Hi Steve here they are, these are the only kind of components that dop the other ones are well fixed on the pcba. Thanks a lot, Carmen (See attached file: 1.bmp)(See attached file: 7.bmp) "Steve Gregory" <[log in to unmask] et> Per <[log in to unmask]>, 19/05/2014 15:13 <[log in to unmask]> CC Oggetto RE: [TN] Rif: Re: [TN] pcb issue led to smt components drop from pcb Hi Carmen! Just reply to this email and I'll post your pictures.... Steve -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Carmen Aloisi Sent: Monday, May 19, 2014 12:58 AM To: [log in to unmask] Subject: [TN] Rif: Re: [TN] pcb issue led to smt components drop from pcb Dear all thanks a lot for your promt reply and suggestions, the pcbs have leaded hasl surface finishing I agree with you about potential intermetallic issues... fail pcbas are travelling right now from customer to our plant here in Italy and then I'll make some cross section. I'd like to share pictures, how shall I contact mr Steve Gregory in order to post them? Have a nice day Carmen Carmen Aloisi Quality Manager Eutron S.p.A. Via Crespi 29 24020 Pradalunga (BG) Italy ph. +39 035697011 fax +39 035697090 m. +39 3355666074 www.eutron.com p.i. 01805190160 Wayne Thayer <wthayer@KEYWCORP .COM> Per Inviato da: <[log in to unmask]> TechNet CC <[log in to unmask]> Oggetto Re: [TN] pcb issue led to smt 16/05/2014 19:32 components drop from pcb Per favore, rispondere a TechNet E-Mail Forum <[log in to unmask]> ; Per favore, rispondere a Wayne Thayer <wthayer@KEYWCORP .COM> Hi Carmen- You must get the surface analyzed. I believe that it "looks like" bare exposed copper, but the odds are highly against that. As Vladimir has suggested, you can hire an expert to do the whole analysis. Or you can try to make this an educational journey for yourself. If you get the surface analyzed, you'll need an analytical technique capable of identifying the various species and thicknesses of intermetallics which are on the metal surfaces. Also, you need to understand the usage environment. I believe that with the appropriate amount of temperature cycling, you can get the components to fall off of anything, provided there is a temperature or temperature coefficient of expansion difference between the component and substrate. Looks like I might be the first to set off some tirades by mentioning "black pad". This is a very ugly intermetallic which is associated with ENIG surface finish, and we providers of electronic assemblies spend many sleepless nights about it because you can have a beautiful joint which fails in even fairly mild usage environments. Obviously we don't have enough information to suggest this as your problem, but it fits the final result (as do many other things!). Shock will take off SMT components also, but that's usually a negligible probability (exceptions include crystals separating from cell phone motherboards when the cell phones are dropped or thrown). Can you provide pictures? We like to see pictures in TechNet. You can't broadcast them directly, and we were using some kind of sharing site, but this guy named Steve Gregory takes pride in making it easy to send him pictures and he'll post them. I think the "cc" address in this email is his current one, but he's changed companies a few times, so I'm not positive. He seems to always watch for opportunities to help like this. Once you post shots, all of the TechNet experts will come out of the woodwork with additional questions and arguments guaranteed to be somewhat amusing and possibly very educational. Wayne Thayer -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Carmen Aloisi Sent: Friday, May 16, 2014 11:48 AM To: [log in to unmask] Subject: [TN] pcb issue led to smt components drop from pcb Hello I'm new to this forum and I'd like to address the following issue to the group: after 3 years from delivery of a batct of pcbas we got back from customer some of them where components are dropping from the pcbas, the solder remains on the component pin and the pads are with exposed copper. Could you help me in understanding what was wrong on pcb supplier process or on ours? Thanks a lot in advance Carmen Aloisi Quality Manager Eutron S.p.A. Via Crespi 29 24020 Pradalunga (BG) Italy ph. +39 035697011 fax +39 035697090 m. +39 3355666074 www.eutron.com p.i. 01805190160 .(See attached file: 1.bmp)(See attached file: 5.bmp)(See attached file: 7.bmp) ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. 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