Send a panel to someone like CSL (Hi Doug) to find out what the contamination actually is, and if the rosin was removed without removing the activators. The residue could be detergents/antifoaming agents/saponifiers...from thier cleaner that dragged into the last rinse or weren't rinsed off. The supplier's DI bed could have died. Technet could probably fill volumes on other sources. The bottom line is, find out what the "contamination" is, and then there is a solution to the problem. P.S. if the panels are properly specified, the supplier should pay for any testing, including replacing panels sent out for testing. ------------- Original Text From: C=US/A=INTERNET/DDA=ID/TechNet(a)IPC.ORG, on 5/20/98 10:26 PM: Hello Technet, A supplier made us some board-assemblies with a ionic contamination at least twice as high as the IPC and MIL-specifications allow. This is probably due to residues from RMA solder paste. The boards are washed after wave soldering with water/detergent, but there is no intermediate cleaning after the reflow soldering. It takes a couple of days before the reflow soldered boards are wave soldered, so the paste-flux is not very cleanable anymore.I've heard so often that bad cleaning of RMA is much worse than good cleaning or no cleaning. I'm not sure, but this is what I think is the cause of the problem.. The question : will this ionic contamination, concentrated around the topside-smd's, really result in early failures ? The boards are built in hermetically sealed boxes, but will be used in a wide variety of temperatures. There are no fine-pitch devices on the boards. Any advice or comments are welcome. Andy ################################################################ 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 web site (http://jefry.ipc.org/forum.htm) 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 web site (http://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################