U.S. patent number RE47,342 [Application Number 15/271,903] was granted by the patent office on 2019-04-09 for high speed bypass cable assembly.
This patent grant is currently assigned to Molex, LLC. The grantee listed for this patent is Molex, LLC. Invention is credited to Ebrahim Abunasrah, Munawar Ahmad, Stephen W. Hamblin, Christopher David Hirschy, Eran J. Jones, Rehan Khan, Brian Keith Lloyd, Darian Ross Schulz, Gregory B. Walz, Todd David Ward.
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United States Patent |
RE47,342 |
Lloyd , et al. |
April 9, 2019 |
High speed bypass cable assembly
Abstract
A cable bypass assembly is disclosed for use in providing a high
speed transmission line for connecting a board mounted connector of
an electronic device to a chip on the device board. The bypass
cable assembly has a structure that permits it, where it is
terminated to the board mounted connector and the chip member, or
closely proximate thereto to replicate closely the geometry of the
cable. The connector terminals are arranged in alignment with the
cable signal conductors and shield extensions are provided so that
shielding can be provided up to and over the termination between
the cable signal conductors and the board connector terminal tails.
Likewise, a similar termination structure is provided at the
opposite end of the cable where a pair of terminals are supported
by a second connector body and enclosed in a shield collar. The
shield collar has an extension that engages the second end of the
cable.
Inventors: |
Lloyd; Brian Keith (Maumelle,
AR), Hirschy; Christopher David (Conway, AR), Ahmad;
Munawar (Maumelle, AR), Jones; Eran J. (Conway, AR),
Hamblin; Stephen W. (Little Rock, AR), Schulz; Darian
Ross (Little Rock, AR), Ward; Todd David (Maumelle,
AR), Walz; Gregory B. (Maumelle, AR), Abunasrah;
Ebrahim (Little Rock, AR), Khan; Rehan (Little Rock,
AR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Molex, LLC |
Lisle |
IL |
US |
|
|
Assignee: |
Molex, LLC (Lisle, IL)
|
Family
ID: |
50065340 |
Appl.
No.: |
15/271,903 |
Filed: |
September 21, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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PCT/US2010/022738 |
Feb 1, 2010 |
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61148685 |
Jan 30, 2009 |
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Reissue of: |
13987296 |
Feb 14, 2011 |
9011177 |
Apr 21, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01B
11/00 (20130101); H05K 1/0243 (20130101); H01B
11/00 (20130101); H01R 13/6593 (20130101); H01R
13/6592 (20130101); H05K 3/222 (20130101); H01R
13/6461 (20130101); H01R 13/6471 (20130101); H05K
3/222 (20130101); H05K 1/0243 (20130101); H01R
13/6593 (20130101); H01R 13/6471 (20130101); H05K
2201/10446 (20130101); H05K 2201/10674 (20130101); H05K
2201/10356 (20130101); H05K 2201/10446 (20130101); H05K
2201/10189 (20130101); H05K 2201/10189 (20130101); H05K
2201/10356 (20130101); H05K 2201/10674 (20130101) |
Current International
Class: |
H01R
13/58 (20060101); H01R 13/6471 (20110101); H05K
3/22 (20060101); H05K 1/02 (20060101); H01B
11/00 (20060101); H01R 13/6593 (20110101) |
Field of
Search: |
;439/108,76.1,465,492,493,607.01,607.47,638,63,342,374,404,483,494,541.5,579,709,79,98
;361/741 ;174/68.1,261 |
References Cited
[Referenced By]
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Other References
US. Appl. No. 61/714,871, filed Oct. 17, 2012, Wig et al. cited by
applicant .
Agilent, "Designing Scalable 10G Backplane Interconnect Systems
Utilizing Advanced Verification Methodologies," White Paper,
Published May 5, 2012, USA. cited by applicant .
Amphenol Aerospace, "Size 8 High Speed Quadrax and Differential
Twinax Contacts for Use in MIL-DTL-38999 Special Subminiature
Cylindrical and ARINC 600 Rectangular Connectors", published May
2008. Retrieved from
www.peigenesis.com/images/content/news/amphenol_quadrax.pdf. cited
by applicant .
Hitachi Cable America Inc., "Direct Attach Cables: OMNIBIT supports
25 Gbit/s interconnections". Retrieved Aug. 10, 2017 from
www.hca.hitachi-cable.com/products/hca/catalog/pdfs/direct-attach-cable-a-
ssemblies.pdf. cited by applicant .
Amphenol TCS, "Amphenol TCS expands the XCede Platform with 85 Ohm
Connectors and High-Speed Cable Solutions," Press Release,
Published Feb. 25, 2009,
http://www.amphenol.com/about/news_archive/2009/58. cited by
applicant .
"File:Wrt54gl-layout.jpg-Embedded Xinu", Internet Citation, Sep. 8,
2006. Retrieved from the Internet:
URL:http://xinu.mscs.edu/File:Wrt54gl-layout.jpg [retrieved on Sep.
23, 2014]. cited by applicant.
|
Primary Examiner: Lee; Christopher E.
Attorney, Agent or Firm: Molex, LLC
Parent Case Text
.Iadd.This is a reissue application of U.S. Pat. No. 9,011,177,
Issued Apr. 21, 2015. .Iaddend.
