[Elecraft] Deflux?

[John, KI6WX]

I was involved in a multi-million dollar product recall that was caused by a
low level contaminant in the flux cleaning process of some boards we had
manufactured.  The problem was intermittent and very difficult to track
down.  It eventually required hand cleaning of the failing boards.

Denatured alcohol sold in hardware stores is designed for uses such as
dissolving shellac.  It is not manufactured to the same purity as the
material used in cleaning electronics, and may contain contaminants that are
detrimental to electronic circuits.  The rubbing alcohol sold in drugstores
not only contains water, but often has fragrances added to it (at least your
boards will smell nice).

Rule #1: Don't clean the flux off of your boards.  Elecraft radios are not
likely to be used in an environment in which the flux would cause circuit
problems.  If you do need to remove the flux, follow Rule #2.

Rule #2: Follow the recommendations of the electronics industry, which has
spent millions of dollars investigating the alternatives.  The standard for
hand cleaning boards in the electronics industry is Anhydrous Isopropyl
Alcohol, which is specifically manufactured to meet the purity standards of
the industry.  Use a cotton tipped swab to wipe the section of the board
which you wish to clean.

If you choose to use alternative cleaning agents, they will probably work
most of the time.  However, when they fail, you may have a radio that
intermittently hiccups and you will have a very difficult time figuring out
why.

-John
 KI6WX


From: "Don Brown" <DolfinDon@msn.com>

Hi

Yes you are correct about the stuff you buy at the drug store. The other 30%
is water and it will not clean the board very well. When I worked at a PC
board assembly house years ago we used Freon TF to clean boards it was a
blend of Freon and 99% isopropyl alcohol. When Freon was outlawed various
forms of alcohol took its place. The 99% isopropyl may be hard to find but
denatured alcohol is in every hardware store. It is pure grain alcohol (etha
nol) with a small amount of wood alcohol (methanol) added to make it
poisonous so you can't drink it. It will work as well as the isopropyl and
will not cause any problems. The white residue I was talking about is the
dissolved flux drying on the board not additives in the alcohol.

Don Brown
KD5NDB