---------Included Message---------- > From: <[log in to unmask]> > Subject: Re: [DC] Blind and Buried Vias > The 0.005 and 0.002 numbers that you quote are not new. They were listed in > IPC-D-275 under "military requirements." Hi Gary, No, these numbers aren't new. Actually they are from the ipc-d-275 (old!) document. What's new are the numbers (if you'll read my previous message again) in ipc-2221 which have been halved (.0025"/.001") from what they were in 275. I would like to ask you why it was deemed ok by ipc to lop off (cut in half) the annular ring "design recommendation". BTW, I most always design by the minimum ipc recommendations, because they still tend to be very conservation. Just my opinion, and I don't argue with any of the "recommendations". Have a great day. Mitch _____________________________________________________________ Tired of limited space on Yahoo and Hotmail? Free 100 Meg email account available at http://www.dacafe.com