Kenny and other Techies,
I understand that Paralene type coatings are particularly sensitive to
"No-clean" residues - they do not adhere.
You will also find that certain coating formulations and polymers will
behave in different ways to different surface conditions. For example,
certain acrylics do not stick well, but other acrylic resins work fine
example: 1B31 and 1B73 from HumiSeal. Urethanes generally stick like you
know what to a blanket, yet we have had instances where the acrylics have
worked better. As regards silicones, how the hell do you run an adhesion
test for these given that no tape will stick to the silicone? Yet silicones
do represent a significant part of the coating business.
As I said in an earlier posting, only if you fail environmentals would poor
adhesion become important. A friend of mine (yeah I do have some :-) )
pointed out rather well - As far as we can tell, coatings are not
intelligent, so if they stick well to metals laminates and plastics, but
don't stick to certain "treated surfaces", how do they know the difference??
I always wonder about thermos flasks for similar reasons - they keep hot
things hot and cold things cold - but how do they know? SPOOKY! :-)
However, the real issue as Bernhard indicated, is to evaluate SIR or IC
measurements. This way you would be able to establish whether there will be
any reliability issues for the end product. Understanding electro-chemical
reactions and maintaining the desired quality or reliability is the subject
of major new developments in SIR testing standards - watch this space....
Regards,
Graham Naisbitt
[log in to unmask]
WEB: http://www.concoat.co.uk
CONCOAT Ltd
Alasan House, Albany Park
CAMBERLEY GU15 2PL UK
Tel: +44 (0) 1276 691100 Fax: +44 (0) 1276 691227
----- Original Message -----
From: Kenny Bloomquist <[log in to unmask]>
To: <[log in to unmask]>
Sent: 19 November 1999 14:54
Subject: [TN] Speaking of Adhesion of Conformal Coating
> I'm curious what other companies do as an in process test for conformal
> coat adhesion, if anything.
>
> I'm particularly interested in Parylene but also curious about UR and AR.
>
> If you do in process testing what spec do you follow, if any, and what
> materials do you use, i.e. tape type, Exacto, etc.
>
>
> Thanks to all responders,
>
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