I'm sure you will get a lot of input from the experts (Iconic Contamination) on this subject and there are varying views on the validity of the established cleanliness values, but it's all a wash. Cleanliness, like luck is the residue of design. Your job is to decide whether the values/requirements are adequate/acceptable given the design/performance parameters you are dealing with. IPC-5702 has just been released. It will give you some insight on acceptance criteria for unpopulated Printed Boards. You can build on that to establish adequate pass/fail criteria for final assembly requirements. Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Chafin, Ken G. Sent: Monday, October 01, 2007 12:47 PM To: [log in to unmask] Subject: [TN] Ionic Cleanliness Does any IPC Standard recommend a minimal level of PC Board, or PC Assembly ionic cleanliness in terms of material per square unit of board or assembly area? E.g. 0.2 micrograms of sodium chloride equivalent per square centimeter. In IPC-A-600D, section 19.1 a solvent resistively value for an IPC-TM-650 test is given (greater than 2 X 10 to power 6 ohm per centimeter is recommended). Even if an appropriate response to this question is complex can the question itself be answered yes or no? Thanks for any guidance. Kenneth Chafin --------------------------------------------------- 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 -----------------------------------------------------