Hi Wayne, Not that often, but once in a while I have a customer with a similar problem. In cases like that we mechanically remove the component(s) of interest (so, no additional heat would be applied) and then run FTIR and SEM/EDS tests on the residue. Guessing is good, but data - much better :-) Regards, Vladimir SENTEC SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca -----Original Message----- From: Steve Gregory <[log in to unmask]> Date: Wed, 27 May 2009 06:59:42 To: <[log in to unmask]> Subject: Re: [TN] humidity test failure Good Morning! Half the week down already. That's another nice thing about 3-day weekends; you also get a 4-day work week either prior to, or after the weekend. I have Wayne's picture posted now. It's at: http://stevezeva.homestead.com/files/C23_Humidity_failure.JPG Definitely some kinda' junk there! Steve -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Thayer, Wayne Sent: Tuesday, May 26, 2009 9:01 PM To: [log in to unmask] Subject: [TN] humidity test failure Hi Technet Gurus! I have attached a picture of a part responsible for excess current draw during an extended humidity/temperature cycling test. (I copied Steve so he can hopefully post!) The board was carefully solvent cleaned, but no SIR test validating the process strips all ionic contamination. The board is in an enclosure where plenty of ionic contaminants are available. Humidity was supposed to not exceed 90% and was to be non-condensing during cycling. There were a handful of components which displayed similar deposits on the same circuit board. These were the only parts biased during the humidity test. I believe the evidence suggests at least some condensation occurred. To me the deposits look like salts. But what do "the experts" think? Is there any rule of thumb as to humidity levels where we are nuts to try to survive without conformal coating? Part of the adjacent circuitry contains RF devices and those guys get panic-stricken when told we probably need to conformal coat! Wayne Thayer This e-mail and any files transmitted with it may be proprietary and are intended solely for the use of the individual or entity to whom they are addressed. If you have received this e-mail in error please notify the sender. Please note that any views or opinions presented in this e-mail are solely those of the author and do not necessarily represent those of ITT Corporation. The recipient should check this e-mail and any attachments for the presence of viruses. ITT accepts no liability for any damage caused by any virus transmitted by this e-mail. --------------------------------------------------- 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 -----------------------------------------------------