Abstract:
An electrical connector for coupling two electrical connectors is described, the electrical connector configured to couple with a first complementary connector by means of a tongue portion and a pair of end walls, the tongue portion comprising first, second and third tongue sections; a plurality of contacts positioned in the connector housing; and wherein the contacts are grouped into first set and second sets of contacts positioned in the first and second tongue sections respectively. In another embodiment, the contacts are grouped into first, second and third sets of contacts positioned in the first, second and third tongue sections respectively. In another embodiment, an interconnect system having at least one electrical connector coupled to two electrical connectors is described.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a connector and in particular to an electrical connector for coupling two electrical connectors. 
       BACKGROUND 
       [0002]    Hard disk drives (HDDs) are used to store digital data content for laptops, desktop computers, servers and other electronic devices in use today. Each of these electronic devices has its own requirements for the storage media to be used such as access time, capacity, form factor, reliability, and data throughput. Throughput represents the amount of data that a HDD can deliver at any given moment. The throughput is usually measured in bit(s) per second (bps). 
         [0003]    Every HDD interface communicates with the rest of the computer via the computer input/output (I/O) bus. The interface is the communication channel over which the data flows as the data is read from or written to the HDD. There are many types of HDD interface and they include Integrated Drive Electronics (IDE), Advanced Technology Attachment (ATA), Small Computer System Interface (SCSI), Serial ATA (SATA), Serial Attached SCSI (SAS), and Fibre Channel. Bridge circuitry is sometimes used to connect HDDs to buses that they cannot communicate with natively, such as IEEE 1394 and Universal Serial Bus (USB). The list of HDD interfaces described in this section is not exhaustive and is constantly increasing to keep pace with the ever changing demands of the electronic devices which dictate the specifications of the HDDs and their interfaces. The interface can be a bottleneck to the overall performance of the electronic device if it cannot support the HDD&#39;s maximum throughput. 
         [0004]    The SATA connector and the SAS connector are the two most commonly used connectors in the HDD industry today. The SATA headers are often used on HDDs that are fitted with laptops and desktop computers while the SAS headers are used on HDDs fitted with enterprise server systems. 
         [0005]    Available in the market today are specialized production test equipment for the testing of HDDs before they are released for sale. However, most of these test equipments are designed specifically for HDDs with a particular type of interface. 
         [0006]    It would be desirable to provide an electrical connector that can be used for the testing of a HDD regardless of whether the HDD is fitted with a SATA header or a SAS header. It would be desirable if the electrical connector can further couple with the existing SAS socket thereby allowing the existing SAS socket to be used on the backplane of the printed circuit board (PCB) for the production test equipment. Additionally, it would also be desirable if the electrical connector can be easily modified to serve its purpose of connecting two other connectors as the HDD interface technology continues to evolve. 
       SUMMARY 
       [0007]    In accordance with one embodiment there is provided an electrical connector for coupling two electrical connectors, comprising:
       an elongated insulative housing comprising a longitudinal base portion, having a first mating surface and a second mating surface;   wherein the first mating surface is configured to couple with a second complementary connector by means of a central slot defined between a first side wall, a second side wall and a pair of end walls, all walls extending from the base portion;   wherein the second mating surface is configured to couple with a first complementary connector by means of a tongue portion and a pair of end walls, both the tongue portion and the end walls extending from the base portion, the tongue portion comprising a first tongue section, a second tongue section and a third tongue section; and   a plurality of contacts positioned in the housing; wherein the contacts are grouped into a first set and a second set of contacts positioned in the first tongue and the second tongue sections respectively.       
