
     As shown in  FIG. 2 , the connector assembly  110  also includes a mating interface  122  having an array of electrical contacts  124 . The electrical contacts  124  include signal contacts  126  and ground contacts (or shields)  128 . The signal contacts  126  are arranged in signal pairs  127  and are configured to transmit differential signals. In the illustrated embodiment, the ground contacts  128  are also C-shaped shields shaped to at least partially surround one of the signal pairs  127 . The C-shaped shields open in a direction along the lateral axis  192 . Accordingly, in the illustrated embodiment, the ground contacts  118  ( FIG. 1 ) are oriented differently than the ground contacts  128 . 
     As shown in  FIG. 1 , the two signal contacts  116  of each signal pair  117  can extend substantially parallel to each other along a contact plane P 1 . The mating axis  191  and the lateral axis  192  extend parallel to and define the contact plane P 1 . With respect to  FIG. 2 , the two signal contacts  126  of each signal pair  127  extend substantially parallel to each other along a contact plane P 2 . The mating axis  191  and the lateral axis  193  extend parallel to and define the contact plane P 2 . As shown by comparing  FIGS. 1 and 2 , the contact planes P 1  and P 2  are orthogonal to each other. 
     The mating interfaces  112 ,  122  may be different with respect to each other. For example, the mating interfaces  112 ,  122  have different rotational orientations or positions with respect to each other. As shown in  FIGS. 1 and 2 , the mating interfaces  112 ,  122  have an identical contact configuration (or pinout) in which the electrical contacts  114  ( FIG. 1 ) and the electrical contacts  124  ( FIG. 2 ) are of the same types and are arranged identically. Nonetheless, the mating interface  122  is rotated substantially 90° with respect to the mating interface  112 . More particularly, the mating interface  122  is rotated substantially 90° with respect to the mating interface  112  when viewing the mating interfaces  112 ,  122  in a direction along the mating axis  191  with the lateral axis  192  as the horizon. 
     The mating interfaces  112 ,  122  can also be different when the contact configurations or pinouts are different. More specifically, the electrical contacts  114  at the mating interface  122  may be arranged differently than the electrical contacts  124  at the mating interface  122 . The electrical contacts  114 ,  124  are arranged differently when at least one of (a) orders of the contacts are different; (b) rotational orientations of associated signal pairs are different; or (c) spacings between the contacts are different. The mating interfaces  112 ,  122  may also be different with respect to each other when the electrical contacts  112 ,  124  are not of the same type. 
     The connector assemblies  108 ,  110  may use interposers, such as the interposer  132  ( FIG. 3 ), to facilitate transitioning conductive pathways from the mating interface  112  to the mating interface  122 . In particular embodiments, the interposers facilitate transitioning between mating interfaces in which the signal pairs of one mating interface are arranged differently than the associated signal pairs of the other mating interface. 
     For example, as discussed above, the signal pairs  117  and the signal pairs  127  are oriented along different contact planes P 1  and P 2 . The signal pairs  117  and the signal pairs  127  may be arranged in a predetermined grid or array (e.g., rows and columns). As shown in  FIG. 1 , the mating interface  112  includes multiple rows of the signal pairs  117  in which the two signal contacts  116  of each signal pair  117  in one row extend within a common plane. By way of example, in one row of the signal pairs  117 , the two signal contacts  116  of each signal pair  117  in the row are positioned within the contact plane P 1 . In an exemplary embodiment, each row of signal pairs  117  may extend within a different contact plane that is parallel to the contact plane P 1 . Such configurations may be referred to as a horizontal contact configuration. 
     As shown in  FIG. 2 , the mating interface  122  includes multiple columns of the signal pairs  127  in which the two signal contacts  126  of each signal pair  127  are positioned within a common plane. For example, in one column of the signal pairs  127 , the two signal contacts  126  of each signal pair  127  in the column are positioned within the contact plane P 2 . In an exemplary embodiment, each column of signal pairs  127  may extend within a different contact plane that is parallel to the contact plane P 2 . Such configurations may be referred to as a vertical contact configuration. Accordingly, the mating interfaces  112 ,  122  have an orthogonal relationship. Likewise, the mating interfaces  112 ,  122  are configured to engage module connectors (not shown) that have an orthogonal relationship with respect to each other. 
