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Subject:	Re: [geda-user] The nature of gEDA layers
To:	geda-user AT delorie DOT com
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From:	John Griessen <john AT ecosensory DOT com>
Message-ID:	<56AA95B5.8030805@ecosensory.com>
Date:	Thu, 28 Jan 2016 16:27:01 -0600
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On 01/28/2016 02:22 PM, Britton Kerin (britton DOT kerin AT gmail DOT com) [via geda-user AT delorie DOT com] wrote:
>> The aim should be to change PCB in small incremental steps.
>> >
>> >- Remove the assumption that all layers except "outline" are conductive.
>> >- Make implicit layers explicit and allow to draw on them, soldermask, solderpaste.
>> >- Allow more/all things inside Elements, on explicit layers.
> This one in particular is not a small incremental step but a fairly
> drastic change.  A lot of work is likely to be required to fix all the
> points that make assumptions about Elements.  I'm not saying it's a
> bad idea, but it's hard.
>


Yeah, but this kind of item is what makes life easier from then on.
Some things are hard and deserve more than a quick patch fix, (More spaghetti code).

On 01/28/2016 02:46 PM, Britton Kerin (britton DOT kerin AT gmail DOT com) [via geda-user AT delorie DOT com] wrote:
 > Everyone seems to want these, to be honest I don't understand what
 > pads on middle layers are for.  Not mounting components for sure.  If
 > it's just a node what's wrong with a trace or poly?

They give strength and increased conductivity by bigger connection cross section area.
They serve as a large enough target for wandering drills to go through off center and still function well.
That kind of connection tolerance is important for low frequency and essential for HF, RF to avoid reflections.

John Griessen

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