First thing to do is run a profile. I would test cross belt temperature uniformity and rise rates. MOST IMPORTANT - get a copy of the recommended reflow profile for the solder paste manufacturer. Ensure you are meeting all specs like rise rate, soak time, time above reflow, etc. Brian Stumm a reflow manufacturer >Hi, > > Need some advice on how to eliminate or reduce the solder on finger >that >we are having right now. So far what we understand is that 90% of the >problem is >due to the reflow process where solder traps in vias causing explosion when >subjected to high temp during reflow. Not sure whether this is the right >assumption but from what we have seen on the reject there are solder balls >all >over the 'exploded' vias. The signature of solder on finger defects is >10-40 >mils of 'dot' which could be caused by solder balls. SO this is my >questions: > >1. Is it possible that the vias can 'explode' during reflow? > >2. Does the ramp from room temp to soaking time(145-160 deg C) and from >soaking >time (160-183 deg C) play an important role in determining the amount of >'explosion'. So far our data shows that it does. > >3. Is there any other possible causes of solder explosion...Solder paste? > > >Thank you and really appreciate the help. > >Masdi Muhammad, >Process Engineer. > >################################################################ >TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. >For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 >################################################################ > > > ETS, LLC - West ETS, Inc. - East 3939 N. Freya St. PO Box 47887 Spokane, WA 99207 Plymouth, MN 55447 509-483-0900 (voice) 612-553-0051 (voice) 509-483-0331 (fax) 612-553-0246 (fax) [log in to unmask] [log in to unmask] Benefit from a direct relationship with the manufacturer! ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################