Scott, I'm surprised at their answer. We have been making immersion silver boards for 6 years now and it has proved to be far superior to ENIG. It is very easy to run and the conveyorized line is the least costly to buy. We do not charge for it unlike ENIG that carries a quite large price adder. Shelf life for ImAg has been 6-12 months if left in the sealed-sulfur free bags that we ship the boards in. Solderability has been excellent AS LONG AS THE ASSEMBLER REALIZES THAT THIS IS NOT HASL OR ENIG ! ! We have had problems with assemblers taking them out of our bags and stacking them on shelves exposed to humidity and picking them up without gloves. Once the assembler is educated that you can't mishandle these boards like HASL or ENIG, the problems go away. It also has been the best finish for lead-free assembly processes. This PCB Fabricator may not have the money to buy a new line for Immersion Silver and so he want you to stay with ENIG. But ENIG corrosion problems go up with increase heat cycles and smaller pitches-so best to make the transition to some other finish NOW. Happy Holden Westwood Associates Scott Lefebvre <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 11/24/2004 01:42 PM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to Scott Lefebvre <[log in to unmask]> To [log in to unmask] cc 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 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------