Linda,
The darkening of the HumiSeal 1A33
that you are seeing is due to the oxidative cross-linking mechanism of the
resin. In many ways, this is a good thing, since it shows that your
product is fully cross-linked, and hence the full properties of the 1A33 coating
have developed.
I have not heard of anybody having
reliability concerns regarding 1A33 - indeed it is used extensively in many
hostile environments, where it's superior chemical resistance is
beneficial. I do not have any reliability data for the 1A33 - I think
you'd need to approach someone building similar boards for similar environments
as yours, to get some comparative data.
Have you tried HumiSeal direct?
Jim Lawrence [log in to unmask] is usually
a good source of information.
Best Regards,
Phil Kinner
Chief Chemist
Please note that Concoat has recently acquired the former Multicore SPCID
business. For more information, please visit our new web site
www.concoatsystems.com
Concoat Ltd
Alasan House, Albany Park,
Camberley, Surrey,
GU16 7PH
Tel: +44 (0) 1276 691100
Fax: +44 (0) 1276
691227
----- Original Message -----
Sent: Wednesday, May 22, 2002 8:24
PM
Subject: [TN] TypeUR conformal
coatings
I am currently using a type UR (Humiseal 1A33) conformal
coating which has
been shown to discolor over time and temp. Granted all
UR's discolor over
time, but this one seams to be worse than others
(Conathane 1155). The 1A33
is QPL approved and is very producible (no
bubbles, very little T/U rework)
Is anyone out there using Humiseal
1A33? And what if any feedback or data
can you provide on reliability of
this material as a conformal coating.
Appreciate any
info
Thanks
Linda Woody
Lockheed Martin
Missiles and Fire
Control
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