Abstract:
A connector provides capacitive coupling between circuit devices such as printed circuitboards and integrated circuits. The connector includes at least a first contact that contacts a conductor of the first circuit device, a second contact that contacts a conductor of the second circuit device, and a capacitor coupled between the first and second contacts. The connector includes an insulative body that encapsulate the capacitor and carries the first and second contacts. The connector may further include a plurality of the first contacts, a like plurality of the second contacts, and a like plurality of AC blocking capacitors with each capacitor being coupled between a respective different pair of the first contacts and second contacts.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     It is often necessary to distribute high-speed signals, such as high-speed differential signals, from one circuit device, such as an integrated circuit or printed circuitboard, to another such circuit device. This may require capacitive or “AC” coupling.  
         [0002]     Typically, high-speed signals requiring such AC coupling are routed within internal layers of multi-layered substrates of printed circuitboards or integrated circuits, as known in the art. To provide AC-coupling, coupling or blocking capacitors are used which are mounted on the circuit device substrates (printed circuitboard). To permit the high-speed signals access to the AC blocking capacitors, the signals must be brought to the surface layers of the circuit devices through vias. These vias can have a significant deleterious effect on the signal quality and integrity, especially for high-speed signals having frequencies in the multiple gigabit range. In addition, the adverse signal quality effects increase as the circuit device substrate thickness increases.  
         [0003]     Unless preventative measures are taken, the problem will only worsen. As signal rate increases, signal energy content increases, and signal frequency increases, the adverse effects of the vias will prove even more difficult to deal with.  
         [0004]     Previous solutions have included ignoring the problem and living with the detrimental effects caused by the vias. Another solution has been to use blind or buried vias where the vias only extend partially through the circuit device substrates. Unfortunately, this increases manufacturing costs of the circuit devices. Another solution has been to back drill the vias to remove unused portions of the vias. This also results in increased manufacturing costs.  
         [0005]     The present invention provides a solution to the above-noted problems. As will be seen subsequently, the present invention permits signals to be distributed from one circuit device to another while negating the need for the previously employed vias for accessing surface mounted AC blocking capacitors.  
       SUMMARY OF THE INVENTION  
       [0006]     In one embodiment of the invention, a connector includes a first contact that contacts a conductor of a first circuit, a second contact that contacts a conductor of a second circuit, and a capacitor coupled between the first and second contacts. As a result, the connector capacitively couples the conductor of the first circuit to the conductor of the second circuit.  
         [0007]     In various embodiments, the connector may further include an electrically insulative body encapsulating the capacitor and carrying the first and second contacts. One of the first and second contacts may be a male contact or a female contact.  
         [0008]     In accordance with further aspects of the invention, the first and second contacts may be disposed along a substantially common line or substantially transverse to each other.  
         [0009]     In accordance with a further embodiment, the connector may include a plurality of first contacts, a like plurality of second contacts, and a like plurality of capacitors with each capacitor coupled between a different respective pair of the first and second contacts. The plurality of first contacts and the plurality of second contacts may lie in a substantially common plane. The connector may further include a plurality of contact sets of the plurality of first and second contacts lying in a substantially common plane. The plural contact sets may be disposed substantially parallel to each other.  
         [0010]     In accordance with the present invention, first and second device circuits may be capacitively coupled together without requiring vias for accessing AC blocking capacitors. One of the first and second circuits may be an integrated circuit or a printed circuitboard.  
