X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com Date: Sun, 06 Jul 2014 16:41:27 +1200 From: Lilith Bryant Subject: Re: [geda-user] pour clearing around pads To: geda-user AT delorie DOT com In-Reply-To: <53B8CC66.2080909@sonic.net> (from davecurtis@sonic.net on Sun Jul 6 16:11:18 2014) X-Mailer: Balsa 2.5.1-79-g9697477 Message-Id: <1404621687.750.40@zotlet.(none)> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id s664fsKD027191 Reply-To: geda-user AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: geda-user AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk On 2014-07-06 04:11:18 PM, Dave Curtis wrote: > I'm working on a footprint where if I follow the data-sheet geometry and > my normal design rules, I end up with a footprint where very skinny > copper peninsulas sneak between pads when it is placed in a polygon. > The peninsulas neck down to less than the minimum copper width rule. > > So, first off, I'm surprised that the Cu polygon allows Cu to pour into > a space less than the minimum width rule. > > Secondly, I'm wondering if fab houses might flag that as a DRC violation > even if pcb doesn't. > I have had a fab house complain about this. I ended up telling them to just ignore it, and so far it hasn't been an issue but it does make me a little nervous, particularly what might happen to fine slivers that get undercut during etching. Also, I don't do RF stuff, so ending up with unconnected islands is not a issue for me. I have been meaning to write a polygon "bake" tool that fixes this, but have been put off by the lack of a workable polygon library. Pretty much just needs to erode then dilate by the minimum clearance. Was going to use shapely/GEOS in python, but it's erosion doesn't seem to work :( So it went into the too hard basket for the time being.