Can't you simply use a ground plane (usually internal, of course, you probably already have one) and tell the pcb house to use it as the top and/or bottom too?
Richard At 04:33 PM 7/30/2002 -0700, you wrote: >Question to smartest of smartest designers out there: > >Here is the delima, we have a board appox 24 x 30 ( a very large >backplane) , many thousands of connections, every layer controlled >impedance. The boards are used for high speed tele comminications >switching and data monitoring. ( No the the tele com industry is not dead). >The designs are as many as 28 layers, some approching .250 inch in >thickness, a very expensive baord to design and manufacture. > >On the outer layers we avoid placing traces, since we embed the entire >design, The outer layer are copper pours tied to gnd to reduce EMI and to >maintain controlled Z on the next inner layer. The copper is poured on both >the top and bottom layers. > >Copper pours of this size are poured last because they are time consuming. >The pours can take 4 hours, and even longer if they are not right the first >time. Question to any of the best out there.....can we avoid a copper pour >and merge a gnd layer to the top? Does anyone have a method or suggestion >to merge copper to flood the top layer. Is there a quicker method? We >are using 99SE on aa 1 gig cpu with 512 meg. > >Mike Reagan >EDSI > > >************************************************************************ >* Tracking #: C05FC4455FDD074E8E0D19C321C392CAC217810D >* >************************************************************************ Cheesecote Mountain CAMAC, 24 Halley Drive; Pomona, NY 10970 voice: 845 364 0211, fax: 845 362 6947, www.cmcamac.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
