Steve and All I installed the first immersion silver line in North America at the AT&T facility in Richmond, VA. We began the evaluations in 95. Initially, Lucent was the only customer, but in time many more followed. I was never disappointed in its reliability or performance. I am sure George Wenger or Bob Furrow can discuss the results at the Lucent assembly sites and the reliability work carried out prior to using the product. Best regards Lee ----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Precision Lab Sent: Thursday, November 04, 2004 1:02 PM To: [log in to unmask] Subject: Re: [TN] PWB Immersion Silver Finish Hello Victor, I hope you do not mind me responding to this message sent to Steve. Steve I also hope that you do not mind as well. However, we have just completed a study for a company that was using immersion silver (IAg) surface finish along with lead-free pastes. As part of our study we did some heavy research into the IAg process and its benefits and pitfalls, as it were. Here is what we found as a result of our research: Advantages of IAg: * Cost, the cost is comaparble to HASL. * The surface after application is flat, unlike that of HASL. * IAg produces better signal integrity, especially in higher frequency applications. * Applied silver by electroless application doesn't require high temperature excursions or exposure to unpleasant chemistries. It is a very simple process. * Shelf life of IAg boards is approxiamately one year, this is comparable to HASL. * Lastly, the IAg surface finish has 100% wettability and is not prone to discoloration. Disadvantage: * Silver nitrate used in the application process is very light sensitive, thus the immersion bath should be enclosed. In the past IAg surface finish had issues with electromigration (dendrites), this is now an urban myth. IAg has progressed to the point that it is no longer at any more of a risk than any other surface finish for electromigration. We were able to derive alot of information about IAg from Don Cullen of MacDermid and our research fell in line with what he told us. He was gracious enough to talk at length with us about this particular finish. I would imagine he would also speak with you or whoever. Should you desire to speak with him, his phone number is (203) 575-5658. As far as what we have seen with LF pastes at this point, it appears to work well, at least for the pastes that we have tested. I hope this helps! Best Regards Joe Russeau Process Analyst Precision Analytical Laboratory Steve, > > Can you share your experience with PWB Immersion Silver Finish? > ie. shelf life, usage after package is opened, storage of non process > PWB, surface oxidation, compatibility with LF solder. > > Victor, > > --------------------------------------------------- > 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 > ----------------------------------------------------- > > --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------