Abstract:
A header assembly includes an insulative housing comprising a plurality of walls defining an interior cavity, and a plurality of contacts within said cavity and extending through one of the walls to an exterior of the housing for surface mounting to a circuit board. The insulating housing comprises at least one alignment rib extending on an exterior surface thereof. The contacts are formed to abut the alignment rib, thereby ensuring coplanarity of the contacts for surface mounting to a circuit board.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to electrical connectors, and, more specifically, to surface mount header assemblies for mating engagement with plug assemblies.  
         [0002]     The mating of a plug assembly into a receptacle assembly to form a connector assembly often involves a high insertion force. This is particularly true when the connector comprises mating connector housings containing many contacts. For example, automobile wiring systems, such as power train systems, typically include electrical connectors. Typically, each electrical connector includes a plug assembly and a header assembly. The plug assembly is mated into a shroud of the header assembly. The header assembly is in turn mounted on a printed circuit board. Each of the plug assembly and the header assembly typically includes a large number of electrical contacts, and the contacts in the header assembly are electrically and mechanically connected to respective contacts in the plug assembly when the header assembly and the plug assembly are engaged. To overcome the high insertion force to connect the plug assembly into the header assembly, an actuating lever is sometimes employed to mate contacts of the plug assembly and the header assembly.  
         [0003]     Surface mount header assemblies provide a number of advantages over through-hole mounted header assemblies. In addition to offering cost and process advantages, surface mounting allows for a reduced footprint for the header assembly and thus saves valuable space on a circuit board or permits a reduction in size of the circuit board. When the header assembly is surface mounted to a circuit board, solder tails extend from one side of the header assembly in an angled manner for surface mounting to a circuit board, and also extend substantially perpendicular from another side of the header assembly for mating engagement with contacts of the plug assembly. In one automotive connector system, fifty two contacts are employed in one version of the header assembly, and the large number of contacts presents manufacturing and assembly challenges in fabricating the header assembly, as well as installation problems during surface mounting of the header assembly to the circuit board.  
         [0004]     For example, it is desirable for surface mounting that the solder tails of the header assembly are coplanar to one another for mounting to the plane of a circuit board. Achieving coplanarity with a large number of contact pins, however, is difficult due to manufacturing tolerances over a large number of contacts. Sometimes additional solder paste is utilized to compensate for tolerances of the contacts or for misalignment of the pin contacts during assembly of the header. Over a large number of header assemblies, however, the incremental cost of the increased amount of solder paste per header assembly can be significant, and non-planarity of the pin contacts with respect to the plane of the circuit board may negatively affect the reliability of the header assembly. Additional solder paste thickness can also cause solder bridging problems for other surface mount components on fine pitch or may require different stencils to be used. Depending upon the degree of non-planarity of the solder tails, some of the contacts may be weakly connected or not connected to the circuit board at all, either of which is an undesirable and unacceptable result.  
         [0005]     Furthermore, the high insertion forces during engagement and disengagement of the header assembly and the plug assembly may be detrimental to the soldered connections of the header assembly. To prevent the soldered connections from being broken, a solder clip is sometimes used which is soldered to the circuit board at the corners of the header. As such, the mechanical connection of the solder clips incur the brunt of mechanical strain as the header assembly is mated and unmated from a mating connector. Tolerances in manufacturing the solder clips, however, introduce additional non-planarity issues when the header assembly is soldered to a circuit board. At one end of the tolerance range, the solder clips may prevent the contacts from fully contacting the circuit board, which may impair the quality of the soldered connections of the contacts. At the other end of the tolerance range, the solder clips may not fully contact the circuit board during soldering, which may impair the ability of the solder clips to spare the contacts from large insertion and extraction forces as the header assembly is engaged and disengaged from a mating connector.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0006]     In accordance with an exemplary embodiment, a header assembly comprises an insulative housing comprising a plurality of walls defining an interior cavity, and a plurality of contacts within said cavity and extending through one of the walls to an exterior of the housing for surface mounting to a circuit board. The insulating housing comprises at least one alignment rib extending on an exterior surface thereof. The contacts are formed to abut the alignment rib, thereby ensuring coplanarity of the contacts for surface mounting to a circuit board.  
