Hello,
You can provide a guard trace next to an EMI critical trace to help shield it.
Usually, it is just a parallel trace connected frequently to the 0V plane.
There is some argument whether it is of any real use however, if the
spacing between the critical trace and the ground plane is less than 2x the
distance to any other tracks.
You can also place a 0V guard trace around the edge of a board (connected
frequently to 0V) to help reduce EMI and also provide some ESD protection.
I hope that this has been of some help.

Phil.

At 00:34 24/10/99 +0900, you wrote:
>Hello Technetters.
>
>What's mean "Edge plating" and "Guard tracking"?
>I guess the edge plating is EMI shielding, right?
>The edge plating is one method of EMI shieldings, right?
>Then what is the Guard tracking?
>
>I want to know about this.
>If possible, please tell me how I can get the detailed information about
this.
>Thank you.
>
>Bye everyone, I will wait for your fast reply.
>


Phil Dutton C.I.D.
Senior CAD Technician
IPC Certified Interconnect Designer
Vision Abell Pty Ltd
Second Avenue, Technology Park,
Mawson Lakes.  SOUTH AUSTRALIA  5095
===============================================================
Phone :         (08) 8300 4400 (reception)
Fax :           (08) 8349 7420
email:          [log in to unmask]
Internet Page:  http://www.vsl.com.au
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