Modular Electrical Connector Having Electrical Contact Modules

The invention is directed to a modular electrical connector assembly capable of receiving the edge of a printed circuit board or circuit card. The electrical connector is an assembly of contact modules arranged within a connector housing.

Electrical connectors of the type receiving an edge of a printed circuit board or circuit card are well known. Typically, a slot is provided in an insulative housing of the electrical connector for accepting an edge of a board or circuit card. The card edge generally has a row or rows of conductive pads or traces on either or both sides of the board. The slot on the electrical connector housing leads to a contact area which is a narrow cavity flanked by one row or two opposing rows of electrical contacts.

In some instances, use of more than two opposing rows of contacts is necessary to accommodate the complexity of the circuitry of the circuit board which is to be received. As the complexity of the contact scheme within the electrical connector increases, problems arise in assembling the connector. Loading contacts within the electrical connector housing becomes more complex as does connecting the electrical contacts to conductors and routing those conductors within the electrical connector housing.

What is needed is an electrical connector for receiving a printed circuit board edge or circuit card edge which is easily assembled, of minimal size and superior electrical performance.

The present invention provides an electrical connector capable of receiving a circuit card edge or printed circuit board edge comprising a housing having a mating end and a rear end. The mating end has a card receiving slot and the rear end has an opening leading to an internal cavity. A first contact module is disposed within the internal cavity proximate a mating end and houses a plurality of electrical contacts. Each electrical contact has a solder tail and a contact portion wherein the contact portion is exposed on a side of the first contact module proximate the card receiving slot. Each solder tail is connected to a conductor which extends rearwardly through the opening in the rear end. A second contact module is disposed behind the first contact module within the internal cavity and houses a plurality of electrical contacts. Each electrical contact has a contact portion and a solder tail wherein the contact portion is exposed on a surface of the second contact module proximate the card receiving slot. Each solder tail is connected to a conductor which extends rearwardly through the opening of the rear end.

An embodiment of the present invention will now be described in detail with reference to the accompanying drawings, in which:

FIG. 1 is an isometric view of the electrical connector assembly of the present invention;

FIG. 2 is an exploded isometric view of the electrical connector assembly of the present invention;

FIG. 3 is a cross sectional view of the first contact module shown in FIG. 2;

FIG. 4 is a side view of the first contact module shown in FIG. 2;

FIG. 5 is a rear view of the second contact module shown in FIG. 2;

FIG. 6 is a cross-sectional view of the second contact module shown in FIGS. 2 and 5;

FIG. 7 is an isometric view of the second contact module;

FIG. 8 is a cross-sectional view of the fully assembled components shown in FIG. 2;

FIG. 9 is a cross-sectional view of the fully assembled electrical connector assembly shown in FIG. 1 with terminations to conductive members;

FIG. 10 is an isometric view of the first contact module shown in FIGS. 2 and 4 with a conductive member terminated to the electrical contacts;

FIG. 11 is an isometric view of the second contact module shown in FIGS. 2, 5, and 7 with a conductive member terminated to electrical contacts; and

FIG. 12 is an isometric view of the fully assembled electrical connector assembly of the present invention.

FIG. 1 shows an electrical connector assembly 10 of the present invention having flexible etched circuitry 12, 14 leading into the electrical connector housing 20. FIG. 2 shows an exploded isometric view of the component parts of electrical connector assembly 10. Specifically, electrical connector housing 20 is shown having a rear opening 22 which leads into internal cavity 24. Internal cavity 24 is bounded by both opposing sidewalls 26 and opposing end walls 28. A first groove 30a and a second groove 30b extend along the length of both end walls 28 from the rear opening 22 toward the front face 29 (best shown in FIG. 12).

A first contact module 40 is also shown in FIG. 2 having an elongated contact housing 42 loaded with an array of electrical contacts 44. A second contact module 50 is also shown comprised of a contact housing 52 which retains two opposing rows of electrical contacts 54. Finally, a retention member 60 is provided for installation behind second contact module 50 within rear opening 22.

