The Present Disclosure relates, generally, to backplane connectors, and, more particularly, to improved cable assembly connectors utilized in backplane applications.
Existing backplane connectors which utilize waferized structures can be prohibitively expensive to tool-up. Wafers are designed to support a set number of signal pairs and ground elements associated with the signal pairs. These elements are supported by a frame typically formed from a thermoplastic and molded over portions of the signal and ground elements. As such, each particular wafer requires its own mold and stamping and forming operation. Thus, the costs required to tool up waferized connectors are large.
A customer usually needs to have very significant volume or a willingness to pay non-recoverable tooling fees for tooling up a new wafer. Each wafer count must be tooled as a new part including stamping dies, mold cavities, plating tooling, assembly tooling, and the tooling for assembling the connectors into finished cable assemblies as a mold for a four-pair wafer cannot be used to make either a three- or five-pair wafer. In essence, multiple sets of tooling are required to produce different pair count wafers. It is also somewhat costly to use the same stamping and forming equipment for terminal assemblies of different pair count wafers as the stamping and forming members must be changed for each particular count wafer, thereby not only incurring labor, but also increasing manufacturing time.
Existing backplane cable connectors that utilize a wafer construction do not easily support wiring schemes that are more complex than connecting all pairs from one column to another column. “Lettered” wiring schemes, such as W, X and Y wiring schemes where the pairs track the configuration of the particular letter are difficult to construct. A need therefore exists for a connector that utilizes signal pair components that reduce the cost of manufacturing.
The Present Disclosure is directed to an improved connector that utilizes individual signal pair elements which may be inserted into a variety of differently configured connector housings and which overcomes the aforementioned disadvantages.
In accordance with the principles of the Present Disclosure, signal pair elements are provided with an integrated structure of signal terminals and ground terminals or shields that permit a connector designer to modify only the connector housing of a backplane connector assembly to accept a variety of signal pair arrangements. This concept eliminates the need for multi-pair wafers and replaces it with a single-pair element, or “chicklet,” concept in which the signal terminals and ground plane are integrated together in a single unit that is insertable and removable from a connector housing. For a new pair count connector assembly, the only structure that needs to be tooled is a front connector housing and its associated tooling, i.e., molds and inserts, should cost less than $25,000.00. This greatly reduces the cost of entry for new connector design programs, even for programs with smaller volumes as tooling for specific count wafers can approach and even exceeds $500,000.00.
If any single pair within a multi-pair wafer is bad (e.g., open, short, miswired, bad impedance or insertion loss) the entire wafer has to be discarded, with all of its associated signal terminals and ground planes. In doing so, a repairman must cut all of the wires associated with the bad wafer and terminate them to the replacement wafer, which increases the time and cost of repair. In the design of the Present Disclosure, only a single pair element needs to be replaced if it is bad and logically, only 2-3 wires will need to be terminated to a replacement signal pair element. This alone minimizes the amount of labor and materials that are lost to a defective single pair. Futhermore, because the smallest unit, or building block, of connectors of the Present Disclosure is a signal pair element, or chicklet, which integrates the signal pair and a ground plane together, it now is feasible to support complex wiring patterns in a connector housing in any W, X or Y fashion. In terms of system architecture, it means that pairs from one column on a line card can be split up to go to many other line cards.
In accordance with an embodiment as described in the following Present Disclosure, a signal pair element is defined by two elongated conductive signal terminals that extend longitudinally in a spaced-apart fashion. An insulative support frame is provided that supports the two signal terminals in their spaced-apart arrangement. The frame may have one or more openings that encompass portions of the terminals to control the characteristic impedance of the signal pair element at that location. The leading ends of the terminals include contact portions preferably formed as pins which engage corresponding contact portions of an opposing, mating connector. The terminals include tail portions at their opposite ends and wires of a cable are terminated to them, preferably by soldering, welding or the like.