REFERENCE To RELATED APPLICATIONS
The Present Disclosure is a continuation-in-part of International
Application No. PCT/US2010/022738, filed Feb. 1, 2010, entitled
"High Speed Interconnect Cable Assembly," filed 01 Feb. 2010 with
the U.S. Patent And Trademark Office (USPTO) as Receiving Office
for the Patent Cooperation Treaty. The '738 Application claims
priority of prior-filed U.S. Provisional Application No.
61/145,685, entitled "High Speed Interconnect Cable Assembly,"
filed 30 Jan. 2009 also with the USPTO. The contents of each of the
above Applications are fully incorporated in their entireties
herein.
Claims
What is claimed is:
1. A cable bypass assembly, the cable bypass assembly comprising: a
first connector, the first connector being configured for mounting
to a circuit board, the first connector including a connector body,
the connector body .Iadd.including a card slot and
.Iaddend.supporting a plurality of conductive terminals .Iadd.that
extend into the card slot.Iaddend., the conductive terminals
including contact portions and tail portions, the contact portions
being held within the .[.connector body.]. .Iadd.card slot
.Iaddend.for contacting a mating blade of an opposing, mating
connector, the tail portions extending .[.out from the connector
body.]. .Iadd.rearward of the card slot.Iaddend.; an elongated
cable, the elongated cable including: a pair of signal conductors,
the signal conductors being disposed within an insulative body
portion of the elongated cable, the signal conductors extending, in
a spaced-apart relationship, lengthwise through a body portion of
the elongated cable, a conductive shield, the conductive shield
extending over an exterior of the elongated cable body portion, an
insulative outer covering, the insulative outer covering extending
over the conductive shield, and opposing first and second free
ends, the first free end terminating directly to selected terminal
tails of the first connector in a manner so that the signal
conductors are in electrical communication with a pair of signal
terminal tails; a shield extension member, the shield extension
member being configured to engage a first length of the conductive
shield exposed at the first free end and extending therefrom over
the signal conductors attached to the pair of signal terminal
tails, the shield extension member including at least two spaced
apart mounting feet; and a second connector, the second connector
including: an insulative body, the insulative body supporting at
least a pair of conductive signal terminals in a spaced-apart
relationship, each conductive signal terminal including contact and
tail portions .Iadd.wherein the second free end is connected to the
tail portions of the at least a pair of terminals in the insulative
body.Iaddend., and a shielding collar, the shielding collar
enclosing a body portion of the second connector, the shielding
collar includes an extension portion, the extension portion
engaging and receiving the conductive shield exposed at the second
free end.Iadd.; wherein the cable bypass assembly is configured to
support 10 GHz signaling.Iaddend..
2. The cable bypass assembly of claim 1, further including a second
cable, the second cable including a pair of signal conductors, the
second cable signal conductors disposed lengthwise therethrough in
a spaced-apart relationship, the second cable signal conductors
being attached to corresponding signal terminal tails of the first
connector alongside the elongated cable.
3. The cable bypass assembly of claim 1, wherein the shield
extension member further includes a cup portion, the cup portion
being configured to receive the first free end therein.
4. The cable bypass assembly of claim 2, wherein the shield
extension member further includes a pair of cup portions, each cup
portion .[.receivings.]. .Iadd.receiving .Iaddend.ends of the two
cables therein.
5. The cable bypass assembly of claim 4, wherein the shield
extension member includes at least three mounting feet, two of the
mounting feet being disposed on opposing side edges of the shield
extension member and a third of the three mounting feet being
disposed between the cup portions.
6. The cable bypass assembly of claim 5, wherein the mounting feet
and the two cable signal conductors are aligned with each
other.
7. The cable bypass assembly of claim 1, wherein the tail and
contact portions extend uninterruptedly lengthwise in a general
horizontal plane through the .[.first.]. connector body.
8. The cable bypass assembly of claim 1, wherein the elongated
cable includes a preselected length of flexible circuitry.
9. .[.The cable bypass assembly of claim 1,.]. .Iadd.A cable bypass
assembly, the cable bypass assembly comprising: a first connector,
the first connector being configured for mounting to a circuit
board, the first connector including a connector body, the
connector body including a card slot and supporting a plurality of
conductive terminals that extend into the card slot, the conductive
terminals including contact portions and tail portions, the contact
portions being held within the card slot for contacting a mating
blade of an opposing, mating connector, the tail portions extending
rearward of the card slot; an elongated cable, the elongated cable
including: a pair of signal conductors, the signal conductors being
disposed within an insulative body portion of the elongated cable,
the signal conductors extending, in a spaced-apart relationship,
lengthwise through a body portion of the elongated cable, a
conductive shield, the conductive shield extending over an exterior
of the elongated cable body portion, an insulative outer covering,
the insulative outer covering extending over the conductive shield,
and opposing first and second free ends, the first free end
terminating directly to selected terminal tails of the first
connector in a manner so that the signal conductors are in
electrical communication with a pair of signal terminal tails; a
shield extension member, the shield extension member being
configured to engage a first length of the conductive shield
exposed at the first free end and extending therefrom over the
signal conductors attached to the pair of signal terminal tails,
the shield extension member including at least two spaced apart
mounting feet; and a second connector, the second connector
including: an insulative body, the insulative body supporting at
least a pair of conductive signal terminals in a spaced-apart
relationship, each conductive signal terminal including contact and
tail portions wherein the second free end is connected to the tail
portions of the at least a pair of terminals in the insulative
body, and a shielding collar, the shielding collar enclosing a body
portion of the second connector, the shielding collar includes an
extension portion, the extension portion engaging and receiving the
conductive shield exposed at the second free end, .Iaddend.wherein
the shielding collar further includes at least one through-hole
terminal, the through-hole terminal extending from the shielding
collar and engaging a through-hole of the circuit board.
