Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
2002-02-05
2004-11-23
Vo, Tim (Department: 2112)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S794000, C361S795000
Reexamination Certificate
active
06822876
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to backplanes, and more specifically to backplane wiring systems for highly interconnected, high-speed modular digital communications systems such as routers and switches.
BACKGROUND OF THE INVENTION
A backplane generally comprises a printed circuit board having a number of card connection slots or bays. Each slot or bay comprises, e.g., one or more modular signal connectors or card edge connectors, mounted on the backplane. A removable circuit board or “card” can be plugged into the connector(s) of each slot. Each removable circuit board contains drivers and receivers necessary to communicate signals across the backplane with corresponding drivers and receivers on other removable circuit boards.
One or more layers of conductive traces are formed on and/or in the backplane. The traces connect to individual signal connection points at the various slots to form data lines and control lines.
Router backplanes present a challenging area of circuit board design (for convenience, routers and switches will be referred to herein collectively as “routers”, as the technical distinctions between the two are unimportant to the invention as described herein). By their very nature, configurable modular routers require a high degree of interconnectivity between their removable router cards. With any appreciable number of cards, it becomes infeasible to build large parallel point-to-point connection buses between each pairing of the cards. This limitation hinders further growth in large router throughput, as the next generation of large routers may well see throughput requirements measured in terabits-per-second. As such throughput requirements may require several tens (or even hundreds) of logical ports to exchange data simultaneously at twenty to one-hundred Gigabit-per-second (Gbps) speeds, it can be appreciated that the connectivity and throughput requirements placed on large router backplanes are extreme.
Many router manufacturers, believing that the limits of electrical circuit boards have been reached in the area of large router backplanes, are now designing optical backplanes for their next-generation products. Optical backplanes avoid some of the most problematic characteristics of electrical backplanes, such as trace density, signal attenuation, signal reflection, radiated noise, crosstalk, and manufacturing limitations-characteristics that become increasingly significant as single-trace signaling speeds push into the multi-Gbps range. Optical backplanes, however, come with their own set of problems, chief among these being cost and complexity.
SUMMARY OF THE INVENTION
This disclosure describes an electrical router backplane that overcomes many of the electrical and mechanical limitations of large prior art electrical backplanes, and methods for its design and fabrication. Generally, this backplane comprises multiple high-speed signaling layers of differential signaling pairs, separated by ground layers. Preferably, power distribution layers and/or low-speed signaling layers are embedded near the center of the backplane stack, between outer groups of high-speed signaling layers. Various additional design features can be combined within this general architecture to produce a backplane that has been tested for reliable communication at single trace pair differential-signaling speeds up to 10.7 Gbps, 200-ampere power distribution, and overall backplane throughput greater than 1.6 Terabits/second.
In the present disclosure, a wide range of new backplane features and manufacturing processes are disclosed, each of which contributes to the overall success of the backplane design. Preferably, these aspects are combined in a single backplane to provide an accumulation of the benefits of each aspect.
REFERENCES:
patent: 4694123 (1987-09-01), Massey
patent: 4862161 (1989-08-01), Schomers
patent: 4891616 (1990-01-01), Renken et al.
patent: 5010641 (1991-04-01), Sisler
patent: 5261153 (1993-11-01), Lucas
patent: 5308926 (1994-05-01), Auerbuch et al.
patent: 5311406 (1994-05-01), Snodgrass et al.
patent: 5397861 (1995-03-01), Urquhart
patent: 5548734 (1996-08-01), Powlowski et al.
patent: 5566083 (1996-10-01), Fang
patent: 5682298 (1997-10-01), Raynham
patent: 5691209 (1997-11-01), Liberkowski
patent: 5841074 (1998-11-01), Egan et al.
patent: 5870274 (1999-02-01), Lucas
patent: 6015300 (2000-01-01), Schmidt, Jr. et al.
patent: 6030693 (2000-02-01), Boyko et al.
patent: 6081430 (2000-06-01), La Rue
patent: 6091609 (2000-07-01), Hutson et al.
patent: 6181004 (2001-01-01), Koontz et al.
