Patent Publication Number: US-2022216638-A1

Title: High density electrical connectors

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and the benefit of French Application Serial No. 1852288, filed Mar. 16, 2018, entitled “HIGH DENSITY ELECTRICAL CONNECTORS.” The entire contents of these applications are incorporated herein by reference in their entirety. 
     BACKGROUND 
     Many electrical devices are controlled by, and/or powered via, printed circuit boards (PCBs). For instance, in an automobile, an electrical connector may be used to connect an LED lamp to a PCB controlling and/or powering the LED lamp. Such a connector may include an electrical terminal configured to be crimped onto an electrically conductive wire (e.g., a wire of a cable connected to the LED lamp) and/or a contact pin configured to be soldered onto the PCB. 
     There is a continuing trend in many fields to miniaturize components. This creates an ongoing need for electrical connectors with high signal density. Furthermore, there is a need for improved vibration endurance. For instance, in an automotive application, it may be desirable to prevent two mated connectors from becoming unmated due to vibration in an operating environment. 
     U.S. Patent Application Publication No. 2015/0050838 (hereafter “the &#39;838 publication”) shows, among other things, examples of terminals for use in a connector. Such a terminal may be securely crimped onto a wire of an electrical cable. The &#39;838 publication also shows a connector having a core and a housing, where the core and the housing are attached to each other with a retention force that is higher than a retention force provided between the connector and a mating connector, so as to prevent the core and the housing from accidentally being pulled apart when a user attempts to unmate the two connectors. 
     SUMMARY 
     In some embodiments, a terminal provided for use in a first electrical connector, the terminal comprising: a mating end configured to receive a contact pin of a second electrical connector; a crimping end configured to be crimped onto an electrical wire; and an intermediate portion between the mating end and the crimping end, wherein: the terminal is elongated along a mating direction; and the intermediate portion comprises a locking feature that is biased outwardly from a center line of the terminal along the mating direction. 
     In some embodiments, an electrical connector is provided, comprising: a housing; a terminal position assurance (TPA) feature attached to the housing, the TPA feature being movable between a disengaged configuration and an engaged configuration; and a terminal inserted into a cavity in the housing, wherein: when the TPA feature is in the engaged configuration, a locking feature of the terminal engages the TPA feature to retain the terminal in the cavity. 
     In some embodiments, an electrical connector is provided, comprising: a housing; a terminal position assurance (TPA) feature attached to the housing, the TPA feature being movable between a disengaged configuration and an engaged configuration; and a terminal inserted into a cavity in the housing, wherein: the TPA feature comprises a protrusion; when the TPA feature is in the disengaged configuration, the protrusion of the TPA feature is aligned with a wall of the cavity to allow insertion of the terminal into the cavity; and the protrusion of the TPA feature has a ramped profile configured to guide the terminal as the terminal is being inserted into the housing when the TPA feature is in the disengaged configuration. 
     In some embodiments, a first electrical connector is provided, comprising: a first housing; and a terminal position assurance (TPA) feature attached to the first housing, the TPA feature being movable between a disengaged configuration and an engaged configuration, wherein: the first electrical connector is configured to mate with a second electrical connector having a second housing; and the TPA feature comprises a latch configured to engage the second housing to secure the first and second electrical connectors together in a mated configuration. 
     In some embodiments, an electrical connector is provided, comprising: a housing; and a hold-down having first, second, and third attachment features, wherein: the first attachment feature impedes lateral movement between the hold-down and the housing; the second attachment feature impedes vertical movement between the hold-down and the housing; and the third attachment feature is configured to be attached to a printed circuit board (PCB), to secure the electrical connector to the PCB. 
     In some embodiments, a first electrical connector is provided, comprising: a first housing; and a connector position assurance (CPA) feature attached to the first housing, the CPA feature being movable between a disengaged configuration and an engaged configuration, wherein: the CPA feature comprises a first latch configured to attach the CPA feature to the first housing when the CPA feature is in the disengaged configuration; the first electrical connector is configured to mate with a second electrical connector having a second housing; the CPA feature comprises a second latch configured to attach the CPA feature to the second housing when the CPA feature is in the engaged configuration; and the first housing is configured to impede the CPA feature from moving into the engaged configuration when the first and second electrical connectors are not fully mated. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  shows an illustrative connector  100 , in accordance with some embodiments. 