10. The cable bypass assembly of claim 1, wherein the shielding
collar further includes a cap portion, the cap portion having a cup
portion formed therein, the cup portion being configured to receive
an exposed second end of the cable therein and contact a length of
exposed cable shielding.
11. .[.The cable bypass assembly of claim 1,.]. .Iadd.A cable
bypass assembly, the cable bypass assembly comprising: a first
connector, the first connector being configured for mounting to a
circuit board, the first connector including a connector body, the
connector body including a card slot and supporting a plurality of
conductive terminals that extend into the card slot, the conductive
terminals including contact portions and tail portions, the contact
portions being held within the card slot for contacting a mating
blade of an opposing, mating connector, the tail portions extending
rearward of the card slot; an elongated cable, the elongated cable
including: a pair of signal conductors, the signal conductors being
disposed within an insulative body portion of the elongated cable,
the signal conductors extending, in a spaced-apart relationship,
lengthwise through a body portion of the elongated cable, a
conductive shield, the conductive shield extending over an exterior
of the elongated cable body portion, an insulative outer covering,
the insulative outer covering extending over the conductive shield,
and opposing first and second free ends, the first free end
terminating directly to selected terminal tails of the first
connector in a manner so that the signal conductors are in
electrical communication with a pair of signal terminal tails; a
shield extension member, the shield extension member being
configured to engage a first length of the conductive shield
exposed at the first free end and extending therefrom over the
signal conductors attached to the pair of signal terminal tails,
the shield extension member including at least two spaced apart
mounting feet; and a second connector, the second connector
including: an insulative body, the insulative body supporting at
least a pair of conductive signal terminals in a spaced-apart
relationship, each conductive signal terminal including contact and
tail portions wherein the second free end is connected to the tail
portions of the at least a pair of terminals in the insulative
body, and a shielding collar, the shielding collar enclosing a body
portion of the second connector, the shielding collar includes an
extension portion, the extension portion engaging and receiving the
conductive shield exposed at the second free end, .Iaddend.wherein
the second connector is configured to connect directly to a chip
member.
12. A cable bypass assembly with low loss performance at high data
frequencies, the cable bypass assembly comprising: a first
connector, the first connector being configured for mounting to a
circuit board, the first connector including a connector body
.Iadd.with a card slot.Iaddend., the connector body supporting a
plurality of conductive terminals, the conductive terminals
including contact portions and tail portions, the contact portions
being held within the .[.connector body.]. .Iadd.card slot
.Iaddend.for contacting a mating blade of an opposing, mating
connector, the tail portions extending .[.out from.].
.Iadd.rearward of .Iaddend.the .[.connector body.]. .Iadd.card
slot.Iaddend.; an elongated cable having, the elongated cable
including: first and second opposing ends, a pair of signal
conductors, the signal conductors being disposed within the
elongated cable in a spaced-apart relationship and extending
lengthwise through the elongated cable, and at least one conductive
shield, each conductive shield extending lengthwise through the
elongated cable and substantially enclosing the signal conductors,
the signal conductors, at the first end, being terminated directly
to selected terminal tails of the first connector in a manner so
that the signal conductors are in electrical communication with a
pair of signal terminal tails along a horizontal extent thereof; a
shield, the shield extending over the signal conductors attached to
the signal terminal tails, the shield including a pair of ground
shields; and a second connector, the second connector including an
insulative body, the insulative body supporting at least a pair of
conductive signal terminals in a spaced-apart relationship, each
conductive signal terminal including contact and tail portions, the
.[.cable.]. signal conductors at the second end thereof being
terminated to the contact portions, and the .[.cable.]. .Iadd.at
least one .Iaddend.conductive shield being terminated to selected
terminals of the second connector designated for ground
purposes.Iadd.; wherein the cable bypass assembly is configured to
support 10 GHz signaling.Iaddend..
13. The cable bypass assembly of claim 12, wherein the cable is an
extent of flexible circuitry, the signal conductors including two
signal conductors.
14. The cable bypass assembly of claim 13, wherein the ground
shields are disposed on opposite sides of the signal
conductors.
