We have been using I.S. for two years, follow manufacturers recommendations for storage and handling and you will be fine. Require your board supplier to vacuum seal the packages and make sure they have a slip sheet (non sulfur bearing paper) on top and bottom of the stack. Since the finish is actually below the surface of the board you don't have to worry about every board getting scratches. Aperture selection of stencils is important. Since there is no HASL to add solder volume you have effectively changed your product to Lead-Lite, some apertures may need to be 1:1 but we have had good results with fine pitch reductions by using a round rectangle. If assembly is double sided you should process the second side as soon as practicle to minimize tarnish which may statistically decrease your solderability. But tarnish does not always mean it won't solder. Replating Immersion silver is very easy. Check out the Alpha Level and Mac Dermid websites for some good papers on Immersion silver finish. Shelf life? 12 months. We don't wear gloves, we started that way but realized NO board should have peoples fingers on them so we follow good handling and you should be fine. Cost should be less than HASL. At the ATE show yesterday I heard many references to Immersion Gold and Black Pad. Most of the Lead Free studies are recommending Immersion Silver for the transition. Dave Chapman Manufacturing Engineer Circuit Service Inc. -----Original Message----- From: Brooks,Bill [mailto:[log in to unmask]] Sent: Thursday, September 25, 2003 3:08 PM To: [log in to unmask] Subject: [TN] Silver Immersion right for fine pitch? Hi Technetters, I have just attended a meeting of the IPC Designers Council where the subject of finishes for PCB's came up and it was revealed that Silver Immersion seems to have great benefits for assembly, shelf life, solderability, rework, etc... Can anyone give me their experiences with the process and its benefits and down sides? Have you personally used it, how long, what sort of problems have you seen, what are the cost issues? Best Regards, Bill Brooks "Politics is more difficult than Physics" - Albert Einstein --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------