From: Knighten, Jim L (JK100005@exchange.SanDiegoCA.NCR.COM)
Date: Mon Jan 15 2001 - 16:10:19 PST
Discrete Wire Technology is the more generic term apparently in use now.
The term "Multiwire" may be specific to a vendor.
While this technology is expensive and not in widespread use, there is
increasing interest in this technology for PCBs containing high densities of
Work in academia is ongoing in examining the signal integrity aspects of
features of this construction. I listened to a paper given this past fall
at a symposium on EMI given in Belgium. This work was gone by a group from
Italy and is obviously work in progress. I can put you in contact with
them, if you would like.
Dr. Jim Knighten e-mail: firstname.lastname@example.org
Technical Consultant - Design
17095 Via del Campo
San Diego, CA 92127 http://www.ncr.com <http://www.ncr.com>
From: Thomas Jackson [mailto:email@example.com]
Sent: Monday, January 15, 2001 2:41 PM
To: 'Zabinski, Patrick J.'; firstname.lastname@example.org
Subject: RE: [SI-LIST] : multiwire experience?
<< File: Thomas Jackson.vcf >> Multiwire is a proprietary
technology. There is a very short list of places
to get it done, so I don't think it is very cheap.
It was favored when making PCBs with more than two layers
It has fallen from favor for a number of reasons. First,
assumes that an insulated wire can be accurately placed in a
layer of liquid
epoxy such that, later on, after the epoxy hardens, a CNC
drill can drill
through that wire and make a through hole in the substrate.
assumption: Plating that hole will form a good electrical
contact with both
of the sheared ends of that wire.
Second, electrically, I have some reservations about its
I don't see how each wire can be a uniform distance from a
power or ground
plane over its entire length, so there must be impedance
Multiwire boards I have seen have had only one pair of power
planes. Therefore, everything is microstrip at various
heights above the
At my previous employer, a defense contractor, they were
Multiwire boards for old systems into PCBs because they were
While Multiwire had its day in the sun, I don't think I
would go that way
today with the current cost and performance of PCBs.
Thomas L. Jackson, P.E.
Staff VLSI Design Engineer
Network Access Development
Systems Solutions Group
FUJITSU MICROELECTRONICS, INC.
3545 North First Street
San Jose, CA 95134-1804
telephone: (408) 922-9574
facsimile: (408) 922-9618
From: Zabinski, Patrick J.
Sent: Monday, January 15, 2001 1:57 PM
Subject: [SI-LIST] : multiwire experience?
On a particular project I'm working on, it has been proposed
that we use multiwire boards in place of traditional
printed circuit boards. Does anyone out there have
good or bad, with multiwire you'd care to share? I'm
in any/all experience, including performance, crosstalk,
reliability, cost, etc....
Pat Zabinski Ph: 507-538-5499
Mayo Foundation Fx: 507-284-9171
200 First St SW Em: email@example.com
Rochester, MN 55905 Wb:
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