.Iadd.15. A cable bypass assembly, the cable bypass assembly
comprising: a first connector, the first connector being configured
for mounting to a circuit board, the first connector including a
connector body with a card slot, the connector body supporting a
plurality of conductive terminals, the conductive terminals
including contact portions and tail portions, the contact portions
extending in the card slot for contacting an opposing mating
connector; an elongated cable, the elongated cable including: a
pair of signal conductors, the signal conductors being disposed
within an insulative body portion of the elongated cable, the
signal conductors extending, in a spaced-apart relationship,
lengthwise through a body portion of the elongated cable, a
conductive shield, the conductive shield extending over an exterior
of the elongated cable body portion, an insulative outer covering,
the insulative outer covering extending over the conductive shield,
and opposing first and second free ends, the first free end
terminating directly to selected terminal tails of the first
connector in a manner so that the signal conductors are in
electrical communication with a pair of signal terminal tails; a
shield extension member, the shield extension member being
configured to engage a first length of the conductive shield
exposed at the first free end and extending therefrom over the
signal conductors attached to the pair of signal terminal tails,
the shield extension member including at least two spaced apart
mounting feet; and a second connector, the second connector
including: an insulative body, the insulative body supporting at
least a pair of conductive signal terminals in a spaced-apart
relationship, each conductive signal terminal including contact and
tail portions, and a shielding collar, the shielding collar
enclosing a body portion of the second connector, the shielding
collar includes an extension portion, the extension portion
engaging and receiving the conductive shield exposed at the second
free end, wherein the cable bypass assembly is configured to
support 10 GHz signaling. .Iaddend.
.Iadd.16. The cable bypass assembly of claim 15, further including
a second cable, the second cable including a pair of signal
conductors, the second cable signal conductors disposed lengthwise
therethrough in a spaced-apart relationship, the second cable
signal conductors being attached to corresponding signal terminal
tails of the first connector alongside the elongated cable.
.Iaddend.
Description
BACKGROUND OF THE PRESENT DISCLOSURE
The Present Disclosure relates generally to cable interconnection
systems, and more particularly, to bypass cable interconnection
systems for transmitting high speed signals at low losses.
Conventional cable interconnection systems are found in electronic
devices such as routers and servers and the like, and are used to
form a signal transmission line that extends between a primary chip
member mounted on a printed circuit board of the device, such as an
ASIC, and a connector mounted to the circuit board. The
transmission line typically takes the form of a plurality of
conductive traces that are etched, or otherwise formed on or as
part of the printed circuit board. These traces extend between the
chip member and a connector 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 FR-4, which is
inexpensive. However, FR-4 is known to promote losses in high speed
signal transmission lines, and these losses make it undesirable to
utilize FR-4 material for high speed applications (10 GHz and
above). Custom materials for circuit boards are available that
reduce such losses but the price of these materials severely
increase the cost of the circuit board and, consequently, the
electronic devices in which they are used. Additionally, when
traces are used to form the signal transmission line, the overall
length of the transmission line typically may well exceed 10 inches
in length. These long lengths require that the signals traveling
through the transmission line be amplified and repeated, thereby
increasing the cost of the circuit board, and complicating 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 in the FR-4 may require multiple
turns and the transitions which occur at terminations affect the
integrity of the signals transmitted thereby. It becomes difficult
to route transmission line traces in a manner so as to achieve
consistent impedance and a low signal loss therethrough.
The Present Disclosure is therefore directed to a high speed,
bypass cable assembly that defines a transmission line for
transmitting high speed signals, 10 GHz and greater that removes
the transmission line from on the circuit board and which has low
loss characteristics.
SUMMARY OF THE PRESENT DISCLOSURE
Accordingly, there is provided an improved high speed bypass cable
assembly that defines a signal transmission line useful for high
speed applications at 10 GHz or above and with low loss
characteristics.
In accordance with an embodiment as described in the disclosure, an
electrical connector assembly is disclosed. The electrical
connector assembly comprises a printed circuit board, a chip
member, a termination member, a first connector member, a bypass
cable member and a second connector member. The chip member and the
termination member are mounted on the printed circuit board, with
the termination member mounted toward the end of the printed
circuit board. The first connector member is in electrical
communication with the chip member at a first end, and the bypass
cable member electrically connects the first connector member,
where it is coupled at a second end thereof, and the termination
member, at a first end. The second connector member, disposed at a
second end of the termination member, is in electrical
communication with the termination member. Generally, the
electrical connector is capable of the transmission of high speed
signals. As the chip member is located a long length from the board
connector, the bypass cable provides a transmission line
therebetween that has a consistent geometry and structure that
resists signal loss and maintains the system impedance at a
consistent level without discontinuities.
In accordance with a second embodiment of the disclosure, the cable
bypass assembly provides a transmission line that is separate from
the circuit board, and may include one or more associated signal
wire pairs, such as is found in "twin-ax" cable. The wires of the
bypass cable are configured at their opposite ends in two fashions.
At a first end of the bypass cable, the wires are configured for a
direct termination to a board mounted connector, and are arranged
in a manner such that the conductors of the signal wires extend in
alignment with terminal termination ends, or feet, of the board
mounted connector. The shielding of the signal wires are rolled
back upon the insulative coating of the wires and exterior shield
extensions are preferably provided to ensure that the signal wire
conductor leads are effectively shielded through the connection. In
this manner of connection, the terminal tails need not be attached
to the circuit board, either as surface mount or through hole
tails, thereby significantly reducing losses and the impedance
discontinuity that occurs in the tail to board mounting
transition.