         [0007]     Optionally, the housing comprises longitudinal side walls and lateral side walls, and alignment ribs extending parallel to each of the longitudinal side walls. The contacts may extend through a bottom wall in a plurality of rows, and the contacts in each of the plurality of rows abut the alignment rib, and the contacts are flexed and preloaded against the alignment rib. A solder clip is attached to one of the longitudinal and the lateral side walls, and the solder clip comprises an engagement surface coplanar with the contacts when the contacts are abutted against the alignment rib. The contacts include rounded ends and the alignment ribs include a crowned surface, and the rounded ends engaging the crowned surface as the contacts are preloaded.  
         [0008]     According to another exemplary embodiment, a header assembly comprises an insulative housing comprising a plurality of walls defining an interior cavity and a contact interface, and at least one alignment rib extending proximate the contact interface. A plurality of contacts having contact sections and solder tail sections are provided. The contact sections are located within the interior cavity, and the solder tail sections extend exterior to the contact interface for surface mounting to a circuit board. The solder tails abut the alignment rib and are preloaded against the alignment rib as the contacts are installed into the housing, thereby ensuring coplanarity of the solder tail sections for surface mounting to the circuit board.  
         [0009]     According to another exemplary embodiment, a method of assembling a surface mount header assembly is provided. The assembly includes an insulative housing including a plurality of walls defining an interior surface, an exterior surface, and a plurality of contact apertures extending therebetween. The housing further includes an alignment rib extending on the exterior surface, and a plurality of electrical contacts. The method comprises inserting the contacts through the contact apertures, and flexing a portion of the contacts against the alignment rib as the contacts are inserted, thereby preloading the contacts against the alignment rib in a coplanar relationship with one another.  
         [0010]     According to still another embodiment, a header assembly is provided. The header assembly includes an insulative housing having a mating face and comprising an alignment rib extending along the mounting face and having a planar alignment edge. A plurality of contacts are positioned relative to said housing, such that a mounting portion of each of said contacts abuts the alignment edge thereby ensuring coplanarity of the contacts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a top perspective view of a housing for a surface mount header assembly formed in accordance with an exemplary embodiment of the invention.  
         [0012]      FIG. 2  is a bottom perspective view of the housing shown in  FIG. 1 .  
         [0013]      FIG. 3  is front elevational view of a first contact assembly used with the housing shown in  FIGS. 1 and 2 .  
         [0014]      FIG. 4  is a side elevational view of the contacts shown in  FIG. 3 .  
         [0015]      FIG. 5  is a front elevational view of a second contact assembly used with the housing shown in  FIGS. 1 and 2 .  
         [0016]      FIG. 6  is a side elevational view of the contacts shown in  FIG. 5 .  
         [0017]      FIG. 7  is a top plan view of a solder clip formed in accordance with an exemplary embodiment of the present invention.  
         [0018]      FIG. 8  is a cross sectional view of a header assembly formed in accordance with the present invention at a first stage of manufacture.  
         [0019]      FIG. 9  is a partial cross sectional view of the header assembly shown in  FIG. 8  along line  9 - 9  of  FIG. 2 .  
         [0020]      FIG. 10  is a partial cross sectional view of the header assembly shown in  FIG. 8  along line  10 - 10  of  FIG. 2 .  
         [0021]      FIG. 11  is a cross sectional view of the header assembly at a second stage of manufacture.  
         [0022]      FIG. 12  is a cross sectional view of the header assembly at a third stage of manufacture.  
         [0023]      FIG. 13  is a cross sectional view of the header assembly at a final stage of manufacture.  
         [0024]      FIG. 14  is a bottom perspective view of the header assembly shown in  FIG. 13 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]      FIGS. 1 and 2  are top and bottom perspective views, respectively, of a an exemplary housing  100 , sometimes referred to as a shroud, for a surface mount header assembly formed in accordance with an exemplary embodiment of the invention.  
