Steve,
In the past I have added dye to fluxes for specific, non-production visual
tests. But if you are going to do this for production, then you are going
to have to requalify the flux via SIR and electromigration. Many dyes have
some very interesting side groups on them, like amine groups. In fact many
families of organic dyes are conjugated systems (alternating single and
double bonds between the carbon atoms in the backbone of the molecule),
making them susceptible to further reaction. I have no idea what they might
do under high humidity conditions or during reflow/wave soldering. I'm not
a dye chemist. Also, even if they survive and do not cause corrosion the
flux residues might be highly colored and thus interfere with visual
inspection. Sorry to rain on your parade.
Bev Christian
Research in Motion
-----Original Message-----
From: Stephen R. Gregory [mailto:[log in to unmask]]
Sent: March 16, 2001 12:10 PM
To: [log in to unmask]
Subject: [TN] Flux dye...
Hi ya'll!
We use three different flux types in our processes here. No-clean (for hand
soldering items that can't be cleaned...unsealed switches, etc.) RMA
(because
some of our customers require it), and OA (for everything else...).
We seem to occasionally have a problem with our operators picking up the
wrong bottle of flux thinking it is no-clean, but it is OA...and yes, the
bottles are labeled, but it still happens...
Is there some sort of dye that could be put into the flux that wouldn't hurt
the chemistry of the flux, would wash off completely, and not turn other
things colored? I'm thinking that if there's a really different color to OA
flux, it would lessen the chance picking-up the wrong bottle, and you can
easily tell when OA's haven't been cleaned from the board.
Just trying to make things "monkey-proof" if ya' know what I mean...hehehe.
-Steve Gregory-
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