Electronics Forum | Thu Aug 20 18:20:21 EDT 2009 | joeherz
Sergey, With that many leads and contact surface area points, it doesn't make sense that the part would move as it has without a gust of wind.... What is your confidence that you don't have an MSD issue on this part. Being that it is a TQFP, it's
Electronics Forum | Wed Aug 26 05:22:59 EDT 2009 | grahamcooper22
Hi Sergey, I agree with your probable cause. Maybe if you still have a component you can bake it before reflow to DRY it. Then if the problem doesn't happen in reflow you have surely proved the cause. Consult IPC JEDEC 33B spec for storage and Drying
Electronics Forum | Thu Aug 20 08:23:23 EDT 2009 | ratsalad
One diagnostic tool that I have found useful in the past is the "hot plate test". Place suspect components and/or PCB's on a hot plate and turn it on High. Then observe. Granted the conditions on the hot plate are not the same as in a reflow oven,
Electronics Forum | Tue Aug 18 10:11:04 EDT 2009 | grantp
Hi, Yes, I think this sounds like a form of tomb-stoning, and we used vapor phase until it ended up driving us totally nuts trying to deal with tomb-stoning. We tried everything, and all kinds of stencil apertures. Vapor phase is an amazing process
Electronics Forum | Mon Nov 07 12:25:32 EST 2005 | Rob
Hi CW, Larger chip caps can be susceptable to cracking, but mainly this is due to handling - flexing of boards is the main culprit (the part being mechanically joined at both ends to the board). PCB's usually flex easiest along one axis, and larger
Electronics Forum | Mon Jul 12 11:35:27 EDT 2004 | Pierre RICHARD
Here are some answers to my questions after a good research. I also added more definitions that could help understand this esoteric language used in assembly, specially surrounding fluxes and their use. In blue italics are comments and extracts from
Electronics Forum | Mon Dec 08 19:40:59 EST 1997 | Alan Brewin
I would appreciate hearing views on vapour phase soldering particularly in respect to BGA's. I know that they used to use CFC's but apparently this is no longer the case? Can anyone help with some info? Thanks, Alan Brewin
Electronics Forum | Fri Aug 31 00:28:09 EDT 2007 | itaig1
We are currently looking at buying a vapour phase reflow batch oven. We currently use an IR convection batch oven and want to know if there is any advantage in switching over to vapour phase?. I've heard that tomb stoning is a common problem do t
Electronics Forum | Tue Jun 17 09:06:33 EDT 2008 | ldavis
We've had very few tombstone problems but all were fixed by reducing the apertures of the affected components.
Electronics Forum | Mon Aug 31 03:18:27 EDT 2009 | grahamcooper22
What is the boiling point of your vapour phase solvent ?
