Friends - On Wed, Feb 01, 2006 at 11:20:38AM -0800, Larry Doolittle wrote: > > If you're doing high speed stuff, it pays to subscribe to > > [SI-list] list. > > Well, lurk through its archives anyway.
http://www.freelists.org/archives/si-list/ The topic of 6-layer stackups is covered in the thread starting http://www.freelists.org/archives/si-list/04-2005/msg00204.html The expert conclusion (from Steve Weir) is http://www.freelists.org/archives/si-list/04-2005/msg00275.html http://www.freelists.org/archives/si-list/04-2005/msg00324.html that my original stack makes perfect electrical sense. They discuss layer thicknesses of 3.2+4+38+4+3.2, similar to but even more aggressive than my original suggestion of 5+5+30+5+5. Discussion of board warpage and workarounds is included. Maybe I should email Graham Davies and ask what fab house he uses. Just because it's electrically "Right", doesn't mean it's properly engineered. If 4+14+4+14+4 is cheaper and more available, I can use that. I just have to know and adapt before I can call my layout finished. I guess this has always been only marginally on-topic in geda-users. It would be nice to work with fab shops that are supportive of gEDA/pcb, like Advanced Circuits, if possible. I look forward to seeing DJ's complete list, and we can start filling in the column "has correctly fabbed a board from pcb snapshot _____". - Larry
