Hi Phil, I agree with the other comments made so far. Also if the "no-clean" flux does not see a correct profile (set temperature for at least a certain time) it can behave differently than if it has been processed correctly. I have also seen more problems with "no-clean" that has been cleaned than a clean only flux. This is why products that our customers require cleaning we have chosen to use water soluble flux. Regards, Jerry Dengler Production Manager Pergamon Corporation -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Nutting Sent: Thursday, October 04, 2007 11:55 AM To: [log in to unmask] Subject: [TN] operational sweet spot for no-clean flux Hello Techsperts, Is there a range in which no-clean is best NOT used? For example, very low current circuits or high voltages greater than 110 up to 25 kV? Our primary problem seems to be with SMT boards and from more than one vendor. I know a lot of companies use no-clean, but for those who insist on washing boards even those with no-clean flux, what is the reasoning? Simply esthetics or an actual circuit related requirement? I'm trying to determine if all our boards must be washed or if there are any that would be a don't care. Thanks in advance, Phil --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------