Good morning Peter, I'm sure Dave Hillman will provide the most accurate response (IMHO) but until he comes around later in the day, I'll give my $.02. The first thing is to determine if the components are solderable upon receipt (reference J-STD-002) by performing a solderability test. If the leads/terminations pass the solderability test and no additional conditioning is performed, the components should be used within 120 days (guidance information developed under MIL-STD-2000 and predecessors). Longer storage can occur based on packaging, temperature, humidity and air particulates (i.e. dust, sulphur dioxide, chloride, ammonia). Previous guidance suggested that storage could be extended if storage conditions do not exceed 25°C and 50% RH, and sealed containers/bags are used. One note of caution is to ensure the storage containers/bags do not introduce contaminates (silicones, sulphur, polysulphides, etc.,) to the components that could degrade the solderability. As you mentioned, nitrogen storage is a good option, as it will minimize oxidation formation dependent on the purity and temp/humidity control, but this option comes with a cost. To summarize: - impose a solderability (coating durability) requirement on suppliers; component packaging requirements - verify solderability upon receipt or obtain certificate of compliance - develop FIFO material control - prepare for storage (repackage if necessary; original supplier packaging is usually suitable) - control environment - periodically perform solderability tests to determine adequacy of methods employed above. Good Luck! Steve Sauer Mfg Engineer Xetron Corporation -----Original Message----- 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 _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------