From IPC-6012B Class 3/A - Performance Specification Sheet for Space and Military Avionics, exception to IPC-6012B Annular Ring Requirement(s): 3.4.2 & 3.6.2.9 Unsupported holes - 0.38 mm [0.015 in] minimum Internal/External Plated-Through Holes - 0.051 mm [0.002 in] minimum allow 20%reduction unless already at 0.051 mm [0.002 in] Regards, Bob -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of [log in to unmask] Sent: Tuesday, May 03, 2005 12:56 PM To: [log in to unmask] Subject: [TN] Annular ring:- What should we sign up for ???? We have a tough brd to manu. and want to know what kind of annular ring requirement should we sign up for. This is for SPACE so it requires IPC-6012 class 3, w/ exceptions to annular ring. 12 layers 1) Burried vias 7-11 2) Burried vias 6-11 3) Blind vias 6-12 4) Burried and blind vias have 16 mill pads for vias (thickness ~ 60 mils) 5) Thru holes (~90 mils) 18 mil pads. 6) Cavity brds w/ broad side coupled diff. impedance control Thanks for your help in advance Rush [log in to unmask] (mailto:[log in to unmask]) 818-768-3919 --------------------------------------------------- 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 -----------------------------------------------------