Hi Bill! I don't know of an IPC specification that designates a given period of shelf life for an of the available pwb finishes. The general consensus for shelf life of either components or pwbs within the JSTD-002 and JSTD-003 committees is one year. However, that one year figure is not a requirement. The shelf life of a specific pwb finish is negotiable between yourself and your pwb fabricator. Many of the pwb finishes types (immersion gold, immersion silver, immersion tin, HASL, OSP) can easily have one year shelf life when properly applied, properly handled and adequately stored. Also realize that some pwb finishes (e.g. thin OSP coating family) are not designed for one year storage. Good Luck. Dave Hillman JSTD-002/003 Chairman [log in to unmask] Bill Page <bill.page@SANMIN To: [log in to unmask] A-SCI.COM> cc: Sent by: TechNet Subject: [TN] Raw card solderability <[log in to unmask]> 04/25/2003 03:48 PM Please respond to "TechNet E-Mail Forum."; Please respond to Bill Page Consider this a hypothetical question :) We have some fabs that, due to reduced production requirements, have been in house for an extended period of time (more than a year). In investigating some solderability concerns, the board house suggested that with thinner HASL coatings, copper migrates through the tin-lead coating, reducing solderability. The vendor seemed to think that a six-month shelf life is now an industry standard...indeed, he involved the magic name of IPC. It has, admittedly, been a long time since I considered myself up to date on PCB fabrication issues. a. Is this a legitimate observation from our supplier? b. Should we expect only a six month shelf life on PCB? c. What rework method is recommended to bring these back in spec? Thanks, Bill Page --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------