Patent Publication Number: US-2001000368-A1

Title: Method of manufacturing electrical connector contacts

Description:
FIELD OF THE INVENTION  
       1. The present invention relates generally to an electrical connector for securement to a printed circuit board. More particularly, the present invention relates to a multi-pin electrical connector having improved contact and connector configuration.  
       BACKGROUND OF THE INVENTION  
       2. In order to make electrical termination to a printed circuit board, the art has developed various electrical connectors which are mounted to the printed circuit board and provide connection capabilities for external components. Typical of these devices are electrical connectors having an insulative housing with plural electrical contacts supported therein. These contacts include tail portions which extend exteriorly of the insulative housing and are insertable into through holes in the printed circuit board. These contact tails may be soldered or otherwise secured to the printed circuit board to provide mechanical and electrical connection thereto. The contacts also include connection portions opposite the contact tails which are designed for connection to contacts of a mating electrical connector. Thus, these electrical connectors establish connection between the mating connector and the printed circuit board.  
       3. These printed circuit board connectors may be used for a wide variety of interconnection purposes. For instance, the printed circuit board connectors may be adapted to mate with a mating electrical connector terminating a flat ribbon cable. The printed circuit board connectors may also be adapted to terminate a connector mounted to an external component such as a disk drive in computer applications.  
       4. One technique to adapt a particular printed circuit board connector to terminate a particular mating connector is to vary the type, position and displacement of the contacts supported in the insulative housing. Variations such as, for example, contact pitch, contact configuration and number and location of contacts may render the printed board connector uniquely connectable with one type of mating connector. As an example, there exists certain mating connectors which employ what is known in the art as a “first-make last-break” feature. This feature assures that when connection between the printed circuit board connector and the mating connector is made, certain contacts such as, for example, ground contacts make electrical connection before the remaining contacts, such as the single contacts. When disconnecting the printed circuit board from the mating connector, this feature assures that the ground contacts break connection after the signal contacts break connection. Thus the contacts positioned with the insulative housing of the printed circuit board must be uniquely configured and positioned within the housing so as to provide such feature.  
       5. Furthermore, it is necessary to assure that the printed circuit board connector is securely mounted to the printed circuit board. While the contact tails make electrical connection and to some degree provide for mechanical connection to the printed circuit board, secure mechanical engagement of the connector to the printed circuit board must be assured. Such securement is provided so that the printed circuit board connector maintains its mechanical and electrical engagement with the printed circuit board during repeated mating and unmating cycles.  
       6. It is, therefore, desirable to provide a multi-contact printed circuit board connector which may be securely mechanically and electrically connected to a printed circuit board and which includes contacts specifically configured and located to provide the desired connection interface.  
       SUMMARY OF THE INVENTION  
       7. It is an object of the present invention to provide an improved electrical connector for securement to a printed circuit board which accommodates a multi-pin contact arrangement of specific construction, arrangement and location within the connector housing.  
       8. It is a further object of the present invention to provide a printed circuit board connector which provides both secure mechanical and electrical engagement to the printed circuit board.  
       9. It is a still further object of the present invention to provide an improved contact arrangement and method of formation which provides for the efficient formation of multiple electrical contacts for support within a printed circuit board connector housing.  
       10. In the efficient attainment of these and other objects, the present invention provides an electrical connector including an insulative housing having a connection face for connection to a mating connector and an opposed mounting face for securement to a printed board. The connector further includes a plurality of elongate electrical contacts. Each contact includes a connection end, an opposed tail and a securement member therebetween. Each contact defines a substantially identical contact expanse as measured between the connection ends and the tails. The contacts are supported within the housing such that the connection ends are positioned adjacent the connection face and the tails extend outwardly of the mounting face for securement to printed circuit board. The housing includes contact support members adjacent the mounting face where at least one of the contact support members is positioned at a location closer to the connection face than the other contact support members so as to position the connection end of at least one contact at different longitudinal position than the other contacts.  
