Steve
Actually, the conditions you are storing it under only "guarantee" the
continued certification of the material to 13949 for 3 months.  To maintain
the 6 month shelf life, the prepreg needs to be stored in the environment
described in 13949 for that length of time (which is basically under
refridgeration at 40 ¡F).

We use a 3 month shelf life on our prepreg, and if there is any remaining
after the expiration as we apply shelf life to it, we retest the prepreg and
based upon the results, will either extend the shelf life an additional 3
months, or discard it.

If you have any questions about shelf life and storage conditions, you could
reference paragrap 3.6.1 of 13949H, it is addressed there.

regards,

Lisa Greenleaf
Teradyne Connection Systems
603-791-3118
email [log in to unmask]

--------------------------------------
Date: 3/5/97 11:06 AM
To: LISA GREENLEAF
From: Steve Sekanina
     We store our prepreg in an enviroment of 10% RH and 65 degrees F 
This prepreg is mil certified FR4.  After 6 months of sitting on the 
shelf, this material is no longer certified by our supplier as mil 
spec.  This material could then be used on non mil spec work.  What 
method and  what time frame should be used to determine when the 
material should be thrown out?  (not used on anything)  In other 
words, after the six months, we know the material is not scrap, but at 
what time will it actually become defective? Any input on this 
subject would be appreciated  Thank you..

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