Kathy, Is the white residue in the coating or on the assemblies surface? It's probably moisture related as has been discussed recently. Do you dry the assemblies prior to coating? Hans ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Hans M. Hinners Process Engineer Toppan Electronics, Inc. 770 Miramar Road San Diego, CA 92126 (858) 695 - 2222 ext. 241 (858) 695 - 6823 fax [log in to unmask] -----Original Message----- From: Kathy Kuhlow [mailto:[log in to unmask]] Sent: Wednesday, July 18, 2001 10:24 AM To: [log in to unmask] Subject: [TN] White residue from conformal coating What causes white residues after conformal coating? The coating is an acrylic and after the first coat there appears to be a white residue and after the 24 hour cure the coating appears very dull and still has some of the white residues. The residues almost look like water flux residue but it isn't. The supplier that the coating was purchased from says it is strictly humidity related and only a cosmetic issue. There is no visible loss of adhesion. The solder mask is a LPI matte finish. Can this be part of the problem? --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------