I will send you a matrix showing the differences. Likely your via's will not have adequate pad to hole to meet class 3. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Jay Otts Sent: Saturday, January 06, 2007 3:24 PM To: [log in to unmask] Subject: [TN] Reliability 6012 Cl2 vs. Cl3 Need help in quantifying difference in reliability prediction for a specific board design meeting 6012 Class 2 vs. Class 3 requirements, given all parameters equal except internal annular rings. My concern is breakout allowed by class 2 vs. 1 mil min. internal annular ring per class 3. Parameters: high quality FR4 material 15" x 15" size 20 layer high density layers 1 -5 contain blind vias finished board thickness appx. 0.110" 1mm dot pitch bga's benign operating environment Jay Otts Raytheon --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------