As shown in FIG. 2, first contact module 40 houses a row of electrical contacts 44 in an elongated contact housing 42. Electrical contacts 44 are comprised of contact portions 45 and solder tails 46 as best shown in FIG. 3. Each electrical contact 44 is received in contact receiving cavity 47 such that the contact portion 45 is exposed on a mating face 48 of the contact housing 42 while the solder tails 46 are received along the a recessed surface 49 located opposite the mating face 48, best shown in FIG. 4. First contact module 40 also provides tongues 41 located on each end 43 of contact housing 42. Tongues 41 provide guidance and retention of first contact module 40 by cooperating with first grooves 30a provided in the electrical connector housing 20.

Second contact module 50 houses two opposing rows of electrical contacts 54 in electrical contact receiving cavities 57, as best shown in FIG. 5. Electrical contacts 54 are shown in FIG. 6 situated in respective contact receiving cavities 57 such that contact portions 55 oppose one another on each side of a card receiving slot 70. Similarly, solder tails 56 provided on each electrical contact 54 oppose one another in a central portion of the contact housing. As can be seen in FIG. 6, contacts 54 need not be situated in direct opposition, rather it may be desirable to stagger contacts 54 such that one row is forward the opposing row thereby reducing mating forces encountered when inserting the edge of a printed circuit board or circuit card. Similarly, contacts within the same row may be staggered in an alternating fashion to achieve lowered mating forces.

FIG. 7 shows in greater detail features of second contact module 50 which assist in the modular assembly of electrical connector assembly 10. For example, the embodiment of the second contact module shown in FIG. 7 illustrates an elongated contact housing 52 having opposing ends 53 each having a pair of tongues 51a and 51b. Tongues 51a and 51b are configured so as to be accepted in grooves 30a and 30b, respectively, in housing 20. The cooperative arrangement of tongues 51a and 51b with grooves 30a and 30b provide the alignment and retention of second contact module 50 upon assembly of second contact module 50 behind first contact module 40 within electrical connector housing 20. A recessed surface 59 is also provided on contact housing 52 disposed between tongues 51a. This recessed surface 59 is arranged such that when electrical connector assembly 10 is fully assembled, recessed surface 59 is in alignment adjacent to recessed surface 49 located on contact housing 42 of first contact module 40. The cooperation of recessed surface 49 with recessed surface 59 allows passage for conductors which have been connected to solder tails 46 of electrical contact 44 between both first contact module 40 and second contact module 50 and sidewall 26 of electrical connector housing 20. For instance, a piece of flexible etched circuitry 12 may be electrically connected to solder tails 46 of electrical contacts 44 and routed between recessed surface 49, recessed surface 59 and sidewall 26 to allow flexible etched circuitry 12 to exit the electrical connector assembly 10.

FIG. 6 and 7 also depict a nose portion 58 extending along one side of card receiving slot 70 between tongues 51a and 51b of each end 53. This nose portion 58 is designed to further secure second contact module 50 within electrical connector housing 20. As best seen in FIG. 8, electrical connector housing 20 is provided with a front face 23 with a forward opening 21 leading to card receiving slot 70. An overhang 25 extending alongside card receiving slot 70 and projecting inwardly into internal cavity 24 is provided which defines an elongated recess 27 that receives nose portion 58 of second contact module 50 upon full assembly.

Finally, as best shown in FIGS. 5, 6, and 7 second contact module 50 is provided with a conductor receiving area 72 defined by opposing rows of solder tails 56. The present illustrated embodiment also provides channels 73 which are aligned on each end of the contact housing 52 with conductor receiving area 72. The conductor receiving area 72, in combination with channels 73, is designed to receive conductors for electrical connection to the solder tails 56 of electrical contacts 54. In the present embodiment, a piece of flexible etched circuitry 14 having conductive traces or pads 16 on both sides is disposed within conductor receiving area 72 and corresponding channels 73 for electrical connection to opposing rows of solder tails 56, best shown in FIG. 9.

