Wayne,

 Putting PCBs into a Dry Chamber will dry them, assuming they are note in a thick stack. How else could a board be dried? Its all diffusion out of the board right? Heat helps but since the vapor pressure os water is so low I recall vacuum does not do much to help.

I know I have seen this subject on the list in the past, I don't recall the final judgement on the need for vacuum.

Bob K.

-----Original Message-----
From: TechNet <[log in to unmask]> On Behalf Of Wayne Showers
Sent: Tuesday, September 11, 2018 3:41 PM
To: [log in to unmask]
Subject: Re: [TN] Vendor Reel Parts Marking

EIA-481 series is minimal in regards to standardized reel and part number markings.  It is an ongoing issue as if they were consistent and with a barcode, incoming inspection would be much easier.

As for the sideline on PCBs in dry chambers:
When stacking in a dry chamber, if the PCBs are already dried, then having a bag keeps the product together without needing seal and dry-pack.
It is nearly impossible to dry PCBs in a dry chamber (hedging my bets, but chambers are designed to, will keep stuff dry, not dry it.)  The PCBs would need to be stickered (air gaps between layers) to even think about drying (as you presumed).
IPC-STD-1601 is the preferred standard for PCB handling, drying, et cetera.