That's a week answer. The real answer will cost me another royalty donation to the Doug Paul's Defense Fund for Battered Chickens, but it depends. The range of time could be from ASAP (a maximum one hour) to eternity (meaning never). Some of the things to consider are as follows: * Laminate * Final surface finish * Solder Mask * Spacing * Component orientation * Assembly surface topography * Material compatibilities * Cleaning chemistries * Solvency capabilities * Flux chemistries * Cleaning process residuals and their chemical make-up * Thermal excursion exposures during processing * Cleanliness requirements * Conformal coating or not * Testing requirements * End use environment * Warranty issues * Cost Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Linda Langley Sent: Tuesday, October 23, 2007 11:40 AM To: [log in to unmask] Subject: [TN] cleaning concerns Can anyone tell me or direct me to documentation that specify how long flux residue from WS609 63/37 can be left on a board before washing? I was informed that it could be left on for 7 days . Linda Langley Jabil Circuit Training Specialist (248) 292-6176 CONFIDENTIALITY NOTICE: The information contained in this electronic communication, including any attachments, is confidential information, is intended only for the use of the recipients named above, and may be legally privileged. If the reader of this message is not an intended recipient, you are hereby notified that any review, use, dissemination, distribution or copying of this communication, or any of its contents, is strictly prohibited. If you have received this communication in error, please notify us immediately of the error by return e-mail and please permanently remove the original message and any copy of it from your system. Nothing herein is intended to constitute an electronic signature or consent. Thank you --------------------------------------------------- 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 -----------------------------------------------------