As much as I dislike OSPs, I agree with Dave. If this is really the case we would like to see how many others have extreme storage conditions. This is something we should discuss in IPC-1601 PB (printed board) storage and handling. Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman Sent: Tuesday, July 14, 2009 12:30 PM To: [log in to unmask] Subject: Re: [TN] Storage life for rigid flex Hi Steve - Wow, if you really are going to sit around for 20 years, I would make the pwb surface finish bare copper and apply an OSP treatment right before assembly. A good tin/lead finish might make 20 years self life but you are really on the edge. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] Steve Kelly <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 07/14/2009 02:11 PM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to Steve Kelly <[log in to unmask]> To [log in to unmask] cc Subject [TN] Storage life for rigid flex Good Afternoon, We have a program for some reasonably simple rigid flex (4-8 layer) where the requirement is a 20 year life in storage conditions from -40C to +125C. Is there any evidence that polyimide rigid material and pre-pregs would be better than a good FR-4 (170C) for long term reliability. Thanks. Steve Kelly Steve Kelly (PLEASE NOTE NEW E-MAIL ADDRESS) (416) 750-8433 (work) (416) 750-0016 (fax) (416) 577-8433 (cell) --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 15.0 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 -----------------------------------------------------