Patent Publication Number: US-8123532-B2

Title: Carrier system for an electrical connector assembly

Description:
BACKGROUND OF THE INVENTION 
     The subject matter herein relates generally to electrical connectors, and more particularly, to multiple electrical connectors arranged in an assembly. 
     Electrical connectors have been developed that are manually installed onto printed circuit boards and other structures. Often, a large number of electrical connectors, such as up to twenty electrical connectors, are installed on a single printed circuit board. Installation of electrical connectors can involve inserting hundreds of pins located on the electrical connectors into corresponding receiving holes in a printed circuit board or other structure. Known systems utilize stiffening devices to hold multiple electrical connectors together for simultaneous mounting to the circuit board. However, such stiffening devices are used on electrical connectors having equal heights and lengths such that the tops and backs of the electrical connectors are all aligned with one another. Additionally, such stiffening devices do not address any needs for maintaining positions of the pins. 
     Typically, there are several different types and sizes of electrical connectors that are mountable on a printed circuit board. Customers often want custom arrangements of electrical connectors for installation onto printed circuit boards. Known stiffening devices are not adequate for use in such situations as the stiffening devices cannot accommodate different height or different length electrical connectors. Rather, in order to attain a desired custom arrangement of modules on a printed circuit board, a customer manually installs the different desired modules one by one onto the printed circuit boards which can be very time consuming. 
     A need remains for an improved device for holding multiple electrical connectors together in an electrical connector assembly. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, an electrical connector assembly is provided including a first connector module including pins configured to be terminated to a circuit board and a second connector module including pins configured to be terminated to the circuit board. The electrical connector assembly also includes a carrier system including an organizer having openings therethrough in a predetermined pattern. The organizer is coupled to the first and second connector modules such that at least some of the pins of the first connector module extend through the openings of the organizer and such that at least some of the pins of the second connector module extend through the openings of the organizer. The first connector module, the second connector module and the organizer are configured to be mounted to the circuit board as a bundled unit. 
     In another embodiment, an electrical connector assembly is provided having that includes walls defining an outer perimeter and pins configured to be terminated to a circuit board. The electrical connector assembly also includes a second connector module having walls defining an outer perimeter and pins configured to be terminated to the circuit board. A carrier system includes an organizer having openings therethrough in a predetermined pattern that is coupled to the first and second connector modules such that at least some of the pins of the first connector module extend through the openings of the organizer and such that at least some of the pins of the second connector module extend through the openings of the organizer. The carrier system also includes a stiffening member being coupled to the first and second connector modules that spans between corresponding walls of the first and second connector modules to hold the first and second connector modules together. The first connector module, the second connector module and the carrier system are configured to be mounted to the circuit board as a bundled unit. 
     In a further embodiment, an electrical connector assembly is provided having a first connector module that includes walls defining an outer perimeter. The first connector module is configured to be mounted to a circuit board. A second connector module includes walls defining an outer perimeter that is configured to be mounted to the circuit board adjacent the first connector module. At least one of the walls of the first connector module is off-set with respect to corresponding walls of the second connector module such that the outer perimeters of the first and second connector modules are out of alignment with respect to one another. The electrical connector assembly also includes a carrier system having a stiffening member coupled to the first and second connector modules that has a transition section spanning between corresponding walls of the first and second connector modules that are offset with respect to one another. The first connector module, the second connector module and the stiffening member are configured to be mounted to the circuit board as a bundled unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an electrical connector assembly having a carrier system. 
         FIG. 2  is a rear perspective view of the electrical connector assembly shown in  FIG. 1 . 
         FIG. 3  is a bottom perspective view of the electrical connector assembly shown in  FIG. 1 . 
         FIG. 4  is another bottom perspective view of a portion of the electrical connector assembly shown in  FIG. 1 . 
         FIGS. 5-8  illustrate alternative carrier systems for the electrical connector assembly. 
         FIG. 9  illustrates a fixture configured to hold the connector modules forming the electrical connector assembly during application of the carrier system to the connector modules. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a front perspective view of an electrical connector assembly  100  having a carrier system  102 . The electrical connector assembly  100  includes a plurality of connector modules  104 ,  106 ,  108  that are, by way of example only, generally of rectangular block shape. The connector modules  104 ,  106 ,  108  are located adjacent to, and in direct contact with one another, at meeting interfaces  110 ,  111 . Any number and any type of connector modules may be provided, including multiple ones of the same types of connector modules. The connector modules  104 ,  106 ,  108  are merely examples of different types of connector modules that may be used depending on the particular application and desired mating interface. The connector modules  104 ,  106 ,  108  may be placed in an order determined by an application in which the connector modules  104 ,  106 ,  108  are to be used. 
