The Present Disclosure relates generally to the construction of plug connectors and, more particularly, to high-speed plug connectors having improved impedance characteristics.
Many different styles of cable connectors are known. One such connector is described in U.S. Pat. No. 7,175,444, the contents of which are incorporated by reference herein in its entirety. In the connector disclosed in the '444 patent, cable wires are connected to contact pads on a printed circuit board used as a mating blade of the connector. The wires are terminated to the contact pads in a termination nest area and then overmolded with plastic. The plastic has a higher dielectric constant than air and, as such, affects the impedance of the connector, typically by lowering it in that area. The resultant dip in impedance may be detrimental to the operation of the connector based upon its magnitude. At low operational speeds and data transmission rates, such as 1 Gbs, an impedance dip of greater than 8-10 ohms may not introduce excessive noise into the connector. However, at higher speeds and data transmission rates, such as upwards to about 8-12 Gbs, noise rises to a level where it becomes an issue. Large dips in impedance are conducive to the introduction of noise into the connector as well as crosstalk.
However, the use of plastic overmolding is desirable because it provides a reliable means for locating the wires and the circuit boards within an exterior housing, as well as forming a unitary connector structure. Additionally, plastic overmolding also provides strain relief which protects the joined or soldered connections to the printed circuit boards from direct pull forces on the cable. Further, removing the overmolded section leads to a non-unitary structure.
The Present Disclosure is therefore directed to a plug connector that has a desirable impedance profile, as well as one with a robust connector structure.
It is an object of the Present Disclosure to provide a plug connector construction which improves the impedance profile thereof, while still maintaining a robust structure therefor.
In this regard, the connectors, as described herein, include a plurality of wire cables with some of the cables including pairs of signal wires and a drain wire. A wire organizer is provided that slips over individual wires to snugly grip the wires. This wire organizer defines a rear wall or portion of the connector assembly that is insertable into an outer housing. The wires have free ends which expose thin inner conductors that are terminated to contact pads on multiple circuit boards. In the preferred execution of the connector, two circuit boards, or cards are utilized.
A spacer element is further provided and firstly spaces the multiple circuit boards apart from each other in the vertical direction. Secondly, certain other aspects are provided in the spacer structure so that when it is assembled to the circuit boards, it orients the circuit boards for proper insertion as a assembly into an exterior connector housing, as well as for mating to an opposing, mating connector. Thirdly, as the spacer is positioned a preselected distance from the wire organizer, it has a rear face that defines a first boundary of a body portion formed from a holt melt (typically a thermosetting adhesive) applied to the cables, while the wire organizer has a front face that defines a second boundary of this body portion. In this manner, the wire organizer and the spacer cooperatively define the boundaries of the body portion.
When the body portion is formed over the cables between the wire organizer and spacer, it fixes the wires in place and forms, in cooperation, with the organizer and spacer, a cable assembly in which the wires are terminated to the circuit boards, which are held in their desired spacing. The exposed ends of the conductors of the wires are terminated to corresponding contact pads on the circuit boards, but the hot melt does not envelop the conductor terminations. Thus, the terminations and their associated conductors are enveloped by air. The lower dielectric constant of air, as compared to the hot melt or a plastic, reduces the capacitance of the connector system at the termination. This rise in capacitance results in a lesser drop in impedance than if the body portion were permitted to flow over the conductor terminations, thus reducing a large dip in the impedance profile which could impart detrimental noise at high data speeds.
The completed cable assembly is insertable into a hollow exterior connector housing that encloses the front (or mating) ends of the circuit boards. The spacer is preferably provided with polarizing features for the entire assembly that permit the assembly only to be inserted into the outer housing in the proper orientation. Furthermore, both the organizer and the spacer may be provided with engagement members in the form of lugs, or catches, that engage complimentary-shaped recesses, or opening, formed in the outer housing.
Further, a multiple connector housing, such as a tandem connector housing, is provided and includes a structure that permits the insertion of two cable subassemblies therein. An insertable wall member is provided that slips into a slot formed in the interior of the outer connector housing. This wall member has one or more latch openings formed therein to engage the latches or catches formed as part of the cable subassemblies. Thus, multiple connectors may be made by modifying the housing to receive the desired number of cable subassemblies.
These and other objects, advantages and benefits of the disclosure will become apparent in a reading of the following detailed description.