A ground member, preferably in the form of a ground shield, is provided in association with each pair of signal terminals. The ground shield may have a general U-shaped configuration to define an elongated ground channel in which the signal pair terminals are supported. In this regard, the ground shield has a wide base that extend transversely to the longitudinal axes of the signal terminals and two spaced-apart sidewalls that are spaced transversely from the terminals and which define sides of the signal pair element. The frame is received within the interior of the ground shield and it serves to space the signal terminals from the ground shield base and sidewalls. Accordingly, the terminals are bounded on at least three of their four sides by a portion of the ground shield. The area where the cable wires are terminated to the signal terminals is filled with an insulative material, such as a hot melt, low density polyethylene, polypropylene or liquid crystal polymer, to enclose and protect the wire terminations and form an integrated assembly in which the signal terminals, ground shield and cable wires are formed as a single piece, which is insertable into and removable from a single opening in a connector housing.
The cross-sectional configuration of the signal pair elements is preferably rectangular, and square configurations can also be utilized so that a manufacturer need only make simple openings in the connector housing to receive the signal pair element. As such, the signal pair element introduces both a signal pair and an associated ground structure that maintains a desired spacing between the pair of signal terminals and between the signal terminals and ground shield. Thus, the in-pair spacing is easy to maintain and the out-pair spacing between nearby other signal pairs is likewise easy to maintain. The openings in the connector housing do not have to be separately made or formed in a complex manner, because the ground plane is already integrated into the signal pair structure itself such that one opening will accommodate one signal pair element.
As such, the signal pair elements of the Present Disclosure and connectors incorporating them distinguish themselves from known waferized connectors in that they utilize individual signal pair elements, or chicklets, rather than columns or rows of multi-pair wafers. Such known wafers populate their columns with two or more differential signal pairs and necessarily further include associated ground terminals or a ground plane, overmolded to maintain the spacing between the signal terminals and the ground structure. Often two wafer halves must be assembled and pressed together to form a completed wafer wherein where the ground structure of one wafer is partially shared by an adjacent wafer. As one can easily see, such a structure is complex and costly to tool.
In contrast, the individual signal pair elements of the Present Disclosure can be inserted into any suitable connector housing in either lettered arrangements for custom mating applications or in conventional rows and columns. The signal pair elements may be inserted either manually or by machine and the channel-like configuration of the ground shield provides a protective shell that protects the contact portions of the signal terminals during insertion into a connector housing. The integration of the ground shield with the terminal support frame means that it is not necessary to form ground elements in the connector housing arranged in a particular pattern to mate with ground elements of an opposing, mating connector.
The individual signal pair elements of the Present Disclosure may be ganged together in a row or a band by means of a metal commoning strap or bar that engages not only the ground shield of each signal pair element, but also the outer conductive wrap of the cable wires to interconnect multiple signal pair elements via their ground shields. An insulative resin may then be molded over portions of the support frame, terminals, cable wires, ground shield and commoning strap to form a single row of signal pair elements which can be easily inserted into a like number of openings in a connector housing.
These and other objects, features and advantages of the Present Disclosure will be clearly understood through a consideration of the following detailed description.
The organization and manner of the structure and operation of the Present Disclosure, together with further objects and advantages thereof, may best be understood by reference to the following Detailed Description, taken in connection with the accompanying Figures, wherein like reference numerals identify like elements, and in which:
While the Present Disclosure may be susceptible to embodiment in different forms, there is shown in the Figures, and will be described herein in detail, specific embodiments, with the understanding that the Present Disclosure is to be considered an exemplification of the principles of the Present Disclosure, and is not intended to limit the Present Disclosure to that as illustrated.
As such, references to a feature or aspect are intended to describe a feature or aspect of an example of the Present Disclosure, not to imply that every embodiment thereof must have the described feature or aspect. Furthermore, it should be noted that the description illustrates a number of features. While certain features have been combined together to illustrate potential system designs, those features may also be used in other combinations not expressly disclosed. Thus, the depicted combinations are not intended to be limiting, unless otherwise noted.
In the embodiments illustrated in the Figures, representations of directions such as up, down, left, right, front and rear, used for explaining the structure and movement of the various elements of the Present Disclosure, are not absolute, but relative. These representations are appropriate when the elements are in the position shown in the Figures. If the description of the position of the elements changes, however, these representations are to be changed accordingly.
In conventional waferized backplane connectors, a series of signal elements are supported by insulative frame portions. Ground elements are also usually incorporated wafers used in these style connectors and because they are supported by the insulative frame, the ground elements must necessarily take the form of flat, planer elements. It is difficult to insert mold complex configured ground elements with “complex” meaning the ground elements have portions that extend in at least two different directions and three distinct planes. This structural limitation can hamper a backplane connector designer on the wafer side of the connector assembly. This may lead to crosstalk issues in the connector.
