I've taken electrostatic field readings after blowing dry nitrogen on various board substrates, at various pressures and under different conditions of relative humidity, and never found any appreciable charging. Because de-ionizing nozzles are available, our customers seem to raise this issue with some frequency. What I've found useful is to document my findings in a project memo that I can pull out and display when challenged. By the way, I don't think that grounding the nozzle has any appreciable effect. If the wire running down the hose is a nuisance, try disconnecting it when you take the readings with your electrostatic field meter. > ---------- > From: [log in to unmask][SMTP:[log in to unmask]] > Reply To: TechNet E-Mail Forum.;[log in to unmask] > Sent: Monday, August 28, 2000 10:41 AM > To: [log in to unmask] > Subject: [TN] Another ESD question > > How do you folks feel about using compressed nitrogen to dry printed > circuit > boards? One of our customers will not allow aqueous cleaning of their > hardware. > As a result we clean all of their hardware in alcohol and dry by blowing > it off > with compressed nitrogen with the regulator at about 100 PSI. The nozzle > is > grounded at the tip. Please note that this is not related to my earlier > quetion > as this is done in a different area and only used on our space flight > hardware. > Thanks again, > Charles Caswell > > ############################################################## > 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 ##############################################################