       11. The present invention further provides that the electrical contacts may be formed from a flat metal stamping strip of conductive material. A contact pattern is stamped in the stamping strip where the contact pattern defines plural side-by-side elongate contact elements. The contact securement member of the contact elements are stamped so as to be in non-traverse alignment with an adjacent contact element. The contacts are then reconfigured so as to place the securement members in traverse alignment. Such a method of stamping contacts allows the contacts to be stamped on closer centers with less scrap material being formed.  
       12. The electrical connector further includes connector securement clips supported by the insulative housing. Each connector securement clip includes an L-shaped component having a first portion extending along the mounting face of the housing and a second portion extending at a substantially right angle therefrom for insertion into a mounting opening in the printed circuit board. The connector securement clip has a needle eye compliant section extending along both the first and second portions of the L-shaped component.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     13.FIG. 1 is a bottom perspective showing of the printed circuit board connector of the present invention.  
     14.FIG. 2 is a vertical sectional showing of the printed circuit board connector of FIG. 1.  
     15.FIG. 3 is a longitudinal end view, partially in section, of the printed circuit board connector of FIG. 1.  
     16.FIG. 4 is a perspective showing of a mounting clip used in accordance with the printed circuit board connector of FIG. 1.  
     17.FIG. 5 is a plan view of a metal stamping used to form the contacts of the printed circuit board connector of the present invention.  
     18.FIGS. 6, 7 and  8 , show respectively, a perspective view, an end view, and a top plan view of the contact stamping of FIG. 5.  
     19.FIG. 9 is a bottom perspective showing of a further embodiment of the printed circuit board electrical connection assembly of the present invention.  
     20.FIG. 10 is a vertical section of the connection assembly of FIG. 10.  
     21.FIG. 11 is an end view, partially in section, of the connection assembly of FIG. 9.  
     22.FIG. 12 is a perspective view of a mounting clip used in combination with the connection assembly of FIG. 9.  
     23.FIGS. 13 and 14 show respectively an end view and a front plant view of the contact stamping used in accordance with the connection assembly of FIG. 9.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     24. Referring to FIGS. 1-3, an electrical connector  10  used for mounting to a printed circuit board is shown. Connector  10  includes an elongate insulative housing  12  formed of a suitable plastic material having electrically insulative properties. Housing  12  defines an upper connection face  14  and an opposed lower mounting face  16 . Connection face  16  may accommodate a mating electrical connector (not shown) for mating engagement with connector  10 . Mounting face  16  may be mounted onto a printed circuit board  11  so that connector  10  establishes electrical connection between the mating connector and the printed circuit board  11 . A plurality of elongate passageways  15  are formed within housing  12 . Passageways  15  extend between connection face  14  and mounting face  16  and receive and electrically isolate the contacts of connector  10 . Insulative housing  12  further includes a pair of securement ears  18  at each longitudinal end thereof. Ears  18  are used to accommodate, in insertable fashion, projections from the mating connector so as to establish mechanical engagement between the mating connector and connector  10 .  
     25. Referring additionally to FIGS. 5-8, insulative housing  12  supports a plurality of electrical contacts  20  individually within passageway  15 . Each electrical contact  20  is an elongate member having a connection end  22  and an opposed contact tail  24 . As particularly shown in FIGS. 2 and 6, connection ends  22  of contacts  20  are configured so as to mate with contacts of the mating connector and establish electrical connection therewith. The opposed contact tails  24  are configured for insertion into plated through-holes in printed circuit board  11  thereby establishing electrical connection therewith. Each contact  20  includes a stabilizing element  25  therealong. Stabilizing element  25  engages the walls of passageway  15  so as to frictionally support contact  20  within the passageways of housing  12 .  
     26. As is known in the art, contact tails  24  may each include a compliant section  26  which in the present illustrative is a “needle eye” compliant contact section. The needle eye compliant section  26  is designed to provide resilient frictional engagement with the plated through-hole of printed circuit board  11  so as to establish both mechanical and electrical engagement therewith. The needle eye compliant section  26  defines an elongate aperture  26   a  therethrough which allows the compliant section  26  to resiliently engage the plated through-hole along a longitudinal segment thereof.  
