Electronics Forum | Tue Mar 25 08:29:33 EDT 2014 | sara_pcb
Please refer the attached jpegs, The problem is noticed after reflow soldering followed by conventional through hole soldering. Flux used one is MIL Std. Brush cleaning in IPA is followed after each soldering step. regards, R.Saravanan
Electronics Forum | Fri Apr 04 14:49:51 EDT 2008 | tombstone
Flux seperation is a common problem observed due to expiration of paste. The symptom is a yellow layer of flux when you open the jar. Excess flux separation will cause priting problems such as smearing and slumping.
Electronics Forum | Thu Dec 10 04:19:55 EST 2009 | cunningham
do you not have a problem with flux seperating from when it was chilled? due to our high mix low volume we really cant afford to have solder paste waiting for an hour or so till its ready before we can build
Electronics Forum | Thu Nov 07 07:35:23 EST 2002 | cyber_wolf
If you are experiencing flux migration, try refrigerating your paste when not in use. This causes the flux viscosity to go up. I have seen flux seperate from the solder is when it is VERY old and out of date.Sometimes warmer ambient temperatures wi
Electronics Forum | Fri Dec 11 09:51:56 EST 2009 | dyoungquist
I won't say never but very rarely do we have problems with the flux seperating. The way we get around the 1-2 hour warmup time is this: The day before we run a particular job, the last person takes out the paste needed from the fridge as the last t
Electronics Forum | Tue Jan 16 10:58:42 EST 2007 | realchunks
Yes, it can evaporate. My point was manufacturers suggest cool storage to avoid seperation. I guess if the flux does seperate and get pushed to the top it could have a greater chance to evaporate. I have only seen such seperation on year + old jar
Electronics Forum | Thu Jul 26 01:50:17 EDT 2001 | mugen
We gave standing order, if its past the expiry date, ditch the can/jar, get a new can/jar.... Visual confirmation, for previously open & recycle can/jar, if you see seperation, of yellowish flux floating above, goolie grey much beneath, then ditch i
Electronics Forum | Tue Apr 15 10:43:44 EDT 2003 | yngwie
Why is it people still prefer to do manual stirring of solder paste versus automated solder paste softener ? I learned that one of the dis-advantage of using the softener is that this method is actually seperating the metal and flux. Is there any oth
Electronics Forum | Fri Nov 22 15:59:43 EST 2002 | GSW
What type of reflow profile are you using ? There is a void reduction profile recommeded by some paste manufacturers, Try that it might help. Did you check the components or the board and see if they have absorbed mositure ? try baking the boards and
Electronics Forum | Fri Apr 18 19:27:29 EDT 2003 | yngwie
Under web search you type solder paste softener. It is meant to replace manual stiring process of solder paste prior use. I heard that the spinner/softener is no use as it will seperate the flux and metal content during the spinning process. But, I h