         [0011]     These and various other features as well as advantages of the present invention will be apparent from a reading of the following detailed description and a review of the associated drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a generally schematic representation of a connector that embodies the present invention and capacitively connects conductors of a first circuit device to conductors or a second circuit device;  
         [0013]      FIG. 2  illustrates a prospective view of first and second printed circuitboards to be capacitively interconnected by a connector embodiment of the present invention;  
         [0014]      FIG. 3  is a cross-sectional side view of one embodiment of the present invention wherein a connector includes contacts disposed substantially transverse to one another with an AC coupling capacitor coupled between the connector contacts;  
         [0015]      FIG. 4  is a cross-sectional side view of a further embodiment of the present invention wherein a connector includes a male contact and a female contact coupled together by an AC blocking capacitor and wherein the contacts are disposed along substantially common line;  
         [0016]      FIG. 5  is a cross-sectional side view of a still further embodiment of the present invention wherein a connector includes a plurality of contact pairs each pair being coupled together by an AC blocking capacitor and wherein all of the contacts lie within a substantially common plane; and  
         [0017]      FIG. 6  is a perspective view of a still further embodiment of the present invention illustrating how a connector may be modularly constructed in accordance with further aspects of the present invention. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0018]     In the following detailed description of an exemplary embodiment of the invention, reference is made to the accompanying drawings, which form a part hereof. The detailed description and drawings illustrates specific exemplary embodiments by which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is understood that other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the present invention. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.  
         [0019]      FIG. 1  schematically illustrates a first embodiment of the present invention. Here, a connector  10 , embodying the present invention, capacitively couples conductors of a first circuit device  12  to conductors of a second circuit device  14 . The first circuit device  12  includes a differential signal driver  16  of the type which generates a high-speed differential signal output on conductors  18  and  20 . The conductors  18  and  20  are coupled to female contacts  22  and  24  respectively, which are carried by the circuit device  12 .  
         [0020]     Similarly, the second circuit device  14  includes a second differential signal driver  30  of the type which may receive the high-speed differential signals provided by the first differential signal driver  16 . The differential signal driver  30  receives the differential signals over conductors  32  and  34  which are coupled to female contacts  36  and  38  respectively, carried by the circuit device  14 .  
         [0021]     The connector  10  capacitively couples the female contact  22  of the first circuit device  12  to the female contact  36  of the second circuit device  14  and the female contact  24  of the first circuit device  12  to the female contact  38  of the second circuit device  14 . The connector  10  includes a first pair of male contacts  40  and  42  and a second pair of male contacts  44  and  46 . Contacts  40  and  42  are arranged to be connectively received by the female contacts  22  and  24 . Similarly, the contacts  44  and  46  are arrangement to be connectively received by the female contacts  36  and  38 . The connector  10  further includes AC blocking capacitors  50  and  52 . The capacitor  50  is coupled between contact  40  and contact  44  and the capacitor  52  is coupled between the contact  42  and the contact  46 .  
         [0022]     As a result of the foregoing, when the contacts  40  and  42  are received by contacts  18  and  24 , and contacts  44  and  46  are received by contacts  36  and  38 , the connector  10  capacitively couples conductors  18  and  20  of the first circuit device  12  to conductors  32  and  34  respectively of the second circuit device  44 . The connector  10  further includes a body  56  of electrically insulative material in which the capacitors  50  and  52  are imbedded and which carries the contacts  40 ,  42 ,  44 , and  46 . The body  56  may be formed by injection molding or in any other manner known in the art.  
         [0023]     Referring now to  FIG. 2 , it illustrates another embodiment of the invention where a first printed circuitboard  60  is capacitively coupled to a second printed circuitboard  62 . The first printed circuitboard  60  includes a connector  64  embodying the present invention. The connector  64  includes a plurality of male contacts  66 .  
         [0024]     The second printed circuitboard  62  also includes a connector  70  which may embody the present invention. The connector  70  includes a plurality of female contacts  72  which are arranged to connectively receive the contacts  66  carried by the connector  64 .  
         [0025]      FIG. 3  shows that the connector  64  may further include a further plurality of male contacts  68  which are arranged substantially transverse to the contacts  66 . Coupled between the contacts  66  and  68  is an AC blocking capacitor  63  which may capacitively couple a conductor on printed circuitboard  60  to a conductor on printed circuitboard  62 .  
         [0026]     Lastly, it will be noted in  FIG. 3  that the connector  64  includes a body  65 . The body  65  is preferably formed of an electrically insulative material for carrying the contacts  66  and  68  and imbedding the capacitor  63 . To that end, the body  65  may be formed by injection molding or many other molding methods known in the art.  
