Electronics Forum | Fri Aug 26 09:57:21 EDT 2005 | russ
The Immersion gold is not a problem with BGAs specifically but "black pad" which can be present anywhere. The unfortunate thing with BGAs is you cannot see it. Personally I hate white tin. It is okay for single sided boards running no-clean, but c
Electronics Forum | Thu Jun 22 07:15:37 EDT 2006 | amol_kane
do you mean microvoids or macrovoids??
Electronics Forum | Tue Jun 27 12:12:05 EDT 2006 | GMan
Yes it does seem like a plating issue and analysis is being done. Thank you for your inputs.
Electronics Forum | Wed Jun 28 02:29:48 EDT 2006 | Loco
Wow, great article there mike! Thanks for digging it up for us! Kind regards, Loco.
Electronics Forum | Sat Oct 06 08:42:21 EDT 2001 | davef
Please give us additional background on your board, solder, process, etc. If you are talking about black pad in ENIG solderability preservative, check the fine SMTnet archives to get started.
Electronics Forum | Mon Jun 26 23:33:20 EDT 2006 | KEN
We saw this condition over 3 years ago. It sometimes is called "champagne bubbles". The intemetalic formation is interrupted due to the micro voiding reducing mechanical strength. I discovered this on lead free test vehicles for a major computer
Electronics Forum | Fri Mar 19 10:27:42 EDT 2010 | karlo
No clean pastes leave more flux residues. These can result in void formation and inhibtion of underfill curing. Selection of an underfill that is compatible with the flux residue is important. One company that has written about the effect of flux
Electronics Forum | Wed Jan 12 13:42:19 EST 2011 | dwonch
Hi All, I'm hoping there is a PCB expert or two hanging around. We're having some solderability issue on our boards. The finish is ENIG but it doesn't seem to be related to the finish process itself. We did SEM and EDX analysis and found aluminum an
Electronics Forum | Wed May 20 17:18:09 EDT 2009 | daxman
Just out of curiosity, how are you or anyone else determining a defect? Last I checked, IPC had no criteria yet for solder defects for QFN components. Has this changed? Biggest problems we see are voids which our x-ray shows a lot of. Our problems
Electronics Forum | Tue Dec 13 17:41:04 EST 2011 | davef
A Study Of 0201’s And Tombstoning In Lead-Free Systems, Phase II Comparison Of Final Finishes And Solder Paste Formulations http://sheaengineering.com/Documents/APEX%2008%200201s%20and%20Tombstoning%20phase%202%20paper.pdf CONCLUSION The condition
