I have seen inner layer repair in China - generally they are repairing or inspecting areas flagged by an AOI system. In the factories I have visited this is closely controlled and any repaired areas are logged and recorded. I have never seen screwdrivers etc used, nor witnessed a high re-work level. There are a lot of people involved since the re-worker is normally the AOI machine operator, and you can see 20 or even 50 AOI machines in use for inner layer inspection in one AOI area. Honestly, if I did find people scraping away with screwdrivers on massive piles of PCB's, I would stop the audit right there............... John ------------------------------------ Avanex John Burke Senior Manager RoHS Compliance [log in to unmask] 40919 Encyclopedia Circle Fremont CA 94538 tel: 510 897 4250 fax: 510 979 0189 mobile: 510 676 6312 ------------------------------------ -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Jack C. Olson Sent: Friday, September 16, 2005 5:49 AM To: [log in to unmask] Subject: [TN] Bare-Board Inner-Layer Fab Quality This is a question for anyone who is intimately familiar with bare-board fabrication. I've recently returned from a trip to China and Taiwan to visit five fab vendors. During one of the tours, I noticed people doing a lot of rework on inner layers, scraping metal flecks off with screwdrivers and scrubbing crud off of conductors with this black (alcohol?) stuff. I asked the tour guide what their inner-layer yield was, and he said 99.5% huh? Is that how people do it? I've only been on maybe two board tours in the states in the last couple of years, and that issue never came up. So maybe that's just the way it is done, but what BUGS me about it is they don't record how many repairs they are doing on each layer, and it looked like different operators had different criteria for what constitutes a reject, and by claming such a high yield no one ever looks at the process right before it that is putting all the crud and metal flecks on the layers to begin with! Jack (the "I thought I'd seen everything" guy) --------------------------------------------------- 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 -----------------------------------------------------