The one time I had this come up while I was at Rogers the concern was
coming out of Europe, and was related to high altitude Corona discharge
resistance. They were incorrectly extrapolating problems with polyimide
coated wires to flex materials. Fortunately we were able to get test
data on the Kapton used in flex from DuPont that allayed their fears.

There's also a series of UL flex circuit electrical tests and a
qualification level called the delta mark that might also be used to
argue against these somewhat unjustified concerns.

Andy Magee
Flex Guru - Consulting
[log in to unmask]
(937) 435-3629

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