         FIG. 1B  is an exploded view of the illustrative connector  100  shown in  FIG. 1A , in accordance with some embodiments. 
         FIG. 2A  shows an illustrative electrical terminal  200 , in accordance with some embodiments. 
         FIG. 2B  shows the illustrative barrels  212   a ,  212   b ,  214   a , and  214   b  of  FIG. 2A  in a crimped configuration, in accordance with some embodiments. 
         FIGS. 3A-F  show, respectively, illustrative connectors  300 A-F, in accordance with some embodiments. 
         FIGS. 4A-D  show cross-sectional views of the illustrative receptacle  130  shown in  FIG. 1B , in accordance with some embodiments. 
         FIGS. 5A-B  show further cross-sectional views of the illustrative receptacle  130  shown in  FIG. 1B , in accordance with some embodiments. 
         FIG. 6A  shows a bottom view of the illustrative receptacle  130  shown in  FIG. 1B , partially cut away to show illustrative locking features of inserted terminals, in accordance with some embodiments. 
         FIG. 6B  shows an enlarged view of an area  602  of  FIG. 6A . 
         FIG. 7  shows another cross-sectional view of the illustrative receptacle  130  shown in  FIG. 1B , in accordance with some embodiments. 
         FIG. 8  shows another cross-sectional view of the illustrative receptacle  130  shown in  FIG. 1B , in accordance with some embodiments. 
         FIG. 9A  shows an illustrative connector  900 A, in accordance with some embodiments. 
         FIG. 9B  shows an illustrative connector  900 B, in accordance with some embodiments. 
         FIG. 10  shows illustrative header housings  1002  and  1004 , in accordance with some embodiments. 
         FIG. 11A  shows an illustrative header  1100 , in accordance with some embodiments. 
         FIG. 11B  shows a cross-sectional view of the illustrative header  1100  of  FIG. 11A , in accordance with some embodiments. 
         FIG. 12A  shows an illustrative connector  1200 , in accordance with some embodiments. 
         FIG. 12B  shows a cross-sectional view of the illustrative connector  1200  of  FIG. 12A , in accordance with some embodiments. 
         FIG. 12C  shows the illustrative latch  1237  contacting the illustrative protrusion  1241  of  FIGS. 12A-B , in accordance with some embodiments. 
         FIG. 12D  shows the illustrative latch  1237  being deflected by the illustrative protrusion  1241  of  FIGS. 12A-B , in accordance with some embodiments. 
         FIG. 12E  shows the illustrative CPA feature  1234  of  FIGS. 12A-B , in an engaged configuration, in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In various embodiments, compact connector designs may be provided that have reduced board pitch (e.g., 1.80 mm, 1.50 mm, 1.27 mm, etc.), but are still capable of accommodating large electrical conductors (e.g., 1.4 mm, 1.1 mm, 0.9 mm, etc.). In this manner, PCB footprint may be reduced (e.g., by 50% when a staggered connector configuration is used), while adequate current carrying capacity may be maintained (e.g., 2 A, 3 A, 4 A, etc.). Additionally, or alternatively, one or more other advantages may be achieved, such as ruggedness (e.g., vibration endurance), error proofing, configuration flexibility, ease of manufacturing, ease of assembly, and/or lowered costs. 
       FIG. 1A  shows an illustrative connector  100 , in accordance with some embodiments. In this example, the connector  100  includes a cable interface  110  and a board interface  120 . The cable interface  110  may be configured receive one or more wires of an electrical cable. For instance, the cable interface  105  may include an opening  115  into which an electrical terminal may be inserted, where the terminal may be crimped onto a wire of an electrical cable. The board interface  120  may be configured to make electrical connections with one or more traces of a PCB. For instance, the board interface  120  may include a contact pin  125  configured to be soldered onto a PCB using any suitable technique such as surface mount device (SMD), pin-in-paste (PiP), etc. 
       FIG. 1B  is an exploded view of the illustrative connector  100  shown in  FIG. 1A , in accordance with some embodiments. In this example, the connector  100  includes a receptacle  130  and a header  140 . The illustrative cable interface  110  and the illustrative board interface  120  shown in  FIG. 1A  may be located, respectively, at the receptacle  130  and the header  140 . 