 
         [0012]    In accordance with another embodiment there is provided an interconnect system having at least one electrical connector for coupling two electrical connectors, said electrical connector comprising:
       an elongated insulative housing comprising a longitudinal base portion, having a first mating surface and a second mating surface;   wherein the first mating surface is configured to couple with a second complementary connector by means of a central slot defined between a first side wall, a second side wall and a pair of end walls, all walls extending from the base portion;   wherein the second mating surface is configured to couple with a first complementary connector by means of a tongue portion and a pair of end walls, both the tongue portion and the end walls extending from the base portion, the tongue portion comprising a first tongue section, a second tongue section and a third tongue section;   a plurality of contacts positioned in the housing; wherein the contacts are grouped into a first set and a second set of contacts positioned in the first tongue and the second tongue sections respectively; and   wherein one or both of a first complementary connector and a second complementary connector is coupled to the electrical connector.       
 
         [0018]    In accordance with another embodiment there is an electrical connector for coupling two electrical connectors, comprising:
       an elongated insulative housing comprising a longitudinal base portion having a first mating surface and a second mating surface;   wherein the first mating surface is configured to couple with a second complementary connector by means of a central slot defined between a first side wall, a second side wall and a pair of end walls, all walls extending from the base portion;   wherein the second mating surface is configured to couple with a first complementary connector by means of a tongue portion and a pair of end walls, both the tongue portion and the end walls extending from the base portion, the tongue portion comprising a first tongue section, a second tongue section and a third tongue section; and   a plurality of contacts positioned in the housing; wherein the contacts are grouped into a first set, a second set and a third set of contacts positioned in the first tongue, the second tongue and the third tongue sections respectively.       
 
         [0023]    In accordance with another embodiment there is provided an interconnect system having at least one electrical connector for coupling two electrical connectors, said electrical connector comprising:
       an elongated insulative housing comprising a longitudinal base portion having a first mating surface and a second mating surface;   wherein the first mating surface is configured to couple with a second complementary connector by means of a central slot defined between a first side wall, a second side wall and a pair of end walls, all walls extending from the base portion;   wherein the second mating surface is configured to couple with a first complementary connector by means of a tongue portion and a pair of end walls, both the tongue portion and the end walls extending from the base portion, the tongue portion comprising a first tongue section, a second tongue section and a third tongue section; and   a plurality of contacts positioned in the housing; wherein the contacts are grouped into a first set, a second set and a third set of contacts positioned in the first tongue, the second tongue and the third tongue sections respectively; and   wherein one or both of a first complementary connector and a second complementary connector is coupled to the electrical connector.       
 
         [0029]    The invention may further be said to consist in any alternative combination of parts or features mentioned herein or shown in the accompanying drawings. Known equivalents of these parts or features which are not expressly set out are nevertheless deemed to be included. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    An exemplary form of the present invention will now be described with reference to the accompanying drawings in which: 
           [0031]      FIG. 1  shows an example of a SATA socket soldered on a rigid PCB that is bonded to a flexible PCB; 
           [0032]      FIG. 2A  shows an example of an interface socket used for coupling a sacrificial SATA socket to a backplane PCB; 
           [0033]      FIG. 2B  shows an example of a sacrificial SATA socket; 
           [0034]      FIG. 2C  shows an example of a SATA header on a PCB for a HDD used for coupling to a sacrificial SATA socket; 
           [0035]      FIG. 3  shows a diagrammatic representation of how a sacrificial SATA socket is coupled to an interface socket on the backplane PCB and a SATA header on the PCB of a HDD; 
           [0036]      FIG. 4A  is a perspective view of an exemplary connector of the present invention in relation to a complementary connector that is intended to be coupled to a backplane PCB of a production test equipment; 
