The Present Disclosure relates generally to high speed data transmission systems suitable for use in transmitting high speed signals at low losses from chips or processors of a chip package to backplanes and devices, and more particularly to connectors suitable for use in integrated connector interface-chip package routing assemblies.
Electronic devices such as routers, servers, switches and the like need to transmit data at high data transmission speeds in order to serve the rising need for bandwidth and delivery of streaming audio and video in many end user devices. Chips are the heart of these routers, switches and other devices. These chips typically include a processor such as an ASIC (application specific integrated circuit) or an FPGA (field programmable gate array) and the like, these chips have dies that are typically connected to a substrate (creating a package) by way of conductive solder bumps or other convenient connection. The package may include micro-vias or plated through holes that extend through the substrate to solder balls. These solder balls comprise a ball grid array by which the package is attached to the motherboard. The motherboard includes numerous traces formed in it that define transmission lines which include differential signal pairs for the transmission of high speed data signal, ground paths associated with the differential signal pairs, and a variety of low speed transmission lines for power, clock and logic signals as well as other components. These traces include traces that are routed from the ASIC to the I/O connectors of the device into which external connectors are connected to provide a connection between one or more external plug connectors and the chip member. Other traces are routed from the ASIC to backplane connectors that permit the device to be connected to an overall system such as a network server or the like.
These conductive traces thus form transmission lines as part of the mother board and extend between the chip member and connectors to provide that provides a connection between one or more external plug connectors and the chip member. Circuit boards are usually formed from a material known as FR4, which is inexpensive. Although inexpensive, FR4 is known to promote losses in high speed signal transmission lines that transfer data at rates of about 6 Gbps and greater. These losses increase as the speed increases and therefore make FR4 material undesirable for the high speed data transfer applications of about 10 Gbps and greater. This drop off begins at about 6 Gbps (or 3 GHz using NRZ encoding) and increases as the data rate increases. In order to use such traces in FR4, a designer may have to utilize amplifiers and equalizers, which increase the final cost of the device.
Custom materials for circuit boards, such a MEGATRON, are available that reduce such losses, but the prices of these materials substantially increase the cost of the circuit board and, consequently, the electronic devices in which they are used. Additionally, when traces are used to form signal transmission lines, the overall length of the transmission lines can exceed threshold lengths at which problems to appear in operation. These lengths may approach 10 inches and longer in length and may include bends and turns that can create reflection and noise problems as well as additional losses. Losses can sometimes be corrected by the use of amplifiers, repeaters and equalizers but these elements increase the cost of manufacturing the circuit board. Do so, however, complicates the design inasmuch as additional board space is needed to accommodate these amplifiers and repeaters. In addition, the routing of the traces of such a transmission line may require multiple turns. These turns and the transitions that occur at terminations affect the integrity of the signals transmitted thereby. These custom circuit board materials thus become more lossy at frequencies above 10 Ghz than cable transmission lines. It then becomes difficult to route transmission line traces in a manner to achieve a consistent impedance and a low signal loss therethrough.
It therefore becomes difficult to adequately design signal transmission lines in circuit boards and backplanes to meet the crosstalk and loss requirements needed for high speed applications. Accordingly, certain individuals would appreciate a cable connector suitable for use in integrated, high speed, connector interface-chip package routing assembly that provides transmission lines for transmitting high speed data signals (above 20 Gbps) without using traces on the circuit board.
The present disclosure is therefore directed to a cable connector that may be used in an integrated routing assembly that is structured to fit within the housing of an electronic device as a single element and provide multiple data transmission channels that lead directly from a chip or processor (of the ASIC or FPGA type) to external connector interfaces. The routing assembly preferably utilizes twin-ax cables as its cables for transmitting differential signals from the chip package to the connector interfaces and vice-versa. The cables may be free in their extent between the chip package and the external connector interfaces and secured to the tray by way of clips or the like. The cable may alternatively be embedded or encased within the body of the tray extending from a selected end of the tray to the chip-receiving opening where the conductors of the cables are terminated to board connectors of the present disclosure that enables the cable conductors to mate with corresponding opposing contacts of the chip package. The embedding of the cables in the body of the tray protects the twin-ax cables from damage during assembly.
The cable connectors help connector the conductors to a board or package that is supporting a chip and can have a low profile to help minimize impact on air flow in the system. The cable connector can be used to terminate the free ends of the conductors of the cables to terminals of the cable connector. In this manner, the mating connectors can be used adjacent (or even on) the chip package in order to retain a low profile and their impedance and other performance parameters are better controlled. The cable connector can include a conductive carrier that holds the cables in place and oriented so their associated signal conductor and drain wire free ends are positioned for termination by welding to the terminals supported by a connector housing. The carrier can include mounting feet.
In addition to the carrier, a grounding collar can be provided and the grounding collar can have multiple tails formed at one end thereof. These tails and the mounting feet of the carrier grounding feet are contacted together, forming a double thickness region, to help common the ground structure and can also be used to adjust impedance. This double thickness extends in the horizontal direction, while a second carrier may be provided and the two carriers provide a second increased thickness in the vertical direction.
