Hi Peter! Steve Sauer did a great job of covering the most important basics so I'll just add few other details. Based on many of the discussions which occur within the JSTD-002A committee, you should expect that your component shelf life should be a minimum of 6 months and very typically 12 months from date of fabrication. You can expect that components with Sn63/Sn62/Sn60 finishes retain their solderability better than Sn85 or Sn100 finish. There is also one general rule - the thicker a finish the better it retains its solderability. A 20 microinch thick Sn63 finish on a DIP component is going to "age" less gracefully than a 60 microinch thick Sn63 finish on the same component. Humidity has the greatest impact on the loss of solderability so if you can control the humidity in your component storage area then you will be better off (most people have typical controls of 30%-60% RH). Lastly, always relate your solderability expectations with the type of flux chemistry you are using in assembly. Typically, the JSTD-004 type M or H fluxes are more robust to solderability variations than the type L fluxes. The JSTD-002A specification, in conjunction with a good logistics plan (as Steve recommended), can serve as a good tool for solderability management. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] Peter Lee <[log in to unmask]>@ipc.org> on 12/11/2001 02:12:15 AM Please respond to "TechNet E-Mail Forum." <[log in to unmask]> Sent by: TechNet <[log in to unmask]> To: [log in to unmask] cc: Subject: [TN] Shelve life for SMT/PTH components Hello, In general, what is the standard shelf life for the normal PTH and SMD components like DIP IC's, SOIC's, PLCC's? Assuming that they are non-MSD critical, what would be the proper storage method to ensure good solderability is being preserved (such as nitrogen storage chamber)? How significant is the impact of storage conditions (e.g. humidity, expose to ambient) and shelf life have on the solderability of component leads? Rgds, Peter --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------