     The connector modules  104 ,  106 ,  108  include walls  112  defining an outer perimeter of the corresponding connector modules  104 ,  106 ,  108 , which may generally be rectangular block shaped or have other shapes in alternative embodiments. The walls  112  may be defined by a housing  120  of the corresponding connector modules  104 ,  106 ,  108  and/or by individual chicklets  122  received in the housing  120 . 
     In an exemplary embodiment, the connector modules  104 ,  106 ,  108  are right angle connector modules, having front mating walls  114 ,  116 ,  118 , respectively, and bottom mounting walls  124 ,  126 ,  128  (shown in  FIG. 2 ), respectively. The front mating walls  114 ,  116 ,  118  are configured for mating engagement with corresponding mating connectors (not shown). The bottom mounting walls  124 ,  126 ,  128  are configured for mounting to a circuit board  130 . Contacts  132  held by the corresponding connector modules  104 ,  106 ,  108  are terminated to the circuit board  130  and are configured for mating engagement with corresponding mating contacts of mating connectors. The front mating walls  114 ,  116 ,  118  are formed at a right angle to the bottom mounting walls  124 ,  126 ,  128 . 
     The connector modules  104 ,  106 ,  108  have rear walls  134 ,  136 ,  138 , respectively, generally opposite the front mating walls  114 ,  116 ,  118 , respectively. The connector modules  104 ,  106 ,  108  have outer walls  144 ,  146 ,  148 , respectively, at a top of the connector modules  104 ,  106 ,  108  generally opposite the bottom mounting walls  124 ,  126 ,  128 . In an alternative embodiment, rather than being right angle connectors, the connector modules  104 ,  106 ,  108  may be vertical connectors that have mating and mounting walls that are opposite to one another, as opposed to being at right angles with respect to one another. 
     In the illustrated embodiment, the connector module  104  constitutes a power electrical connector. The connector module  106  constitutes a signal electrical connector. The connector module  108  constitutes a guide module. Other types of connector modules may be used in alternative embodiments, and the electrical connector assembly  100  may be utilized without a power electrical connector, a signal electrical connector and/or a guide module. 
     The connector module  104  includes a width  150 , a height  152 , and depth  154 . The connector module  106  includes a width  160  that is different than the width  150  of the connector module  104 , a height  162  that is different than the height  152  of the connector module  104 , and a depth  164  that is different than the depth  154  of the connector module  104 . As such, the outer wall  146  is off-set with respect to the outer wall  144  by a predetermined amount, the rear wall  136  is off-set with respect to the rear wall  134  by a predetermined amount and/or the front mating wall  116  is off-set with respect to the front mating wall  114  by a predetermined amount. Optionally, at least one of the width  160 , height  162  or depth  164  may be the same as the corresponding width  150 , height  152  or depth  154  of the connector module  104 . 
     The connector module  108  includes a width  170  that is different than the widths  150 ,  160 , a height  172  that is different than the heights  152 ,  162 , and a depth  174  that is different than the depths  154 ,  164 . As such, the outer wall  146  is off-set with respect to the outer wall  148  by a predetermined amount, the rear wall  136  is off-set with respect to the rear wall  138  by a predetermined amount and/or the front mating wall  116  is off-set with respect to the front mating wall  118  by a predetermined amount. Optionally, at least one of the width  170 , height  172  or depth  174  may be the same as the corresponding widths  150  and/or  160 , heights  152  and/or  162 , or depths  154  and/or  164 . 
     In an exemplary embodiment, the bottom mounting walls  124 ,  126 ,  128  are aligned with one another, however because the connector modules  104 ,  106 ,  108  have different heights  152 ,  162 ,  172 , the outer walls  144 ,  146 ,  148  are non-coplanar with one another. In the illustrated embodiment, the front mating walls  114 ,  116 ,  118  are non-coplanar with one another and the rear walls  134 ,  136 ,  138  are non-coplanar with one another. In alternative embodiments, any of the walls  112  may be co-planar with any of the other walls  112 . 
