You don't need additional coupons to tell you it is not aligned. The whole panel is a coupon when you view the cores after inner-layer imaging, I could never understand why they would add "more coupons" to tell you what your eyes or AOI will tell you when inspecting the usable image. Just put the core layers on a light table and in 5 seconds you can tell if it is registered, in what orientation any mis-registration might be, etc. Just look at your A or B coupons, if you see quarter moon shaped images where the pads do not align correctly, there is your shifting..... just my opinion of course. Franklin -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Ted Tontis Sent: Wednesday, July 09, 2008 4:08 PM To: [log in to unmask] Subject: Re: [TN] PCB Inner layer shifting 5) How would you know if you have inner layer shifting? Take a look at IPC 2221A, table 12-1 and figure 12-14 show registration coupons that could be used. http://members.ipc.org/committee/drafts/7-11_d_Coupons.pdf Ted T --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 -----------------------------------------------------