We use silicone conformal coatings for some of our products. The most common applications for the silicones is when you have liquid water running across the assembly. Applications like our weather radar, which is in the nose cone of the plane and it rains inside the nose cone as you come down from the cold. Other places it has been used when the assembly is likely to sit in liquid water, such as the bottom side of a motherboard. Against liquid water, it is superior. Against water vapor, not so much. They also have a tendency to be very porous to sulfur compounds, which is very important if you are using any silver. Like any other material, it has its positives and negatives and you have to weigh them with respect to the design life of the product, the end use environment, and the consequences of failure. Dow Corning has a good knowledge base on its web site (www.dowcorning.com) that I often use. What is your end use application? Doug Pauls Rockwell Collins Jean-François Bissonnette <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 03/16/2010 10:44 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to Jean-François Bissonnette <[log in to unmask]> To [log in to unmask] cc Subject [TN] Conformal Coatings: Resistance to Humidity and Moisture Hello Technetters, I'm preparing a informative document on conformal coatings so I did some searching around the Net. There seems to be diverging opinions on the pros and cons for Silicone coatings. Some places that they have a good moisture/humidity resistance, some other say that they are not the best for moisture resistance. Anyone with hands on experience can share a bit of knowledge on that matter? Thanks! JF ______________________________________________________________________ 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 ----------------------------------------------------- ______________________________________________________________________ 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 -----------------------------------------------------