Is there any chance that the boards have moisture in them which is then
reacting with the coating?

We used to get very pretty acrylic coated CCAs by prebaking the masked,
clean assy.

Phil



At 7:56 AM -0500 11/8/96, Paul Stolar wrote:
>     Sometimes the cause is the CC is too thick and does not allow the
>     gaseous products to get out. Try thinning the CC.
>
>
>______________________________ Reply Separator
>_________________________________
>Subject: Bubbles in Conformal Coating
>Author:  [log in to unmask] at Internet
>Date:    11/7/96 5:06 PM
>
>
>     I threw this question out once before but I still cannot determine the
>     source of bubbles in our conformal coating process.  We are using an
>     acrylic coating and a Nordson Select Coat System.   The bubbles come
>     and go from day to day.
>
>     We have looked at viscosity, temperature, humidity, pressure,
>     z-height, contamination, micro-adjust, and a few other variables. Has
>     anyone else seen this phenomenon or do you have any insight on it?
>
>     Any help is very much appreciated.
>
>     Thank you.
>
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Regards,


Phillip A. Bavaro
Senior Manufacturing Engineer
[log in to unmask]
(619) 658-2542


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