     In some embodiments, the receptacle  130  and the header  140  may be configured to mate with each other. Once mated, one or more electrical terminals of the receptacle  130  (e.g., a terminal  132  inserted into the opening  115 ) may be electrically connected to one or more corresponding contact pins of the header  140  (e.g., the contact pin  125 ). In some embodiments, the terminal  132  may be crimped onto a wire of an electrical cable, and the contact pin  125  may be soldered onto a PCB. Thus, when the receptacle  130  and the header  140  are mated with each other, an electrical connection may be made between the wire and a conductive trace of the PCB. 
     In the example shown in  FIG. 1B , the header  140  includes a cavity  142  configured to receive the receptacle  130 . The contact pin  125  may be held in the header  140  such that, when the receptacle  130  is inserted into the cavity  142 , a mating end of the contact pin  125  forms an electrical connection with a mating end of the terminal  132 . Additionally, or alternatively, the header  140  may include one or more features (e.g., hold-down  144 ) configured to secure the header  140  to a PCB. 
     In the example shown in  FIG. 1B , the receptacle  130  includes a connector position assurance (CPA) feature  134  and a terminal positional assurance (TPA) feature  136 . In some embodiments, the CPA feature  134  may be in one of at least two configurations, such as a disengaged configuration and an engaged configuration. When the receptacle  130  is not mated with any header, the CPA feature  134  may be in a disengaged configuration, and may be prevented from moving into the engaged configuration. When the receptacle  130  is mated with a header (e.g., the header  140 ), the CPA feature  134  may be allowed to move into the engaged configuration, where the CPA feature  134  may prevent the receptacle  130  and the header  140  from being unmated (e.g., due to vibration in an operating environment). In some embodiments, the TPA feature  136  may be engaged to prevent one or more terminals (e.g., the terminal  132 ) from being dislocated within the receptacle  130  (e.g., due to vibration in an operating environment). Additionally, or alternatively, the TPA feature  136  may be used to ensure that an electrical connection is made only when a terminal is in a desired position. 
       FIG. 2A  shows an illustrative electrical terminal  200 , in accordance with some embodiments. The terminal  200  may be used in any suitable connector, such as the illustrative connector  100  shown in  FIGS. 1A-B . For instance, the terminal  200  may be used as the illustrative terminal  132  shown in  FIG. 1B . 
     In the example of  FIG. 2A , the terminal  200  includes a crimping end  210  and a mating end  220 . The crimping end  210  may be configured to be crimped onto a wire of an electrical cable. For instance, the crimping end  210  may include one or more barrels (e.g.,  212   a  and  212   b ) configured to be crimped onto an insulated portion of the electrical cable, and/or one or more barrels (e.g.,  214   a  and  214   b ) configured to be crimped onto a stripped portion of the electrical cable, where insulation has been stripped away and the conductive wire is exposed.  FIG. 2B  shows the illustrative barrels  212   a ,  212   b ,  214   a , and  214   b  of  FIG. 2A  in a crimped configuration, in accordance with some embodiments. 
     In some embodiments, the barrels  212   a  and  212   b  may be offset from each other, so that when crimped, the barrels  212   a  and  212   b  may hold the insulation portion of the cable at different locations along a length of the cable, which may improve retention. Additionally, or alternatively, the barrels  214   a  and  214   b  may be elongated along a length of the terminal  200  to provide a larger contact region (and hence improved electrical connection) between the terminal  200  and the wire onto which the terminal  200  is crimped. The inventors have recognized and appreciated that one or more of these techniques may be used to improve vibration endurance (e.g., in an automotive application). 
     In the example of  FIG. 2A , the mating end  220  includes a contact beam  222  configured to mate with a corresponding contact pin (e.g., the illustrative contact pin  125  shown in  FIGS. 1A-B ). For instance, the contact beam  222  may be a box-shaped beam configured to receive the contact pin  125 . However, it should be appreciated that aspects of the present disclosure are not limited to the use of a box-shaped beam, as other mating contact configurations may also be suitable. 
     In the example of  FIG. 2A , the terminal  200  includes an intermediate portion  230  between the crimping end  210  and the mating end  220 . In some embodiments, the intermediate portion  230  may include a locking feature  232  configured to engage with one or more features of the receptacle  130 , for example, to retain the terminal  200  at a desired position within the receptacle  130 . For instance, the locking feature  232  may be biased outwardly from a center line of the terminal  200 , and may fit into a corresponding recess in the receptacle  130  to prevent the terminal  200  from being dislocated (e.g., due to vibration in an operating environment). 