Referring back to FIG. 2, retention member 60 is provided with tongues 61a and 61b at each end 63. Similar to second contact module 50, first tongues 61a are aligned to correspond with first tongues 51a of second contact module 50 and tongues 41 of first contact module 40. Second tongues 61b are similarly aligned behind second tongues 51b of second contact module 50. Thus, upon assembly of electrical connector 10, retention member 60 is received behind first and second contact modules 40 and 50, respectively, within electrical connector housing 20. The retention member 60 is therefore received in first and second grooves 30a and 30b and is seated within rear opening 22 of electrical connector housing 20.

Retention member 60 is also provided for routing conductors, for example flexible etched circuitry 12 and 14, through rear opening 22 and out of the electrical connector assembly 10. Retention member 60 is provided with a central conductor routing slot 62 extending from one end 63 into the retention member 60. The central conductor routing slot 62 passes through the retention member 60 from a forward face 66 to a rear face 67 such that the conductor routing slot 62 is in alignment with conductor receiving area 72 and channels 73 of second contact module 50. Upon assembling electrical connector assembly 10, conductor routing slot 62 allows conductors connected to solder tails 56, such as flexible etched circuitry 14, to pass through retention member 60 and thus exit the electrical connector assembly 10.

As with second contact module 50, a recessed surface 69 is provided between tongues 61a of each end 63. Recessed surface 69 is arranged to align with recessed surface 49 of first contact module 40 and recessed surface 59 of second contact module 50 so as to allow passage of conductors connected to solder tails 46, such as flexible etched circuitry 12, between first and second contact modules 40 and 50, retention member 60, and sidewall 26 of electrical connector housing 20.

In the present embodiment, first contact module 40 and second contact module 50 are retained within electrical connector housing 20 by retention member 60 secured by latching protrusions 64 located on each first and second tongues, 61a and 61b, respectively. Latching protrusion 64 are, upon full assembly, received within latching detents or openings 34 located within first and second grooves 30a and 30b of electrical connector housing 20. In addition, enlarged tongue portions 65 are located on first and second tongues 61a and 61b proximate the rear face 67. These enlarged tongue portions 65 are slightly larger in dimension than the portions of the first and second tongues 61a and 61b proximate the forward face 66 and are designed to interferingly engage grooves 30a and 30b of the housing 20, thereby snugly retaining retention member 60 within housing 20.

Finally, latches 36 are provided on the exterior of electrical connector housing 20 for latching engagement with a housing of a printed circuit board edge or card edge, not shown.

Referring now to FIG. 9, a cross-section of the fully-assembled electrical connector assembly 10 is shown. Within the electrical connector housing 20, first contact module 40 is loaded proximate forward opening 21. Inserted behind first contact module 40 is second contact module 50 abutting first contact module 40 while also seating nose portion 58 in recess 27. The retention member 60 is received behind both first and second contact modules, 40 and 50, thus securing them within electrical connector housing 20.

One advantage of the present invention is the modular arrangement of both first and second contact modules within the electrical connector assembly. This modular arrangement allows electrical contacts to be loaded into the modular contact housings and conductors to be connected to the electrical contacts of both modules prior to the modules being inserted into the electrical connector assembly. FIGS. 10 and 11 show first and second contact modules, respectively, terminated to flexible etched circuitry prior to insertion into electrical connector housing 20. In FIG. 10, flexible etched circuitry 12 is surface mount soldered to solder tails 46 located along recessed surface 49. Similarly, in FIG. 11 flexible etched circuitry 14 is terminated to both rows of solder tails 56 and is seated in channels 73.

Although flexible etched circuitry 12 and 14 are illustrated in the present embodiment, various types of conductive media may be electrically interconnected to electrical contacts 44 and 54 of first and second contact modules. For instance, ribbon cable or flat flexible cable could easily substitute flexible etched circuitry without defeating the advantages of modularity in the present design.