         [0026]     The housing  100  includes a pair of longitudinal side walls  102 , a pair of lateral side walls  104  extending between the ends of the longitudinal side walls  102 , and a bottom wall  106  extending between the longitudinal and lateral side walls  102  and  104 . The side walls  102  and  104  and the bottom wall  106  collectively define a contact cavity  108  in the top side of the housing  100  ( FIG. 1 ), and a contact interface  110  on the bottom side of the housing  100  ( FIG. 2 ). A first or outer row of contact apertures  112  and a second or inner row of contact apertures  114  are provided through the bottom wall  106  in a parallel relationship to each of the longitudinal side walls  102  of the housing  100 , thereby providing four rows of apertures extending from the contact cavity  108  through the bottom wall  106  to the contact interface  110 . In the illustrated embodiment, each of the rows of contact apertures  112  and  114  includes thirteen contact apertures, thereby providing a fifty two (13×4) position housing  100 . It is recognized, however, that greater or fewer apertures may be provided in greater or fewer rows in various alternative embodiments without departing from the scope and spirit of the present invention.  
         [0027]     Lever slots  116  are formed in each of the longitudinal side walls  102  in communication with the contact cavity  108  ( FIG. 1 ). The lever slots  116  are configured for receiving and maintaining an actuation lever of a mating connector (not shown) for engaging electrical contacts of the mating connector with electrical contacts (described below) in the header  100 . Various slots and keying features  118  are provided in the longitudinal side walls  102 , the lateral side walls  104 , and the bottom wall  106  of the housing  100  for guiding mating portions of the mating connector to align the electrical contacts of the header and the mating connector. It is understood, however, that in alternative embodiments the lever slots  116  and/or the slots and keying features  118  may be omitted in a manual (i.e., not assisted) connector assembly.  
         [0028]     Solder clip mounting lugs  120  extend outwardly from exterior surfaces  122  of each of the lateral side walls  104  between the longitudinal side walls  102 . Alignment lugs  124  are also extended outwardly from each of the exterior surfaces  122  of the lateral side walls  104  at the corners of the housing  100 . Each of the alignment lugs  124  includes an alignment rib  126  ( FIG. 1 ) on an end surface  127  thereof. As explained below, the mounting lugs  120 , the alignment lugs  124  and the alignment ribs  126  serve to locate solder clips (described below) on each of the lateral side walls  104  of the housing  100  so that surfaces of the solder clips are positioned coplanar with solder tails on the contact interface  110  ( FIG. 2 ) of the housing  100 . Troughs or slots  121  may be provided around the mounting lugs  124  for collection of skived or shaved portions of the lugs  120  as the solder clips are installed. Notches  127  are provided in the bottom end of the lateral side walls  104 , and the notches are employed to retain the solder clips to the lateral side walls  104  as explained below.  
         [0029]     Optionally, and in an exemplary embodiment, lugs  128  extend outwardly from the longitudinal side walls  102  at the corners of the housing  100 . The lugs  128  provide a keying feature for a mating connector on an exterior surface  130  of the longitudinal side walls  102 . While the lugs  124  and  128  are illustrated as substantially rectangular in shape, it is recognized that other shapes of lugs  124  and  128  may be alternatively used in other embodiments of the invention.  
         [0030]     Referring to  FIG. 2 , the contact interface  110  of the housing  100  includes a slotted positioning member  132  extending parallel to the longitudinal side walls  102 , and one slot is provided in the positioning member  132  for each contact aperture in the outer row of apertures  112  and the inner row of apertures  114 . When solder tails of the contacts (described below) are receiving in the respective slots of the positioning member  132 , the solder tails are prevented from moving in the direction of arrow A which extends substantially parallel to a longitudinal axis  133  of the housing  100 . The contact interface  110  further includes an alignment surface  134  extending upon an alignment rib  136  adjacent each of the longitudinal side walls  102 . The alignment surfaces  134  are coplanar to one another and are laterally spaced from the positioning members  132  such that the positioning members  132  are located between the alignment surfaces and the respective outer row of contact apertures  112 . As explained below, the alignment surfaces  134  provide a registration surface which ensures that ends of the solder tails on the contact interface  110  are coplanar to one another. Preloading of the solder tails against the alignment surfaces  134 , as explained below, prevent the solder tails from moving in the direction of arrow B which extends perpendicular to the longitudinal axis  133 .  
         [0031]     In an exemplary embodiment, the positioning member  132 , the alignment rib  136  and the alignment lugs  124  are integrally formed with one another. By forming the alignment rib  136  and the alignment lugs  124  in an integral fashion, the top surface  127  ( FIG. 1 ) of the alignment lugs  124  are located a fixed distance from the alignment surfaces  134 . As such, the solder clips may be precisely positioned with respect to the alignment surface as described below to achieve coplanarity of the solder clips with the alignment surfaces  134 . Alternatively, the alignment rib  136 , the positioning member  132 , and the alignment lugs  124  may be separately fabricated and attached to the housing  100 .  