Throughout the Present Disclosure, reference will be made to the drawings in which like reference numbers identify like elements, and in which:
The connector 50 is shown in a normal orientation with its upper flat surface on the connector housing 51 forming the “top” of the connector and a latching mechanism 110 disposed on the “bottom” of the connector 50. This orientation is for connecting to an electronic device that has a latching engagement surface along the bottom of a mating receptacle of the device. It will be understood that the connectors of this disclosure may be used in applications where the latching mechanism 110 is on disposed on the top of the connector housing 51 and, as such, the terms “top,” “bottom,” “upper” and “lower” are used to describe the environment in which the connector is used and not intended to be limiting to a particular orientation.
The leading edges 60 of the circuit boards 58, 59 extend forwardly with respect to the connector 50 and serve as mating blades that are received within opposing slots of a mating connector (not shown). Inasmuch as the leading edges 60 of the circuit boards 58, 59 extend forwardly to be received within opposing slots, the connector 50 illustrated is considered as a male, connector having a plug end which can be inserted and removed from a mating connector repeatedly. The mating connector may be a singular connector, that is, receiving only a single plug, or it may receive multiple plugs as described herein below.
The circuit boards 58, 59 have contact pads disposed on their exterior surfaces proximate to the leading and of trailing edges 60, 62. The contact pads 64 near the trailing edges 62 are termination pads where the free ends of the wire conductors 55 are attached such as by soldering the like, while the contact pads 65 near the leading edges 60 of the circuit boards are mating pads that are contacted by terminals of the mating connector (not shown). The two sets of contact pads 64, 65 are spaced apart from each other longitudinally of the circuit boards 58, 59 and are connected to each via conductive circuitry of the boards as is known in the art. The circuit boards 58, 59 are further spaced apart from each other in the vertical direction so that they may be accommodated in similarly spaced apart slots of a mating connector.
A spacer 70, as shown best in
The spacer 70 also has two opposing front and rear planar surfaces 78, 79. The front surface 78 forms a part of a mating face of the connector in combination with portions of the connector housing 51. The rear surface 79 extends between the two circuit boards and, in combination with other things, forms a stop surface that will be explained in greater detail below. In order to ensure that the circuit boards 58, 59 are assembled in their correct orientation, the circuit boards 58, 59 are preferably provided with notches, or cutouts 80 that engage posts, or lugs, 82a-b that extend away from the spacer 70, and particularly its base portion 72. The posts 82 are shown projecting upwardly and downwardly from the spacer 70 in the drawings. As can be seen from the drawings, especially
In addition to orienting the individual circuit boards 58, 59 with respect to their placement on the spacer 70 and in the resultant cable assembly 68, the spacer 70 also includes a keying, or polarizing, feature in the form of different lengths of the projecting posts 82. The length, or height, of the posts 82a on one side of the spacer 70 is different than the length or height of the posts 82b or the other side of the spacer 70. In the drawings, the posts 82a on the top half of the spacer 70 are shown as taller than the posts 82b on the bottom side of the spacer 70. The difference in height of the posts correspond to a like difference in heights of the upper and lower portions of the internal passage 53 after the cable assembly is inserted into the connector housing 51 (
In order to provide the spacer 70 and the cable assembly with a means to engage the connector housing 51, the spacer 70 includes at least one engagement, or latch member 90, with two such latch members 90 being shown in
The enlarged end portion of the cantilevered arms contains molded steps that provide a holding location of the spacer depending on how far forward the spacer is pushed into the housing. Tolerances of components can cause variation in the spacer location, therefore the steps provide a means of always locating the spacer/paddles cards in the most forward location independent of the tolerance stack-up of all the individual components.
The width of the tail portion 73 is less than that of the base portion 72 so as to define an area into which the latch members 90 can deflect. The front face of the spacer 70, and particularly of its base portion 72 is contoured to engage the interior of the connector housing 51. As illustrated, the spacer 70 includes a projecting portion 95 that is flanked by two shoulders 96. The connector housing 51 has an inner stop wall 98 that extends inwardly around the interior of the hollow passage 53 and it includes an opening 99 disposed therein that is smaller in size than its surrounding hollow passage 53. This opening receives the base portion projecting portion 95, and the shoulders steps 96 engage, and preferably abut the stop wall 98. In this regard, the circuit boards 58, 59 have a width that is preferably slightly less than that of the width of the opening 99 so as to project forwardly without interference within the mating receptacle 97 defined by the front of the connector housing 51.
A wire organizer 85 is also provided and includes a block-like member 86 that has a plurality of openings 87a, 87b disposed therein. The openings 87a-b are arranged to accommodate the cables 52 and are so arranged to organize selected cables 52 in an array of rows, or columns, depending on the viewer's frame of reference. In the illustration, as shown best in
The openings 87a-b are all preferably tapered along the insertion direction of the cables 52, so that the diameter at the rear face 118a of the wire organizer 85 is less than the diameter of the openings 87a-b at the front face 118b of the wire organizer 85. This tapering permits the wire organizer 85 to be slid onto the wires to a point where the openings 87a-b thereof snugly engage the cables 52 at one end, while the openings are slightly larger at the other end.
