Hi Peter - I agree with Vlad, we still have a mixed metallurgy situation for the solder joint so I would treat it as having the same solder joint integrity concerns that would need to be reviewed and assessed. Dave Peter Barton <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 09/26/2012 09:45 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to Peter Barton <[log in to unmask]> To <[log in to unmask]> cc Subject [TN] Using Tin/Lead balled BGA in a Lead-Free process Hi Technetters, Interesting that this question has arisen for me when there has been a question posed here on the reverse scenario in the last couple of days. Firstly, I agree with other posters that full reflow and alloy mixing must be achieved when using Lead free BGA's in a Tin Lead process. There is quite a lot of data out there supporting this. My problem is finding research data on using a Tin/Lead BGA on an otherwise fully Lead free assembly. This appears to be much more limited. So far I have only found one paper that refers to this particular scenario and some of it's conclusions are carefully qualified. Assuming that all the other the packaging materials for the Tin/Lead BGA part in question are capable of surviving a suitable reflow process to successfully solder the lead free parts whilst minimising thermal input, can anyone out there comment on potential reliability issues. For information the BGA balls are 63/37 Sn/Pb and the solder paste alloy is SAC305. Many thanks in advance, Peter Barton ______________________________________________________________________ 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] ______________________________________________________________________