     27. Each contact  20  further includes a securement member deformed intermediate of connection end  22  and contact tail  24 . Securement member  28  includes a pair of oppositely directed securement shoulders  29 .  
     28. As shown in FIGS. 6, 7 and  8 , securement members  28  may be deformed out of the plane of contact  12  to have rounded shoulders  29  so as to facilitate the positional locating of contacts  20  within passageways  15 , however, straight shoulders may be preferably employed. As will be described in further detail hereinbelow, securement member  28  is engageable with insulative housing  12  to positionally confine contacts  20  at predetermined positions within passageway  15 .  
     29. Referring specifically to FIGS. 5-8, the formation of contacts  20  may be described. Contacts  20  are formed of a suitably electrically conductive metal from a flat metal stamping strip  30 . Stamping strip  30  is stamped by a suitable tool (not shown) to define a contact pattern thereon. The contact pattern includes a plurality of side-by-side transversely spaced contacts  20  attached adjacent contact tail  24  to a carrier strip  32 . The stamping may be achieved in conventional fashion where material is removed from between the desired contact pattern formation.  
     30. In prior art techniques where it is desirable to form a plurality of identical electrical contacts in side-by-side orientation, it is typically required that the stamping pattern be designed such that spacing between the stamped contacts is greater than the transverse expanse of the contact pattern. Such transverse expanse is defined by any transverse component of the contacts such as provided by securement members  28  or compliant sections  26 . The utilization of such transverse components causes the pattern to include contacts which are transversely spaced apart a greater distance to accommodate such transverse component. The present invention contemplates stamping side-by-side electrical contacts having substantial transverse components in a manner where the contacts are stamped on closer spacing so as to reduce scrap and waste material, yet provide contacts with identical longitudinal expanse so as to properly locate the contacts within housing  12 .  
     31. As shown in FIG. 5, contacts  20  are stamped such that the transverse components of the contacts, specifically, the needle eye compliant sections  26 , securement members  28  and stabilizing elements  25  are positioned at longitudinally alternating locations along the length of adjacent contacts  20 . This allows contacts  20  to be stamped at closer spacings yet permits the formation of the transverse components of the contacts. For example, it can be seen that securement member  28  of one contact  20   a  transversely overlaps the location of securement member  28  of the next adjacent contact  20   b.  But for the different longitudinal formation of such element, the stamping of both securement members on such close spacings would not be possible. As may be appreciated, by varying the longitudinal position of the transverse components of contacts  20  to accommodate such close spacing, it necessarily also longitudinally staggers the connection ends  22  and contact tails  24 . However, as connector  10  is designed to accommodate contacts having identical longitudinal expanses (the overall distance between the ends of the contacts), the contacts  20  on carrier strip  32  are, therefore, reconfigured so as to define an identical longitudinal expanse between the contact tails  24  and the connection ends  22 .  
     32. Referring specifically to FIGS. 6-7, it can be seen that each contact  20  formed from stamping strip  30  may be reconfigured. For clarity of explanation, FIGS. 6-8 show only one pair of side-by-side contacts. Contact pair  20  includes a longer contact  20   a  and a shorter contact  20   b  formed in side-by-side fashion. One contact  20   a  of each pair is reconfigured by placing a bend or a jog at a location  21  adjacent the carrier strip  32 . A similar reconfiguration or jog is placed in the other contact  20   b  of the pair at a location  23  adjacent carrier strip  32 . The jog of contact  20   a  of the pair which has been stamped to have the greater length is jogged to a greater degree than the other contact  20   b  of the pair. The jogging or reconfiguring of the contacts  20  is such that it brings into transverse alignment the transverse components of contacts  20 . Thus, as particularly shown in FIG. 7 and  8 , the contacts are reconfigured on carrier strip  32  so as to place in transverse alignment needle eye complaint section  26 , securement members  28  and stabilizing elements  25 . The jog in contacts  20  adjacent carrier strip  32  also places the distal ends of contact tails  24  in transverse alignment. The jogs placed in each of the side-by-side contacts adjacent carrier strip  32  are in opposite directions. Such opposite formation of the jog locations  21  and  23  places the contact tails  24  in different planes. This arrangement allows the contact tails  24  to be aligned in multiple rows in housing  12 . In order to place connection ends  22  in alignment, a second jog is placed in each contact at a location  21   a  and  23   a  between securement member  28  and stabilizing elements  25 . These jogs are also in opposite directions so as to place the connection ends  22  in both longitudinal and transverse alignment. Thus, in the configurations shown in FIGS. 6, 7 and  8 , the contacts  20  may be severed from the carrier strip  32  at a position beyond each jog location  21  and  23 . This leaves the contact tails  24  arranged in two rows with the connection ends  22  in a single row.  
