Some people are still inspecting to mil specs and see the J Stds as weak and troublesome. There are defects and there are process indicators. A process indicator tells that a process or training needs to be looked at and perhaps adjusted or changed and do not need to be reworked. Concentrate on the real important problems, such as missings, shorts and so on. Regards, Ramon -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Ofer Cohen Sent: Monday, April 25, 2005 8:16 AM To: [log in to unmask] Subject: Re: [TN] Inspection and touch-up of visual defects Daan, On one hand, I think that the visual inspection is important. Our process calls for 100% inspection during the touch up, then two different stages of sampling with AQL=1%. On the other hand, I am fighting my QC and touch operators on a daily basis to avoid unnecessary repairs. Meaning: I want to know what is the process quality, but not necessarily to repair it. Regards Ofer Cohen Manager Quality Assurance, Reliability and Production Technologies Seabridge Ltd. - A Siemens Company Siemens COM FN A SB TQM -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Daan Terstegge Sent: Monday, April 25, 2005 12:22 PM To: [log in to unmask] Subject: [TN] Inspection and touch-up of visual defects Hi Technet, I have a question about inspection, touch-up, and how far you need to go to get a product that meets the required IPC-spec. According to some reports (i.e. "New Study Reveals Component Defect Levels" by Stig Oresjo of Agilent) the average defect level in PCB assembly is around 1100 dpmo. Even with much better dpmo-figures it is easy to see that except for very simple boards almost every one of them will have one or more defects before touch-up. A significant portion of these defects will be visual defects like an isolated spot of flux residue, overhang of an occasional bent lead, micro-solderballs, an occasional insufficient solder, an overlooked spike from handsoldering, etcetera. Although these are all actual defects according to IPC-A-610,the chance that they will cause the product to fail during their service-life is minimal. Now the point of this posting is: how much effort do you need to put into finding and correcting visual defects. You could argue that every board that still has a visual defect simply does not meet the IPC-requirement, and therefore every boards needs to be 100% visually inspected until you can be sure that you have found and reworked all visual defects. Subsequent to the 100% touch-up inspection, another 100% inspection by quality control might be needed to achieve this. The result is a nice-looking product which meets all the inspection requirements of IPC-A-610, but unfortunately it will be an expensive board. Another approach is to visually inspect the boards mainly for the purpose of feedback to the assembly process (on sample basis), and rely on electrical tests for finding defects to be reworked. Quick and effective, but only some of the visual defects will be found and thus, formally, the product (or at least some of them) will not meet the inspection requirements of IPC-A-610. I try to convince others that we spend more time on inspecting than we should, but so far every visual defect that is found is seen as proof that I am wrong. I am interested to hear how others are coping with this issue. Best Regards, Daan Terstegge Production Engineering Thales Land&Joint Systems Tel: +31(0)35 524 8297 Fax: +31(0)35 524 8181 Unclassified Email --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------