We conformally coat over no-clean without any problems. At previous employers, I evaluated coating and no-clean flux compatability. The biggest variable for coating performance was no-clean flux residue. Most coatings and flux (but not all) combinations are compatable, provided that no-clean deposition is below a certain level. Above that level, all coatings have cosmetic problems. The specific level is flux specific and can still pass IPC standards for SIR and ROSE testing. Once I even traced a coating adhesion problem to a supplier's HASL flux residues. The process can work with adequate process control if you do your homework first. Aric Parr Sr. Process Engineer Eaton Corporation 1400 S. Livernois PO Box 5020 Rochester Hills, MI 48308-5020 248 608 7780 [log in to unmask] ---------- Original Text ---------- From: C=US/A=INTERNET/DDA=ID/TechNet(a)IPC.ORG, on 7/21/99 12:08 PM: Hi, My company is currently running a no-clean PCB assembly process, and we have started conformally coating one of our PCB assemblies, without cleaning. The decision not to coat was based on a ROSE measurement on our existing process and the fact that other companies were not cleaning. I would be interested to hear from anyone else that conformally coats without cleaning and why that decision was made. I would especially like to understand what the differences are between non-ionic and ionic contamination and the effects each can have on a PCB in certain climates. Thanks for any replies Ben Hammond ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################