In the past, I have observed problems with PbSn solder and Ag filled epoxy. The symptoms were high resistance readings between the soldered end terminations and the silver filled epoxy. Sometimes the resistance readings were intermittent. Our supplier indicated that soldered end terminations should not be used with silver filled epoxy. Reasons for the incompatibility were: 1. The conductive epoxy has poor adhesion to solder. 2. The curing process (or other elevated temperature conditions) may result in an oxide formation on the solder surface, resulting in increased contact resistance. I suggest you contact your supplier. I believe that the problem is epoxy dependent. Some epoxies seemed to exhibit the failure mode, and some did not. Dave Anderson >>> Sheila Smith <[log in to unmask]> 08/07/97 07:20am >>> Jan, What sort of problems have you seen with Ag filled adhesives & PbSn solders?? We are experiencing a mystery anamoly after elevated temp burn-in and suspect the Ag filled epoxy is doing something unexpected ... could you elaborate? Thanks, Sheila Smith, TRACOR AES At 11:10 AM 8/7/97 +0200, you wrote: >***** Unclassified ***** >> >>I have been told that gold and silver are incompatible materials for >>bonding together, and that, therefore, gold finishes and silver-filled, >>electrically conductive adhesives will not work well together. Does >>anyone have any data to corroborate or contradict this information? >> >>Steve Murphy >> >------------------------------------------------------------------------------- > >Steve, > >We have a very long experience with silver-filled, electrically conductive adhesives on gold. We use it, among others, for die bonding. We have never experienced problems due to incompatibility between gold and silver. We have seen problems with both materials in combination with PbSn solders, maybe thats where this 'rumour' comes from. >Hope this helped....... >Jan Bokhove >Dep. CQM >Hollandse Signaalapparaten >tel. +31 74 2482949 >e-mail [log in to unmask] >