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October 2016

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Subject:
From:
Joyce Koo <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, [log in to unmask]
Date:
Thu, 6 Oct 2016 08:18:16 -0400
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agree with Matthias.  cure, you get skin 1st (tack free - oxidation or
surface cure), it would be hard for bubble to pop, most likely, the least
resistance place to expand - adjacent area that is not form the skin - big
bubble - bridge few sj...
> On 6 Oct 2016 at 4:59, Nigel Burtt wrote:
>
>> Are "solvent bubbles" a peculiar problem with this type of conformal
>> coating or a generic problem for coatings?
>>
>> Hypothetically if coating penetrates under the body of a low stand-off
>> component and a solvent bubble remains trapped under there after the
>> cure/dry, could that bubble "pop" under thermal cycling or high stress
>> service environment with enough force to fracture the solder joints on
>> the part?
>
> Just a guess, but I would be afraid that the solvent (which is
> assumed to be away after curing) remains for "ever" or at least long
> enough to make trouble. Remaining solvent in any traps does, what it
> is supposeed to do: solve stuff, especially if it is well trapped in
> its own bubble and has in the worst case really long time to attack
> stuff.
>
> Regards
>
> Matthias
>
> --
> Matthias Mansfeld Elektronik * Printed Circuit Board Design and
> Assembly
> Neithardtstr. 3, D-85540 Haar, GERMANY
> Phone: +49-89-4620 0937, Fax: +49-89-4620 0938
> Internet: http://www.mansfeld-elektronik.de
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>

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