Both the wire organizer 85 and the spacer 70 have flat surfaces 120, 121 that oppose each other and serve to define stop surfaces that cooperatively define the boundaries of an internal area of the cable assembly therebetween, that is injected with a hot melt, typically a thermosetting adhesive, in order to bind the cables 52 together into a group and to add rigidity and mass to the cable assembly to, among other things, facilitate its insertion into an associated connector housing 51. This hot melt, when set, defines a body portion 100 of the cable assembly 68 because it encloses the cable wires 54 in a block to prevent them from deflecting outwardly when the cable assembly 68 is inserted into the connector housing passage 53 as they may be prone to do, given their fixed points at both the wire organizer and the trailing edges of the circuit boards 58, 59. This body portion 100 preferably abuts the wire organizer 85 and the spacer and so prevents movement of the wires 54 in a back and forth direction as would occur if the wires 54 were fixed along their length at two spaced-apart locations such as at the wire organizer 85 and the termination to the circuit boards 58, 59. The use of hot melt is beneficial because of the low application pressures utilized with it. If a thermoplastic were used to form the body portion, the high injection pressures required would crush the insulation of the twinax wires 54 of the cables 52, as well as possibly bleed or flash out onto the termination area on the circuit boards 58, 59, and this would detrimentally affect the impedance of the connector in this area by increasing the capacitance and lowering he impedance to an undesired level.
The body portions 100 also provides strain relief to the wire terminations at the trailing edges 62 of the circuit boards 58, 59, and due to adhesion of the hot melt during the molding process, joins to the wire organizer along its front face 118b and into its openings 87a-b, and also joins to the flat, rear surface 79 of the spacer 70 and the trailing edges 62 of the circuit boards 58, 59. This, coupled with the termination of the conductor free ends to the termination pads 64, fixes the multiple circuit boards 58, 59 in place within the assembly 68.
In the past, as exemplified by the aforementioned '444 patent, the free ends of the cables wires were terminated to the circuit card(s) in a termination nest area between the walls of a housing perform and then plastic or hot melt formed over the wires, including the exposed conductors terminated to the circuit card. This was done largely to ensure the structural integrity of the resulting connector. However, the plastic has a dielectric greater than that of air and therefore increased the capacitance of the connector in that area, which resulted in a lowering (a “dip”) of the impedance in that section of the connector. The dip in the impedance in such a connector proved detrimental in that the dip would result in about an 11-ohm reduction from a peak value of about 103 ohms to a dip value of about 92 ohms. This can be too large of a reduction at high speeds and will tend to introduce noise and crosstalk into the system. The goal in high speed data transmission is to flatten out as much as possible, the typical impedance profile, and prevent large dips and peaks. One standard tolerance ranges is 100 ohm+/−10%, meaning that the boundaries of the impedance profile through the mating interface are desirably about 90 to about 100 ohms. As stated earlier, this may be suitable for data transmission speeds of 1-2 Gbs, but at high speeds, of about 10 to about 12 Gbs and above, noise will be introduced into the system at the mating interface. In connectors of this disclosure, the impedance drop is reduced to a drop of about 8 ohms, with a peak on the profile of about 103 ohms to a dip of about 96 ohms, thereby softening the magnitude of the impedance profile through the cable connector.
The dividing member 205 is elongated and preferably extends the entire length of the connector housing 201 and it may include engagement members formed at its opposing ends, such as clips 208 and fingers 210. The clips 208 extend into slots 212 formed along the rear face 213 of the connector housing 201, while the fingers 210 are cantilevered projections disposed at the front of the dividing member 205 and which are bent outwardly with respect to a central axis of the dividing member 205. As shown in the sections of
It will be understood that there are numerous modifications of the Present Disclosure, which will be readily apparent to one skilled in the art, such as many variations and modifications of the compression connector assembly and/or its components including combinations of features disclosed herein that are individually disclosed or claimed herein, explicitly including additional combinations of such features, or alternatively other types of contact array connectors. Also, there are many possible variations in the materials and configurations. These modifications and/or combinations fall within the art to which the Present Disclosure relates and is intended to be within the scope of the following Claims. It is also noted that the use of a singular element in a claim is intended to cover one or more of such an element.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US11/29236 | 3/21/2011 | WO | 00 | 11/13/2012 |
Number | Date | Country | |
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61315801 | Mar 2010 | US |