Once conductors are terminated to first and second contact modules, the modules are inserted into the electrical connector housing in a tongue and groove arrangement which aligns and secures the modules within the housing. In the present embodiment, grooves 30a and 30b are located on the interior of the electrical connector housing 20 while tongues 41, 51a and 51b are provided on the first and second contact modules 40 and 50. Certainly, other equally advantageous alignment and securing means may be implemented without departing from the spirit of the invention. For example, the tongue and groove arrangement may be reversed such that tongues are provided on the interior of the electrical connector housing while grooves are located on the contact modules. Likewise, placement of the tongue and groove arrangement may be modified as may the number of cooperating tongues and grooves. Also, use of tongues at each end of contact modules 40 and 50 may in some instances be unnecessary in that the use of one tongue and groove at one end of the modules may be sufficient. Such variations to the alignment and securing arrangement would, of course, also hold true for retention member 60.

In the present embodiment, retention number 60 serves several functions. First, the retention member serves to secure both first and second contact modules firmly within electrical connector housing 20. Latching protrusions 64, in cooperation with latching detents 34, ensure a tight and secure assembly. Certainly, numerous latching arrangements may be implemented for securing the member 60 within electrical connector housing 20 while yielding equally desirable results. For example, protrusions could be provided on the interior of the electrical connector housing with complimentary detents being located on the retention member 60.

Another function served by retention member 60 is that of routing conductors, in this case flexible etched circuitry 12 and 14, from first and second contact modules, through the rear opening 22, and outside the electrical connector housing 20. To this end, central conductor routing slot 62 is provided in retention member 60 so that when first and second contact modules 40 and 50 are fully inserted into electrical connector housing 20, flexible etched circuitry 14 may be slid into central conductor routing slot 62 in a direction transverse to the insertion direction of the modules, while flexible etched circuitry 12 is received along recessed surface 69.

Yet another function served by retention member 60 is that of providing strain relief for conductors 12 and 14, thereby reducing the potential for fracture of solder joints located at solder tails 46 and 56.

It should be apparent that there may exist environments that do not demand wire dressing or strain relief nor require the added security of a latching retention member. In such environments it may be sufficient to provide retention means on the modules themselves rather than utilizing a separate retention member. This could be accomplished by using a latching protrusion and latching detent configuration similar to the one described on retention member 60 and electrical connector housing 20. This may be particularly desirable when it is critical to minimize the length of the electrical connector assembly.

It should be apparent from the foregoing description that the present invention provides a simple and advantageous electrical connector assembly for connection to an edge of a printed circuit board or circuit card. A modular assembly is achieved which allow conductors to be terminated to contact modules prior to their insertion into an insulative housing thus simplifying the assembly process.

The present invention also provides a simplified means of configuring a multi-row card edge connector. Although the present embodiment illustrates the use of three rows of contacts, more or less rows may also be used while still taking advantage of the modular design. Similarly, more or less modules may be used in the assembly of the present invention. For instance, a four row card edge connector could be assembled by using two opposed first contact modules and a second contact module inserted behind both first contact modules. Of course in accomplishing various different modular arrangements, different electrical contact shapes, sizes and placements employed as necessary.

A further advantage of the present invention is the simple and secure way in which the contact modules are aligned and retained within the electrical connector housing. A multi-function retention member is described which effectively secures contact modules within the electrical connector housing, while providing routing and strain relief of conductive members.

The electrical connector assembly of the present invention and many of its attendant advantages will be understood from the foregoing description. It is apparent that changes may be made in the form, construction, and arrangement of parts thereof without departing from the spirit of the invention, or sacrificing all of its material advantages. Thus, while the present embodiment of the invention has been disclosed, it is to be understood that the invention is not strictly limited to such embodiment but may be otherwise variously embodied and practiced within the scope of the appended claims.