Jim, I'm assuming that this is a surface mount design with square or
rectangular lands.  The best control over the planarity and thickness
control is achieved by angling the panel as close to 45 deg as possible
through the air knifes.  Also, best results will be achieved with
horizontal equipment.  Pad surface geometry is still the major influence
in determining overall planarity and thickness control.  Having said
this, there is currently a new generation of equipment that provides a
much higher level of control than ever before.

Also, don't confuse the surface tension phenomena with non or
de-wetting. They are very different.  Even though the thin areas of a
HAL'd surface are subject to some accelerated ageing due to a thinner
level of fused SN63, a year or more in normal storage conditions is
routine.  It may be that in this case the copper surface was improperly
prepared, to be sure, go ahead and do a dip test or hand solder a pad
without flux and see if it flows back.  A heavily oxidised surface or an
underlying copper prep problem will reject the flow very clearly.  Yes
rework is possible. I recommend an experienced shop such as Solder
Station One, in Santa Ana, CA (714) 558-1019.  They can at least help in
your evaluation.

Mark Simmons, V-Score Central

##############################################################
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.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
##############################################################