Here we go again! This thread nevers dies, it just comes back every 3-6
months!
Go to your local hardware, paint store, builder's supply, drug store,
whatever. Get some plain old denatured alcohol (sometimes called Laquer
Thinner). Scrub your PC boards with a toothbrush, and the denatured
alcohol. No not the one you use on your teeth as Chuck says. :-)
A polyethylene squeeze bottle with a squirt tube is what I use. Use a
small stream of clean alcohol from time to time as you clean the board,
always spraying from the top of the board and rinsing the dirty alcohol
and flux toward the bottom.
There will be a little bit of dry residue left behind sometimes. If so,
and you want to get rid of it, use some Formula 409, Fantastik, or
similar household cleaner and SPARINGLY spray it onto the foil side only.
Scrub again with the toothbrush for a few moments. Rinse with clean
water, de-ionized is best if you have access to it, but clean, soft water
will do. If there are potentiometers or trimmer caps, etc. on the
componet side, try to not get any cleaner or water in them, but if you
do, it isn't the end of the world.
If the PC board has a lot of unused holes and "vias" on it, holding the
board nearly vertical as you clean it will help prevent the alcohol,
cleaner, and water from draining through the holes to the other side.
I always hold the PC board at a slight angle from vertical, with any
components that shouldn't get water in them facing upward to prevent any
excess flux residue and cleaner / water from draining into them. After
you rinse the board, shake off the excess water. If you have a compressed
air supply, use 20psi or less and blow the remaining water off of the
board, starting from one side and working across the PC board to the
other side. Also apply the compressed air to the component side, but be
careful if there are any delicate components.
Allow the PC board to completely dry a few minutes before applying power
to it. I usually set mine outside for a few minutes in the sun if the
weather is dry, as it almost always is in Arizona. Lacking a dry climate,
you could place the PC board in front of the refrigerator if you have one
that blows warm air out the bottom. A small fan would also encourage
accelerated drying.
The result is a sparkling clean PC board, free of all residues and
contaminants.
--------------------------------------------------------------------------------------------------------------------
BTW, when I worked at Harris Semiconductor, we were looking for a way to
clean some burned on flux residue from old burn-in boards that had been
through the burn-in ovens many hours. We wanted to modify them and re-use
them for another device. After trying everything, including a mega-buck
freon-vapor cleaning chamber, I found nothing worked better than
Fantastik household cleaner and de-ionized water.
After soaking in the Fantastik, some scrubbing and the DI water rinse
made them so clean everybody asked what I used. "Why, just the Fantastik
cleaner that was sitting on the lab tables that we use to clean up after
lab work" I replied. Everybody just shook their heads and grinned. ;-)
The Fantastik must be very slightly caustic, so use care and keep it off
your fingers if you don't want sore fingers. I use Formula 409 now, and
it seems to be a little gentler on your fingers. You gotta keep them
fingers healthy so you can wind toroids, you know! ;-)
I have used Ersin 63/37 Multicore solder, and prefer it the most. But I
haven't been able to get any lately, so I've been using the 62/36/2 %
tin/lead/silver alloy R/S sells, pn. 64-013. It is very nice but a little
pricey in such a small roll. Gotta check the catalogs for some more Ersin
Multicore if they still carry it.
Don't fret about using a little cleaner and water on your PC boards. I've
never had any problems. Just let them dry properly. If there are any
devices you don't want to get wet, leave them off until you clean the
boards and then install them. Then there will only be a few connections
to clean with cotton swabs and denatured alcohol.
72,
Gary Surrency AB7MY
S&S TAC-1(40&80m) and ARK30, OHR100 20m, AT-11 (QRO and QRP)
QRP-L #571 Chandler, AZ (near Phoenix)Grid Square DM43BH
Az ScQRPions
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