More questions on Plastic Parts:


IPC-SM-786A is a great document.  Covers most of the bases quite well.  But
here is my question:

Section 4.3.2.1 states that shipping tubes or tape and reels may be placed
in an oven at 40 C (+5/ -0C) for 192 hours at <5% RH.  The time required to
desorb moisture down to the target level  can vary from one week to a month.



QUESTIONS:

1) How do you keep the humidity in the oven down to less than 5% RH?




2) It states that the time required may be 1 week to a month, but the same
paragraph seem to say that if baked for 192 hours, the parts will have the
same life as if baked at 125 C...   So is more than a week of baking
required, or not?




3)  Will the supplier indicate the proper low temperature bake parameters
(temp, RH, time) on his packaging?



Thanks,

Mike
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