Richard, you basically hit the strategy I was working toward. I guess my question would bettee be how to configure the signal layer pairs in 99se & any other size/optimal settings regrading blind/buried vias.
____________ Brian G. ----- Original Message ----- From: "Richard Sumner" <[EMAIL PROTECTED]> To: "Protel EDA Discussion List" <[email protected]> Sent: Wednesday, June 21, 2006 5:08 PM Subject: Re: [PEDA] First BGA design with blind-buried vias. > Brian, > > I'm currently debugging a 6 layer board with a 676 pin bga. I > actually needed only 316 of the i/o pins, and I simply avoided the > deep rows of the bga. With only 1 trace between bga pads, I can get > the first two rows (counting from the outside in) on the top layer, > and using thru vias I can get the next two rows (equivalent, you have > to avoid blocking the planes with adjacent clearance around the vias) > on the bottom (or any other layer). This is a low volume product, not > very (parts) cost sensitive, so I can justify the larger package > (It's actually a trade off with a more expensive board). It was my > first board with ad2004, and I did make use of the fpga pin swapping > (much easier than with 99se, but still not simple) > > Richard > > > At 04:14 PM 6/21/2006, you wrote: >>Ok, I'm still using P99SE. >> >> I need to upgrade an existing project with the main IC being a 240 >> QFP, >>going to an Altera 484 pin, 1mm fineline BGA, however, there are some >>parts >>under the chip. >> >> My PCB is only 6 layers. I've never done blind/buried vias before in >>protel. How should I configure protel to handle the blind-buried vias >>under >>the BGA pads. Am I attempting something that shouldn't be done? Can some >>BGA pads just be pads with no holes at all without upsetting the mounting? >>Is there any good reason to switch to microvias? >> >> >>____________ >>Brian G. >> >> >> >>____________________________________________________________ >>You are subscribed to the PEDA discussion forum >> >>To Post messages: >>mailto:[email protected] >> >>Unsubscribe and Other Options: >>http://techservinc.com/mailman/listinfo/peda_techservinc.com >> >>Browse or Search Old Archives (2001-2004): >>http://www.mail-archive.com/[email protected] >> >>Browse or Search Current Archives (2004-Current): >>http://www.mail-archive.com/[email protected] > > Cheesecote Mountain CAMAC, 24 Halley Drive; Pomona, NY 10970 > voice: 845 364 0211, NEW fax: 877-840-0023, Skype: cmcamac, > www.cmcamac.com > > ____________________________________________________________ > You are subscribed to the PEDA discussion forum > > To Post messages: > mailto:[email protected] > > Unsubscribe and Other Options: > http://techservinc.com/mailman/listinfo/peda_techservinc.com > > Browse or Search Old Archives (2001-2004): > http://www.mail-archive.com/[email protected] > > Browse or Search Current Archives (2004-Current): > http://www.mail-archive.com/[email protected] > ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[email protected] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