     The carrier system  102  is connected to each of the connector modules  104 ,  106 ,  108  to secure the connector modules  104 ,  106 ,  108  together as a bundled unit. The carrier system  102  locates the connector modules  104 ,  106 ,  108  adjacent to, and in direct contact with, one another at the meeting interfaces  110 ,  111  in an order determined by a particular application for which the electrical connector assembly  100  is intended. The carrier system  102  gives structural support to the electrical connector assembly  100  such that the electrical connector assembly  100  may be mounted to the circuit board  130 . 
       FIG. 2  is a rear perspective view of the electrical connector assembly  100  mounted to the circuit board  130 . The carrier system  102  is coupled to the connector modules  104 ,  106 ,  108 . The carrier system  102  includes one or more organizer(s)  200 , one or more rear stiffening member(s)  202  and one or more front stiffening member(s)  204 . The carrier system  102  may be provided without the organizer  200 , the rear stiffening member  202  and/or the front stiffening member  204  in alternative embodiments. 
     The organizer  200  is provided at the bottom mounting walls  124 ,  126 ,  128  between the connector modules  104 ,  106 ,  108  and the circuit board  130 . The organizer  200  holds the relative positions of the connector modules  104 ,  106 ,  108  for mounting the electrical connector assembly  100  to the circuit board  130  as a bundled unit. The organizer  200  spans across corresponding meeting interfaces  110 ,  111  to engage corresponding connector modules  104 ,  106 ,  108 . 
     The rear stiffening member  202  is provided proximate to the rear walls  134 ,  136 ,  138 . The rear stiffening member  202  holds the relative positions of the connector modules  104 ,  106 ,  108  for mounting the electrical connector assembly  100  to the circuit board  130  as a bundled unit. In the illustrated embodiment, two rear stiffening members  202  are provided, each spanning across a corresponding meeting interface  110 ,  111 , however a single rear stiffening member  202  may be provided in an alternative embodiment. Each rear stiffening member  202  is a metal component that is shaped to conform to the corresponding connector modules  104 ,  106 ,  108  to engage the corresponding connector modules  104 ,  106 ,  108 . The metal component is rigid and is configured to retain its shape once formed, which allows the rear stiffening member  202  to securely hold the connector modules  104 ,  106   108  together. The rear stiffening member  202  may be stamped and formed into a predetermined shape corresponding to the particular layout of connector modules  104 ,  106 ,  108 . When formed, the rear stiffening member  202  includes keys  206  that extend into corresponding keyways  208  formed in the walls  112  of the connector modules  104 ,  106 ,  108 . The position, shape and orientation of the keys  206  may be specific to the geometry of the particular connector modules  104 ,  106 ,  108 . For example, the size, shape, relative position, location of keyways  208 , and the like of the connector modules  104 ,  106 ,  108  may dictate the positioning of the keys  206 . The shape of the rear stiffening member  202  may be configurable, such as by a bending or forming process, to accommodate varying connector geometries, such as by transitioning across off-set walls  112  to the particular connector modules  104 ,  106 ,  108 . 
     Optionally, as in the illustrated embodiment, the rear stiffening member  202  may engage the rear walls  134 ,  136 ,  138  and the outer walls  144 ,  146 ,  148 . For example, the rear stiffening member  202  includes a rear arm  210  and an outer arm  212  extending from the rear arm  210 . Alternatively, the rear stiffening member  202  may include only the rear arm  210  engaging the rear walls  134 ,  136 ,  138  or the outer arm  212  engaging only the outer walls  144 ,  146 ,  148 , but not both. In an exemplary embodiment, because the rear walls  134 ,  136  are non-coplanar, with the rear wall  134  being closer to the front of the electrical connector assembly  100  than the rear wall  136 , the rear stiffening member  202  engaging the connector modules  104 ,  106  includes a transition section  214  that transitions between the plane of the rear wall  134  and the plane of the rear wall  136 . The rear arm  210  of the rear stiffening member  202  includes a first rear arm section  216  that extends along, and engages, the rear wall  134  and a second rear arm section  218  that extends along, and engages, the rear wall  136 . The first rear arm section  216  is generally parallel to, and non-coplanar with respect to, the second rear arm section  218 . The transition section  214  extends between the first and second rear arm sections  216 ,  218 . The transition section  214  is not parallel to the first and second rear arm sections  216 ,  218 , but rather extends at an angle between the first and second rear arm sections  216 ,  218 . Optionally, the transition section  214  may be angled at approximately a 45° angle. Alternatively, the transition section  214  may be angled at a 90° angle or any other angle. The length of the transition section  214  may depend on the amount of off-set between the rear walls  134 ,  136 . 
