Steve My only addition to the mix is for you to detemine where the "ferns" are located. Under the solder mask or on top of the mask. This will tell you what process is most likely responsible for the problem. Of course if you have a crack in the mask - you could subsequently contaminate under the mask too A little detective work is needed Susan Mansilla Robisan Lab ############################################################## 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 Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################