Electronics Forum | Mon Mar 09 07:14:35 EDT 2009 | gregoryyork
wow enig is usually not associated with this failure
Electronics Forum | Tue Mar 03 14:07:07 EST 2009 | macisaint
I'm having shorts appear on my QFN packages between pins, usually only after a week or so of power-on operation. The shorts are 1K and slowly down to hard shorts over time. Typically a defective part will have failures on multiple pins. I tried havi
Electronics Forum | Wed Mar 04 08:25:49 EST 2009 | scottp
I don't think anyone can give you an answer until you've had some failure analysis done. Silver migration? Dendritic growth? Tin whiskers? Lots of possibilities, but you won't know without failure analysis.
Electronics Forum | Fri Mar 06 19:40:34 EST 2009 | gregoryyork
I would imagine it is lead free HASL finish board from the sounds of it am I right. Cheers Greg
Electronics Forum | Wed Mar 04 11:47:42 EST 2009 | patrickbruneel
I have to correct something from my previous post (before someone else corrects me). You can grow dendrites from any conductive surface (Cu, Ni etc.) but the final stage would be lower SIR. In my experience other metals except for tin do not lead to
Electronics Forum | Wed Mar 04 08:21:42 EST 2009 | rgduval
It seems familiar, but nothing that I've actually experienced. I've read some articles about tin-whiskering in lead-free solder. I think NASA has some pretty good analysis (or, at least they did a couple of years ago). The summary is that without
Electronics Forum | Wed Mar 04 11:16:25 EST 2009 | patrickbruneel
From your description of the problem first reduced SIR to dead short is exactly what happens with dendrite growth. What is needed to form them is low bias voltage (10 volt range is ideal with low current), a surface, 2 conductors (containing tin), io
Electronics Forum | Fri Mar 06 10:32:34 EST 2009 | fountain42
Yes, We've already experienced this same problem. 1) What kind of flux are you using? No Clean? Rosin? OA? 2) If it's OA, What kind of water wash do you do? Do you use DI water? How Hot? Who's machine? What are the pressures? 3) Have you performed a
Electronics Forum | Tue Nov 27 20:51:18 EST 2007 | chs
Anyone can share experience on package crack for QFN package. This package is so sensitive to any external force. Any good recomendation on desoldering / rework procedure.