           [0037]      FIG. 4B  is a perspective view of the exemplary connector of the present invention viewed from the second surface of the connector; 
           [0038]      FIG. 5  is a perspective view of the exemplary connector of the present invention and the contacts which will be inserted into the exemplary connector of the present invention; 
           [0039]      FIG. 6A  is a perspective view of the exemplary connector of the present invention viewed from the first mating surface; 
           [0040]      FIG. 6B  is a perspective view of the exemplary connector of the present invention viewed from the second mating surface; 
           [0041]      FIG. 7  is a perspective view of the different parts of a contact located in the exemplary connector of the present invention; 
           [0042]      FIG. 8  is a cross-sectional view of the exemplary connector of the present invention with one contact exposed; 
           [0043]      FIG. 9  is a perspective view of the exemplary connector of the present invention in relation to a first complementary connector that is intended to be coupled to a backplane PCB of a production test equipment and to a second complementary connector that is intended to be coupled to a PCB which is further coupled to a data storage device; 
           [0044]      FIG. 10A  is a perspective view of one other exemplary connector of the present invention in relation to a complementary connector that is intended to be coupled to a backplane PCB of a production test equipment; 
           [0045]      FIG. 10B  is a perspective view of the exemplary connector of  FIG. 10A  with a different base extension portion; 
           [0046]      FIG. 11  is a perspective view of the exemplary connector of  FIG. 10A  and the contacts which will be inserted into the connector; 
           [0047]      FIG. 12A  is a perspective view of the exemplary connector of  FIG. 10A  viewed from the first mating surface; and 
           [0048]      FIG. 12B  is a perspective view of the exemplary connector of  FIG. 10A  viewed from the second mating surface. 
       
    
    
     DETAILED DESCRIPTION 
       [0049]    The SATA connector and the SAS connector are the two most commonly used connectors in the HDD industry today. The SATA headers are often used on HDDs that are fitted with laptops and desktop computers while the SAS headers are used on HDDs fitted with enterprise server systems. The SATA interface comprises one segment with 7 pins (contacts) used for the transmission of data signals and another segment with 15 pins (contacts) used for the conduction of electrical power, both segments having a pitch of 1.27 mm (0.05″). For the SAS interface, in addition to the two segments mentioned earlier, there is one more segment with 7 pins having a pitch of 0.80 mm (0.03″) used for the transmission of data signals. 
         [0050]    Available in the market today are specialized production test equipment for the testing of HDDs before they are released for sale. However, most of these test equipments are designed specifically for HDDs with a particular type of interface such as SATA. 
         [0051]      FIG. 1  shows an example of a SATA socket  20  soldered on a rigid PCB  22  that is bonded to a flexible PCB  24 . The flexible PCB  24  will be coupled to a production test equipment via another connector (not shown) when in use. A SATA header (not shown) on a PCB of a HDD-to-be-tested is plugged into the SATA socket  20  on the rigid PCB  22  before the test sequences on the production test equipment which the flexible PCB  24  is coupled to are executed. The SATA header on the PCB of the HDD that is tested is unplugged from the SATA socket  20  on the rigid PCB  22  after the tests are completed. Each plugging and unplugging of the SATA header to and from the SATA socket  20  is known as a mating cycle. The performance of the SATA socket  20  on the rigid PCB  22  drops with repeated mating. The SATA socket  20  on the rigid PCB  22  is replaced as soon as the number of mating cycles reaches the number specified by the manufacturer of the SATA socket  20 . To replace the SATA socket  20  on the rigid PCB  22 , one has to de-solder the existing SATA socket  20  from the rigid PCB  22  and then re-solder a new SATA socket  20  to the rigid PCB  22  before both rigid PCB  22  and flexible PCB  24  can be re-used with the production test equipment for testing HDDs. This is time consuming and repeated de-soldering and re-soldering of the SATA socket  20  from and to the rigid PCB  22  may damage the rigid PCB  22 . 
         [0052]    An alternative solution is to couple an interface socket to a backplane PCB of a production test equipment and then use a sacrificial connector to couple a header on a PCB of a HDD to the interface socket on the backplane PCB of the production test equipment. The sacrificial connector should have a socket that is able to accept the interface of the header coupled on the PCB of the HDD. 