The free ends of the cables are held together in a first spacing by spacers so that the signal conductors and drain wires of the cables are arranged in a desired spacing. Sets of cables may be held together in groups of four cables to accommodate four complete signal transmission channels of four transmit paths and four corresponding receive paths. The spacers are mounted on carriers, which can be conductive and mirror images of each other. The carriers can be elongated with top and base flanges. The top flanges extend vertically and the base flanges are offset from the top flanges and extend horizontally from them. The top and base flanges provide reference ground planes in two directions for the signal pairs provided by the cables.
The carriers include structure that allows the free ends of the signal conductor and drain wire free ends to extend in opposite directions. In this arrangement, the free ends of the signal conductors extend downwardly and outwardly, while the free ends of the drain wires extend upwardly. The base flange is configured with multiple slots that are spaced apart for their length. A ground collar can be attached to each carrier and the collars extend over the spacers in a manner so that the collars and carriers cooperatively define a continuous shield that encircles a selected portion of each spacer and over the free ends of the cables fixed therein. The free ends of the signal conductors and drain wires can exit the cables about even with an edge of each collar.
The ground collar has a plurality of tails that extend generally downwardly and out from the carriers at angles to the cables. The first tails are narrow and slightly uniform in their extent. The second tails have a tapered configuration and have a width that tapers along the length of the second tails from the ground collar to their tips. The third tails can be wider than the first and second tails and the third tails preferably extend to contact multiple terminals of the sub-connector. The first tails are arranged at the lengthwise ends of the carrier, while the second tails are positioned so they extend between the signal conductors of each cable signal pair. The third tails are positioned between each cable signal pair.
An elongated, insulative wire comb is provided for each carrier and it extends lengthwise of the carrier and has a series of wire-receiving slots that receive the free ends of the signal conductors. The comb holds the free ends in place for attachment but also isolates them from contacting one another in shorting contact. The second tails have openings formed in their wider (neck) sections occurring near the top of the tails and these openings receive the free ends of the drain wires. The free ends of the drain wires are bent upwardly and lie on the exterior surface of the collar. The wider tail extend down from the ground collar and then double back inwardly to match the exterior configuration of the spacers. In this manner the widthwise edges of the tails are generally aligned with the signal conductors so that edge coupling may occur with the third tails. The widths of the carrier flange feet tends to match those of the ground collar third tails.
The present disclosure is illustrated by way of example and not limited in the accompanying Figures in which like reference numerals indicate similar elements and in which:
The detailed description that follows describes exemplary embodiments and is not intended to be limited to the expressly disclosed combination(s). Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity.
In the known structure of the device of
In order to overcome these actual disadvantages, we have developed an integrated routing assembly 50 that incorporates the external connector interfaces of a host devices 51 into a single assembly and which provides a support for high speed differential pair signal transmission lines in the form of elongated cables 62 that extend between the connector interfaces and the chip package 88, eliminating the need for high speed routing traces on the motherboard 53. An embodiment of such an assembly is illustrated at 50 in
The connector housings 60 define the external connector interfaces for the device 50 in the form of connector ports 54, 56 and each such connector housing 60 contains a high speed connector 57, which can be a receptacle style connector. As can be appreciated, the connectors 57 can be arranged in horizontal rows in an integrated fashion, such as is depicted in
The tray 75, as illustrated in
The depicted connectors 57 of the connector housings 60 that form the array of connector ports 54, 56 are of the receptacle type having signal and ground terminals arranged in transmit and receive channel configurations to mate with opposing connectors having a plug connector style. Cables 62, which can be in a twin-ax configuration, are directly terminated at their distal ends 82 to the connector terminals of each connector 57 at first ends of the cables 62 and are seen in
Both the cables 62 and low speed wires 64 are terminated directly at their first ends to first terminals of the first connector 57. The first terminals are thus not required to be mated to the motherboard 53 and this helps avoid the impedance discontinuities which normally occur at a connector-circuit board mounting interface. The cables 62 are illustrated as arranged in vertical rows at the rear of the connector housings 60. The cables 62 are arranged in vertical rows as best shown in
The cables 62 lead from the rear of the connectors to the front edge of the tray 75 where they enter the body of the tray 75. The proximal ends 84 of the cables 62 extend into the tray opening 76 as illustrated where they are mated to connectors 86 that will mate with the chip package 88. These connectors 86 are preferably of the wire-to-board style so that the signal conductors and ground of the cables 62 can be easily connected to contacts on the chip package substrate 91. The second ends of the cables 62 exit the tray 75 to enter the chip package-receiving opening 76. In one aspect of the present disclosure, the chip package 88 and associated chip 90 are disposed on the device motherboard 53, and the chip package 88 includes a plurality of contacts in the form of receptacle style connectors 86 that are preferably arranged around the perimeter thereof and aligned with the tray opening 76 to align with the connectors 86 at the cable proximal ends 84. In another aspect, the chip package/processor 88, 90 may be included as part of the overall routing assembly 74. In another aspect, as illustrated in
The cables 62 (and low power wires 64) may be positioned as part of the tray 75 in a variety of ways that suitably holds them in place from where they enter the routing assembly 74, such as along the leading edge 83 of the tray 75 to where they exit the tray 75 and enter the tray opening 76. The cables 62 can be accommodated in the tray 75 by enclosing them in a suitable dielectric material, such as a plastic. The body portions of the cables 62 can be completely surrounded by the dielectric material of tray 75 so that the two are integrally formed as a single part that can be inserted into the routing assembly 74 as a tray portion. One routing pattern of the cables 62 is illustrated in
The cables 62 are terminated at their second ends 84 to the aforementioned chip package connectors 86 either before or after the forming of the tray 75. Inasmuch as the first ends of the cables 62 are directly terminated to the terminals of the cable direct connectors 57, the second connectors 86 permit the cables 62 to be directly connected to the chip package 88, thereby completely bypassing the motherboard 53 as a routing support. In such an instance, the routing assembly 74 may be inserted into the host device housing and the motherboard 53 is placed in the housing of the device 51 over the tray 75, where it may be spaced apart from and above the motherboard by standoffs 92 or the like.
