Alberto,

We also bake our boards for 2 hours prior to conformal coating, but at 100C.
The conformal coat masking cures during this step (yes, I know this is more
than needed for curing), but the goal is to remove moisture.  We have
actually found it necessary based on experimentation to bake some boards for
24 hours at 100C if they have certain components susceptible to absorbing
moisture on them.  The extended time is obviously undesirable, but it sure
beats system failures.

-Steve


Steven K. Lustig
Process Engineer
EMS Technologies, Inc.
Norcross, GA
(770) 263-9200 x4714
[log in to unmask]


-----Original Message-----
From: Alberto Callo [mailto:[log in to unmask]]
Sent: Thursday, October 14, 1999 6:38 PM
To: [log in to unmask]
Subject: [TN] Baking-Conformal Coating


Hello everyone,

Does anyone know anything about baking populated boards prior to
conformal coating?

We are trying to decide if we should bake them at all.  Currently we
bake them at 60C for 2hr, however the cost associated with this process
is pretty high.  The reason we bake them is because we supply a 15 year
warranty with our products.  Also, by baking them we ensure that no
moisture is present on the boards just before conformal coating,
therefore increasing the reliability of our products. That's what we
want to think?.

Our company produces control systems for the mass transit industry.

Thanks

Alberto

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