At the second end of the bypass cable the signal wires are
terminated in a fashion so that they can either be connected
directly to the chip member or to the board in close proximity to
the chip member. In this regard, and as disclosed in this second
embodiment, the signal wire conductors are terminated to associated
tail portions that are aligned with the conductors, similar to the
termination which occurs at the first end. These tails are
maintained in a desired spacing and are further completely shielded
by a surrounding conductive enclosure to provide full EMI shielding
and reduction of cross talk. The termination of the ends of the
bypass cable assembly are done in a manner such that to the extent
possible, the geometry of the conductors in the bypass cable is
maintained through the termination of the cable to the board
connector and/or the chip.
These and other objects, features and advantages of the Present
Disclosure will be clearly understood through a consideration of
the following detailed description.
BRIEF DESCRIPTION OF THE FIGURES
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:
FIG. 1 illustrates a perspective view of one embodiment of a high
speed interconnect cable assembly, developed in accordance with the
Present Disclosure;
FIG. 2 illustrates a perspective view of another embodiment of a
high speed interconnect cable assembly, developed in accordance
with the Present Disclosure;
FIG. 3 illustrates a perspective view of another embodiment of a
high speed interconnect cable assembly, developed in accordance
with the Present Disclosure;
FIG. 4 illustrates a perspective and inset view of the via transfer
connector of the interconnect cable assembly of FIG. 3;
FIG. 5 illustrates a perspective and inset view of the first
connector member of the interconnect cable assembly of FIG. 3;
FIG. 6 is a perspective view of a second embodiment of a cable
bypass assembly constructed in accordance with the Present
Disclosure;
FIG. 7 is a top plan view of the cable bypass assembly of FIG.
6;
FIG. 8 is an exploded view of the assembly of FIG. 6, illustrating
in greater detail the board connector to which the cable bypass
assembly is terminated;
FIG. 9 is a perspective view of the board mounted connector of FIG.
8, with the first ends of the bypass assembly attached thereto;
FIG. 10 is a partially exploded view of FIG. 9;
FIG. 11 is a top plan view of FIG. 9, with the EMI shield removed
for clarity;
FIG. 11A is a side elevational view of FIG. 11;
FIG. 12 is perspective view of four pairs of signal wires
terminated to the board connector terminal assembly and with one
set of the shielding extensions removed for clarity;
FIG. 12A is the same view as FIG. 12, but taken from the rear
thereof;
FIG. 12B is a end view of two pairs of signal wires with an
associated shielding extension in place, illustrating the relative
alignments of the signal conductors with each other and to the
shielding of the cables;
FIG. 13 is a perspective view of one manner of terminating the ends
of the cables of the cable bypass assembly which is opposite that
of the termination to the board mounted connector;
FIG. 13A is the same view as FIG. 13, but with one of the exterior
shielding components removed for clarity;
FIG. 13B is the same view as FIG. 13A but with the lower shielding
component removed and the terminal support in place on the
terminals attached to the second end of the cable;
FIG. 13C is the same view as FIG. 13B but with the terminal support
removed for clarity;
FIG. 13D is the same view as FIG. 13C, but taken from the other end
thereof;
FIG. 13E is a sectional view of FIG. 13;
FIG. 14 is an embodiment of a termination structure for direct
connection to a chip member;
FIG. 14A is an exploded view of FIG. 14;
FIG. 14B is an enlarged detail view of FIG. 14A.
FIG. 15 is a partially exploded view of an extent of flexible
circuitry which may be used as a signal transmission line in cable
bypass assemblies of the disclosure; and,
FIG. 16 is a graph comparing the losses between 12-inch lengths of
signal transmission lines incorporated on a circuit board made from
FR-4 material and a cable bypass assembly constructed in accordance
with the principles of the disclosure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
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 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.
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 Application, 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.
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 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.
FIGS. 1-5 provide various perspective views of some basic
components of a high speed interconnect cable assembly, developed
in accordance with the teachings and tenets of the Present
Disclosure.
Referring more specifically to FIG. 1, high speed interconnect
cable assembly 10 generally comprises chip member 12 mounted on
printed circuit board member 14, first connector member 16
interfacing between chip member 12 and bypass cable member 18, and
termination member 20 interfacing between bypass cable member 18
and second connector member 22 disposed at the edge of printed
circuit board member 14.
Preferably, chip member 12 may comprise a PHY Chip, or any other
surface-mounted, physical layer device, known in the art, from
which a high speed signal is generated, such as an ASIC and
transmitted to a cable assembly. Chip member 12 is mounted to any
currently-known printed circuit board, using preferably any of the
various currently-known mounting means. Preferably, an FR-4 type
printed circuit board is used, in an effort to take advantage of
its low cost and wide usage. For purposes of the Present
Disclosure, the generated high speed signal may be any type of
signal, but typically a data signal, generally having a frequency
of 5 GHz and above, and most preferably and is a data signal having
a frequency of 10 GHz or more.
Bypass cable member 18 is connected to chip member 12 by means of
first connector member 16. First connector member 16 is capable of
transmitting a signal greater than 10 GHz between chip member 12
and bypass cable member 18. The interface between first connector
member 16 and chip member 18 may be by any known means, including,
for example, a plug-receptacle connection, a friction-based
connection or the like. It is preferred that the interface be
removable. First connector member 16 is preferably capable of
receiving the high speed signal generated by the chip member and
transmitting it to the bypass cable member without need for a
repeater or an amplifier, and without having to use the conductive
properties of printed circuit board 14.
