Hi Adam,
these tracks certainly help (but should be open-ended), as we have done test on boards up to 8 Layers, with very high speeds (up to 1 Gig).

Kind regards,
Dieter

D.A. Beisiegel
Natech (Pty) Ltd.
P.O.Box 482
Wendywood
2144
South Africa
eMail: [log in to unmask]

----------
From:   Hawes, Adam[SMTP:[log in to unmask]]
Reply To:       DesignerCouncil E-Mail Forum.; Hawes, Adam
Sent:   Tuesday, 27 July, 1999 10:07
To:     [log in to unmask]
Subject:        [DC] Ground Shield Tracks

        I feel sure this is probably an issue for a lot of PCB
designers......

        Recently, I have come across an increasing number of engineers who
wish to have certain tracks on multilayer PCB's shielded by ground traces
running adjacently. It seems to be a case of jumping on the bandwagon to me
because we never used to do this until about 12 months ago.

        I was under the impression that ground tracks only served a useful
purpose on 1or 2 layer boards and that on a multilayer they were essentially
a waste of space as most of the capacitive coupling would be straight to the
ground plane.

        I don't like to tell the engineers their jobs obviously so can
anybody put forward their views so I have a more solid argument!

        Thanks all,

Adam Hawes
PCB Design Eng.
GenRad Ltd.

Tel: 0161  491 9290
Fax: 0161 491 9106