Electronics Forum | Fri Aug 26 09:48:11 EDT 2005 | David
I have heard that there are problems using immersion gold on PCBs when working with BGAs. Is this correct? Is white tin more suitable?
Electronics Forum | Thu Sep 08 14:03:50 EDT 2005 | chunks
You're right, but my neighbor borrowed my X-ray fluoroscope XRF and never brought it back! Actually, I just read the spec sheet which told me it was tin/silver leads.
Electronics Forum | Thu Sep 08 14:25:20 EDT 2005 | kris
what did you reprofile to ? did you increase the peak reflow temperature ? can you tell form what to where ? I bet your vendor told you process guys that it was " drop in" for a tin leaded plated part.
Electronics Forum | Tue Sep 27 17:25:12 EDT 2005 | scombs
Hi Jay, Have you used those methods before? The muffin tin is a good idea as long as you buy enough. Thanks
Electronics Forum | Wed Nov 02 03:35:09 EST 2005 | Slaine
I thought it was the tin content that leached the copper so presumed 100Sn would be more aggressive?
Electronics Forum | Thu Nov 03 13:35:46 EST 2005 | Amol
the copper forms intermetallics with tin to get Cu3Sn and Cu6Sn5. thus intermetallics formation consumes Cu and depends upon the cooling rate, faster the cooling rate, lesser the intermetallic formation
Electronics Forum | Thu Jan 05 17:10:04 EST 2006 | russ
The CCGA packages that we install are still a tin/lead alloy and not a SAC alloy. They were 90/10 SN/PB. I beleive that this may be one reason why the difference.
Electronics Forum | Tue Jul 25 11:30:47 EDT 2006 | DC
Russ, we had similiar issue on the corner seperation. The board is ENIG and the part is Altera FBGA 1020 (Super BGA) and reflowed by tin/lead paste. Please comment your concern on Altera parts! Is CTE mismatch?
Electronics Forum | Thu Dec 08 18:59:04 EST 2005 | KEN
Is this a wire dip tinning process? If yes, then your flux is probably trapped under the insulator, causing corrosion. BAD BAD BAD (hopefully you don't make wire harnesses for air planes or passenger trains). More info please.
Electronics Forum | Sat Dec 10 18:17:19 EST 2005 | Sergei
http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=9595&#Message38364
