I just got off the phone with one of our PCB FAB shops and was surprised on his response to Immersion Silver as a solder finish.  
He suggested that we do not use it as a replacement for HASL and to use gold instead.  All the things I've read and did research on IAg in 
contraction to he said.   The shop said shelf life is less than 6 months and tarnish was a big issue.  It was more expensive than ENIG and not that many shops do it in-house.

My understanding is the shelf life is 6-12 months if stored and handled properly.  They silver used today has an anti-tarnishing agents to prevent tarnishing.  I was also under the impression that IAg is less costly than ENIG.

Your opinion in this matter would be greatly appreciated.

Thank you,

Scott

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