     Additionally, or alternatively, the intermediate portion  230  may include a blocking feature  234  configured to engage with a TPA feature (e.g., the illustrative TPA feature  136  shown in  FIG. 1B ). For example, as explained below in connection with  FIG. 4C , when a TPA feature is in an engaged configuration, a protrusion of the TPA feature may come into contact with the blocking feature  234 , thereby preventing the terminal  200  from being dislocated. 
     The inventors have recognized and appreciated that it may be desirable to provide different connector configurations for use in different applications. For instance, it may be desirable to provide connectors that have different configurations (e.g., top vs. side latch, staggered vs. side-to-side, single vs. double row, etc.) but are capable of receiving terminals of a same design (e.g., the illustrative terminal  200  shown in  FIG. 2A ). This may simplify manufacturing and/or installation. Furthermore, cost of tooling to make a terminal may be high relative to cost of the terminal itself, and overall costs may be reduced by amortizing the tooling cost over a larger number of terminals. Therefore, it may be desirable to provide a terminal design that may be used in many different connector configurations. However, it should be appreciated that aspects of the present disclosure are not limited to the use of a universal terminal design. 
       FIGS. 3A-F  show, respectively, illustrative connectors  300 A-F, in accordance with some embodiments. For instance, each of the connectors  300 A-F may be configured for use with terminals having the illustrative design shown in  FIG. 2A . 
     In the example shown in  FIG. 3A , the connector  300 A includes a receptacle having two terminals  302 A and  304 A, and a header having two pins  312 A and  314 A. The terminals  302 A and  304 A may be disposed in a staggered configuration. For instance, the terminal  302 A may be offset from the terminal  304 A both horizontally and vertically, and likewise for the pins  312 A and  314 A. In this manner, a horizontal distance between the pins  312 A and  314 A may be reduced while maintaining an overall distance between the pins  312 A and  314 A (square root of sum of square of horizontal distance and square of vertical distance). Thus, a board pitch may be reduced while still allowing the use of sufficiently large conductors for carrying high currents. 
     In this disclosure, a “vertical” direction may be a direction that is orthogonal to a PCB onto which a connector is mounted, and a “horizontal” direction may be a direction that is parallel to the PCB. Moreover, a first feature of the connector may be said to be “above” (respectively, “below”) a second feature of the connector if the first feature is vertically offset from the second feature and is further from (respectively, closer to) the PCB than the second feature. Likewise, a “top” of the connector may be facing away from the PCB, and a “bottom” of the connector may be facing towards the PCB. 
     Returning to the example of  FIG. 3A , the receptacle of the connector  300 A includes a latch  322 A (mostly obscured in this view), and the header of the connector  300 A includes an opening  324 A configured to engage the latch  322 A. The latch  322 A and the opening  324 A may be located at a top of the connector  300 A, and may engage each other when the receptacle is mated with the header. When engaged, the latch  322 A and the opening  324 A may prevent the receptacle and the header from becoming unmated (e.g., due to vibration in an operating environment). 
     In the example shown in  FIG. 3B , the connector  300 B is similar to the illustrative connector  300 A shown in  FIG. 3A , except a latch  322 B (mostly obscured in this view) and a corresponding opening  324 B may be disposed at a side of the connector  300 B, instead of a top of the connector  300 B. Such a side latch may be used in an application where vertical space is limited, and/or there is limited access from above. 
     In the example shown in  FIG. 3C , the connector  300 C is similar to the illustrative connector  300 A shown in  FIG. 3A , except terminals  302 C and  304 C are in a side-to-side configuration, instead of a staggered configuration, and likewise for pins  312 C and  314 C. For instance, the terminals  302 C and  304 C may be in a same horizontal row, and likewise for the pins  312 C and  314 C. Such a side-to-side configuration may be used in an application where vertical space is limited. Moreover, using different configurations in a same environment may reduce a likelihood of mating connectors that are not intended to be mated together. 
     In the example shown in  FIG. 3D , the connector  300 D is similar to the illustrative connector  300 B shown in  FIG. 3B , except terminals  302 D and  304 D are in a side-to-side configuration, instead of a staggered configuration, and likewise for pins  312 D and  314 D. For instance, the terminals  302 D and  304 D may be in a same horizontal row, and likewise for the pins  312 D and  314 D. 
     In the example shown in  FIG. 3E , the connector  300 E is similar to the illustrative connector  300 A shown in  FIG. 3A , except a mating direction between a header  302 E and a receptacle  304 E of the connector  300 E is vertical, as opposed to horizontal. 
