I am in over my head. I have little to no experience with conformal
coating. Can anyone with more experience comment?
thanks,
Guy
---------- Forwarded message ----------
From: Guy Ramsey <[log in to unmask]>
Date: Thu, Sep 22, 2016 at 9:51 AM
Subject: Fwd: coating complaint
To: [log in to unmask]


I sent this message on to a friend who posts images for review by members
of the IPC technet.
We are looking for technical support and user experiences with this
material.
If we inspect at 5x-10x magnification we can observe the conditions that
our customer is complaining about.
But, our application process seems well controlled and the condition does
not exist when the material is first dispensed. The material flows as it
cures and becomes thin at the edges of the components. Thin enough so that
is does not glow under UV light. In some instances components appear to
have no coating (when viewed under UV). However under normal light it is
easy to see the parts are coated.
Is this normal behavior for the material?  Can we expect normal performance
from the the coating?
Guy Ramsey

---------- Forwarded message ----------
From: Guy Ramsey <[log in to unmask]>
Date: Thu, Sep 22, 2016 at 9:41 AM
Subject: coating complaint
To: Steve Gregory <[log in to unmask]>


Hi Steve,
Can you post these images on your homestead page for the group please?
The images are of acrylic coating  Humiseal 1B31. We are applying a thinned
mix using a dispenser through a fine needle (25AWG).

Under room lighting we can see coating. Under UV light, at this
magnification our customer is complaining about skips. I don't have enough
experience with the material to know if this is normal or not.
Notice how the resistor appears to have no coating under UV, but in normal
light it is clearly coated.
Also notice how the coating flows off of the components at the edges,
leaving only a thin coating that may not glow under UV light.
Are these normal attributes of this type coating.

We do not see this with Urethane spray coatings.