Got any pictures?

----- Original Message -----
From: "Richard MacCutcheon" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, August 22, 2000 3:09 PM
Subject: [TN] White powdery board residue


We have bare Polyimide multilayer boards using Arlon 35N.  We have been
seeing a light powdery residue on the barrels and surfaces of the PTHs and
on the substrate and soldermask.  Under high magnification they appear to be
crystalline structures.  Cylindrical crystals in clumps.  Solvent cleaning,
Axarel, Ethanol, Alcohol, all seem to partially dissolve them and then leave
behind a film on the surface.  The film becomes insoluble.  The Undissolved
crystals do not come off with any solvents and must be abraded from the
surface.
A water and soap wash removed quite a bit of these crystals on a fresh
board, but again any unremoved material was insoluble and needed abrasion.
Boards were from two different suppliers, one had a 45-99 date code another
had a 32-00.
Who can identify this material?
Is this some byproduct of poor HASL flux cleaning?

Thanks for the input,
Richard MacCutcheon

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following
text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - 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 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################