Mike, In building the types of high reliability, hostile environment products that your company appears to produce, validation of the quality of the PWB is critical. While working in an EMS environment building these types of products, my experience has been that the PWB is always the number 1 defect source. We would normally perform receiving inspection on PWB's as follows (typical) to the appropriate IPC specification (and/or customer quality specifications). * Visual inspection * Warpage measurement * Critical Dimension verification * Inspection of Cross Sections (we made our own if not provided by the supplier) * Ionic contamination testing * X-Ray fluorescence to validate the composition and thickness of the surface finish * Other techniques as necessary (SEM, EDX, etc. to obtain more specifics) The level of validation was determined on the basis of performance over time. Typically, a new PWB supplier, or a new design was inspected at 100%, then adjusted down as performance warranted. It might be possible to eliminate inspection completely if a supplier's performance was exceptional over an extended period of time, but we never achieved that level. The cost of building defective product for a critical performance application is much higher than the cost of not validating the quality of the incoming material (my experience). Phil Yates -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Mike Williams Sent: Wednesday, October 22, 2003 9:00 AM To: [log in to unmask] Subject: [TN] Skip Lot inspection I am looking for some input on skip lot inspection of bare pwb's upon receipt from the supplier. We are currently performing our own destructive analysis to determine acceptability over and above what the supplier performs. Any opinions pro and con are welcome. Mike --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------