Bypass cable member 18 comprises a flexible circuit member, such as
a cable, extending from first connector member 16 to termination
member 20. Preferably, bypass cable member 18 is capable of
receiving and carrying signals above 10 GHz. Preferably, bypass
cable member 18 includes one or more wire pairs that transmit
differential signals at high speeds. Each such wire pair may have a
ground, or drain, wire associated with it. Further, the pairs may
be enclosed within bypass cable member 18 and within an associated
cable shield. Like first connector member 16, bypass cable member
18 is preferably capable of receiving the high speed signal
generated by first connector member 18 and transmitting it to
termination member 20 without need for a repeater or an amplifier,
and without having to use the conductive properties of printed
circuit board 14.
Termination member 20 is electrically connected to bypass cable
member 18, and receives the signal from bypass cable member 18.
Like all other elements in interconnection assembly 10, termination
member 20 is capable of receiving signals greater than 10 GHz.
Preferably, termination member 20 is located at or near the edge of
printed circuit board 14. Termination member 20 may be mounted to
the edge of printed circuit board 14. Alternatively, termination
member 20 may be "freestanding," and not connected to any aspect of
assembly 10. Termination member 20 may receive bypass cable member
18 though any methods and means as currently described in the
art.
Second connector member 22 preferably provides one end of a
male-female relationship with termination member 20 (with
termination member 20 providing the second end). It is not
imperative that second connector member 22 (or termination member
20) be specifically relegated to the male or female end, as the
teachings of the Present Disclosure will nevertheless be
realized.
Second connector member 22 is preferably not disposed on any other
aspect of interconnection assembly 10 of the Present Disclosure,
i.e., second connector member 22 is not mounted on printed circuit
board 14. Second connector member 22 receives the signal from
termination member 20, and transmits the signal to its next or
final destination.
The discussion above focused on a single interconnection assembly.
Nevertheless, a plurality of interconnection assemblies may be used
on a single printed circuit board, each generally comprising the
above-referenced elements. A plurality of assemblies is generally
illustrated in FIG. 1. Further, in a second embodiment, which is
illustrated in FIG. 2, lamination member 24 may encompass all or
part of multiple bypass cable members 18 for ease in assembly, as
well as to maintain order on printed circuit board 14 and reduce
the cost of assembly 10. Preferably, lamination member 24 may
comprise a rigid, formable polymer material that can be molded over
both first connector member 16 and bypass cable member 18.
Further, in another embodiment, a plurality of interconnection
assemblies, used on a single printed circuit board, may be
channeled to a single termination member 26 for transmission of
signals beyond the printed circuit board. As illustrated in FIG. 3,
bypass cable members 18 extend from chip members 12, via first
connector member 16, towards first via transfer connectors 28. Each
via transfer connector 28 allows the signal being carried in bypass
cable members 18 to pass through holes (or vias) in the printed
circuit board where they connect with termination member 26.
FIG. 4 illustrates a perspective close up of the connection of via
transfer connectors 28 to termination member (not shown in FIG. 4).
As illustrated, each via transfer connector 28 houses the
termination of bypass cable members 18. Individual wires 30
extending from bypass cable members 18 are mounted within connector
housing 32. Connector housing 32, along with individual wires 30
and a portion of bypass cable members 18, are overmolded with
terminal housing .[.34.]. .Iadd.38.Iaddend.. Terminal housing
.[.34.]. .Iadd.38 .Iaddend.is then inserted into the via hole of
the printed circuit board, where it couples to termination
member.
FIG. 5 illustrates a perspective close up of first connector member
16. As illustrated, each first connector 16 houses the termination
of bypass cable members 18. Individual wires 36 extending from
bypass cable members are overmolded with terminal housing 38.
Terminal housing 38 is then coupled to chip member 12.
FIGS. 6-13E illustrate another embodiment of a bypass cable
assembly 100 constructed in accordance with the principles of the
Present Disclosure. As shown in FIG. 6, a circuit board 101 that is
used in an electronic device (not shown) has mounted thereon a chip
member 104, such as an ASIC, at one location and a shielding cage
102 mounted to the circuit board at another location, remote from
the one location. The shielding cage 102 houses a receptacle
connector assembly 110 that includes a receptacle connector 112
configured to receive the mating blade (typically the leading edge
of a circuit card) of an opposing, mating connector (not shown) in
a elongated card-receiving slot 113. The connector 112 may also
include a channel 114 disposed underneath the card slot 113 to
receive a polarizing member of the mating connector. The connector
112 is accessible through an opening 103 at one end of the
shielding cage 102. A portion of the shielding cage 102 extends
past the edge of the circuit board 101 and out of the enclosure
which houses the circuit board 101. This opening 103 permits access
to the connector 112 from the exterior of the device and permits
the insertion of a mating connector, typically in the form of a
plug connector, therein in order to connect the device to another
device and permit the transfer of signals between them.
