Barbara, Your choice of coating depends on the desired protection level for the expected environment, and how much your customer is willing to invest. In the case of paralene / paraxylene (XY), the investment is significant. XY is one of the coatings flown in space when we need ultimate protection. Properly coated boards can be immersed in seawater without any problems. XY is resistant to radiation degradation and atomic oxygen attack, and provides the ultimate in environmental and foreign-object-debris (FOD) protection. XY has high material and application costs, with extremely low quantity production rates. It is extremely difficult to remove, resulting in the coated assembly being considered non-repairable (it can be done, but it's painful). We also fly silicone (SR) and urethane (UR) coatings, which can easily be applied by spray, brush, or dip process. Both of these coatings are user friendly, with relatively inexpensive material and application costs, offering good production rates, environmental, and FOD resistance. Both are considered removable and repairable. In a previous life, I worked for a manufacturer that sprayed boards with clear acrylic (AR) purchased from the local home supply store (brand name starts with the letter "K"). Worked great, inexpensive, and some of the environments the finished products were exposed to would be considered worse than what we see in some of our space applications. AR is fairly easy to remove and repair, but glass diodes and other sensitive components may need resilient protection. You're more than welcome to contact me off-line if you wish. Regards, Robert Wm. Cooke Technical Expert, Special Processes Advanced Programs and Analysis Division NASA / Johnson Space Center 2101 Nasa Parkway, M/S NX23/WGI Houston, TX., USA 77058-3607 Tel.: 281.244.1903 E-mail: [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Barbara Burcham Sent: Monday, May 16, 2005 4:56 PM To: [log in to unmask] Subject: [TN] Conformal Coating of Assembled Boards Well, my company now has an application requiring conformal coating on some small assembled boards. We need to mask off 3 connectors and coat everything else. I have some information on a product called Parylene applied by Parylene Coating Services, Inc. in Katy, Texas. We did a small lot with a simple spray-on process, but that is not the way to do production runs, of course. What would you recommend? Thanks, Barbara Barbara J. Burcham, C.I.D. Fairfield Industries, Inc 281-275-7687 [log in to unmask] --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 1.8e 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 -----------------------------------------------------