Message-ID: <524FB65F.9050604@gmail.com>
Date: Sat, 05 Oct 2013 08:49:03 +0200
From: onetmt <onetmt AT gmail DOT com>
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To: geda-user AT delorie DOT com
Subject: Re: [geda-user] polygons, arcs and footprints
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Il 04/10/2013 23:56, Evan Foss ha scritto:
> Hi folks,
> 
> I am trying to make a footprint for an LTC3441. The bottom pad is a
> polygon. I know they are not possible in PCB footprints but does
> anyone have a good way to emulation one?

For other components - for instance the BSC159 mosfet by Infineon - I
used several square pads partially overlapped, in order to get the right
"polygonal" pad. But in your case, imho, you should use a "normal"
footprint and then design the polygons on layer, placing vias also on
central powerpad as indicated in datasheet.

> 
> Also I am trying to use a MEMS microphone that uses a ring to seal it
> to the PCB. Again I know that does not exist but is there a way around
> it?

It's difficult to say without knowing the component, but you can obtain
a ring - well, a sort of - by using appropriate clearance around an
"octagon" pad and placing a rectangle, maybe on a ground layer, around it.

> 
> -Evan
> 


-- 
Hofstadter's Law:
"It always takes longer than you expect, even when you take into account
Hofstadter's Law."