Peter,

You are correct.  I was not thinking of conformal coating, just tape as
insulation.  Which I have used on a PCB to solve primary to secondary
creepage and clearance problems.

Regards,

Duane Marcroft
Telecom Consultant
Peer Communications
[email protected]


>Duane -
>
>As far as I know, safety certification agencies don't accept tapes as a
>conformal coatings; if you know otherwise, please share your experience.
>
>Silk-screened coatings can be considered as conformal coatings, depending on
>which test house you're talking to, provided they go through whatever level
>of type evaluation, follow-up inspection and quality control.  The hassle is
>hardly worth the effort, in most cases.
>
>
>Regards,
>
>Peter L. Tarver
>Nortel
>[email protected]
>
>> Duane J. Marcroft wrote:
>> >
>> > Richard,
>> >
>> > The PCB coating is silkscreened.   Because it is a silkscreen, it is by
>> its
>> > very nature unreliable as an insulator.  Silkscreening produces many
>> voids
>> > in the surface (air bubbles) and too much variation in coating
>> thickness.
>> > As a consequence it cannot be considered.
>> >
>> > To be an viable insulator (in calculating creepage and clearance)
>> coating must
>> > be at least 2 layers of film (sheet or tape of Kapton.. etc).  In the
>> > opinion of many in the industry a silkscreen coating is too unreliable
>> to
>> > be considered.
>> >
>> > Duane Marcroft
>> > Telecom and Data Communications Consutant
>> >
>> > ___________________________________
>> >
>>


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