Hi Dave! There are a couple of topics of investigation to chase which may
help determine the source of the tarlike material. First investigate the
possibility that the flux is undergoing a long term degradation which
results in the contamination. Clean out on of the wave fluxers completely,
put in new flux and monitor the heck out of it. If no contamination appears
for a week then add some of the "old" flux you removed from the system back
in to see if it causes the contamination to reappear. A second possibility
is that the flux vendor sent you a bad batch of flux which has contaminated
the system. Again, cleaning out the system is the solution mode. Good Luck.

And if Doug Paul's suggests that the contamination is Diet Coke just ignore
him!

Dave Hillman
Rockwell Collins
[log in to unmask]




Dave Pahlas <[log in to unmask]>@ipc.org> on 09/13/2002 09:02:47 AM

Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond
       to Dave Pahlas <[log in to unmask]>

Sent by:    TechNet <[log in to unmask]>


To:    [log in to unmask]
cc:

Subject:    [TN] Black Tar in Wavesolder


Technetters,

We are currently experiencing an issue with a black tar-like substance
accumulating in our solder pot. Samples of the substance were sent to the
manufacturer of the OA flux that we are using and they confirmed through
FTIR testing that it was thermally cycled flux. The buildup is seen on
machines using spray fluxers, but is much more prevalent on the machine
using a wave fluxer due to the added volume of flux being applied. We had
been using the flux for a little over four months with no issues, then the
substance started showing up even though there had been no process change
that we are aware of. At first I thought that it may have been a result of
some spilled Dew, but quickly ruled this out since I already know that Dew
burns off very quickly in the wave with no lasting residue.

The supplier claims that no changes have been made to their chemistry but I
am wondering if anyone else has seen this lately.

The substance accumulates in the machine around the chip nozzle, contour
nozzle, nitrogen diffuser rods, etc. resulting in the need for time
consuming 3-4 hour cleanings every two to three shifts.

Thanks in advance,
Dave

---------------------------------------------------------------------------------

Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
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 or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/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 1.8e
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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/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
---------------------------------------------------------------------------------