A bypass cable assembly 105 is provided to connect together, the
connector 112 and the chip member 104, in order to form a signal
transmission line extending therebetween for transmitting signals
at high speeds of approximately 5 GHz and greater and preferably of
approximately 10 GHz and greater. The cable assembly 105 includes a
preselected length of cable 107 that has at a first end 107a
thereof, a first termination assembly and at a second and opposite
end 107b thereof, a second termination assembly. As shown best in
FIG. 12B, each cable 107 may be of the "twin-ax" type, in which a
pair of signal conductors 144A, 144B are positioned in spaced-apart
relationship within an insulative body 142. This cable body 142 is
surrounded by an outer conductive shielding layer 148 that is
located underneath an exterior, insulative covering 140 and all of
the cable elements may be formed as the single component
illustrated. The structure of this particular type of twin-ax cable
lends itself to uniformity throughout its length so that a
consistent impedance profile is attained for the length of the
cable. The cable assemblies 105 of this disclosure may include as
few as one or two cables, or they may include greater numbers, such
as the eight cables shown in FIGS. 6, 9 & 11.
In order to avoid losses that normally occur in the use of signal
transmission lines in the circuit board 101 using FR-4 as the board
material, the cables 107 are used as the signal transmission lines.
As noted above, the cables 107 are made in a manner that controls
their size, thickness and the position and spacing of the signal
conductors 144A, 144B so as to define a constant impedance profile
throughout the lengths of the cables. Accordingly, twin-ax type of
cable is desirable as well as flexible circuitry where positioning
of the conductors and insulators may be controlled to a high degree
of tolerance. Problems with impedance profiles typically occur at
the termination points of cables where the geometry of the cable
disrupted in order to effect a termination. One such solution to
this problem is disclosed in U.S. Pat. No. 6,454,605, issued Sep.
24, 2002 and assigned to the assignee of the Present Disclosure and
which is hereby incorporated by reference, in its entirety.
The cable assemblies of the Present Disclosure are terminated at
their opposite ends 107A, 107B in a manner that seeks to reduce the
modification of the cable geometry in order to reduce the magnitude
of the aforementioned discontinuities and to prevent to the extent
possible excessive loss, noise and crosstalk. Returning to the
drawings and in particular FIGS. 12 & 12A, it can be seen that
the terminals 120 of the receptacle connector 112 have tail
portions 132 that extend outwardly from the rear face of the
terminal assembly supports 118A, 118B and contact portions 130 that
extend forwardly within the card-receiving slot 113 of the body of
the receptacle connector 112. The terminal contact and tail
portions 130, 132a, 132b, extend in a continuous, generally
horizontal extent through the connector without any vertical
terminal extents that would provide an interruption of the
horizontal extent. Consequently, as used herein, the term
uninterrupted means a generally horizontal extent without any
vertical portions. Similarly, "generally horizontal extent" also
means that there are no vertical portions of the terminals that
change the levels of the terminal contact and tail portions as
would be found in terminals configured for surface mounting such as
the low speed, power and status terminals 134 that are interposed
between the high speed terminal sets. These non-high speed
terminals 134 may be positioned with the use of a tail aligner
block 116 or the like. In order to provide strain relief and to
facilitate assembly, two cables may be held together by a block 106
applied to the cables 107 downstream of the termination areas.
In this manner, a "direct connection" is effected between the cable
first end 107A and the connector 112, in a manner such that the
signal terminal tail portions 132a, 132b are aligned with the
exposed leads of the cable conductors 144A, 144B so that the
exposed leads may be placed on the flat surfaces which the terminal
tail portions 132a, 132b preferably provide. The inner shielding
148 of each cable 107 is pulled back over the exposed end of the
cable and a shield extension 146 is provided for engaging these
cable ends. The extension 146 is shown as a dual extension that can
accommodate two cables. The shield extension 146 has what may be
considered a cup portion 145 that is formed in a configuration that
is generally complementary to the exterior configuration of the
cable 107, and it is provided with contact feet 146a-c for
contacting the associated terminal tail portions 132c of ground
terminals in the receptacle connector 112.
The dual shield extension 146 shown in the drawings has two such
cup portions 145 and three contact feet. Two contact feet 146a,
146b are formed along the outer edges of the cup portion 145, while
the third contact foot 14c is formed between the cup portions 145.
The contact surfaces 147 formed on the bottom of the contact feet
are preferably aligned with each other along a common plane, shown
as "H" in FIG. 12B. The conductors 144A, 144B of the cable 107 are
also preferably aligned with the contact feet, along H as
illustrated best in FIG. 12B. In this manner a "direct" connection
is effected between first ends 107A of the cables 107 and the board
mounted connector 112, thereby eliminating the need for surface
mounting or through hole mounting of the connector high speed
terminal tails, all of which contribute to loss, noise and
crosstalk at high speeds. Terminals of the connector 112 for which
high speed performance is not an issue, such as low speed signal
terminals and/or power and status terminals 134, may be terminated
in conventional manners mentioned above and they are shown in FIGS.
12 & 12A as surface mounted, and such terminals may be disposed
between sets of high speed terminals as illustrated for additional
separation between the high speed terminal sets. Removing the high
speed signals of the receptacle connector from attachment directly
to the board, reduces the cost in formation and manufacture of the
circuit board 102. Additionally, the termination style shown in the
drawings mirrors the geometry of the cable and provides generally
complete shielding at the direct connection.
