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
Electronics Forum | Mon Feb 02 18:05:20 EST 2009 | stepheniii
What flux are you using? We use a low-solids No-Clean water-based flux. Maybe some of what you are seeing is not residue from the flux but is from reaction with the solder mask.
Electronics Forum | Tue Feb 03 13:53:41 EST 2009 | allwave
The spec for all PCB suppliers is "solder mask over bare copper using LPI on external layers (green)". The flux we use is No clean 270WR flux (AIM). As far as process parameters, like I mentioned before, same parameters for several suppliers, only on
Electronics Forum | Mon Feb 02 11:57:39 EST 2009 | allwave
Hello everybody, We are running a product through wave solder process using three different PCB suppliers. I have noticed that you can see more flux residues (water-based, No-clean flux) on one supplier than on the other two. All three PCBs run unde
Electronics Forum | Mon Feb 02 16:49:05 EST 2009 | davef
Questions are: * What are the soldermasks used by your three board suppliers? * What tests have you run to assess the compatibility between these three soldermasks and your flux?
Electronics Forum | Tue Feb 03 15:23:21 EST 2009 | gregoryyork
Hi George This is down to the different cure temperatures used during PCB process. No problem with the flux or your settings You should be seeing a waxy greasy oil like substance on the dirtier board. Or the resist has absorbed the flux residues not
Electronics Forum | Wed Feb 04 16:33:40 EST 2009 | davef
Your specification for all PCB suppliers of 'solder mask over bare copper using LPI on external layers (green)' is broad and open to the use of material from many possible LPI suppliers by your board fabricator. In at least one case, it appears that
Electronics Forum | Tue Feb 03 03:57:37 EST 2009 | sachu_70
Hi George, I would suggest you to re-look your process parameters, especially for the pre-heat temperatures and the amount of flux deposited. The mask properties and that of your flux also play a role, but you could zero down to the root cause after
Electronics Forum | Mon Jul 26 16:31:02 EDT 2004 | Sue PH
We use Kester 186 flux and the STU people would sometimes find white residue after cleaning with Isopropyl at the solder station. We have Lenium (Petroferm)in our vapor degreasers, and now they use Lenium at their stations as well as final clean, an
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