         [0053]      FIG. 2A  shows an example of an interface socket  30  used for coupling a sacrificial SATA connector to a backplane PCB.  FIG. 2B  shows an example of a sacrificial SATA connector  40  specially designed to be used with the interface socket  30 .  FIG. 2C  shows an example of a SATA header  50  used on a PCB of a HDD that can couple to the sacrificial SATA connector  40 . 
         [0054]      FIG. 3  shows a diagrammatic representation of how a sacrificial SATA connector  40  is coupled to an interface socket  30  on a backplane PCB  601  of a production test equipment  610  and a SATA header  50  on a PCB  602  of a HDD  620 . The interface socket  30  has a plurality of socket holes  32  on a first major side to accept a plurality of long tails  44  of the sacrificial SATA connector  40  to be coupled. On a second major side of the interface socket  30 , there is a plurality of long tails (not shown) corresponding to the positions of the socket holes  32  on the first major side, the long tails on the second major side are used for bonding the interface socket  30  to the backplane PCB  601  of the production test equipment  610 . 
         [0055]    With this arrangement, the SATA header  50  on the PCB  602  of the HDD  620  mates with the sacrificial SATA connector  40  instead of mating directly with the interface socket  30  that is bonded to the backplane PCB  601  of the production test equipment  610 . Therefore, it takes a longer period of use before there is a need to replace the interface socket  30  on the backplane PCB  601 . The sacrificial SATA connector  40  is replaced as soon as the usage reaches the number of maximum mating cycles specified by the manufacturer of the sacrificial SATA connector  40 . As the sacrificial SATA connector  40  is temporarily bonded to the interface socket  30 , there is less damage to the interface socket  30  when the sacrificial SATA connector  40  is replaced. And since it takes a longer period of use before the interface socket  30  has to be replaced, the lifespan of the backplane PCB  601  can be increased. 
         [0056]    The above design works only if the header on the PCB of the HDD-to-be-tested is of the SATA interface. The production test equipment  610  with the interface socket  30  cannot be used to test a HDD with a SAS header on its PCB unless the sacrificial SATA connector  40  is replaced with a similar sacrificial connector that has a SAS socket. At the same time, the interface socket and the backplane PCB of the production test equipment will need to be redesigned to accept the additional seven long tails of the sacrificial SAS connector corresponding to the additional segment in the SAS interface used for the transmission of data signals. 
         [0057]    As previously highlighted, the additional segment on the SAS interface is of a smaller pitch (0.80 mm or 0.03″) compared to the two segments on the SATA interface (1.27 mm or 0.05″). This reduced pitch poses additional challenges to the manufacture of the additional seven long tails in the sacrificial SAS connector. 
         [0058]    The need to redesign the backplane PCB, the interface socket and the sacrificial connector coupled with the need to have a dedicated production test equipment for testing HDDs with SATA headers and another production test equipment for testing HDDs with SAS headers, increase the manufacturing costs for HDD manufacturers. 
         [0059]    A solution to the above problem is to have a sacrificial connector that can be used for the testing of both the SATA and SAS HDDs using the same production test equipment without a need for a major redesign to the existing backplane PCB of the production test equipment. It will also be useful if the sacrificial connector has a header that can couple with a commonly available SAS interface socket on the backplane PCB instead of having long tails on the sacrificial connector which then require an interface socket that has holes specially designed to match the long tails on the sacrificial connector. 
         [0060]    An exemplary electrical connector  100  of the present invention is a sacrificial connector that can be used for the testing of both the SATA and SAS HDDs. In addition, the electrical connector  100  will mate with a commonly available SAS interface socket thereby minimizing the amount of design changes needed on the backplane PCB of the production test equipment. 
         [0061]    With reference to  FIGS. 4A ,  4 B,  5 ,  6 A,  6 B and  9 , the exemplary electrical connector  100  of the present invention comprises an elongated, insulative housing  110  with a longitudinal base portion  115  and a plurality of first set, second set and third set of contacts  310 ,  320 ,  330  received in the housing  110 . The housing  110  forms a first mating surface  160  and a second mating surface  165 . 