     Although the illustrated embodiment shows the mating interfaces  112 ,  122  having different rotational orientations relative to each other, the mating interfaces  112 ,  122  can be different for other reasons. For example, the mating interfaces  112 ,  122  may have substantially the same rotational orientation, but the mating interfaces  112 ,  122  may use different types of contacts and/or have different spatial arrangements. 
     Embodiments described herein include conductive pathways that extend through the connector assembly  108 , the circuit board  102 , and the connector assembly  110 . Each conductive pathway may include, among other things, one of the signal contacts  116  and an associated signal contact  126 . As used herein, signal contacts are associated with each other if the two signal contacts are electrically coupled to each other along a conductive pathway to transmit data signals. Likewise, a pair of signal contacts is associated with another pair of signal contacts if the two signal contacts of one pair are electrically coupled to the two signal contacts of the other pair through respective conductive pathways. Other conductive elements (e.g., plated vias, conductive traces, ground contacts or shields) can be associated with another conductive element if the two conductive elements are electrically coupled to each other along a conductive pathway. 
     Conductive pathways between the mating interfaces  112 ,  122  are established when the connector assemblies  108 ,  110  are mounted and communicatively coupled to the circuit board  102 . Embodiments described herein are configured to transition the conductive pathways from the mating interface  112  to the mating interface  122 . In the illustrated embodiment, the connector assemblies  108 ,  110  are configured to effectively rotate the pairs of conductive pathways about 90° so that the module connectors (not shown) having an orthogonal relationship can be communicatively coupled by the communication system  100 . However, in other embodiments, the pairs of conductive pathways can be rotated more than or less than 90°. 
       FIGS. 3 and 4  illustrate exploded front-perspective and rear-perspective views, respectively, of the connector assembly  108 . Although the following description is with specific reference to the connector assembly  108 , the connector assembly  110  ( FIG. 1 ) may also be constructed in a similar manner. The connector assembly  108  may include an electrical connector  130 , an interposer  132 , and a contact organizer  134 . In an exemplary embodiment, the electrical connector  130 , the interposer  132 , and the contact organizer  134  can be stacked side-by-side in which the interposer  132  is located between the electrical connector  130  and the contact organizer  134 . The interposer  132  can be sandwiched between the electrical connector  130  and the contact organizer  134 . 
     The electrical connector  130  includes a connector body  136  having a mating side  140  and an interior side  142 . In an exemplary embodiment, the electrical connector  130  is a vertical header connector in which the electrical contacts  114  are exposed. However, in other embodiments, the electrical connector  130  may be a vertical receptacle connector in which the electrical contacts  114  are located in socket cavities. Other types of electrical connectors that transmit data signals may be suitable as well. The mating and interior sides  140 ,  142  face in opposite directions along the mating axis  191 . The connector body  136  is configured to hold the electrical contacts  114 . The mating interface  112  includes the mating side  140  and the electrical contacts  114 . In the illustrated embodiment, the interior side  142  is substantially planar and the electrical contacts  114  project away from the interior side  142  and are configured to couple to the interposer  132 . As shown, the connector body  136  can include a plurality of sidewalls  144 - 147  that define a connector-receiving space  148  ( FIG. 3 ). 
     The sidewalls  145 ,  147  include alignment features  156 ,  158 , respectively, that are configured to engage the module connector (not shown) during a loading operation. As shown, the alignment features  156 ,  158  are slots or recesses in the sidewalls  145 ,  147 . However, the alignment features  156 ,  158  can be other structural elements (e.g., projections) in alternative embodiments. In an exemplary embodiment, the electrical contacts  114  project into the connector-receiving space  148  ( FIG. 3 ) such that the electrical contacts  114  are only separated by space. However, in alternative embodiments, the connector body  136  may define socket cavities having electrical contacts located therein. In such embodiments, the electrical contacts may be separated by dielectric material that defines the socket cavities. 
