Hello Technetters, We are about to embark into our first foray into the world of silver immersion circuit boards. We currently assemble PCBs using ENIG and HASL circuit boards. Colleagues in this company are primarily worried about the electromigration problems. I have a few questions: 1) What is the impact of areas on the board that are left unsoldered (silver finish still intact) is that area more susceptible to electromigration. 2) Is anyone using the silver finish for touch pads and if so what has the reliability been like. 3) Do most companies who use silver boards design the boards as SMOBC and then selectively silver plate or can you (or should you) immersion silver the entire board. 4) If the whole board received silver plating would it be more or less susceptible to electromigration then a SMOBC board. Thanks for your help. Richard Lepa, B.Sc. (I.E.) Manufacturing Engineer Vansco Electronics Ltd. EMT Division 1305 Clarence Ave. Winnipeg, MB R3T 1T4 Tel: (204) 453-3339 Ext 629 Fax: (204) 453-3663 Email: [log in to unmask] --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------