There is a significant difference between humidity exposure and water exposure. If high humidity then the issue is corrosion of the connector materials and you should be concerned with galvanic potential of the metals in the connector. If it is water exposure, then the entire connector should be sealed wherever the water can touch. In vehicles we see water wicking through the wires from connectors which are not sealed into connectors which are sealed all too often. Best Regards, eric -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Carl VanWormer Sent: Monday, August 23, 2010 1:53 PM To: [log in to unmask] Subject: [TN] humid environments and long term reliability We are considering conformal coating our boards that will go into a chassis that may be an occasional high humidity environment. I have been told that the humidity (and water) is "slowed down" by the conformal coating, and that good cleaning before the conformal coating is essential for reliability. Assuming we have done all we can do for the PC board assembly, my worry goes to the next level; the cables that connect between boards and also to the valves, relays, and sensors. Is it worth considering messing up the system with silicone grease smeared on all of the 2-pin, 5-pin, and 50 pin (IDC) plugs and sockets? I know some of the cute little phone-wire crimp-on IDC button connectors are filled with a dielectric grease, so it must have some value. And what about the IDC connector, with its pins just piercing the ribbon cable . . . Is there a long term reliability problem there, too? I'm looking for "fatherly guidance" on making a system that won't ever need a field service call. Thanks for tolerating my paranoia, Carl Carl Van Wormer, P.E., AE7GD Senior Hardware Engineer Cipher Systems 1800 NW 169th Place, Suite B-100 Beaverton, OR 97006 Cipher Systems (503) 617-7447 x 5163 Direct Line (503) 425-5163 [log in to unmask] This message may contain confidential and/or proprietary information, and is intended for the person/entity to whom it was originally addressed. Any use by others is strictly prohibited. If I sent this to you by mistake, please be nice and delete it, then tell me of my mistake so I can send it to the right person. ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- 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 ----------------------------------------------------- ********************** ** LEGAL DISCLAIMER ** ********************** This E-mail message and any attachments may contain legally privileged, confidential or proprietary information. If you are not the intended recipient(s), or the employee or agent responsible for delivery of this message to the intended recipient(s), you are hereby notified that any dissemination, distribution or copying of this E-mail message is strictly prohibited. If you have received this message in error, please immediately notify the sender and delete this E-mail message from your computer. ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- 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 -----------------------------------------------------