Please advice, Did anybody experienced sputtering solder effect? When the PCB passes though the wave soldering machine, we observe solder splatters though the multiple vias in the board. This splatter causes solder shorts on the top side of the PCB. I guess ,we may have some moisture trapped in the vias, and as it passes through the solder wave turns to steam causing the sputter. Our PCB design allows solder mask over the vias. Because the mask is applied wet, is fairly viscous, and the holes are small, most of the vias are plugged with mask. We may be having two issues: 1) Because not all of the holes can be plugged reliably, some of them are left partially open. Because of the partial part, the inside of the hole can be quite rough allowing moisture to collect. Of course each hole will be closed to a different amount. 2) Since the solder mask is polymerized with light, the areas that are to be covered with mask (like the vias in this case) need to be exposed so that it doesn't develop off. Because of the thickness of the solder mask in the hole, all of the mask may not be polymerized inside of the hole, which may not be allowing it to fully cure. What would you advice from the deign standpoint? Any recommendations? Sincerely, Stella Neyman ############################################################## 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 ##############################################################