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 | 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 Sep 23 18:11:10 EDT 2002 | steveb
On an assembly reflowed in air saw the same thing: 0201's with a grainular solder joint, but 0402's and above with perfectly formed joints. Reflow profile all within acceptable tolerances. Reflowing in nitrogen solves this problem, but increases t
Electronics Forum | Tue Nov 28 21:16:17 EST 2006 | davef
J Rose at EMPF says: The introduction of no-clean solder fluxes in electronics manufacturing has given rise to greater levels of solder balling simply because the opportunity to remove them in the wash process does not exist. They are typically cause
Electronics Forum | Thu May 30 10:31:03 EDT 2002 | robbied
Hi Yannick. This is an issue that we are just recently getting into but here is some ifo that I have gathered so far. I have seen/ used 2 different rework machines. The one we have bought is a 'PACE TF2000' which was at the lower cost end of the mar
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 | Mon Aug 24 06:12:31 EDT 2009 | ghepo
joanne please pay attention, each heavy no-clean flux residues not completely heated due to hand soldering becomes a moisture absorbing conductive pathway, causing electrical leakage. So I suggest you to clean well the board after hand soldering or
Electronics Forum | Wed Aug 21 10:26:08 EDT 2002 | stownsend
We are using OSP coated boards and no-clean solder paste. In a few instances, we are seeing increased distortion in an audio circuit. Has anybody seen or heard of surface insulation resistance (SIR) decreasing after reflow on OSP boards? Is it possib
Electronics Forum | Wed May 10 00:46:32 EDT 2006 | Chris
I agree! I am using a SAC305 no clean from Alpha. I have noticed that even hand probing with volt meter leads requires me to press very hard on the pads to bust through the flux residue.
Electronics Forum | Thu Nov 04 19:51:28 EST 1999 | John
Thanks folks. The current vendor is doing an alcohol wash, top and bottom, then performing an ionic test on 100 boards. I'm not to confident in the testing because the readings for a "clean" board are 25 ugm/sq in and a "dirty" board are 40 ugm/sq in
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