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 Apr 03 17:25:49 EDT 2008 | alexs
Hi All, I have some question about expired solder paste. What would be some of the effects regarding assembly quality. Is there any changes in flux composition toward the end of shelf life? Thanks in advance for any replies.
Electronics Forum | Thu Apr 03 22:56:48 EDT 2008 | davef
Potential impacts of using expired solder paste are [University of Bolton]: * Changed paste rheology. Result: poor print quality * Loss of solvents. Result: reduced flux activity * Changed flux formulation. Result: More difficult to clean flux residu
Electronics Forum | Mon Mar 25 21:45:22 EDT 2024 | buckeye
I got an inquiry from one of our electronics labs with regards to their soldering processes. They use eutectic (63% Sn, 37% Pb) solder. For liquid flux they are currently using Kester 186, which is an old-school, full rosin (RMA and ROL1) flux that c
Electronics Forum | Tue Jan 02 14:12:23 EST 2001 | Dave Miller
I work for an R&D company that is starting to do some prototype and limited production circuit cards. We are deciding how we want to build these boards, and we are wondering what we should do about flux and cleaning. We have circuits that run at 15
Electronics Forum | Tue Sep 21 13:10:10 EDT 1999 | Dave F
| Dear All, | | In order to understand the soldering technologies in SMT, I'd like to understand why some cards are soldered and then cleaned, or only soldered whitout water cleaning nor "ultra sound" wavelength. | | I mean that I wonder why we use
Electronics Forum | Wed Sep 22 02:45:23 EDT 1999 | Brian
| | Dear All, | | | | In order to understand the soldering technologies in SMT, I'd like to understand why some cards are soldered and then cleaned, or only soldered whitout water cleaning nor "ultra sound" wavelength. | | | | I mean that I wonder
Electronics Forum | Wed Jul 21 17:49:52 EDT 2004 | jsk
problem: Too many solvents and boards are not clean Flux remains on the board after vapor degreaser and "Powdery" white residue after vapor degreasing Flux type is kester 186 Process: hand solder High Temp alloy, spot clean after hand solder e
Electronics Forum | Thu Apr 05 12:25:01 EDT 2001 | davef
Talk about bucking the trend!!! OK, OK, I know some US military work still requires RMA. You�re both correct. Cleaning decisions for RMA fluxed boards are based on customers requirements. [Some do (clean) and some don�t.] Older US military speci
Electronics Forum | Fri Jul 23 14:41:41 EDT 2004 | Steve Stach
Dear JSK, It sounds like the root causes of your problem are two fold. First, excessive heat will polymerize the abietic acid found in rosin forming neo-abietic diamers and polymers which are much less soluble than the parent monomer. There are
