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Message-ID: <4F9C3813.90403@ecosensory.com>
Date: Sat, 28 Apr 2012 13:33:55 -0500
From: John Griessen <john AT ecosensory DOT com>
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To: geda-user AT delorie DOT com
Subject: Re: [geda-user] Metric vs Imperial, Grid snapping
References: <4F9BFF5D DOT 9010407 AT schinagl DOT nl> <1335634972 DOT 2539 DOT 13 DOT camel AT AMD64X2 DOT fritz DOT box>
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Reply-To: geda-user AT delorie DOT com

On 04/28/2012 12:42 PM, Stefan Salewski wrote:
> On Sat, 2012-04-28 at 16:31 +0200, Oliver Schinagl wrote:
>> Also, he mentions using 0.05 mm routing grid as most component lead pin
>> pitches are 0.05mm.
.
.
.
Do you really mean 0.05mm? That is very fine.

That's 50 microns.  The lead pitches are 0.5mm, so a routing grid  for fine BGAs
would be less than that, and he supports/works-for a name brand CAD company
that claims "do anything" capability, so he might have suggested 1/10 the
lead pitch for routing between them.  A 4 mil trace is 0.004 inches--> 0.102mm,
so a grid of half a trace width could make sense, even though 50 microns is small...

Hair is 60-80 microns varying a lot from person to person.