On Tue, 15 Apr 1997, Ely Mercado wrote: > 1. Where can I get the specfication or criteria on IC SMD > shelf life? This is really two questions. Component susceptibility to moisture absorption is determined by the vendor, who classifies it to 1 of 6 levels. These levels are generally per J-STD-020, a standard jointly developed by IPC and JEDEC. Shelf life is affected by moisture susceptibility. Of course, parts come with date codes, and typically assemblers must get special approval to use parts with old date codes. I'm not aware of any standard that specifically indicates how "long" a component is reliable, solderable, etc. No doubt many of the large military contractors, and probably the parts suppliers, have data on this. Whether they are willing to share it is another issue altogether. > 2. I understand there's the IPC-SM-786A but it's more oriented > to specific IC moisture/reflow sensitivity. This is correct. > 3. Is there a criteria for how long for an IC or SMD parts > for that matter can be stored prior to reflow. Yes. J-STD-020. Note that IPC-SM-786A (published January 1995) and J-STD-020 (published October 1996) are almost identical in terms of classification criteria. The difference is that IPC-SM-786A includes handling procedures. IPC and JEDEC plan to develop a joint spec on handling, too (J-STD-021, perhaps?). Mike Buetow IPC Staff 2215 Sanders Road Northbrook, IL 60062 P: 847-509-9700, ext. 335 F: 847-509-9798 [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************