     In the example shown in  FIG. 3F , the connector  300 F has two horizontal rows of terminals and two horizontal rows of corresponding contact pins. For instance, there may be a top row  302 F and a bottom row  304 F. In this example, terminals in the top row  302 F may be oriented such that one or more engagement features (e.g., the illustrative locking feature  232  and the illustrative blocking feature  234  shown in  FIG. 2A ) may face upward, so as to engage a top TPA feature, whereas terminals in the bottom row  304 F may be oriented such that one or more engagement features (e.g., the illustrative locking feature  232  and the illustrative blocking feature  234  shown in  FIG. 2A ) may face downward, so as to engage a bottom TPA feature. However, it should be appreciated that aspects of the present disclosure are not limited to any particular orientation of terminals, nor to the use of any TPA feature. 
       FIGS. 4A-C  show cross-sectional views of the illustrative receptacle  130  shown in  FIG. 1B , in accordance with some embodiments. In the example of  FIG. 4A , a housing  402  of the receptacle  130  includes elongated cavities  404  and  406  configured to receive terminals  132  and  138 , respectively. The terminal position assurance (TPA) feature  136  is shown in  FIG. 4A  in a disengaged configuration, providing sufficient clearance in the cavities  404  and  406  to allow insertion of the terminals  132  and  138 . 
     In the example of  FIG. 4B , the terminals  132  and  138  are fully inserted into the cavities  404  and  406 , respectively. The TPA feature  136  may then be engaged to hold the terminals  132  and  138  in their respective positions in the housing  402 . For instance, in the example of  FIG. 4C , the TPA feature  136  is pushed into the housing  402  to engage the terminals  132  and  138 . 
     In some embodiments, the TPA feature  136  may include one or more protrusions configured to engage, respectively, one or more terminals inserted into the housing  402 . For instance, in the example of  FIG. 4C , the TPA feature  136  includes a protrusion  408  configured to fit into a recess  412  formed in the terminal  138 , as well as a protrusion  410  configured to fit into a recess  414  formed in the terminal  132 . The protrusions  408  and  410  may be of different heights. For instance, the protrusion  410  may be shorter than the protrusion  408 , because the terminal  132  may be disposed at a bottom row of the receptacle  130 , whereas the terminal  138  may be disposed at a top row. 
     In some embodiments, the terminal  132  may include a blocking feature  416  that is similar to the illustrative blocking feature  234  shown in  FIG. 2A  and discussed above. When the TPA feature  136  is pushed into the housing  402 , the protrusion  410  may be disposed adjacent the blocking feature  416  of the terminal  132 . In this engaged configuration, a movement of the terminal  132  in a withdrawal direction may cause the blocking feature  416  to come into contact with the protrusion  410 , thereby preventing of the terminal  132  from being withdrawn from the cavity  404 . 
       FIG. 4D  shows a cross-sectional view of the illustrative connector  100  shown in  FIG. 1B , in accordance with some embodiments. In this example, the TPA feature  136  is in a disengaged configuration, and may block the header  140  from becoming fully mated with the receptacle  130 . For instance, as shown at  416 , the TPA feature  136  may, in the disengaged configuration, be vertically aligned with a lower edge of the header  140 , thereby blocking the header  140 . Once the TPA feature  136  is pushed upward to be in an engaged configuration, there may be sufficient clearance for the receptacle  130  to be inserted into the header  140 . In this manner, electrical connections may be made between terminals of the receptacle  130  and respective contact pins of the header  140  only when the TPA feature  136  is in an engaged position, which may ensure that the terminals of the receptacle are in desired positions when electrical connections are made. 
       FIGS. 5A-B  show further cross-sectional views of the illustrative receptacle  130  shown in  FIG. 1B , in accordance with some embodiments. The views shown in  FIGS. 5A-B  may be orthogonal to the views shown in  FIGS. 4A-C . In the example of  FIG. 5A , the TPA feature  136  is in a disengaged configuration. For instance, as shown at  502 A, the housing  402  may include two protrusions configured to engage with protrusions of the TPA  136 . In some embodiments, when the TPA feature  136  is in a disengaged configuration, only one of the two protrusions of the housing  402  (e.g., a lower protrusion) may be engaged with the TPA feature  136 . In this manner, the TPA feature  136  may be attached to the housing  402 , while leaving sufficient clearance for insertion of terminals (e.g., the illustrative terminals  132  and  138 ). 