     33. Referring again to FIGS. 1 and 2, the contacts  20  are arranged in insulative housing  12  such that the connections ends  22  are disposed adjacent connection face  14  and contact tails  24  extend from mounting face  16 . The contacts are inserted into passageways  15  from adjacent mounting face  16  until securement members  28  engage the bottom wall of mounting face  16  which provides a mechanical stop to positionally locate the contacts therein. It is contemplated that the contacts  20  may be inserted into housing  12  while attached to carrier strip  32 . Once properly located, the carrier strip may be cut from the inserted contacts.  
     34. As shown in FIGS. 1 and 2, the present invention provides a further feature by allowing the contacts to be located within housing  12  at longitudinally staggered positions. The bottom wall of mounting face  16  may include a securement surface  40  adjacent each passageway  15 . The securement surfaces  40  may be positioned at longitudinally distinct locations with respect to mounting face  16 . Thus, certain of the securement surfaces  40  may be located closer to connection face  14  of housing  12  than other securement surfaces. Upon insertion of contacts  20  into passageways  15 , the contacts will be inserted and positionally located at different longitudinal positions. As particularly shown in FIG. 2, such arrangement positions the connections ends  22  at different locations with respect to connection face  14 . It is advantageous in certain electrical applications to position certain of the connection ends of the contacts at longitudinally distinct positions. Thus, upon mating engagement with a mating connector, the contacts having connection ends  22  at a position closer to connection face  14  will make electrical engagement with the mating contacts prior to establishing connection with the other contacts. This provides a “first make last break” feature. Such a feature is particularly desirable where certain contacts are designated as ground contacts while other contacts are designated as signal contacts. In order to prevent electrical damage to the components being connected, it is often necessary to assure ground connection prior to making signal connection. The construction and arrangement of the connector of the present invention allows the connector to function in a first make last break environment.  
     35. While positioning the connection ends at different locations, the longitudinally staggered securement surfaces  40  also dispose the contact tails  24  and the compliant sections  26  at differing longitudinal positions. The particular elongate needle eye compliant section  26  formed adjacent contact tails  24  is configured so as to provide a range taking feature with respect to the through-holes of the printed circuit board. Thus, even though the compliant sections  26  are longitudinally staggered, the elongate needle eye configuration of compliant section  26  allows each compliant section to make mechanical and electrical engagement with aligned through-holes of the printed circuit board.  
     36. A further feature of the present invention is shown with respect to FIGS. 1-4. While a certain degree of mechanical securement is provided by the compliant frictional engagement of the needle eye compliant sections  26  with the through-holes of the printed circuit board, additional mechanical securement between the connector  10  and the printed circuit board  11  is desired. Connector  10  provides a pair of mounting clips  50  within securement ears  18  which are engageable with a mounting aperture (not shown) in printed circuit board  11 . As shown particularly in FIG. 4, mounting clip  60  is generally a planar member formed of electrically conductive spring metal. Mounting clip  50  includes an upstanding contact finger  52  extending upwardly from a planar base  54 . A depending mounting tail  56  extends at a right angle to base  54  to provide an L-shaped mounting section  51 . The contact finger  52  includes a pair of outwardly projecting lances  58  which are designed for frictional insertion within securement ears  18  to secure mounting clip  50  to housing  12 . The base  54  of mounting clip  50  extends along mounting face  16  of housing  12  and mounting tail  56  extends downwardly in the direction of contact tails  24  of contacts  20 . In order to frictionally secure mounting clip  50  in a mounting opening of the printed circuit board, the mounting clip  50  includes a needle eye compliant portion  60  formed in L-shaped section  51  through both base  54  and mounting tail  56 . Needle eye compliant portion  60  extends in two planes thus providing resilient flexibility to permit the mounting tail  56  to be inserted into and frictionally engage a mounting aperture in the printed circuit board. By providing a compliant portion in two planes, the mounting clip  50  provides secure resilient engagement with the through-hole assuring secure connection therewith.  
