Traceability went out the window with cots. Used to maintain traceability to the second metallization layer. If a pilot crashed, his/her remains seldom recoverable but components were at times.

Earl

By the way, if you're out on the great American highways and byways, you'll notice almost as many trucks/truckers/f------, etc. Hell, they get paid 50 cents a mile and make nearly 50K a year. Whoopie shit, where do I sign up - truckmasters I think it is.
  ----- Original Message ----- 
  From: fullname 
  To: [log in to unmask] 
  Sent: Tuesday, April 30, 2002 1:57 AM
  Subject: Re: [TN] Proposed lifting of component date code restrictions


  I agree with Steve strongly. 
  Without any date code, it is mission impossible to trace which batch of the components failed. 

  Regards - Wee Mei 

  [log in to unmask] wrote: 

    I guess my first question is; If the datecodes currently mean different things depending on the manufacturer, why not standardize what datecodes really mean rather than get rid of them? 
    The paper talks about all the advances that have been made understanding root causes concerning solderability issues, improved storage and handling methods, etc., then why do I continue to get moisture sensitive components from distributors in un-sealed packaging? But that's another issue... 

    A recent issue here at my facility underscores the importance of a datecode on the part. We build an assembly for a customer that uses three 240-pin QFP DSP's from a well known manufacturer. So far, we've built-up over 200 assemblies for our customer. We shipped the assemblies to our customer and they integrated them into the higher level assembly, and discovered they don't work...not communicating at all with the rest of the system. 

    Numerous phone calls to the manufacturer trying to find out what the problem could be resulted in "Nothing has changed with the part, the die hasn't changed, nothing..." 
    Funny thing was our first pre-production shipment of the assemblies worked fine!! 

    After looking a little closer, the first lot of assemblies contained DSP's that had a datecode that was 2000 or earlier, everything that's failing are later...but still, according to the device manufacturer; "Nothing has changed..." 

    If there wasn't a datecode on the part, we wouldn't know what we could put on the assemblies and work. There is a lot of effort being expended to try and isolate what the problem really is (with no help from the device supplier), but for now we need to find parts that work so that it doesn't shut down production, the only solid way (for now) is to find parts within a certain date code. 

    Now I'm faced with the possible task of reworking 200 assemblies, each with three 240-pin QFP's, with a early datecode part...fun stuff I know. 

    -Steve Gregory- 
      
      

      IPC has become aware that the National Electronics Distributors Association (NEDA) has posted a white paper discussing the proposed lifting of date code restrictions and they have requested comments from end users as well as component suppliers and distributors. The paper can be viewed at http://www.nedassoc.org/whitedat.html. 
      Comments can be provided to me on or off net; we'll compile them and forward to NEDA. If you comment to NEDA directly [log in to unmask], please cc: me on your reply [log in to unmask] 

      Cordially 
      Jack