That's way too much baking... Your laminate may become brittle and the tin
oxidised. You are using too much power to build boards at that point. We do
not bake unless the boards are more then 6 months old or polyimide. We bake
only once if required at all.

Just my personal opinion,

Alain Savard, B.Sc.
Chemical Process Analyst

-----Original Message-----
From: Dieselberg, Ron [mailto:[log in to unmask]]
Sent: August 10, 2000 6:14 AM
To: [log in to unmask]
Subject: Re: [TN] Baking Bare PCB's?


Rick, I cannot speak for everyone, but this is what we have been using for
about the last 15 to 17 years (or more). ""Bake the PWB for 3.5 +/- 0.5
hours at 185 +/- 25 deg. F and 27 in. Hg (685.8 torr) minimum. Rebake the
board every 14 calendar days at 145 +/- 10 deg F for 12 hours minimum unless
the PWB or PWA is not in work. If not in work, store in a dry Nitrogen box
and rebake before the next soldering operation.""

Hope this helps you. It did us!

Ron Dieselberg
BAE SYSTEMS
Cincinnati Electronics Corp.

-----Original Message-----
From: Rick Thompson [mailto:[log in to unmask]]
Sent: Wednesday, August 09, 2000 14:27
To: [log in to unmask]
Subject: [TN] Baking Bare PCB's?


I'm trying to establish some basic guidelines for the baking of bare PCB's
that have potentially absorbed moisture due to unknown storage conditions
and time.  Are there any industry guidelines for this type of process or
would someone mind sharing their general procedures?  I thought I had read
somewhere about times in the 2-8 hour range at 125 C but can't find that
information anywhere.

Thanks in advance.

Rick Thompson
Ventura Electronics Assembly
2665A Park Center Dr.
Simi Valley, CA 93065

+1 (805) 584-9858 voice
+1 (805) 584-1529 fax

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