         [0062]    At the first mating surface  160 , a first side wall  120 , a second side wall  122  and a pair of end walls  124 ,  126  extend from the base portion  115 . A central receiving slot  130  is defined between the longitudinally extending side walls  120 ,  122  and the laterally extending end walls  124 ,  126  for engaging with a second complementary connector  48  at the first mating surface  160 . In at least one embodiment, the second complementary connector  48  is a SATA header. In at least one other embodiment, the second complementary connector  48  is a SAS header. 
         [0063]    The first side wall  120  has a recess  132  recessed from an inner face thereof which divides the first side wall  120  into a first mating section  1601  and a second mating section  1602 . The first mating section  1601  of the first side wall  120  is longer than the second mating section  1602 . The second side wall  122  has a third mating section  1603  at a position opposing to the recess  132  of the first side wall  120 . 
         [0064]    A pair of guiding posts  146  protrude from the base portion  115  and next to the respective end walls  124 ,  126 . Each guiding post  146  forms a tapered guiding portion  1461  extending beyond the first mating surface  160  of the housing  110  for guiding an insertion of a second complementary connector  48 . 
         [0065]    At the second mating surface  165 , a tongue portion  200  and a pair of opposite end walls  210  extend from the base portion  115 . Each end wall  210  has a guiding space  143  for guiding the insertion of the first complementary connector  45 . The tongue portion  200  includes opposite first and second surfaces  201 ,  202  and forms a first tongue section  221  adjacent to one end wall  210 , a second tongue section  222  adjacent to the other end wall  210 , and a third tongue section  223  between the first and the second tongue sections  221 ,  222 . The first and second tongue sections  221 ,  222  have a plurality of passages  240  in the first surface  201  of the tongue portion  200  and the third tongue section  223  has a plurality of passages  240  in the second surface  202  of the tongue portion  200 . In at least one embodiment, the first complementary connector  45  is a SAS socket. 
         [0066]    The first, the second and the third mating sections  1601 ,  1602 ,  1603  at the first mating surface  160  each has a plurality of passageways  245  that extends from the first mating surface  160  to the second mating surface  165  and respectively communicate with the corresponding passages  240  in the tongue portion  200 . The passageways  245  in the first and the second mating sections  1601 ,  1602  are arranged in a same row. The passageways  245  in the third mating section  1603  are arranged in another row and this row is located lower than the row for the first and the second mating sections  1601 ,  1602 . 
         [0067]    Referring to  FIG. 5  in conjunction with  FIGS. 7 to 9 , the contacts  300  include a set of first set of contacts  310  mainly for power transmission, a second set and a third set of contacts  320 ,  330  both for signal transmission. 
         [0068]    The first set, second set and third set of contacts  310 ,  320 ,  330  respectively protrude through the passageways  245  of the first, second and third mating sections  1601 ,  1602 ,  1603  and are received in the corresponding passages  240  of the tongue portion  200 . The three sets of contacts  300  are substantially identical in structure, and only one of the contacts  300  is illustrated here for simplicity. 
         [0069]    Each contact  300  comprises a first contact portion  302  which will reside at central receiving slot  130  of the housing  110 , a second contact portion  303  which will reside at tongue portion  200  of the housing  110 , and a housing retaining portion  308  interconnecting the first contact portion  302  and the second contact portion  303 . 
         [0070]    In the design of the first contact portion  302  of the contact  300  at the first mating surface  160 , one has to take into consideration the desired insertion and normal forces  400 ,  410  permissible for the second complementary connector  48 . In order for the electrical connector  100  to be able to withstand a higher number of mating cycles, the insertion and normal forces  400 ,  410  have to be kept to a minimum. 
