Our epoxy vendors have given two reasons for not using silver filled adhesives with tin lead solder: 1. The conductive epoxy adhesion to solder is poor. 2. The curing process may result in an oxide formation on the solder surface, resulting in increased contact resistance. This may not be evident at first, but can increase over time. The epoxy is not hermetic, and oxygen can migrate to the interface, resulting in latent failures. For components, a silver-palladium or gold end termination is recommended. For substrates gold over nickel should work well. Dave Anderson Medtronic, Inc. "Opinions may or may not reflect those of my employer" >>> <[log in to unmask]> 06/09/98 04:34am >>> Salve TechNet. What happens when you try to use silverepoxy on Sn60/Pb40? Especially if the electrolytically applied solder is greenish because of surface acting brightners (nanometers or less). Adhesives on solders are not recommended, but why? What happens chemically in the interface that can give you a weak bond or no bond at all? Will the epoxy's curing media be defect by som interference with the solder? Or will the epoxy start oxydizing of the Lead? Or something with the surface energies? Or what....? / Ingemar @ Ericsson Microwave Systems ################################################################ 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 ################################################################