     The interposer  132  includes a substrate  150  that has a connector side  152  and a board side  154  that face in opposite directions along the mating axis  191 . The substrate  150  has a thickness T 1  that is defined between the connector and board sides  152 ,  154 . For example, the thickness T 1  can be about 1.0 mm or less. 
     In some embodiments, the interposer  132  includes or constitutes a circuit board. The substrate  150  may comprise a plurality of stacked substrate layers (e.g., four layers) with conductive elements embedded or patterned thereon. In an exemplary embodiment, the interposer  132  includes plated vias  160  that are distributed throughout the substrate  150  in a predetermined pattern. The vias  160  may be thru-holes or extend only partially into the substrate  150 . The vias  160  may extend into the interposer  132  from at least one of the connector or board sides  152 ,  154 . In the illustrated embodiment, at least some of the vias  160  extend entirely through the thickness T 1  of the substrate  150 . However, some of the vias  160  can extend partially into the interposer  132  from the connector side  152 , and some of the vias  160  can extend into the interposer  132  from the board side  154 . In particular embodiments, all of the vias  160  extend entirely through the substrate  150 . 
     The connector side  152  is configured to engage or interface with the interior side  142  of the connector body  136 , and the board side  154  is configured to engage or interface with the contact organizer  134 . In other embodiments, the contact organizer  134  may not be used and the board side  154  is mounted to the circuit board  102  ( FIG. 1 ). Also shown, the connector assembly  108  can include an array of the board contacts  164  that are coupled to the interposer  132  along the board side  154 . The board contacts  164  are inserted into corresponding vias  160  along the board side  154  and project along the mating axis  191  toward the circuit board  102 . 
     The contact organizer  134  includes an organizer body  170  having an interior side  172  and a mounting side  174  that face in opposite directions along the mating axis  191 . The interior side  172  is configured to engage the board side  154  of the interposer  132 , and the mounting side  174  is configured to engage the circuit board  102  ( FIG. 1 ). The organizer body  170  includes an insulative or dielectric material that is molded or otherwise formed to include the features described herein. The contact organizer  134  includes a plurality of contact holes  176  that extend entirely through the organizer body  170 . The contact holes  176  are sized and shaped to receive corresponding board contacts  164  and permit the board contacts  164  to project through the contact holes  176  into an exterior of the connector assembly  108 . The contact holes  176  may be sized and shaped to form a snug fit or an interference fit with the board contacts  164 . In such embodiments, the contact organizer  134  may provide additional support for the board contacts  164  when the connector assembly  108  is mounted to the circuit board  102 . 
     As shown in  FIGS. 3 and 4 , the interposer  132  may be located between two different dielectric bodies (i.e., the connector body  136  and the contact organizer  134 ) that each supports corresponding contacts when the connector assembly  108  is constructed. Accordingly, the connector body  136  may be characterized as a first contact organizer and the contact organizer  134  may be a second contact organizer. In an exemplary embodiment, the electrical contacts  114  and the board contacts extend through the first and second contact organizers, respectively, and are directly coupled to corresponding vias  160  of the interposer  132 . 
       FIG. 5  illustrates a portion of the interior side  142 , and  FIG. 6  illustrates a corresponding portion of the connector side  152  that is configured to engage the interior side  142  along an interface  240  (shown in  FIG. 9 ). With respect to  FIG. 5 , the connector body  136  includes a dielectric material that is molded or otherwise formed to hold the electrical contacts  114 . In some embodiments, the connector body  136  may be molded separately to include contact holes or openings  202  and the electrical contacts  114  can be subsequently inserted into the contact holes  202 . In other embodiments, the connector body  136  may be molded to surround the electrical contacts  114 . 
     As shown in  FIG. 5 , the signal contacts  116  include contact-terminating ends  206 , and the ground contacts  118  include contact-terminating ends  208 . In the illustrated embodiment, the contact-terminating ends  206 ,  208  are pins, but may have different structures in other embodiments. For example, alternative contact-terminating ends may be compliant eye-of-needle tails or socket-shaped contacts. The contact-terminating ends  206 ,  208  are configured to be inserted into corresponding vias  160  ( FIG. 3 ) of the interposer  132  ( FIG. 3 ). 