         [0027]      FIG. 4  illustrates a form in which the connector  70  may take to embody the present invention. Here, one female contact  72  of the plurality of female contacts is illustrated disposed substantially in line with a corresponding male contact  73 . Although not illustrated, the connector  70  may include a male contact for each female contact  72 . An AC blocking capacitor  75  couples the female contact  72  to the male contact  73 . The connector  70  further includes a body  76  which is molded to encapsulate the capacitor  75  and carry the contacts  72  and  73 .  
         [0028]     In order to provide capacitive coupling between a conductor of printed circuitboard  60  and a conductor of printed circuitboard  62 , only one of the connectors  64  and  70  need incorporate an AC blocking capacitor. Hence, if connector  64  includes the capacitor  63 , then connector  70  need not include capacitor  75  and the contact  72  may be directly coupled to the contact  73  without an intervening AC blocking capacitor. Similarly, if the connector  70  is to provide the capacitive coupling with capacitor  75 , then connector  64  need not include capacitor  63 . In this case, contact  68  would be coupled directly to contact  66  without an intervening capacitor  63 .  
         [0029]      FIG. 5  illustrates a further embodiment of the present invention. Here, a connector  80  is shown in cross-section. The connector  80  includes a plurality of first contacts  82  and a plurality of second contacts  84 . Coupling each respective first contact with a respective second contact is an AC blocking capacitor  86 . In accordance with this embodiment, the first contacts  82  and second contacts  84  lie within a substantially common plane. Also, the contacts  82  and  84  are disposed substantially transverse to each other.  
         [0030]     The connector  80  still further includes a body  88 . The body  88  may be molded to carry the contacts  82  and  84  and encapsulate the capacitors  86 .  
         [0031]      FIG. 6  illustrates how the connector  80  may be employed to form one segment of a bladed style connector  100 . In  FIG. 6 , it will be noted that the connector  100  includes a plurality of connector segments  80 ,  110 ,  120 ,  130 , and  140 , for example. Although five such segments are illustrated in  FIG. 6 , it is to be understood that the connector  80  may include any number of connector segments without departing from the present invention.  
         [0032]     The modularized structure of connector  100  permits a plurality of connector segments to be disposed with contact substantially parallel to each other. Further, the modularized structure of the connector  100  permits connector segments which provide capacitive coupling, such as segment  80  to be utilized along with connector segments, such as segment  130 , which provide coupling but not capacitive coupling. Connector segment  130  is illustrated as an example of one connector segment which may be provided for providing direct and not AC coupled coupling. As will be noted in  FIG. 6 , the segment  130  includes a first male contact  132  and a second male contact  134 . The contacts  32  and  34  are directly coupled together by a conductor  136 . Of course, as will be appreciated by those skilled in the art, the connector segment  130  may incorporate a plurality of the male contacts  132  and a corresponding plurality of male contacts  134 .  
         [0033]     Also, a modularized structure of the connector  100  permits the contacts providing capacitive coupling to be distinguishable from the contacts which do not provide capacitive coupling. To that end, the contacts  82  and  84  may have a characteristic which distinguishes them from the contacts  132  and  134 . This distinguishing characteristic may be, for example, cross-sectional shape or other physical distinguishing characteristic.  
         [0034]     As can be appreciated from the foregoing, the present invention provides a connector for distributing signals from one circuit device to another circuit device with capacitive coupling without requiring the circuit devices to incorporate surface mounted AC blocking capacitors and vias for accessing such capacitors. As a result, the deleterious effects of such vias are avoided without increasing the manufacturing costs of the circuit devices.  
         [0035]     Although the present invention has been described in considerable detail with reference to certain preferred embodiments, other embodiments are possible. Therefore, the spirit or scope of the appended claims should not be limited to the description of the embodiments contained therein. It is intended that the invention resides in the claims.