As a further comment on the posting below, I believed one of the current immersion silver finishes was not in fact a pure silver deposit, but rather used a co-deposited antitarnish to stop silver migration. This seemed plausible enough, what do other silver finishes use? Has anybody tested all of them? Dr Thomas Peters To: [log in to unmask] Subject: Re: [TN] silver migration Earl, Out of the two commercially available immersion silver processes at least one was proven not to exhibit electromigration in numerous studies carried out by some of the most reputable independent labs in the country. For details please contact me off line. Eric Yakobson [log in to unmask] on 11/20/98 05:36:32 PM To: [log in to unmask] cc: (bcc: Eric Yakobson/AlphaPCFabUS/Cookson) Subject: [TN] silver migration Joe, It seems the issue is dead and buried except many of us would like to use such a good conductor. I can only recount the "good old days" at Sperry Flight Systems (in the '60's and beyond) when we were all taught about silver migration. We were assured there was no way silver could be used as a conductor or conductive coating because of the issue in question. Therefore, palladium/silver compositions were developed and used on PCB's and hybrid thick film circuitry. This minimized the effect until gold became the conductor of choice. It's amazing how nothing is really new. It just keeps on coming around. I understand today's immersion silver, in such small amounts and thicknesses, does not pose migration problems. However, I also would like to know about the work done to prove or disprove the facts. Earl Moon ################################################################ 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 ################################################################ ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ################################################################ 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 ################################################################