Accordingly, the Present Disclosure is directed at new backplane connectors and signal pair elements used therein. As shown in
In practice, the terminals are spaced from the inside surface of the ground shield sidewalls a distance of L and the terminals of the pair are preferably spaced apart a distance equal to about or equal to 2L as a preferred spacing. The terminals are also preferably spaced above the ground shield a height of about 40% of the height from the inner surface of the ground shield base to the top edge, with “top” taking the orientation as shown in
The terminals 32a, b are supported in an insulative frame 34 that includes a front mounting portion 35 and a rear mounting portion 36 that are spaced apart from each other in the longitudinal direction. These two mounting portions 35, 36 extend transversely with respect to the terminals 32a, b and are overmolded onto the terminals. The mounting portions 35, 36 include body portions that are disposed in the space between the terminal pair and may be joined, as illustrated in
The support frame 34 is shown as further including an endwall 44a that extends transversely and a pair of shoulder portions 44b that extend longitudinally rearwardly from the endwall 44a to define a termination nest 44c in which the terminal tail portions 40 extend. This area is overmolded with an insulative material 45 which serves to fix the termination of the signal pair element 30 to the cable wires 48 as well as maintains the signal pair spacing and alignment. The signal pair conductive elements include the aforementioned signal terminals 32a, b and also a ground plane element that is shown in the Figures as an elongated ground shield 56. The ground shield 56 includes a base portion 75 which is generally flat and the shield includes a pair of upturned flanges that define sidewalls 58a, b that extend for almost the length of the ground shield 56. The general U-shape that the ground shield 56 has provides a ground plane for each terminal pair that extends along three of the four sides of the terminal pair. Such a structure promotes coupling by the terminals in three different directions. The front end of the ground shield 56 may take the form of a mating blade as shown that provides a flat surface for contacting an opposing ground element of a conventional mating connector.
The rear end of the ground shield 56 is provided with a cable nest 59 that receives and supports a wire cable 48 having two signal wires 49a, b that are surrounded by outer insulative coverings 50. A drain, or ground wire 51, is typically provided for each wire pair 49a, b and it extends lengthwise through the pair underneath an outer conductive wrap 52. A free end of the cable 48 is prepared as a termination end and has a length of the free end of each wire conductor 49a, b exposed and the cable drain wire 51 folded back upon the cable 48 over the cable outer conductive wrap 52. The cable nest 59 is spaced apart from the ground shield base 57 and offset by way of a tab 62 in the vertical direction from the ground shield base 57, as best illustrated in
The endwall 44a and shoulders 44b form a horizontal, general U-shape in the horizontal direction that partially encloses the terminal tail portions 40 and they cooperatively form a foundation for the overmolded portion 45 to adhere to the support frame 34 while enclosing the termination area, the cable nest 59 and the free ends of the cable wires 48. The cable nest wings 61 are captured by this overmolded portion 45, and they at least partially reinforce the area to resist failure during the assembly process if stress is applied to the signal pair elements. This area, as shown in
Turning to
The support frame 34 preferably engages the ground shield 56 in a manner that retains it and its terminals 32a, b in a desired proper position. As shown one means for securing the support frame 34 to the ground shield 56 may include pairs of first and second stops, 46, 47 respectively that protrude outwardly from the support frame sidewalls 37a, b. These stops are preferably received within corresponding pairs of first and second slots 65, 66 so that the facing edges of the stops 46, 47 and the slots 65, 66 contact each other. The slots 65, 66 maybe configure as illustrated to include indentations or the like that engage protuberances on the stops 46, 47. An alternate means of engagement may include depressions formed on the support frame 34 and complementary-shaped indentations formed on the ground shield sidewalls 58a, b.