Although the cable connector 105 can be used in an upside-down manner, as shown in
A carrier 110 is formed in an elongated fashion out of conductive material and has a general L-shaped configuration that is formed from a top flange 112 and a base flange 114. The base flange 114 defines a base of the carrier 110 that abuts the mating surface 171 of the sub-connector 129 when the cable connector 105 is assembled. The base flange 114 has a series of pairs of slots 116 formed in it that extend widthwise of the assembly 105 as illustrated. The slots 116 can be seen to be generally perpendicular to a centerline of the assembly 105 and which define mounting feet 117, 118 of the carrier. These mounting feet 117, 118 contact selected ground terminals 132b of the sub-connector 129.
The top flange 112 and the base flange 114 extend in two different directions, the top flange 112 extending alongside the ends of the cables and the base flange 114 extending beneath the cable ends. This extent provides two reference ground planes in two planes with respect to the ends of the cables. The carrier 110 can provided on two opposing sides of the cable connector 105.
The base flange 114 contacts the mating surface 170 of the sub-connector 129. This mating surface 170 extends lengthwise along the sub-connector 129 and includes a center base 171 that is flanked by two side slots 172 through which the terminals 132 extend in spaced-apart order along the length of the mating surface 170. As illustrated in
As noted above, the base flange 114 abuts the mounting surface 171 of the sub-connector 129 so that the slots 116 are aligned with signal terminals 132a of the sub-connector 129. The slots 116 extend along a length of the sub-connector 129 and have a width sufficient to prevent shorting contact from occurring between the base flange 114 and the signal conductors 119 and connector signal terminals 132a. As depicted, a ground terminal is positioned between the signal pair and two adjacent slots 116 are separated by the mounting foot 117, which provides a contact point for a ground terminal 132b of the sub-connector 129 and a second tail 142. Wider mounting feet 118 are shown located between two pairs of slots 116 and the mounting feet 118 can contact multiple adjacent ground terminals 132b in order to maintain a desired pinout and common the grounds. If two carriers 110 are aligned back to back, as illustrated, the carriers 110 may be aligned so that the cables 62 are offset (as shown).
The cables 62 are held in a spaced apart relationship by a spacer 124, which can be formed of an insulative material, and can be in the form of a lengthwise bar. The spacer 124 has a series of shoulder portions 126 also spaced apart in the lengthwise direction. These shoulder portions 126 are preferably aligned with the cables 62 as shown in
The spacer 124 further includes scallop-shaped recesses 128 that are located between the shoulder portions 126 and the ends of the spacer 124. The recesses 128 accommodate portions of the tails when they are bent inwardly as shown in
As can be appreciated from
In order to provide additional shielding to the cables 62 near the proximal ends 84 thereof, a ground collar 134 formed of a conductive material can be provided for each carrier 110. The depicted ground collars 134 have general U-shaped configurations with a lengthwise body 136 having two attachment flanges 137 at opposite ends of the body 136. The attachment flanges 137 attach to the top flange 112 near the ends of the cable connector 105. The ground collar body 136 and attachment flanges 137 cooperate with the top flange 112 to provide a conductive structure that can completely encircle the cable proximal ends as a group.
The ground collars 134 also have additional structure of importance. It can be seen that the ground collar 134 has a series of tails 138 and slots 139. The tails 138 extend downward to contact the base flange 114. They also, as illustrated in
Second tails 142 are shown as wider than the first tails 140 (
The ends of the tails 138 may be considered as contact ends, and the ends of the third tails 146 are also wider than the tip portions of the first and second tails 140, 142 as illustrated in
The disclosure provided herein describes features in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.
This application claims priority to U.S. Provisional Application No. 62/277,230, filed Jan. 11, 2016.
Filing Document | Filing Date | Country | Kind |
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PCT/US2017/012988 | 1/11/2017 | WO | 00 |
Number | Date | Country | |
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62277230 | Jan 2016 | US |