         [0071]    In one embodiment of the present invention, the first contact portion  302  may be a cantilever beam structure which comprises a first part  3021  of the first contact portion  302 , a second part  3022  of the first contact portion  302  and a kink  3020  separating the first part  3021  and the second part  3022 . As illustrated in  FIG. 7 , the first part  3021  of the first contact portion  302  is inclined at a first angle  3024  to the horizontal position while the second part  3022  of the first contact portion  302  is inclined at a second angle  3025  to the horizontal position. This cantilever beam design forms a convex contact end exposed in the central receiving slot  130  of the housing  110  for electrically engaging with a corresponding terminal of the second complementary connector  48  at the first mating surface  160 . Preferably the first angle  3024  is of a value of about less than 20 degrees and the second angle  3025  is of a value of about 20 degrees to 25 degrees. 
         [0072]    The second contact portion  303  has a flat shape and is exposed in the corresponding passage  240  of the tongue portion  200  of the housing  110  for electrically engaging with a corresponding terminal of the first complementary connector  45  at the second mating surface  165 . The second contact portion  303  may be bonded to the housing  110  by incorporating a ‘U’ hook structure  306  at the second mating surface  165  to prevent the second contact portion  303  from lifting away from the housing  110  as a result of repeated mating with the first complementary connector  45 . Other methods of bonding the second contact portion  303  to the housing  110  may be adopted and are within the scope of the invention. The housing retaining portion  308  provides a barb on a lateral edge for interfering within the housing  110 . 
         [0073]    Conventional electrical connectors are able to withstand a minimum of 500 mating cycles to about 5,000 mating cycles. The exemplary electrical connector  100  of the present invention is able to withstand a minimum of 5,000 mating cycles to about 10,000 mating cycles. Different materials such as phosphor bronze or beryllium copper with nickel and gold plating, or other types of copper alloys with the equivalent metal plating, may be used to manufacture the contacts  300 . The design of the contacts  300  as well as the choice of material used for the contacts  300  will determine the maximum limit of mating cycles for the electrical connector  100 . 
         [0074]    In another embodiment of the present invention, the electrical connector  100  may further comprise a bonding device  140  coupled to at least one end wall  210 . The bonding device  140  may be any device that is able to temporarily hold the electrical connector  100  in place with respect to the first complementary connector  45  at the second mating surface  165  as the second complementary connector  48  connects and disconnects to and from the electrical connector  100  at the first mating surface  160  during each mating cycle. The bonding device  140  may be integrally assembled with the housing  110  and should enable the electrical connector  100  to be easily de-coupled from the first complementary connector  45  as and when there is a need to remove the electrical connector  100  from the first complementary connector  45  or replace the electrical connector  100  with another electrical connector  100 . 
         [0075]    In another embodiment of the present invention, the bonding device  140  is a latching device with a latch release  1401 , a latch member  1402  extending in the direction of the second mating surface  165  and a hole  1403  in the latch member  1402 . With reference to  FIG. 4A , as the electrical connector  100  mates with the first complementary connector  45  at the second mating surface  165 , a protrusion  142  coupled to an end wall on the first complementary connector  45  pushes the latch member  1402  outwards away from the end wall of the first complementary connector  45  as the latch member  1402  rides over the slope of protrusion  142 . As the latch member  1402  passes the ridge of the protrusion  142 , the hole  1403  in the latch member  1402  engages with the protrusion  142  of the complementary connector  45  causing the latch member  1402  to fall back to its original horizontal position. This is the locked position of the latching device and the electrical connector  100  is firmly coupled to the first complementary connector  45 . 
         [0076]    To de-couple the electrical connector  100  from the first complementary connector  45 , the latch release  1401  is depressed inwards towards the housing  110  of the electrical connector  100 . In doing so, the hole  1403  in the latch member  1402  disengages with the protrusion  142  on the first complementary connector  45 , and the two connectors  100 ,  45  can be easily de-coupled by pulling the electrical connector  100  in a direction away from the first complementary connector  45 . 