The ground shield 56 may also include a raised member in the shape of an elongated button 63 that aligns the support frame with the ground shield. Elongated button 63 may be embossed, to aid in strength and rigidity of the ground shield at the location of the slots 66. In order to retain the signal pair element 30 in place within the connector housing 22, the ground shield 56 may include a catch portion, shown as a tongue or tab member 64 that is stamped in the ground shield base 57 and formed at an outward angle as shown best in
It can be seen that each of the signal pair elements, or chicklets, 30 form an integrated signal pair with two terminals suitable for transmitting differential signals and which are supported within an associated ground shield that at least partially encloses the terminals on three different sides thereof, leaving only one side with selected surfaces of the terminals exposed. These exposed terminals will be spaced apart from the ground shield bases of the signal pair elements above (or below, depending on the orientation) so that coupling may occur with the ground shield of an adjacent signal pair element. This is best shown in
This provides connectors utilizing the signal pair element with larger flexibility in design. These chicklets 30 are, in essence, individual building blocks of a backplane connector and may be arranged in a variety of different arrangements within a connector housing such as in lettered styles that display a C, H, O, U, X, Y or W configuration. Using such individual building block signal pair elements requires tooling costs only for simple the connector housings, which may only involve a single mold with different inserts, and not a complex one for complex wafers. For a new pair count in a connector design, only the connector housing needs to be tooled. If any signal pair in the connector is bad, only the bad signal pair element need be replaced, rather than discarding the entire wafer. The single signal pair element design therefore minimizes the labor and materials required to only that of a single pair element and not a multi-pair wafer, in which the conductive elements thereof need to be inserted into multiple openings in a connector housing.
The rear end of the ground shield 74 includes a wire nest 75 that receives the free ends of a cable wire pair 49a, b therein; this nest 75 includes portions of the ground shield sidewalls 74b, c and an inner shoulder 76 that is stamped and formed from part of the ground shield 74. Preferably, this inner shoulder 76 contacts the outer wrap 52 of the wire pair 49a, b and urges it into contact with the opposing sidewall 74c of the ground shield 74. A second lower shoulder 76a may be provided as shown in
A commoning member 78 is provided to interconnect multiple signal pair elements by way of their ground shields. The commoning member 78 extends transversely across the ground shield 74 and engages the ground shield sidewalls 74b, c by way of complementary shaped shield tabs 77 and commoning member slots 79. The commoning member 78 extends transversely with respect to the signal pair element 70 and may include, as illustrated, a raised bump or detent, 80 that accommodates the difference in heights between drain wire 51 and the cable pair outer wrap 53. The commoning member 78 may be a singular member, that is, extending across only a single signal pair element ground shield, or it may extend further transversely and commonly connect multiple signal pair elements by way of their associated ground shields in the fashion of a linear array. As such, the commoning member 78 of this embodiment 70 serves a similar purpose as the wire nest ground clamp 60 of the prior embodiment.
An insulative material 82 is molded over the terminal tail portions, the wire pair free ends, the ground shield 74 and the commoning member 78 to form a structure that interconnects the signal pair elements 70 together in a linear array 71 that holds individual signal pair elements 70 in a desired arrangement. Although shown as an entirely linear array, it will be understood that the signal pair elements of such array may be out of plane, as if they were interconnected in an alternating arrangement of peaks and valleys or if they were interconnected in a vertical direction. The integrated structure of the singular signal pair element that permits single insertion of such elements into single openings of a connector housing permits the interconnection or ganging of multiple elements together to form arrays of elements. Such arrays will cut down the time needed for insertion of singular elements while still maintaining the integrated structure of the signal pair element which permits insertion of a single signal pair element into a single opening of a connector housing.
The signal pair elements of the Present Disclosure not only provide an economic benefit to a connector designer due to their reduced cost, especially when repair and/or replacement is considered, but also in electrical performance. A connector design of the type illustrated in
While a preferred embodiment of the Present Disclosure is shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the foregoing Description and the appended Claims.
The application is a continuation of U.S. application Ser. No. 14/776,344, filed Mar. 13, 2014, now U.S. Pat. TBD, which in turn claims priority to prior-filed U.S. Provisional Patent Application No. 61/779,757, entitled “Integrated Signal Pair Element And Connector Using Same,” filed on 13 Mar. 2013 with the United States Patent And Trademark Office, both of which are incorporated herein by reference in their entirety.
Number | Date | Country | |
---|---|---|---|
61779757 | Mar 2013 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 14776344 | Sep 2015 | US |
Child | 15268776 | US |