     In an exemplary embodiment, because the outer walls  144 ,  146  are non-coplanar, with the outer wall  144  being lower than the outer wall  146  (e.g. closer to the circuit board  130 ), the rear stiffening member  202  engaging the connector modules  104 ,  106  includes a transition section  224  that transitions between the plane of the outer wall  144  and the plane of the outer wall  146 . The outer arm  212  of the rear stiffening member  202  includes a first outer arm section  226  that extends along, and engages, the outer wall  144  and a second outer arm section  228  that extends along, and engages, the outer wall  146 . The first outer arm section  226  is generally parallel to, and non-coplanar with respect to, the second outer arm section  228 . The transition section  224  extends between the first and second outer arm sections  226 ,  228 . The transition section  224  is not parallel to either of the first or second outer arm sections  226 ,  228 , but rather extends at an angle between the first and second outer arm sections  226 ,  228 . Optionally, the transition section  224  may be angled at approximately a 45° angle. Alternatively, the transition section  224  may be angled at a 90° angle or any other angle. The length of the transition section  224  may depend on the amount of off-set between the outer walls  144 ,  146 . 
     The rear stiffening member  202  coupling the connector module  106  and the connector module  108  is different than the rear stiffening member  202  being used to couple the connector module  106  and the connector module  104 . The rear stiffening member  202  being used to couple the connector modules  106 ,  108  includes a rear arm  230  and an outer arm  232 . The rear arm  230  only engages the connector module  106  and does not engage the connector module  108 . The outer arm  232  engages both the connector modules  106 ,  108 . The outer arm  232  includes a transition section  234  that bends the outer arm  232  at a 90° angle, and the outer arm  232  extends from the transition section  234  vertically into the keyway  208  in the outer wall  148  of the connector module  108 . The outer arm  232  holds the top of the connector module  108  in proper position against the connector module  106 . 
     The connector modules  104 ,  106 ,  108  each include overhang portions  240  that are located proximate the front mating walls  114 ,  116 ,  118 . The overhang portions  240  extend downward from the bottom mounting walls  124 ,  126 ,  128  to form a shelf  242  therebetween having abutment surfaces  244  that abut against an edge of the circuit board  130 . A portion of the circuit board  130  has been illustrated as cut away to illustrate the overhang portion  240 , shelf  242  and abutment surface  244  of the connector module  104 . The connector modules  106 ,  108  include similar overhang portions  240 , shelves  242  and abutment surfaces  244 . In an exemplary embodiment, the abutment surfaces  244  are coplanar. The front stiffening member  204  is coupled to the connector modules  104 ,  106 ,  108  proximate to the overhang portions  240  to hold the connector modules  104 ,  106 ,  108  together. In an exemplary embodiment, the front stiffening member  204  engages the abutment surfaces  244  to hold the connector modules  104 ,  106 ,  108  together. 
       FIG. 3  is a bottom perspective view of the electrical connector assembly  100  illustrating the front stiffening member  204  coupled to the overhang portions  240 . The connector modules  104 ,  106 ,  108  have different overall geometries, but share the abutment surfaces  244  along a common plane for abutting against a front edge  246  of the circuit board  130 . The abutment surfaces  244  define rear walls of the overhang portions  240 , and may be referred to hereinafter as rear walls  244 . The overhang portions  240  also include outer walls  248  at a bottom of the overhang portions  240 . In the illustrated embodiment, the front stiffening member  204  is coupled to the overhang portions  240  at the outer walls  248  and the rear walls  244 . 
     The front stiffening member  204  holds the relative positions of the connector modules  104 ,  106 ,  108  for mounting the electrical connector assembly  100  to the circuit board  130  as a bundled unit. The front stiffening member  204  is a metal component that is shaped to conform to the corresponding connector modules  104 ,  106 ,  108  to engage the corresponding connector modules  104 ,  106 ,  108 . The metal component is rigid and is configured to retain its shape when formed, which allows the front stiffening member  204  to securely hold the connector modules  104 ,  106 ,  108  together. 