     As shown in  FIG. 6 , the vias  160  include ground vias  210 ,  212 , and signal vias  214 ,  216 . The ground vias  210  are configured to receive corresponding contact-terminating ends  208  ( FIG. 5 ) through the connector side  152 , and the ground vias  212  are configured to receive corresponding board contacts  164  through the board side  154 . The signal vias  214  are configured to receive corresponding contact-terminating ends  206  ( FIG. 5 ) through the connector side  152 , and the signal vias  216  are configured to receive corresponding board contacts  164  through the board side  154 . 
     In an exemplary embodiment, the interposer  132  includes conductive traces  220  that extend between and electrically couple associated signal vias  214 ,  216 . When the connector assembly  108  ( FIG. 1 ) is fully assembled, the conductive traces  220  extend in a direction that is transverse to the mating axis  191  ( FIG. 1 ). In the illustrated embodiment, the conductive traces  220  extend along a surface of the connector side  152 . However, in other embodiments, the conductive traces  220  may extend within the substrate  150 . For example, the conductive traces  220  may extend along an interface between adjacent substrate layers and electrically couple associated signal vias  214 ,  216 . In particular embodiments, paths taken by the conductive traces  220  may be non-linear. Although not shown, associated ground vias  210 ,  212  are electrically coupled to each other through conductive traces that are similar to the conductive traces  220 . In other embodiments, the ground vias  210 ,  212  may be electrically coupled on a separate ground plane (not shown) within the substrate  150  and also along the connector side  152 . Also in other embodiments, the ground vias  210 ,  212  can be electrically coupled to each other on the same plane as the conductive traces  220 . 
       FIG. 6  shows a predetermined arrangement of the ground and signal vias  210 ,  212 ,  214 ,  216  in an exemplary embodiment. By way of example, the signal vias  214  associated with one signal pair  117  ( FIG. 1 ) of signal contacts  116  ( FIG. 1 ) may be aligned with respect to an alignment axis  290 , and the signal vias  216  associated with the same pair of signal contacts  116  may be aligned with an alignment axis  292 . As shown in  FIG. 6 , the alignment axes  290 ,  292  intersect each other and form an angle θ. In an exemplary embodiment, the angle θ is about 45°. In some embodiments, the angle θ is at least about 45°. However, the angle θ may be more or less in other embodiments. In an exemplary embodiment, multiple pairs of the signal vias  214  can be aligned along the alignment axis  290 , and multiple pairs of the signal vias  216  can be aligned along the alignment axis  292 . 
     In the illustrated embodiment, the ground and signal vias  210 ,  212 ,  214 ,  216  extend entirely through the thickness T 1  of the interposer  132  or substrate  150 . However, in alternative embodiments, the ground and signal vias  210 ,  212 ,  214 ,  216  may extend partially through. More specifically, the ground vias  210  and the signal vias  214  may extend into the interposer  132  from the connector side  152 , and the ground vias  212  and the signal vias  216  may extend into the interposer  132  from the board side  154 . 
       FIG. 7  illustrates the board side  154  of the interposer  132  having the board contacts  164  coupled thereto. The board contacts  164  include signal contacts  222  that are configured to transmit data signals and ground contacts  224  that are configured to facilitate shielding the signal contacts  222 . The signal contacts  222  are arranged in signal pairs  226 . As shown, the two signal contacts  222  of one signal pair  226  are adjacent to each other and do not have an intervening ground contact  224  therebetween. Instead, the ground contacts  224  are positioned between adjacent signal pairs  226 . In the illustrated embodiment, the signal and ground contacts  222 ,  224  have identical structures. However, the signal and ground contacts  222 ,  224  may have different structures in alternative embodiments. 