     In some embodiments, when the TPA feature  136  is in an engaged configuration (e.g., as shown in  FIG. 5B ), both of the protrusions of the housing  402  may be engaged with the TPA feature  136  (e.g., as shown at  502 B). In this manner, protrusions of the TPA feature  136  (e.g., the illustrative protrusions  408  and  410 ) may fit into corresponding recesses of inserted terminals (e.g., the illustrative terminals  132  and  138 ) to retain the inserted terminals at their respective positions. 
     In some embodiments, the TPA feature  136  may include one or more recesses (e.g., a recess  504 ) configured to receive a locking feature of a corresponding inserted terminal (e.g., the illustrative locking feature  232  shown in  FIG. 2A ). For instance, in the example shown in  FIG. 5B , the locking feature may be vertically aligned with the recess  504  when the corresponding terminal is correctly inserted, and the recess  504  may fit over the locking feature when the TPA feature  136  is pushed up into the engaged position. 
       FIG. 6A  shows a bottom view of the illustrative receptacle  130  shown in  FIG. 1B , partially cut away to show illustrative locking features of inserted terminals, in accordance with some embodiments.  FIG. 6B  shows an enlarged view of an area  602  of  FIG. 6A . 
     In the example shown in  FIGS. 6A-B , each of the housing  402  and the TPA feature  136  has one or more recesses configured to receive a locking feature of a inserted terminal. For instance, the housing  402  may have recesses (e.g., a recess  606 ) configured to receive locking features of inserted terminals at a top row (e.g., a locking feature  608 T), whereas the TPA feature  136  may have recesses (e.g., a recess  604 ) configured to receive locking features of inserted terminals at a bottom row (e.g., a locking feature  608 B). 
     The inventors have recognized and appreciated that spacing between terminals (and therefore board pitch) may be reduced by providing one or more recesses at the TPA feature  136 , as opposed to all recesses being provided at the housing  402 . However, it should be appreciated that aspects of the present disclosure are not limited to having any recess at the TPA feature  136  to receive a locking feature of an inserted terminal, or to the use of any TPA feature at all. 
       FIG. 7  shows another cross-sectional view of the illustrative receptacle  130  shown in  FIG. 1B , in accordance with some embodiments. In this example, the protrusion  410  of the TPA feature  136  has a ramped top profile  702  configured to facilitate gliding of the terminal  132  into the cavity  404 . For instance, the ramped top profile  702  may prevent damage of the terminal  132  due to stubbing during insertion. 
       FIG. 8  shows another cross-sectional view of the illustrative receptacle  130  shown in  FIG. 1B , in accordance with some embodiments. In this example, the TPA feature  136  has a tapered side profile  802  configured to facilitate gliding of a terminal into a cavity adjacent the tapered side profile  802 . For instance, the tapered side profile  802  may prevent damage of the terminal due to stubbing during insertion. 
       FIG. 9A  shows an illustrative connector  900 A, in accordance with some embodiments. In this example, the connector  900 A has a receptacle with a latch  902 A, as well as a header with an opening  904 A configured to engage the latch  902 A. The latch  902 A and the opening  904 A may engage each other when the receptacle is mated with the header. When engaged, the latch  902 A and the opening  904 A may prevent the receptacle and the header from becoming unmated (e.g., due to vibration in an operating environment). 
     In the example of  FIG. 9A , the connector  900 A also includes a TPA feature  906 A, which may be similar to the illustrative TPA feature  136  in the example of  FIG. 1B . For instance, the TPA feature  906 A may be configured to retain terminals inserted into the receptacle of the connector  900 A. 
       FIG. 9B  shows an illustrative connector  900 B, in accordance with some embodiments. The connector  900 B may be similar to the illustrative connector  900 A shown in  FIG. 9A , although the connector  900 A may have a single row of terminals, whereas the connector  900 B may have two rows of terminals. Furthermore, in some embodiments, the connector  900 B may have two TPA features, instead of one. For instance, a bottom TPA feature  906 B may be configured to engage with terminals in a bottom row, and a top TPA feature  908 B may be configured to engage with terminals in a top row. 