     The front stiffening member  204  includes keys  250  that extend into corresponding keyways  252  formed in the outer walls  248  and the rear walls  244 . Optionally, if the outer walls  248  and/or rear walls  244  are not coplanar, the shape of the front stiffening member  204  may be configurable, such as by a bending or forming process, to accommodate varying connector geometries. 
     The front stiffening member  204  includes a rear arm  254  and an outer arm  256  extending from the rear arm  254 . The rear arm  254  engages the rear walls  244  and the outer arm  256  engages the outer walls  248 . Alternatively, the front stiffening member  204  may include only the rear arm  254  engaging the rear walls  244  or the outer arm  256  engaging only the outer walls  248 , but not both. 
       FIG. 4  is a bottom perspective view of a portion of the electrical connector assembly  100  illustrating the connector module  106  and the connector module  108  coupled to the organizer  200 . The connector module  106  includes a plurality of pins  260  extending from the bottom mounting wall  126  (shown in  FIG. 2 ). The pins  260  may form part of the contacts  132  (shown in  FIG. 1 ) routed through the connector module  106 , which are also configured to be mated to corresponding mating contacts of a mating connector. The pins  260  are configured to be terminated to the circuit board  130  (shown in  FIGS. 1 and 2 ). For example, the pins  260  may be press-fit pins configured for press-fit attachment to vias in the circuit board  130  or through-hole pins that are configured to be soldered within vias in the circuit board  130 . The contacts tails  260  are arranged in a predetermined pattern, depending on the particular type of connector module being used. The pins  260  make electrical contact with the circuit board  130  to route signals or power through the connector module  106 . 
     The connector module  108  includes a plurality of pins  262  extending from the bottom mounting wall  128 . The pins  262  are configured to be mechanically terminated to the circuit board  130  to physically secure the connector module  108  to the circuit board  130 . The pins  262  are integrally formed with a housing of the connector module  108  and extend outward from the bottom mounting wall  128 . In the illustrated embodiment, the connector module  108  constitutes a guide connector module. No electrical connection is made between the connector module  108  and the circuit board  130 , but rather, the connector module  108  includes an opening  264  configured to receive a guide pin or other guidance feature for mating engagement with a mating connector assembly. The connector module  108  operates as a guide module for the electrical connector assembly  100 . The contacts tails  262  are arranged in a predetermined pattern, depending on the particular type of connector module being used. 
     The organizer  200  includes a plurality of openings  266  therethrough arranged in a predetermined pattern. The openings  266  receive the pins  260 ,  262  of the connector modules  106 ,  108 . When assembled, the organizer  200  abuts against the bottom mounting walls  126 ,  128  of the connector modules  106 ,  108 , with the pins  260 ,  262  extending through the openings  266 . The pattern of the openings  266  corresponds to the pattern of the pins  260 ,  262 . The openings  266  are arranged in a first set of openings  268  and a second set of openings  270 . The organizer  200  is coupled to the connector modules  106 ,  108  such that at least some of the pins  260  of the connector module  106  extend through the first set of openings  268  and such that at least some of the pins  262  of the connector module  108  extend through the second set of openings  270 . The pattern of the first set of openings  268  may be different than the pattern of the second set of openings  270 . 
     The organizer  200  spans across the meeting interface  111  between the connector modules  106 ,  108 . The organizer  200  holds the true position of the pins  260  and/or  262 . As such, when the connector modules  106 ,  108  and organizer  200  are mounted to the circuit board  130 , the pins  260  and/or  262  are rigidly held, and properly positioned, with respect to the corresponding vias. Stubbing of the pins  260 ,  262  is therefore reduced by having the organizer  200  position the pins  260 ,  262 . By engaging the pins  260  and the pins  262  of both connector modules  106 ,  108 , the organizer rigidly holds the connector modules  106 ,  108  together as a bundled unit. The organizer  200  reduces the possibility of the connector modules  106 ,  108  spreading apart at the meeting interface  111 . 
