Greetings DC,
Lets see, I got these suggestions; match trace width, in this case that
would be 10 mills, and three times trace width and 5 or 6 times trace width.
The dielectric thickness on this would be about 7 mills so any of these
would be thicker than that.
What of you engineer types, what do you guys say?  And does IPC say anything
about this?
In the past I have either matched trace width or for stronger signals
doubled trace width.  But either way I have never come across a clear study
of how to make a best judgment.

> -----Original Message-----
> From: Ray Dwyer
> Sent: Thursday, February 05, 2004 11:58 AM
> To:   [log in to unmask]
> Subject:      copper pour stand-off
>
>
> Greetings,
> I am concerned about rules for stand-off distance for copper pour on an
> outer layer to provide added isolation to a pair of sensitive low current
> traces.  There are other traces on the top layer as well.  The basic info
> is 50 ohm impedance, 10 mil wide microstrip, digital TTL signal current as
> low as in 10s of mili-amps, FR-4 material, 1 oz copper.
> Ray Dwyer
> 972-371-4046
> Maxim
> 4401 Beltwood Parkway
> Dallas, Tx. 75244
>
>

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