     In the example of  FIG. 9B , the connector  900 B includes a receptacle with a latch  902 B and a header with an opening  904 B configured to engage the latch  902 B. The latch  902 B and the opening  904 B may engage each other when the receptacle is mated with the header. When engaged, the latch  902 B and the opening  904 B may prevent the receptacle and the header from becoming unmated (e.g., due to vibration in an operating environment). However, unlike the illustrative latch  902 A in the example of  FIG. 9A , which is located at a receptacle housing, the latch  902 B in the example of  FIG. 9B  is located at the top TPA feature  908 B. 
     The inventors have recognized and appreciated that molding operations may be simplified by having a latch at a top TPA feature (e.g., as in the example of  FIG. 9B ), instead of a receptacle housing (e.g., as in the example of  FIG. 9A ). For instance, a number of mold slides may be reduced, thereby reducing manufacturing costs. However, it should be appreciated that aspects of the present disclosure are not limited to any particular location for a latch, or to the use of any latch at all. 
       FIG. 10  shows illustrative header housings  1002  and  1004 , in accordance with some embodiments. In this example, the header housings  1002  and  1004  are configured to be attached to each other. For instance, the header housing  1002  may include a tongue  1006  and the header housing  1004  may include a similar tongue (obscured in this view), while the header housing  1004  may include a groove  1008  and the header housing  1002  may include a similar groove (obscured in this view). The tongue of the header housing  1004  and the groove of the header housing  1002  may be configured to sliding engage each other, thereby attaching the header housings  1002  and  1004  to each other. In this manner, a number of desired electrical connections may be provided by attaching two or more connectors together. 
     In the example of  FIG. 10 , the tongue of the header housing  1004  and the groove of the header housing  1002  form a dovetail joint, which may provide improved tensile strength. However, it should be appreciated that aspects of the present disclosure are not limited to the use of any particular technique for joining together multiple connectors, or to the used of joined connectors at all. 
       FIG. 11A  shows an illustrative header  1100 , in accordance with some embodiments. The header  1100  may be used in any suitable connector, such as the illustrative connector  100  shown in  FIGS. 1A-B . For instance, the header  1100  may be used as the illustrative header  140  shown in  FIG. 1B . 
     In the example shown in  FIG. 11A , the header  1100  has a housing  1105  with a cavity  1142  configured to receive a receptacle (e.g., the illustrative receptacle  130  shown in  FIG. 1B ). One or more contact pins, such as a contact pin  1125 , may be held in the housing  1105  such that, when a receptacle is inserted into the cavity  1142 , a mating end of the contact pin  1125  forms an electrical connection with a mating end of a terminal of the receptacle (e.g., the illustrative terminal  132  shown in  FIG. 1B ). 
     In some embodiments, the header  1100  may include one or more features configured to secure the header  1100  to a PCB. In the example shown in  FIG. 11A , the header  1100  includes a hold-down  1144  configured to be fastened to the header  1100  and a PCB. For instance, each vertical edge of the hold-down  1144  may be configured to slide into a respective vertical groove formed in the housing  1005 , such as a groove  1110 . In this manner, once the hold-down  1144  is fastened to a PCB, the header  1100  may be prevented from moving laterally (e.g., x or y direction) relative to the PCB. 
     Additionally, or alternatively, as shown at  1115 , the hold-down  1144  may include one or more beams, such as a beam  1120 , configured to exert a spring force against the housing  1105 .  FIG. 11B  shows a cross-sectional view of the illustrative header  1100  of  FIG. 11A , in accordance with some embodiments. In this example, the beam  1120  has an angled end portion configured to engage a ledge  1130  formed on a side wall of the housing, thereby exerting a downward spring force against the housing  1105 . Thus, once the hold-down  1144  is fastened to a PCB, the header  1100  may be prevented from moving vertically (e.g., z direction) relative to the PCB. 
     Although not visible in  FIGS. 11A-B , a hold-down similar to the hold-down  1144  may be fastened to an opposite side of the housing  1105  in a similar manner. Together, these hold-downs may hold the header  1100  in place despite vibration in an operating environment (e.g., in an automotive application). However, it should be appreciated that aspects of the present disclosure are not limited to any particular design for a hold-down, or to the use of any hold-down at all.  FIG. 12A  shows an illustrative connector  1200 , in accordance with some embodiments. The connector  1200  may be similar to the illustrative connector  100  shown in  FIG. 1A , and may include a receptacle  1230  and a header  1240  configured to mate with each other. 
