Fulton, Just a quick note: if caught before part placement, we instruct our operators NOT to wipe the boards before cleaning, and this all but eliminated the solder balls. If there are parts on, there is not much choice. We use an alcohol based wash/spray system without ultrasonics (can damage multilayers?) Good Luck. Jeff Hempton United Technologies Electronic Controls ______________________________ Forward Header __________________________________ Subject: [TN] Solder-ball Author: Fulton Feng <[log in to unmask]> at Internet Date: 7/28/98 11:46 AM Hi, TechNetter I am wondering anybody out there ever experienced solder ball with mis-print PCB. The scenario is when we have mis-printed PCB in solder paste printing process, we used to wipe off the paste with alcohol from the PCB surface and send them to aqueous cleaner. What happened is when we looked at the PCB under microscope, we found all the masking edge and vias sticked with solder-balls(Solder paste). The solder paste we used was no-clean water-soluable paste. The questions are: * Is there any difference in between clean and no-clean paste for cleaning PCB? * Has anybody used ultra-sonic cleaner for PCB cleaner? * What kind of cleaning agent are your guy using? * Any different approach to take care of this solder-ball issue? Any input is appreciated! Thanks in advance! Fulton Feng Nortel MPK ################################################################ 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 ################################################################ ################################################################ 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 ################################################################