Hi Joe! This topic has come up before, and there has been inputs from Brian Ellis, and Doug Pauls on this issue...if I remember correctly, it's not a good idea. If I'm wrong, please correct me. Thinking about the big picture, I have my own thoughts. Once an assembly is coated, you have effectively sealed everything that's on the board in beneath the coating. If the bare board came in absolutely clean, and everybody wore gloves when handling the fabs so as to not contaminate the board with skin salts, all the flux was activated from reflow or wave, and no touch-up was done on the assembly...then maybe, just maybe, I might say it's okay. If an assembly needs coating because of the environment it will be in, I just think it's best to clean it as well as possible to remove everything and then coat it. I may be paranoid, but that's just me... -Steve Gregory- Fellow Techeads, It has been suggested by one of our CMs that it is acceptable to conformal coat (type AR) over no clean flux residue. Would anyone like to share their opinions or experience on this subject. Conformal coating over residue does not sound like the correct thing to do. thanks joe --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------