         [0077]    It is preferable that the electrical connector  100  has a bonding device  140  at each end wall  210  so that the electrical connector  100  can be properly aligned to the first complementary connector  45  when they are coupled. Accordingly, there should be a protrusion at each end wall of the first complementary connector  45 . In another embodiment of the present invention, the bonding device  140  may be cantilevered and may be made of sheet metal. 
         [0078]    A new type of HDD interface that is emerging today is the Micro SATA interface. This type of interface is currently targeted at HDDs which have the requirement of small form factor and low power consumption. At this moment, HDDs with this type of HDD interface are used in laptops where the there is limited real estate within the laptops for the HDDs and the power consumption of these HDDs is a concern. Like the SATA interface, the Micro SATA interface comprises one segment for the transmission of data signals and another segment for the conduction of electrical power, both segments having a pitch of 1.27 mm (0.05″). The difference between the SATA interface and the Micro SATA interface is that for the Micro SATA interface, the number of pins (contacts) used for the conduction of electrical power has been reduced from 15 to 9 and the segment allocated for the conduction of electrical power is further divided into 2 smaller segments by a base portion extension. Of the 9 pins (contacts) allocated for the conduction of electrical power, 7 pins (contacts) are in the longer segment and the remaining 2 pins are in the shorter segment. 
         [0079]    In another embodiment of the present invention, the electrical connector  2000  is a sacrificial connector that can be used for the testing of the Micro SATA HDDs. In addition, the electrical connector  2000  will mate with both a standard Micro SATA interface socket and a Micro SATA header. The circuitry on the backplane PCB of existing production test equipment may need to be slightly modified to accept the Micro SATA interface socket. 
         [0080]    With reference to  FIGS. 10A ,  10 B,  11 ,  12 A and  12 B, the exemplary electrical connector  2000  of the present invention comprises an elongated, insulative housing  2110  with a longitudinal base portion  2115  and a plurality of first set, second set and third set of contacts  2310 ,  2320 ,  2330 , received in the housing  2110 . The housing  2110  forms a first mating surface  2160  and a second mating surface  2165 . 
         [0081]    At the first mating surface  2160 , a first side wall  2120 , a second side wall  2122  and a pair of end walls  2124 ,  2126  extend from the base portion  2115 . A central receiving slot  2130  is defined between the longitudinally extending side walls  2120 ,  2122  and the laterally extending end walls  2124 ,  2126  for engaging with a second complementary connector  2048  at the first mating surface  2160 . In at least one embodiment, the second complementary connector  2048  is a Micro SATA header. 
         [0082]    The first side wall  2120  has a first base recess and a second base recess  2132 ,  2134  recessed from an inner face thereof which divides the first side wall  2120  into a first mating section  21601 , a second mating section  21602  and a third mating section  21603 . The first mating section  21601  of the first side wall  2120  is shorter than the second and the third mating sections  21602 ,  21603 . The second mating section  21602  of the first side wall  2120  may be of the same length as the third mating sections  21603 . 
         [0083]    A pair of guiding posts  146  protrude from the base portion  2115  and next to the respective end walls  2124 ,  2126 . Each guiding post  146  forms a tapered guiding portion  1461  extending beyond the first mating surface  2160  of the housing  2110  for guiding an insertion of a second complementary connector  2048 . 
         [0084]    At the second mating surface  2165 , a tongue portion  2200  with opposite first and second surfaces  2201 ,  2202  and a pair of opposite end walls  2210  extend from the base portion  2115 . Each end wall  2210  has a guiding space  143  for guiding the insertion of the first complementary connector  2045 . The tongue portion  2200  is divided into a first tongue section, a second tongue section and a third tongue section  2221 ,  2222 ,  2223  by a first base extension portion  2721  and a second base extension portion  2722  respectively. 