     37. It is further contemplated that as mounting clip  50  is formed of conductive spring metal, it may also be used to make electrical engagement with a mating component of the mating connector. Such conductive engagement may establish ground connection between a plated mounting aperture into which clip  50  is inserted and grounded elements of the mating connector. In situations where mounting clip  50  establishes both mechanical and electrical engagement, it may be necessary to space the conductive base  54  from the printed circuit board so as to prevent inadvertent electrical contact with the printed elements on the printed circuit board. Thus, housing  12  provides mounting feet  62  extending from mounting face  16  adjacent securement ears  18 . As shown in FIG. 2, mounting feet define a space between mounting face  16  and the printed circuit board which spaces the base  54  of mounting clip therefrom.  
     38. Referring now to FIGS. 9-14, a further feature of the present invention is shown. In certain situations where multiple electrical components are mounted to a printed circuit board, it is often necessary to place the components at closer spacings due to the need to occupy most of the available space on the printed circuit board. In situations where the mating connector designed to mate with connector  10  includes a component directly thereon, such as a disk drive, it may be difficult to place two such components in close proximity. The present invention provides the ability to place adjacent connectors  10  at different heights with respect to the printed circuit board so as to facilitate close connection of several components.  
     39. The present invention provides a connector spacer  70  which may be interposed between connector  10  and the printed circuit board. Spacer  70  is an elongate insulative member formed of suitably insulative plastic. Spacer  70  has a board mounting face  72  and opposed connector mounting face  74 . Spacer  70  is attachable to the mounting face  16  of insulative housing  12  so as to space mounting face  16  above the printed circuit board. Suitable mechanical coupling members such as posts  79  may be provided between the mounting face  16  of housing  12  and the connection mounting face  74  of spacer  70  to provide mechanical attachment therebetween.  
     40. Spacer  70  includes plural passageways  75  between board mounting face  77  and connector mounting face  74 . Passageways  75  of spacer  70  are alignable with passageways  15  of housing  12  so as to permit the accommodation of contacts therein. In situations where spacer  70  is employed, the contacts must be modified to accommodate the extended length. As particularly shown in FIGS. 13 and 14, contacts  80  are formed in a similar manner to contacts  20  described above. Contacts  80  include connection ends  82  for mating the electrical connection and opposed contact tails  84  for insertion into plated through-holes of the printed circuit board. Contacts  80  include a needle eye compliant section  86  adjacent contact tails  84 . Contacts  80  further includes an extended length section between needle eye compliant section  86  and securement member  88  so as to traverse the distance of spacer  70 . Due to the extended length of contact  80 , additional stabilizer elements  89  are positioned between needle eye compliant section  86  and securement members  88 . Such stabilizing elements are engageable with the walls of the passageways  75  formed within spacer  70  so as to laterally confine movement of contacts  80 . This positions the contact tails  84  at precise locations for insertion into the through-holes of the printed circuit board.  
     41. Referring to FIGS. 11 and 12, due to the position of spacer  70 , a reconfigured mounting clip  90  is provided. Mounting clip  90  is substantially similar to mounting clip  70  described above having a contact finger  92  extending upwardly from a base  94 . A mounting tail  96  extends at a right angle from base  54 . Mounting tail  96  includes a compliant portion  99  therethrough for mechanical and/or electrical engagement with a mounting aperture of the printed circuit board. As the mounting tail is of extended length, a securement barb  97  is placed within mounting tail  96  adjacent compliant portion  99 . The securement barb  97  is engageable with the walls of spacer  70  as shown in FIG. 11 to laterally confine the mounting tail therein.  
     42. Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.