Yves, A good case can be made, to maintain a reasonably current datecode component in stock, for logic and analog ic's. Beyond a few years old, you become more susceptible to problems with older die revisions that fail to meet the demands of the design. Occasionally it works the other way, where a new die causes difficulties with an older board, but the aforementioned scenario is probably more common. Other age & datecode related concerns include potential component solderability, and long term moisture absorption / packaging issues. Bruce Tostevin Benchmark Electronics Hudson, NH ______________________________ Reply Separator _________________________________ Subject: [TN] Electronic Devices - Age Limits Author: Yves Trudell <[log in to unmask]> at 0UTG0ING Date: 3/23/98 11:37 AM I have seen guidelines for the maximum age (date code limitations) that electronic devices can be in order to be purchased (purchasing guidelines) and in order to be assembled (assembly guidelines). I've seen maximums in the range of 1 year to 2 years based on date code, but I've never seen the reasoning/data behind these limits. The guidelines that I've seen do not differentiate between device technology. If you have guidelines, what are they and what are your reasons for setting them? Yves Trudell Quality System Engineering Nortel, Wireless Networks Calgary ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################