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From:	"Roger Traylor (traylor AT engr DOT orst DOT edu) [via geda-help AT delorie DOT com]" <geda-help AT delorie DOT com>
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Subject:	Re: [geda-help] Four layer board
Date:	Thu, 2 Apr 2020 15:24:47 -0700
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Cam,

Just about finished with a new 2-layer board myself.  I thought it probably could not
be done. It takes a few tries till you see the patterns of where signals need to go.  I
started just making routes work with no DRC checking.  Then I went back and 
cleaned it up.  I was surprised what I could do and how much room was left over.
It does take more time though. 

Before, I’ve done 4-layer boards with PCB as you describe with very good results. 
This one had to be a minimal-cost board so it had to go in two layers.  Realize that 
the cost is roughly half with 2 layers versus 4.

Best wishes,
Roger Traylor

> On Apr 2, 2020, at 2:26 PM, Cam (camfarnell AT bitflipper DOT ca) [via geda-help AT delorie DOT com] <geda-help AT delorie DOT com> wrote:
> 
> I'm using PCB 4.0.2. The board is too complex and tight to route with two layers. My next thought is to use four layers with the inner layers being devoted to power and ground with almost the entire layer copper and using thermals where it connects to pins and a gap for non-power pins. But I could see no way to achieve this with PCB. Am I missing something or is that just not supported?
> 
> I could simply do thick routes for power and ground on the interior layers but then there is the question of how to get power and ground to SMT components which exist only on the component layer. Hand placed vias near where power/ground pins are on the SMT devices?
> 
> Any advice appreciated.
> 
> Cam Farnell

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