Jeff

The HFCs from DuPont and HFEs from 3M are both much milder than even
CFC-113. They are both very expensive and their vapours have a high
global warming potential. For these two reasons, they should be used
only in relatively expensive zero-emission machines. There are a number
of blends available, mostly azeotropic, with better cleaning power than
the pure solvents, but still less powerful than, for example, Freon TMS
which many considered as the only CFC-113 blend any good at defluxing.
The stronger blends contain trans-1,2-dichloroethylene (TDCE) which is a
chlorinated solvent whose tox data is not entirely clear. It may also be
incompatible with some plastics. In fact, 3M are just marketing a new
blend with a high percentage of TDCE, which should be cheaper and better
for degreasing, but I frankly can't see the advantage of the small
quantity of HFE in it!

I would seriously suggest that, if you wish to try these solvents, you
may find them better with a good old-fashioned RA wire, rather than a
"no-clean".

Hope this helps

Brian

Jeff Meier wrote:
>
> We currently do most of our soldering using water soluble flux that we
> wash off in an in-line wash system.  We occasionally have to hand solder
> parts that are considered not water washable so we use no clean flux
> that leaves a flux residue on the board.  Our customers are requiring no
> flux residue to be left on the boards.  We currently try to remove
> residue by scrubbing and cleaning by hand which is very labor intensive
> and probably does not totally remove residue.  I am looking for
> alternate cleaning method suggestions that have been successful that you
> have used.  Has anyone had much luck with the HFE solvents that are
> freon alternatives and how difficult were they to implement use of.
> Thanks,
> Jeff Meier
>
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