         [0085]    The first base extension portion  2721  is narrower in width than the second base extension portion  2722 . The base extension portion may adopt different forms. In  FIG. 10A , the first and the second base extension portions  2721 ,  2722  are solid portions with thickness greater than that of the first, the second and the third tongue sections  2221 ,  2222 ,  2223 . In  FIG. 10B , the second base extension  2722  is a channel defined by two channel side walls  2723  and a channel base  2724  with the thickness of the channel base  2724  being the same as that of the first, the second and the third tongue sections  2221 ,  2222 ,  2223 . 
         [0086]    The first, second and third tongue sections  2221 ,  2222 ,  2223  have a plurality of passages  2240  in the first surface  2201  of the tongue portion  2200 . The first, the second and the third mating sections  21601 ,  21602 ,  21603  at the first mating surface  2160  each has a plurality of passageways  2245  that extends from the first mating surface  2160  to the second mating surface  2165  and respectively communicate with the corresponding passages  2240  in the tongue portion  2200 . 
         [0087]    Referring to  FIG. 11 , the contacts  2300  include a set of first set and a second set of contacts  2310 ,  2320  both for power transmission and a third set of contacts  2330  for signal transmission. The first set, second set and third set of contacts  2310 ,  2320 ,  2330  respectively protrude through the passageways  2245  of the first, second and third mating sections  21601 ,  21602 ,  21603  and are received in the corresponding passages  2240  of the tongue portion  2200 . The three sets of contacts  2300  are substantially identical in structure and function to the contacts  300 . The material and embodiments described earlier which pertain to the contacts  300  are applicable to the contacts  2300  and are within the scope of the invention. 
         [0088]    Referring to  FIGS. 12A and 12B , the second side wall  2122  has a fourth mating section  21604  at a position opposing to the second base recess  2134  of the first side wall  2120 . A fourth tongue section  2224  which resides between the second and the third tongue sections  2222 ,  2223  has a plurality of passages  2240  in the second surface  2202  of the tongue portion  2200 . The fourth mating section  21604  at the first mating surface  2160  each has a plurality of passageways  2245  that extends from the first mating surface  2160  to the second mating surface  2165  and respectively communicate with the corresponding passages  2240  in the fourth tongue section  2224 . The passageways  2245  in the first, the second and the third mating sections  21601 ,  21602 ,  21603  are arranged in a same row. The passageways  2245  in the fourth mating section  21604  are arranged in another row and this row is located lower than the row for the first, the second and the third mating sections  21601 ,  21602 ,  21603 . The contacts  2300  include an additional set of a fourth set of contacts  2340  which may be used for signal transmission. The 4 sets of contacts respectively protrude through the passageways  2245  of their corresponding mating sections and are received in the corresponding passages  2240  of the tongue portion  2200 . 
         [0089]    In another embodiment of the present invention, at the position on the second side wall  2122  opposing to the first base recess  2132  of the first side wall  2120 , there is another mating section (not shown) with a plurality of passageways  2245  and correspondingly, there is another tongue section (not shown) with a plurality of passages  2240  in the second surface  2202  of the tongue portion  2200  opposing to first base extension portion  2721 . The passageways  2245  extend and communicate with the corresponding passages  2240  in the same manner as described earlier. In this embodiment, the contacts  2300  include an additional set of a fifth set of contacts (not shown) which may be used for signal transmission. 
         [0090]    In another embodiment of the present invention, the electrical connector  2000  may further comprise a bonding device  140  (described earlier) coupled to at least one end wall  2210 . 
         [0091]    As can be seen, electrical connector  100  and its various other embodiments provide extensive versatility in connecting SAS headers and sockets, SATA headers and SAS sockets and interconnecting Micro SATA headers and sockets. 
         [0092]    The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed, since many modifications or variations thereof are possible in light of the above teaching. All such modifications and variations are within the scope of the invention. The embodiments described herein were chosen and described in order best to explain the principles of the invention and its practical application, thereby to enable others skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated thereof. It is intended that the scope of the invention be defined by the claims appended hereto, when interpreted in accordance with the full breadth to which they are legally and equitably suited.