Hello there! In regards to your reply about witness marks, I do agree that having them CENTERED on the pads are no problem whatsoever. I do agree with you that seeing them on the pads is a indication that the fab did indeed go on to some sort of fixture, but it is not an absolute guarantee that the board is free from internal shorts or opens. Yes, a indication that it is likely free from defects, but NOT a guarantee. But as I stated, having them off-centered to the extent that they deform the intended outline of the pad is completely unacceptable. The fab vendor needs to be competent in the design of the fixture to ensure that each board is repeatably and accurately located during the bed of nails testing so that the assembler recieves a PCB that is free from the kind of defects that WILL affect yeild. If you've never experienced the problem that I spoke of, then you are lucky to have a good fab vendor... The times that I've had these problems was when I've been employed at contract assembly companies and have had no control over the quality of the fab or the parts. I've had to deal with kits containing 100-piece strips of passives, IC's in plastic bags, and fabs with what I'll call; "witness gouges", all thrown into a cardboard box and expected to turn this crap into gold turning it around in three days...I'm sure there are some of you out there that know what I'm talking about... -Steve Gregory- ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################