       FIG. 8  is a perspective view of an exemplary board contact  164 . The board contact  164  may be used as a signal contact  222  ( FIG. 7 ) or as a ground contact  224  ( FIG. 7 ). The board contact  164  has an elongated structure that extends along a central longitudinal axis  294 . The board contact  164  is stamped from a sheet of conductive material, but the board contact  164  may also be partially shaped or formed in other embodiments. As shown, the board contact  164  includes first and second contact-terminating ends  232 ,  234  and a base section  236  that extends between the first and second contact-terminating ends  232 ,  234 . In an exemplary embodiment, the first contact-terminating end  232  is a pin that is configured to be inserted into one of the vias  160  ( FIG. 3 ), and the second contact-terminating end  234  has a compliant eye-of-needle construction that is configured to be inserted into a via (not shown) along the circuit board  102  ( FIG. 1 ). The base section  236  is configured to provide structural integrity to the board contact  164  and support the contact-terminating ends  232 ,  234 . In the illustrated embodiment, the base section  236  is sized and shaped to be received by one of the contact holes  176  ( FIG. 3 ) of the contact organizer  134 . 
     In some embodiments, the contact-terminating end  232  is soldered within one of the ground vias  160  or along one of the sides of the substrate  150  ( FIG. 3 ). However, the contact-terminating end  232  may take other shapes than shown in  FIG. 8  and may be terminated to the substrate  150  in a variety of manners. In other embodiments, the contact-terminating end  232  may be similar to the contact-terminating end  234  (e.g., eye-of-needle structure) or may have another shape that allows the contact-terminating end  232  to be press-fit. 
     Returning to  FIG. 7 , the signal contacts  222  and the ground contacts  224  may have different rotational orientations with respect to the longitudinal axis  294  ( FIG. 8 ). In the illustrated embodiment, the base sections  236  of the signal contacts  222  and the base sections  236  of the ground contacts  224  are oriented perpendicular with respect to each other. More specifically, the signal contacts  222  are rotated about the respective longitudinal axes  294  ( FIG. 8 ) about 90° relative to the ground contacts  224 . 
       FIG. 9  is a side view of the fully constructed connector assembly  108 . The interposer  132  and the electrical connector  130  (or the connector body  136 ) engage each other at an interface  240  and the interposer  132  and the contact organizer  134  engage each other at an interface  242 . The interfaces  240  and  242  can be substantially planar. As shown, the board contacts  164  extend through the contact organizer  134 . More specifically, the board contacts  164  extend through the contact holes  176  ( FIG. 3 ) and project beyond the mounting side  174  so that the contact-terminating ends  234  are exposed to an exterior of the connector assembly  108 . 
       FIG. 10  is a rear-perspective view of the fully constructed connector assembly  108 . The board contacts  164  are arranged in a predetermined contact configuration, which may be different than the contact configuration of the electrical contacts  114  ( FIG. 1 ). As described above, the signal contacts  116  ( FIG. 1 ) may be arranged in rows and columns. Each row may have the same number of signal contacts  116 , and each column may have the same number of signal contacts  116 . However, as shown in  FIG. 10 , the signal contacts  222  and the signal pairs  226  are arranged in diagonals along the mounting side  174 . Adjacent diagonals may have different numbers of signal contacts  222 . Accordingly, the contact configuration along the mating side  140  is different from the contact configuration along the mounting side  174 . 
     More specifically, the two signal contacts  222  of each signal pair  226  can extend substantially parallel to each other along the mating axis  191  and a contact plane P 3 . One diagonal is indicated by dashed lines where the contact plane P 3  intersects the contact organizer  134 . As shown, the two signal contacts  222  of each signal pair  226  are positioned within the contact plane P 3 . The contact plane P 3  is not parallel to either of the contact planes P 1  and P 2  ( FIG. 1 ) and does not coincide with either of the contact planes P 1  and P 2 . Although not shown, the contact plane P 3  would intersect either of the contact planes P 1  and P 2  along a line that is parallel to the mating axis  191 . For example, the contact planes P 1  and P 3  may intersect each other and form at least about a 45° angle. 
     The contact configurations along the mating side  140  and the mounting side  174  may be different in other manners other than signal pair orientation. For example, the mating side  140  includes a single ground contact  118  ( FIG. 1 ) for each signal pair  117  ( FIG. 1 ) whereas the mounting side  174  includes a plurality of ground contacts  224  for each signal pair  226 . As another example, the ground contacts  118  are C-shaped in the illustrated embodiment and the ground contacts  224  are compliant pins configured to be inserted into corresponding vias (not shown) of the circuit board  102  ( FIG. 1 ). 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.