Patent Application
20100068944
The present invention relates to interconnections made between a printed circuit board and a high speed electrical connector. More particularly, it relates to a printed circuit board-connector combination for establishing contact between a printed circuit board and electrical cables.
The interconnection of integrated circuits to other circuit boards, cables, or other electronic devices is well known in the art. Such interconnections typically have not been difficult to form, especially when the circuit switching speeds (also referred to as edge rates or signal rise times) have been slow when compared to the length of time required for a signal to propagate through a conductor in the interconnect or on the printed circuit board. However, as circuit switching speeds continue to increase with modem integrated circuits and related computer technology, the design and fabrication of satisfactory interconnects has grown more difficult.
Specifically, there is a growing need to design and fabricate printed circuit boards and their accompanying interconnects with closely controlled electrical characteristics to achieve satisfactory control over the integrity of the signal. In addition, there is a need to design the interconnects such that electrical cables can be properly connected without jeopardizing the integrity of the interconnect system.
Unfortunately, currently available high speed interconnect solutions are typically complex, requiring extremely accurate component designs which are very sensitive to even small manufacturing variations and which, as a result, are expensive and difficult to manufacture. What is needed is a printed circuit board interconnect system which provides the necessary impedance control for high speed integrated circuits and facilitates proper electrical cable connections, while still being inexpensive and easy to manufacture.
In one aspect, the present invention provides an electrical connector assembly including a printed circuit board, a header coupled to the printed circuit board, a carrier configured to mate with the header, and a plurality of electrical cable assemblies retained by the carrier. The printed circuit board has a printed circuit board ground contact. The header includes a plurality of contact pins. Each electrical cable assembly includes an electrical cable termination and an electrical cable coupled to the electrical cable termination. The header and electrical cable terminations are configured such that each of the electrical cable terminations makes electrical contact with at least one of the contact pins and printed circuit board ground contact when the header and carrier are in a mated configuration. The carrier includes a retention clip having a plurality of separating elements configured to separate at least a portion of the electrical cables from each other.
In another aspect, the present invention provides an electrical connector including a carrier and a plurality of electrical cable assemblies retained by the carrier. Each electrical cable assembly includes an electrical cable termination and an electrical cable coupled to the electrical cable termination. The carrier includes a retention clip having a plurality of separating elements configured to separate at least a portion of the electrical cables from each other.
In another aspect, the present invention provides a method including providing an electrical connector, positioning a retention clip, and assembling the retention clip to the electrical connector. The electrical connector includes a carrier and a plurality of electrical cable assemblies retained by the carrier. Each electrical cable assembly includes an electrical cable termination and an electrical cable coupled to the electrical cable termination. The retention clip has a plurality of separating elements. Each separating element is positioned in between at least a portion of two adjacent electrical cables.
The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The Figures and detailed description that follow below more particularly exemplify illustrative embodiments.
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof. The accompanying drawings show, by way of illustration, specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized, and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined by the appended claims.
For purpose of clarity, aspects of the invention are described and illustrated herein as used with twinaxial cables and twinaxial cable terminations. However, such illustration is exemplary only, and it is understood and intended that other types of electrical cables and their associated electrical cable terminations can be used, including but not limited to coaxial cables and other cable configurations with signal and ground elements.
In one embodiment of the present invention, the first row 16a of contact pins 14 is secured to the printed circuit board 4 only to lend additional mechanical stability to header 6. That is, contact pins 14 in row 16a are not electrically connected to any elements on printed circuit board 4 and could be eliminated. Alternately, contact pins 14 of row 16a may remain in electrical contact with the ground plane of printed circuit board 4. It should be noted that first row 16a is the row with the longest unshielded path through the interconnection, and for that reason contact pins 14 of second row 16b are preferably used for electrical connection to the signal traces on printed circuit board 4. It will also be recognized that a header having only a single row of pins could be used, with the header being stabilized on printed circuit board 4 by means other than a second row of contact pins 14 as is illustrated in the Figures.
