Carl/ALCON:
- Regarding cleaning with pressurized shop air.  Lost in antiquity is a study
done by the Navy several years ago that addressed the use of shop air for
cleaning/drying pwa's.  Seems to me that we concluded that the use of shop
air was non-damaging as long as pressure was no greater than 40 psi.
Although there was some concern about ESD generation, no ESD charges were
found to be developed.  Note however that the pressurized air was used to
remove solvent (IPA/DI) after pwa's were cleaned.  Needless to say, the
propensity to develop static charges via triboelectric generation was nil
with that much fluid in the areas being subjected to the pressurized air.
- In today's world of smaller components and smaller (SMT) solder connection
geometry's I would lower the air pressure to 30 psi or less, assure that the
air is mechanically filtered (entrained particulate matter increases the
build up of ESD charges) and, if ESD were a major consideration (i.e. if
parts with threshold sensitivities of less than 100 volts are present) I
would look into getting and using an ionized air nozzle.
- Hope the above information is helpful.  Regards, Jim Moffitt, Technical
Director, Electronics Training Advantage

##############################################################
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
##############################################################