[Elecraft] defluxing PCB's

[Stuart Rohre]

Defluxing in the commercial production line is usually done with specialized
production vapor phase degreaser equipment, which in former times used Freon
products.  Since the rush to ban the so called ozone depleteors, The Ozone
hole has continued to be present, even though the total freon type gases
have gone very low in quantity.  Since heating solvents and vapor defluxing
are beyond the reach of the home builder,and the vapors of replacement
solvents are more hazardous to both the plastics and the human, I think the
advocate of defluxing in this course was of course thinking of commercial
shops with specialized closed cycle equipment that meets all EPA guidelines,
not the occasional board built at home.

We use a lot of prototype boards at work and test them in equipment used in
corrosive environments, (at sea, in salt air), and do not have any problems
with properly soldered boards that have used low flux residue solders, like
Multicore.

And as someone else mentioned, most of the manufacturers of instrumentation
we use and repair, say to NOT deflux the boards for fear of creating more
problems with the circuits.  I have seen junior technicians create white
residue on a board from improper cleaning.  IN FACT, have had to go over the
board again at high cost, to correct their problems!
73,
Stuart K5KVH