Contact pins 14 in second row 16b electrically connect to printed circuit board 4 via a plurality of signal contact pads (not shown). The first end 14a of each contact pin 14 in row 16b is connected to one of the signal contact pads. As illustrated in
As seen in
Electrical cable terminations that can be used in conjunction with carrier 8 can be constructed substantially similar to the shielded controlled impedance (SCI) connectors for a coaxial cable described in U.S. Pat. No. 5,184,965, incorporated by reference herein. Each of the plurality of electrical cable terminations 18 is adapted to receive second ends 14b of a mating contact pin 14. Each electrical cable termination 18 includes a contact beam 22 adjacent its leading edge 18a for making electrical contact with the printed circuit board ground contact 12 on the printed circuit board 4 as carrier 8 engages header 6. In this manner, the electrical path from printed circuit board 4 to electrical cable 20 is made as short as possible, thereby dramatically improving the performance of carrier 8 over what would be otherwise expected with a surface mount header 6.
In the embodiment illustrated in
Carriers 8 placed on opposite sides of printed circuit board 4 include guides 24 to properly align carriers 8 with headers 6. Carriers 8 are preferably resiliently secured against each other, such as by a plurality of dove tails 26 (as shown in
Carrier 8 includes a retention clip 30 (as best illustrated in
In one embodiment, retention clip 30 and carrier 8 further comprise cooperative latch elements 40 configured to retain retention clip 30 and carrier 8 in an assembled configuration. In the embodiment illustrated in
Retention clip 30 has a plurality of separating elements 32 configured to separate at least a portion of electrical cables 20 from each other (as best illustrated in
Separating elements 32 of retention clip 30 may be configured to organize and/or provide strain relief to electrical cables 20. Separating elements 32 assist in keeping electrical cables 20 parallel to each other near carrier 8. In one aspect, this provides improved visibility of the relative position of each electrical cable 20 and electrical cable termination 18, e.g., to facilitate visual inspection of the assembly. In another aspect, this reduces bending of electrical cables 20 near carrier 8, thereby preserving the integrity of electrical cables 20 near carrier 8 and the connection of each electrical cable 20 to its corresponding electrical cable termination 18.
In one embodiment, retention clip 30 is designed such that it separates the individual electrical cables 20 from each other during its positioning and assembling to carrier 8. The initial separation of electrical cables 20 happens when retention clip 30 is positioned such that each separating element 32 of retention clip 30 is positioned in between at least a portion of two adjacent electrical cables 20. After positioning retention clip 30, it is assembled to carrier 8.
In one embodiment, assembling retention clip 30 to carrier 8 includes sliding retention clip 30 along electrical cables 20, pivoting it, and snapping it onto carrier 8. Sliding retention clip 30 along electrical cables 20 towards carrier 8 continues the separation of electrical cables 20. The positioning and sliding of retention clip 30 is also referred to as the combing of electrical cables 20. Retention clip 30 and separating elements 32 are designed such that the combing of electrical cables 20 can take place with retention clip 30 tilted backward (as illustrated by arrow A in
It is understood and intended that different and/or additional assembly methods may be provided as is suitable for the intended application, including but not limited to snap fitting, friction fitting, press fitting, mechanical clamping, and adhering.
In each of the embodiments and implementations described herein, the various components of the electrical connector assembly and elements thereof are formed of any suitable material. The materials are selected depending upon the intended application and may include both metals and non-metals (e.g., any one or combination of non-conductive materials including but not limited to polymers, glass, and ceramics). In one embodiment, the electrically insulative components, such as, e.g., carrier 8 and retention clip 30, are formed of a polymeric material by methods such as injection molding, extrusion, casting, machining, and the like, while the electrically conductive components, such as, e.g., contact pins 14 and portions of electrical cable terminations 18 are formed of metal by methods such as molding, casting, stamping, machining, and the like. Material selection will depend upon factors including, but not limited to, chemical exposure conditions, environmental exposure conditions including temperature and humidity conditions, flame-retardancy requirements, material strength, and rigidity, to name a few.
Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the mechanical, electromechanical, and electrical arts will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