     In an exemplary embodiment, the organizer  200  has a stepped configuration, with a first step  272  generally accommodating the pins  260  of the connector module  106  and a second step  274  generally accommodating the pins  262  of the connector module  108 . The first step  272  accommodates only a subset of the pins  260 , leaving a dead space for another organizer  200  to connect to the pins  260  in such dead space. For example, another organizer  200  may be provided beneath the connector module  104  (shown in  FIGS. 1 and 2 ) and the connector module  106 , which spans across the meeting interface  110  (shown in  FIGS. 1 and 2 ). Similarly, the second step  274  accommodates only a subset of the pins  262 , leaving a dead space  276  for another organizer  200  to connect to the pins  262  in such dead space. For example, another organizer  200  may be provided beneath the connector module  108  and an adjacent connector module when another connector module is used on the opposite side of the connector module  108  from the connector module  106 . In an alternative embodiment, when the connector module  108  (or the other connector modules  104 ,  106 ) defines an outermost connector module, wherein no connector modules are provided outside of the connector module  108 , the organizer  200  may fill the dead space such that the organizer  200  accommodates all of the pins  262 . 
     Many different configurations and shapes of organizers  200  are possible in alternative embodiments. Organizers  200  may be provided that extend across more than two connector modules, and may even extend across all of the connector modules utilized within the electrical connector assembly  100 .  FIGS. 5 and 6  illustrate alternative carrier systems, showing other possible geometries and arrangements for organizers. 
       FIG. 5  shows three T-shaped organizers  280  mounted to connector modules  282 ,  284  having similar pinouts of pins  286 ,  288 , respectively. The middle organizer  280  spans across the meeting interface between the connector modules  282 ,  284  and receives at least some of the pins  286  and at least some of the pins  288 . The outer organizers  280  are rotated 180° with respect to the middle organizer  280 . The outer organizers  280  may be trimmed or shaped differently, such as an L-shape, if no other connector modules are provided, or may have a different pattern of openings for receiving pins of a different type of connector module. 
       FIG. 6  shows rectangular organizers  290  arranged in an off-set, stacked configuration, similar to how bricks are stacked. Some of the organizers  290  span across a meeting interface between connector modules  292 ,  294  and receive pins of both of the connector modules  292 ,  294 . Other organizers  290  only receive pins from one of the connector modules  292  or  294 . 
       FIG. 7  illustrates an alternative electrical connector assembly  300  having two connector modules  302 ,  304  that have similar outer perimeters defined by walls  306 ,  308 , respectively. A carrier system  310  ties the connector modules  302 ,  304  together. The carrier system  310  includes an organizer  312  extending beneath both connector modules  302 ,  304 . The carrier system  310  also includes a rear stiffening member  314  and a front stiffening member  316 , which may be similar to the front stiffening member  204  (shown in  FIG. 3 ). 
     The rear stiffening member  314  holds the relative positions of the connector modules  302 ,  304  for mounting the electrical connector assembly  300  to a circuit board  318  as a bundled unit. The rear stiffening member  314  is a metal component that is shaped to conform to the corresponding connector modules  302 ,  304  to engage the corresponding connector modules  302 ,  304 . The metal component is rigid and is configured to retain its shape when formed, which allows the rear stiffening member  314  to securely hold the connector modules  302 ,  304  together. 
     The rear stiffening member  314  includes keys  320  that extend into corresponding keyways  322  formed in the walls  306 ,  308 . The rear stiffening member  314  includes a rear arm  324  and an outer arm  326  extending from the rear arm  324 . The rear arm  324  engages rear walls  330  and the outer arm  326  engages outer walls  332 . Alternatively, the rear stiffening member  314  may include only the rear arm  324  engaging the rear walls  330  or the outer arm  326  engaging only the outer walls  332 , but not both. In an exemplary embodiment, single keyways  322  are formed in both the rear walls  330  and the corresponding outer walls  332 . As such, the keys  320  extending from the rear arm  324  are received in the same keyways  322  as the keys  320  extending from the outer arm  326 . 
       FIG. 8  illustrates an alternative electrical connector assembly  400  having two connector modules  402 ,  404  that have outer perimeters defined by walls  406 ,  408 , respectively. The outer perimeters of the connector modules  402 ,  404  are different. For example, the connector module  404  has a depth that is less than a depth of the connector module  402 . 
     A carrier system  410  ties the connector modules together. The carrier system  410  includes an organizer  412  extending beneath both connector modules  402 ,  404 . The carrier system  410  also includes a rear stiffening member  414  and a front stiffening member  416 , which may be similar to the front stiffening member  204  (shown in  FIG. 4 ). 
