Hi, Matt, The commonly used coatings are either Acrylics, like Humiseal 1B31 which we use, Urethanes or Epoxies. All three have the same good resistance to moisture and salt fog, but the difference between them is that Acrylics are not very chemical resistant (which makes them great for rework), Urethanes are more difficult to rework and need much more sggressive stripping agents to remove them, and Epoxies are darned near impossible to shift. I remember the days of PC54, which was the common coating for military PCBA's up til the early 80's, and repairing boards nicely was a major pain. If it's purely Humidity and Salt Fog you're up against, use an acrylic conformal coating. It's easily applied by brushing, dipping or spraying. Peter "Gray, Matthew D HS-SNS" <[log in to unmask]> 22/05/2003 09:54 PM Sent by: TechNet <[log in to unmask]> Please respond to "TechNet E-Mail Forum."; Please respond to "Gray, Matthew D HS-SNS" To: [log in to unmask] cc: (bcc: DUNCAN Peter/Asst Prin Engr/ST Aero/ST Group) Subject: [TN] Conformal Coating Application Method for BGA Hello - I am requesting feedback to material and processes that have provided environmental performance protection for BGAs and other large array packages. The performance environment of consideration is corrosion and humidity. Can users provide particular details regarding application process spray (inclusion of steps used for flood/fill/etc), dip, other, and material that has provided a high amount of coverage and ability to protect electrical connections and components in humidity and salt fog environments. Ideally, these materials are below the parylene step. All feedback is appreciated. Regards - Matt --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- [This e-mail is confidential and may also be privileged. If you are not the intended recipient, please delete it and notify us immediately; you should not copy or use it for any purpose, nor disclose its contents to any other person. Thank you.] --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------