delorie.com/archives/browse.cgi   search  
Mail Archives: geda-user/2016/01/28/16:46:07

X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f
Date: Thu, 28 Jan 2016 16:45:55 -0500
Message-Id: <201601282145.u0SLjtD5003045@envy.delorie.com>
From: DJ Delorie <dj AT delorie DOT com>
To: geda-user AT delorie DOT com
CC: geda-user AT delorie DOT com
In-reply-to:
<CAC4O8c_EjSO7Bgk8Tk=zy2-TjkXXwAtFwgnvguuw3zGor=vh2w AT mail DOT gmail DOT com>
(geda-user AT delorie DOT com)
Subject: Re: [geda-user] The nature of gEDA layers
References: <alpine DOT DEB DOT 2 DOT 00 DOT 1601180756390 DOT 9035 AT igor2priv>
<201601261804 DOT u0QI4KEQ009550 AT envy DOT delorie DOT com>
<E7D351BF-5BBB-41AC-B996-D5E27079A82C AT noqsi DOT com>
<CAC4O8c-ZyNnCzCDHXkYYabSD4fG8vf+CKmhMycNJujGMPKzQDQ AT mail DOT gmail DOT com>
<s6nr3h49hrq DOT fsf AT blaulicht DOT dmz DOT brux>
<DDB07351-7C94-4B5C-99FA-83750CD4592A AT noqsi DOT com>
<20160126233332 DOT dec2f06f5c74354a3841989c AT gmail DOT com>
<s6n1t93h4ub DOT fsf AT blaulicht DOT dmz DOT brux>
<20160127091746 DOT 1c7a976c2752f913921688ac AT gmail DOT com>
<s6npowne74w DOT fsf AT blaulicht DOT dmz DOT brux>
<20160127141334 DOT c738feb9dbeb54a7dec3dff8 AT gmail DOT com>
<s6n37tjt1tv DOT fsf AT falbala DOT ieap DOT uni-kiel DOT de>
<56A8F74B DOT 8080304 AT ecosensory DOT com>
<CAC4O8c9UKLsh5FAAwUMEtHThKH-w3gUmCU2i9dRW9igkyRt-TQ AT mail DOT gmail DOT com>
<CAJZxidDmjMtd_fKvR5qZVRa+hwDUbvfaz79oZjkBgDuE1m8RBg AT mail DOT gmail DOT com>
<56A961BC DOT 3040405 AT ecosensory DOT com>
<CAJZxidC=nbxAinOtpfGHHqwPXbEMrhfat7jKgA9KBp3EVVg4_Q AT mail DOT gmail DOT com>
<s6nbn863xlu DOT fsf AT blaulicht DOT dmz DOT brux>
<56A9E416 DOT 8080500 AT ecosensory DOT com>
<s6nfuxirm0b DOT fsf AT falbala DOT ieap DOT uni-kiel DOT de>
<CAC4O8c9D-F3p8sAm2UumoE+uoMZM1ufSP=mNEPeHHpn8YrcSyg AT mail DOT gmail DOT com>
<s6nmvrp31r9 DOT fsf AT blaulicht DOT dmz DOT brux> <CAC4O8c_EjSO7Bgk8Tk=zy2-TjkXXwAtFwgnvguuw3zGor=vh2w AT mail DOT gmail DOT com>
Reply-To: geda-user AT delorie DOT com

> >  - pad stacks, with differnet pad sizes on middle layers
> 
> 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?

Internal pads provide structural integrity to the hole plating.
However, the alignment accuracy for internal pads is not the same as
for external pads, so the DRC rules are different, but OTOH you
sometimes want big outer pads for strength but smaller inner pads to
allow more traces between pins.  Etc.

> >  - hierarchical layout
> 
> It can be done now...

PCB doesn't support it, you need to flatten the design first, and
using external scripts (which I've done) to replicate the design is
just hacks.

> I've never done these.  I guess the flexing connector layer is on
> top, but only where it exists so you can still have components on
> the layer below?  There's still only one top layer at any given
> point?

It depends - there's lots of options for how flex assemblies are put
together.  There might, indeed, be multiple "top" layers for one X,Y
coordinate.

- Raw text -


  webmaster     delorie software   privacy  
  Copyright 2019   by DJ Delorie     Updated Jul 2019