Try baking the stained board at 300 oF for 60 min immediately after the cleaner as a test, if it gets rid of the stains you may very well be looking at moisture. To prevent it, do look at the solder mask cure, a UV Bump will prevent this but you may also want to look into your temperature going into the washer, keep it low (talk to your SM vendor or board supplier). I just had a similar issue here. Apparently most SM will 'open up' under high temp and absorb some moisture and exhibit 'hazing' or white staining. Denis Dionne Coretec Inc. > -----Original Message----- > From: Barry Gallegos [SMTP:[log in to unmask]] > Sent: Thursday, June 08, 2000 2:14 PM > To: [log in to unmask] > Subject: [TN] Laminate condition > > Dear Sirs, Madams, Guru's. > > I have an assembly that we processed thru SMT and then thru the wave > solder operations. Wave solder flux was with Alpha metals 856 > water-soluble. The assembly is exhibiting a white cloudy / milky > appearance that looks almost as if the laminate/solder mask has changed > color. No matter how much we wash this assembly, it will not go away. > > Is this due to possible moisture in, around or under the solder mask / > laminate. What is it and is it acceptable. > > > Any advice would be appreciated. > > > > Yours truly, (wana-be guru.) > > Barry Gallegos > Western Electronics. > 208-377-1557 > ############################################################## 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 ##############################################################