         [0032]     In an exemplary embodiment, the housing  100 , including each of the aforementioned features, is integrally formed from an electrically insulative (i.e., nonconductive material), such as plastic, according to a known process, such as an injection molding process. It is recognized, however, that the housing  100  may alternatively be formed of separate pieces and from other materials as those in the art may appreciate.  
         [0033]      FIG. 3  is front elevational view of a first contact set  150  which may be employed in the outer row of contact apertures  112  (shown in  FIGS. 1 and 2 ) of the housing  100 . In an exemplary embodiment, the contact set  150  includes contact sections  152 , aperture sections  154  and solder tail sections  156 . The aperture sections  154  are dimensioned to produce an interference fit when inserted into an aperture in the row of contact apertures  112 , and the contact sections  152  and the solder tail sections  156  are aligned with one another along a common centerline  157 .  
         [0034]     Transverse carrier strips  158  join the aperture sections  154 , and when the carrier strips  158  are sheared during assembly of the header, the contact set  150  is separated into individual contacts. While only two contacts are shown in  FIG. 3 , it is understood that the contact set  150  includes a number of contacts corresponding to the number of contact apertures in the contact rows  112  (shown in  FIGS. 1 and 2 ). The contact set  150  may be fabricated from a single piece of metal, such as copper or a copper alloy, and further may be coated or plated with tin, lead, gold, etc. as necessary to obtain desired electrical and mechanical characteristics and properties of the contact set  150 .  
         [0035]      FIG. 4  is a side elevational view of the contact set  150  illustrating a small radius formed in an end  160  of the solder tail sections  156 . The radius creates a rounded end  160  which, as will be seen below, mitigates tolerances or misalignment of the contact set  150  as the header is assembled. In an alternative embodiment, the radius may be omitted and the ends of the contact set  150  may be straight.  
         [0036]      FIG. 5  is a front elevational view of a second contact assembly  170  which may be employed in the inner row of contact apertures  114  (shown in  FIGS. 1 and 2 ) of the housing  100 . In an exemplary embodiment, the contact set  170  includes contact sections  172 , aperture sections  174  and solder tail sections  176 . The aperture sections  174  are shaped and dimensioned to produce an interference fit when inserted into an aperture in the row of contact apertures  114  and the contact sections  172  and the solder tail sections  176  are offset with respect to one another relative to the aperture sections  174 . That is, the contact sections  172  and the solder tail sections  176  have spaced centerlines. The offset in contact sections  172  and solder tail sections  176  achieves a desired centerline spacing of the solder tail sections  176  relative to the solder tail sections  156  (shown in  FIGS. 3 and 4 ) when the contact sets  150  and  170  are installed in the housing  100 . Because the contact set  170  is installed to the inner row of contact apertures  114 , the contact set  170  has a greater length L than the first contact set  150  which is installed to the outer row of contact apertures  112  in the housing  100 .  
         [0037]     Transverse carrier strips  178  join the aperture sections  174 , and when the carrier strips  178  are sheared during assembly of the header, the contact set  170  is separated into individual contacts. While only two contacts are shown in  FIG. 5 , it is understood that the contact set  170  includes a corresponding number of contacts as there are contact apertures in the contact rows  114 . The contact set  170  may be fabricated from a single piece of metal, such as copper or a copper alloy, and further may be coated or plated with tin, lead, gold, etc. as necessary to obtain desired electrical and mechanical characteristics and properties of the contact set  170 .  
         [0038]      FIG. 6  is a side elevational view of the contact set  170  illustrating a small radius formed in an end  180  of the solder tail sections  176 . The radius creates a rounded end  180  which, as will be seen below, mitigates tolerances or misalignment of the contact set  170  as the header is assembled. In an alternative embodiment, the radius may be omitted and the ends of the contact set  170  may be straight.  