     The rear stiffening member  414  holds the relative positions of the connector modules  402 ,  404  for mounting the electrical connector assembly  400  to a circuit board  418  as a bundled unit. The rear stiffening member  414  is a metal rod that is shaped to conform to the corresponding connector modules  402 ,  404  to engage the corresponding connector modules  402 ,  404 . In the illustrated embodiment, the rear stiffening member  414  is generally cylindrical in shape, however other shapes are possible in alternative embodiments. The rear stiffening member  414  includes a transition section  420  that transitions between the connector modules  402 ,  404  to engage both connector modules  402 ,  404 . The transition section  420  is formed by bending the rear stiffening member  414  to generally follow the outer perimeter of the connector modules  402 ,  404 . 
     The walls  406 ,  408  include keyways  422  that receive the rear stiffening member  414 . The keyways  422  represent a groove formed in rear walls  424  of the connector modules  402 ,  404 . Because the connector module  404  is off-set with respect to the connector module  402 , the rear stiffening member  414  transitions across the meeting interface to engage both keyways  422 . Optionally, the keyways  422  may both be positioned at approximately the same height from the circuit board  418 . Alternatively, the keyways  422  may be at different heights from the circuit board  418  and the rear stiffening member  414  must transition either up or down to be loaded into the corresponding keyways  422 . 
       FIG. 9  illustrates a fixture  430  configured to hold the connector modules  402 ,  404 , as well as other connector modules  426 ,  428 , forming the electrical connector assembly  400  during application of the carrier system  410  to the connector modules  402 ,  404 ,  426 ,  428 . The fixture  430  may form part of the carrier system  410 , and may be used during mounting of the electrical connector assembly  400  to the circuit board  418  (shown in  FIG. 8 ). The fixture  430  may be removed from the connector modules  402 ,  404 ,  426 ,  428  after the connector modules  402 ,  404 ,  426 ,  428  are mounted to the circuit board  418 . 
     In the illustrated embodiment, the connector modules  402 ,  404  constitute signal electrical connectors. The connector module  426  constitutes a power electrical connector. Two of the connector modules  428  are provided, which flank the other connector modules  402 ,  404 ,  426 . The connector modules  428  constitute guide modules. 
     During assembly, the connector modules  402 ,  404 ,  426 ,  428  are loaded onto the fixture  430 . The connector modules  402 ,  404 ,  426 ,  428  may be secured to the fixture  430 , such as using adhesives, latches, tape, fasteners, an interference fit, and the like. The fixture  430  includes steps  432  that position the connector modules  402 ,  404 ,  426 ,  428  in a particular orientation with respect to one another. For example, front mating walls  434  of the connector modules  402 ,  404 ,  426 ,  428  rest on the fixture  430 . The steps  432  allow the front mating walls  434  to be staggered, which orients the rear walls  424  at particular locations, such as aligned with one another, as in the illustrated embodiment. As a result, the keyways  422  of each of the connector modules  402 ,  404 ,  426 ,  428  are generally aligned with one another. 
     The organizers  412  are coupled to bottom mounting walls  436  of the connector modules  402 ,  404 ,  426 ,  428 . The organizers  412  have a stepped configuration, where the organizers  412  are interfitted with adjacent organizers  412 . The organizers  412  have openings  438  that receive pins  440  extending from the bottom mounting walls  436  of the connector modules  402 ,  404 ,  426 ,  428 . 
     The front stiffening member  416  is coupled to the connector modules  402 ,  404 ,  426 ,  428 . Similarly, the rear stiffening member  414  (shown in  FIG. 8 ) is coupled to the connector modules  402 ,  404 ,  426 ,  428  by loading the rear stiffening member  414  into the keyways  422 . Once assembled, the fixture  430  may be removed and the remaining electrical connector assembly  400  may be mounted to the circuit board  418 . Alternatively, the fixture  430  may be utilized as part of the carrier system  410 , wherein the electrical connector assembly  400 , including the fixture  430 , is mounted to the circuit board  418 . After being mounted, the fixture  430  may be removed. In another alternative embodiment, the fixture  430  may be used to replace the front stiffening member  416 , whereby the fixture  430  holds the front mating walls  434  in position relative to one another during mounting to the circuit board  418 . As such, the fixture  430  may define a front stiffening member. 
     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.