The shield extensions 146 provide as close as can be attained
complete shielding at the direct termination to the board connector
and they extend forwardly to completely cover the exposed ends of
the cable signal conductors 144A, 144B as shown in FIG. 11. The
shield extension mounting feet 146a-c thereof are spaced apart and
contact opposing tail portions of ground terminals of the first
connector 112. The shield extension feet 146a-c and the conductors
144A, 144B of the cables 107 can be soldered or welded in their
attachment to the connector terminals and the shield extensions 146
may be attached to the cables 107 by contact, a conductive
adhesive, soldering or other suitable means. In this manner, the
cable geometry is closely replicated in the termination area and
more effective shielding is provided than just an ordinary ground
wire to ground terminal connection. An EMI housing 109 may be
utilized to provide an enclosure, in combination with the shielding
cage 102 about the cable termination area.
FIGS. 13A-D illustrate one form of termination that may be applied
to the second ends of the cables 107, which may be either connected
directly to the chip member or to the circuit board 101 in close
proximity thereto. As illustrated in FIGS. 13B-D, the exposed leads
of the cable conductors 144A, 144B are attached to signal terminals
160, shown as a pair of signal terminals 160A, 160B. These terminal
preferably have flat tail portions 163 and through hole contact
portions 162. The flat tail portions 163 preferably provide a flat
surface to which the exposed conductors 144A, 144B may be contacted
and attached via solder, welding or the like. The signal terminal
160 may be held in by an insulative support 156 that as shown is
molded over body portions of the terminal 160, leaving the tail and
contact portions 163, 162 exposed for termination purposes. A
shield collar 152 is provided that houses the signal terminal
support 156 and substantially encloses the signal terminals with a
conductive shield. The shield collar 152 has a shield extension
153B that is similar in configuration to cable first end shield
extensions 146 in that is has a cup portion 145 that contacts and
receives the cable 107 and its inner shielding 148 therein. A cap
member 153 is also provided and the cap member includes a block
portion 154 that preferably abuts the terminal support 156 and
which further preferably engages the shield collar 152 by way of
tabs 156 that engage like holes 157 in the walls of the collar
152.
FIGS. 14-14B illustrate another embodiment of a manner or
termination to a second connector. In this embodiment, the second
connector 200 is one that is used to attach directly to the chip
member 104, and typically to a top surface thereof. In this regard,
the second connector 200 has a housing 202 that receives a
plurality of cables 204, and the type of cables illustrated are of
a different twin-ax structure, namely one in which each cable 204
contain a pair of signal wires 205 and a drain (ground) wire 206.
The signal wires 205 have signal conductors 207 running their
length and surrounded by an outer insulative covering 208 and an
outer covering 209 is provided that encloses a pair of the signal
wires 205 and an associated drain wire 206. A perforated base
portion 210 of the housing 202 has a plurality of slots, or
cavities 211, each of which is configured to receive a single
terminal 212 therein. LGA-style terminals are illustrated and each
such terminal 212 includes a body portion 213 that engages the
housing cavity 211, a tail portion or mounting stub 214 that
extends out of the cavity 211 and into contact with an exposed
conductor 207 of the signal wires 205, and a contact portion 215
that extend out of the opposite end of the cavity 211. The second
connector 200 also includes second cavities 216 that receive ground
terminals (not shown) that are connected at their upper ends to the
drain wires 206 and at their lower ends to the chip member 104. The
termination arrangement of this connector 200 also maintains, to
the extent possible the geometry of the cables 204 through the
connector termination, in the sense that the triangular arrangement
of the three wires of each cable is maintained until the point
where the drain wire is attached to the ground terminal and then
the extent of the ground terminal is spaced from the ends of the
signal wire terminals 212 as evidenced by the pattern of the first
and second terminal cavities 211, 216.
FIG. 15 illustrates an alternate construction for use as a signal
transmission line in accordance with the disclosure and takes the
form of an extent of flat flexible circuitry 300. The extent
includes a pair of signal conductors 302 that are spaced apart from
each other and which run lengthwise between opposite ends of the
cable 300. The conductors 302 are surrounded on their top and
bottom surfaces and sides by insulative portions 304, 305. Ground
shields 306 are provided to enclose the signal conductors 302, and
although shown only as above and below the signal conductors 302,
it will be understood that they may be disposed alongside of the
signal conductors. With this sort of structure, the signal
conductors may be exposed and aligned with terminal tails, while
the ground shield extended to cover the termination areas in a
manner similar to that shown above.
FIG. 16 is a graph comparing the loss between two 12-inch lengths
of signal transmission lines, with one of the transmission lines
comprising a pair of circuit traces formed in or on FR-4 circuit
board material and the other transmission line comprising cables of
the Present Disclosure. It can be seen from FIG. 16 that the use of
the cable of the Present Disclosure leads to a very low loss
transition that only breaks past the 5 dB mark at approximately the
20 GHz frequency. Within the range of testing error, we believe
that the cables of the Present Disclosure have low loss
characteristics of no greater than between about 5 dB and about 8
dB at frequencies greater than about 19 Ghz.
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.
* * * * *
References