     In some embodiments, the connector  1200  may include a connector position assurance (CPA) feature configured to provide an indication of whether the receptacle  1230  and the header  1240  are properly mated with each other. For instance, in the example shown in  FIG. 12A , the connector  1200  includes a CPA feature  1234  that is movable between a disengaged configuration and an engaged configuration. 
       FIG. 12B  shows a cross-sectional view of the illustrative connector  1200  of  FIG. 12A , in accordance with some embodiments. In this view, the receptacle  1230  and the header  1240  are partially mated, and the CPA feature  1234  is in a disengaged configuration. 
     In some embodiments, the CPA feature  1234  may be attached to the receptacle  1230 . For instance, in the example shown in  FIGS. 12A-B , the CPA feature  1234  includes a first latch  1235  configured to engage with the receptacle  1230 . The first latch  1235  may be made of a resilient material, and may be configured to exert a spring force against the receptacle  1230 , thereby preventing the CPA feature  1234  from being detached from the receptacle  1230 . Additionally, or alternatively, an end portion of the first latch  1235  may have a protrusion configured to engage a corresponding protrusion  1236  formed on a housing of the receptacle  1230 , thereby preventing the CPA feature  1234  from being detached from the receptacle  1230 . 
     In some embodiments, when the receptacle  1230  is not fully mated with the header  1240 , the CPA feature  1234  may be prevented from moving into the engaged configuration. For instance, in the example shown in  FIGS. 12A-B , the CPA feature  1234  includes a second latch  1237 , and a protrusion  1238  is formed on the housing of the receptacle  1230  to stop the second latch  1237 , thereby preventing the CPA feature  1234  from moving into the engaged configuration. 
     In some embodiments, when the receptacle  1230  becomes fully mated with the header  1240 , the CPA feature  1234  may be allowed to move into the engaged configuration, For instance, in the example shown in  FIGS. 12A-B , the second latch  1237  may be made of a resilient material, and a protrusion  1241  may be formed on a housing of the header  1240  so that, as the receptacle  1230  is inserted into the header  1240 , the protrusion  1241  formed on the header  1240  causes the second latch  1237  to deflect away from the protrusion  1238  formed on the receptacle  1230 . Once the second latch  1237  clears the protrusion  1238  formed on the receptacle  1230 , the CPA feature  1234  may be pushed fully into the receptacle  1230 . 
       FIG. 12C  shows the illustrative latch  1237  contacting the illustrative protrusion  1241  of  FIGS. 12A-B , in accordance with some embodiments. In this example, the protrusion  1241  formed on the header  1240  has an angled surface  1242  configured to guide the latch  1237 . As the receptacle  1230  is inserted into the header  1240  along a mating direction D, an end portion of the second latch  1237  may glide along the angled surface  1242 , which may cause the second latch  1237  to deflect away from the protrusion  1238  formed on the receptacle  1230 . (in  FIG. 12C , the protrusion  1238  is obscured from view by the protrusion  1241 .) 
       FIG. 12D  shows the illustrative latch  1237  being deflected by the illustrative protrusion  1241  of  FIGS. 12A-B , in accordance with some embodiments. In this example, the second latch  1237  is just about to clear the protrusion  1238  formed on the receptacle  1230 . (In  FIG. 12C , the protrusion  1238  is obscured from view by the protrusion  1241 .) Once the second latch  1237  clears the protrusion  1238 , the second latch  1237  may enter a passageway  1239 , thereby allowing the CPA feature  1234  to be pushed fully into the receptacle  1230 . 
       FIG. 12E  shows the illustrative CPA feature  1234  of  FIGS. 12A-B , in an engaged configuration, in accordance with some embodiments. In this configuration, the CPA feature  1234  is pushed fully into the receptacle  1230 , and the end portion of the second latch  1237  may engage the protrusion  1241  formed on the header  1240 , thereby preventing the receptacle  1230  and the header  1240  from being unmated (e.g., due to vibration in an operating environment). 
     Techniques described herein may be used in connectors having configurations other than those described above. For example, techniques described herein may be used in mezzanine connectors or in backplane connectors. 
     Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Further, though advantages of the present invention are indicated, it should be appreciated that not every embodiment of the invention will include every described advantage. Some embodiments may not implement any features described as advantageous herein and in some instances. Accordingly, the foregoing description and drawings are by way of example only. 
     Various aspects of the present invention may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described in the foregoing and is therefore not limited in its application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments. 
     Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. 
     All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. 
     The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” 
     As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. 
     The phrase “and/or.” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc. 
     As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law. 
     Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.