Many years ago in another life, this was a question that came up
fairly frequently, usually in the context of inspection fluxes,
measuring repair rates and so on. In the middle of much lab research
and customer surveys the following emerged. (From customers)
permanent blue black ink (the sort that goes in fountain pens)
coloured flux red, and disappeared on soldering. At the time I
understood the chemistry of this which was quite simple/elegant, but I
can't remember it now.
Food dyes were effective and dissipated on soldering, some were
bleached by the cold flux, so a trial and error approach was needed.
Food grade dyes are alcohol based/soluble and by definition safe to
personnel, also pure.
As either method was infinitely cheaper than anything we could come up
with, we gave up the lab approach. Of course things have moved on
since then, but might be worth revisiting if you can't go the simple
route and colour code bottles /labels.
Mike
----- Original Message -----
From: "Stephen R. Gregory" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, March 16, 2001 5:09 PM
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-
>
> --------------------------------------------------------------------
-------------
> Technet Mail List provided as a free service by IPC using LISTSERV
1.8d
> To unsubscribe, send a message to [log in to unmask] with following
text in
> the BODY (NOT the subject field): SIGNOFF Technet
> To temporarily halt delivery of Technet send the following message:
SET Technet NOMAIL
> Search previous postings at: www.ipc.org > On-Line Resources &
Databases > E-mail Archives
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
> information, or contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
> --------------------------------------------------------------------
-------------
>
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
|
