My concern is that when purchasing buys directly from the manufacturer use know the date of manufacture. 

When you buy from a component distributor or when you have to build from consigned parts supplied by the customer you don't know the date of manufacture and have no idea how the parts were stored and repackaged. 

We would like to generate an Iso procedure relative to this issue and would like some advice. 



What I'm seeing are circuits boards that have been reflowing perfectly for  quite some time are now built with more and more components that are plated with 100% tin. Soldering to tin with a eutectic OA solder paste shouldn't cause a problem if the leads or termination on QFNs, a bigger problem are not oxidized or contaminated. 

I checked on the internet to see if you need to adjust the profile when soldering to tin coated parts with  eutectic solder but found nothing. You get two sets of profile families, one for eutectic and one for Pb-free. Nothing for a mix so I'm leaning toward a contamination or age problem.    

Thanks for any help you can offer. 

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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
-----------------------------------------------------