patent: 6229095 (2001-05-01), Kobayashi
patent: 6333981 (2001-12-01), Weir et al.
patent: 6423909 (2002-07-01), Haynie et al.
patent: 6630627 (2003-10-01), Tobita
patent: 6751699 (2004-06-01), Langley, Sr. et al.
patent: 2002/0060366 (2002-05-01), Kikuchi et al.
patent: 0594200 (1994-04-01), None
patent: 1143761 (2001-10-01), None
patent: 2001102755 (2001-04-01), None
patent: 00 78105 (2000-12-01), None
Johnson and Graham; “High-Speed Digital Design, A Handbook of Black Magic”; 1993; pp. 257-262.
Markstein, H.W.: “Ensuring Signal Integrity in Connectors, Cables, and Backplanes,” Electronic Packaging and Production; vol. 36, No. 11; Oct. 1, 1996, pp. 61-69.
Scaminaci, J: “Avoiding Signal Integrity Problems in Backplanes,” Electronic Packaging and Production; vol. 34, No. 7; Jul. 1, 1994, pp. 40-44.
Markstein, H.W.: “Impedances Dictate Backplanes,” Electronic Design, Packaging and Production; vol. 33, No. 12; Dec. 1, 1993, pp. 38-40.
Teradyne: Web ProForum Tutorial;Design Considerations for Gigabit Backplane Systems Tutorialprinted on Nov. 6, 2000 from website located at www.iec.org/tutorials/design_backplane/; pp. 1-43.
Teradyne: VHDM Home Page;Backplane Assemblies and Connectorsprinted on Nov. 6, 2000 from website located at www.teradyne.com/prods/bps/vhdm/into.html; pp. 1-3.
Teradyne: Products;Backplanesprinted on Nov. 6, 2000 from website located at www.teradyne.com/prods/bps/vhdm/intro.html; pp. 1-2.
Teradyne: VHDM Home Page;VHDM High-Speed Differentialprinted on Nov. 6, 2000 from website located at www.teradyne.com/prods/bps/vhdm/intro.html; pp. 1-3.
Teradyne: Virtual Exhibits;Total Interconnect Solutions printed on Nov. 6, 2000 from website located at www.iec.org/exhibits/teradyne_02/; pp. 1-5.
Cahners EDN Access;New printed-wiring-board materials guard against grabled gigabitsprinted on Nov. 6, 2000 from website located at www.cdnmag.com/ednmag/reg/1999/111199/23ms593.htm; pp. 1-5.
PARKnelco;N4000-6 Overviewand product description; pp. 1-2.
PARKnelco;N6000andN6000SIOverview and product description; pp. 1-2.
PARKnelco;N7000-2 HT LaminateandN7000-3 Prepeg Overviewand product description; pp. 1-2.
PARKnelco;N8000 Overviewand product description; pp. 1-2.
Original Submission Request for Non-Publication-Rescinded Ser. No. 10/068,420; dated Jul. 31, 2002; 1 page.
Original Submission Request for Non-Publication—Rescinded Ser. No. 10/068,616; dated Jul. 31, 2002; 1 page.
Corrected filing receipt for '616 application; dated Sep. 9. 2002; 2 pages.
Resubmission copies of Request for Non-Publication-Rescinded and coversheet Ser. No. 10/068,420; dated Jun. 13, 2003; 2 pages.
Notice Regarding Rescission Ser. No. 10/068,420; dated Jun. 13, 2003; 1 page.
Notice of Publication Ser. No. 10/068,420; dated Sep. 25, 2003; 1 page.
Markstein, H.W.:Impedances Dictate Backplanes, Electronic Design, Packaging and Production; vol. 33, No. 12; Dec. 1, 1993, pp. 38-40.
Markstein, H.W.:Packaging for High-Speed LogicElectronic Packaging and Production, No. 9, Sep. 27, 1987 pp. 48-50.
Force10 Networks, Inc.
Marger & Johnson & McCollom, P.C.
Vo Tim
LandOfFree
High-speed electrical router backplane with noise-isolated... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High-speed electrical router backplane with noise-isolated..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-speed electrical router backplane with noise-isolated... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3361151