         [0039]      FIG. 7  is a top plan view of a solder clip  190  formed in accordance with an exemplary embodiment of the present invention. The clip  190  includes a main body section  192  having mounting apertures  194  and alignment apertures  196 . The mounting apertures  194  are shaped and dimensioned for press fit insertion over the mounting lugs  120  of the housing  100  (shown in  FIGS. 1 and 2 ), and the alignment apertures  196  are sized and dimensioned to receive the alignment lugs  124  (shown in  FIGS. 1 and 2 ) of the housing  100 . As such, the solder clip  190  may be aligned vertically in the direction of arrow C and horizontally in the direction of arrow D when the solder clips  190  are installed on the respective lateral walls  104  of the housing  100 .  
         [0040]     A retention tab  198  is formed on an edge  200  of the body section  192  which faces the contact interface  110  (shown in  FIG. 2 ) of the housing  100  when the solder clip  190  is installed. The tab  198  may be folded over a lateral side wall  104  and retained in the notch  127  (shown in  FIG. 2 ) therein. Edges  202  of the alignment apertures  196  contact the biasing ribs  126  (shown in  FIG. 1 ) of the alignment lugs  124  of the housing  100 . Assurance is therefore provided against movement of the solder clip  190  along two mutually perpendicular axes indicated by arrows C and D.  
         [0041]     In an exemplary embodiment, the solder clip  190  is fabricated from a sheet of metal according to a stamping and forming operation. It is recognized, however, that the solder clip  190  may be fabricated from a variety of materials according to various known processes in the art in alternative embodiments.  
         [0042]     While in an exemplary embodiment the retention tab  198  is formed in the shape of a T, it is understood that various shapes may be used in lieu of a T shape in alternative embodiments to retain the solder clip  190  to a side wall  104  of the housing  100 .  
         [0043]     Alignment tabs  204  project from the edge  200  and include solder clip board engagement surfaces  206  which are flat and smooth. The board engagement surfaces  206  contact a planar surface of a circuit board during surface mounting of the header assembly and are soldered to the circuit board. The soldering of the alignment tabs  204  provides structural strength and rigidity which provides strain relief to the soldered connections of the contact sets  150  and  170 .  
         [0044]      FIG. 8  is a cross sectional view of a header assembly  200  at a first stage of manufacture. The header assembly  200  includes the housing  100  with the contact sets  150  and  170  inserted into the outer and inner rows of contact apertures  112  and  114  (shown in  FIGS. 1 and 2 ). The contact sections  152  and  172  of the respective contact sets  150  and  170  are partly located in the contact cavity  108  while the solder tail sections extend from the contact interface  110  of the housing  100 .  
         [0045]      FIG. 9  is a partial cross sectional view of the header assembly  200  through the outer row of contact apertures  112 . The aperture sections  154  of the contact set  150  extend partially into the contact apertures of the row  112  for a predetermined distance, and the aperture sections  154  of the contact set  150  partly extend from the contact interface  110  of the housing  100 . The carrier strips  158  (shown in  FIG. 3 ) have been sheared from the contact set  150 , thereby forming discrete contacts in the apertures in the contact aperture row  112 . The solder tail sections  156  of the contact set  150  are located between the solder tail sections  176  of the contact set  170 , and the centerlines of the solder tail sections  176  and  156  are consistently spaced from one another.  
         [0046]      FIG. 10  is a cross sectional view of the header assembly  200  through the inner row of contact apertures  114 . The aperture sections  174  of the contact set  170  extend partially into the contact apertures of the row  114  for a predetermined distance, and the aperture sections  174  of the contact set  170  partly extend from the contact interface  110  of the housing  100 . The carrier strips  178  (shown in  FIG. 5 ) have been sheared from the contact set  170 , thereby forming discrete contacts in the apertures in the contact aperture row  114 . The solder tail sections  176  of the contact set  170  are located between the solder tail sections  156  of the contact set  150 , and the centerlines of the solder tail sections  176  and  156  are consistently spaced from one another.  
         [0047]      FIG. 11  is a cross sectional view of the header assembly  200  at a second stage of manufacture wherein tooling, such as forming dies  210  is employed to bend the solder tail sections  156  and  176  toward the contact interface  110  of the housing  100 . Once the forming die  212  is removed, the contacts may be further inserted through the contact interface  110  by seating the forming die  210  in the direction of arrow E to bring the bent solder tail sections  156  and  176  to the contact interface  110 .  
