My guess is your PCB FAB shop has ENIG and is trying to sell you what he has to offer.  If you ask a PCB FAB shop that has IAg they will probably try to tell you ENIG is more expensive than IAg and you won't get Black Pad failures from IAg.  My advice is to ask a PCB FAB shop that offers both ENIG and IAg and see what they like best and what their reasons are.  Better yet ask users of IAg and ENIG what they think.

Regards,
George

George M. Wenger (908)-546-4531 
Reliability / FMA Engineer
Base Station and Subsystems Group
Andrew Corporation,  40 Technology Drive, Warren, NJ 07059
[log in to unmask]



-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Scott Lefebvre
Sent: Wednesday, November 24, 2004 1:43 PM
To: [log in to unmask]
Subject: [TN] Immersion Silver


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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