         [0048]     While the embodiment described thus far includes bending of the contact sets  150 ,  170  after they are partially installed in the housing  100 , it is recognized that the contact sets  150 ,  170  could be bent prior to installation to the housing  100  in an alternative embodiment.  
         [0049]      FIG. 12  is a cross sectional view of the header assembly  200  at a third stage of manufacture wherein the aperture sections  154  and  174  (shown in  FIGS. 9 and 10 ) are fully inserted into the respective rows of contact apertures  112  and  114  in the housing  100  to a final position. In the final position, the solder tail sections  156  and  176  are fitted through the slots in the positioning member  132  (also shown in  FIG. 1 ), and the rounded ends  160  and  180  of the respective solder tail sections  156  and  176  are aligned with one another and in abutting contact to the positioning rib  136 . As shown in  FIG. 12 , the alignment surface  134  is rounded or crowned and shaped to smoothly establish contact with the rounded end  160  and  180  of the contact sets  150  and  170 . The solder tail sections  156  and  176  are flexed from the position shown in  FIG. 11  and are obliquely oriented to the contact interface  110  of the housing  100 , thereby creating in internal biasing force in the contact sets  150  and  170  which preloads the solder tail sections  156  and  176  against the alignment surfaces  134  of the alignment ribs  136 . Such biasing or preloading of the solder tail sections  156  and  176  substantially prevents vertical movement of the solder tail sections  156  and  176  in the direction of arrow B as the header assembly  200  is handled prior to surface mounting and during surface mounting installation. Further, a final angle a of the solder tails  156  and  176  with respect to a top surface  230  of the lateral side walls  104  assures a satisfactory solder joint to a circuit board.  
         [0050]     The crowned alignment surfaces  134  of the alignment ribs  136  and the rounded ends  160  and  180  of the solder tail sections  156  and  176  permits some misalignment of the solder tail sections  156  and  176  as the contact sets  150  and  170  are installed. The rounded engagement surfaces of the alignment surfaces  134  and the ends  160  and  180  of the contact sets  150  and  170  allow for shifting points of contact among the engagement surfaces as the contact sets  150  and  170  are moved to the final position. As the solder tail sections  156  and  176  are preloaded against the alignment ribs  136 , relative misalignment of the solder tails is substantially, if not entirely, eliminated and the rounded ends  160  and  180  of the contact sets  150  and  170  are substantially aligned to produce coplanar contact points tangential to the rounded ends for mounting to a circuit board.  
         [0051]     While in the illustrated embodiment the alignment surfaces  134  are crowned and the ends  160  and  180  of the contact sets  150  and  170  are rounded, it is appreciated that in an alternative embodiment the alignment surface may be substantially flat and the contact ends may be substantially straight while nonetheless aligning the contacts in a planar relationship to one another for surface mounting to a circuit board.  
         [0052]      FIG. 13  is a cross sectional view of the header assembly  200  at a final stage of manufacture wherein the solder clips  190  are attached to the housing  100 . The engagement surfaces  206  of the solder clip alignment tabs  204  are coplanar with the contact ends  160 ,  180  of the contacts sets  150  and  170 . The contact interface  110  is therefore well suited for surface mounting to a planar surface  220  of a circuit board  222 .  
         [0053]      FIG. 14  is a bottom perspective view of the header assembly  200  when completely assembled. The solder clips  190  are coupled to the lateral side walls  104  of the housing  100  and retained thereto by the retention tabs  198 . The solder tail sections  156  and  176  are preloaded and abutted against the alignment surfaces  134  adjacent the longitudinal side walls of the housing  100 . Manufacturing tolerances in fabricating the contact sets  150  and  170  are mitigated and the solder tail sections  156  and  176  are substantially aligned and coplanar for mounting to the planar surface  220  of the board  222  (shown in  FIG. 13 ). The solder clip board alignment surfaces  206  are substantially aligned and coplanar with the solder tail sections  156  and  176  for secure mounting to the circuit board  222  in the plane of the solder tail sections  156  and  176 . Relatively thin and consistent films of solder paste may therefore be used for reliably soldering the header assembly  200  to the circuit board  222 .  
         [0054]     For all the above reasons, a secure and reliable header assembly is provided for surface mounting applications which capably resists high insertion and extraction forces when the header assembly  200  is engaged and disengaged from a mating connector.  
         [0055]     While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.