Normally I would agree with Werner, but this time the end of the tear is 
right at the junction of the rigid flex....probably not a good place to 
drill a hole stopping propagation.

It depends on the intended use, but all sorts of fixes come to mind, 
anywhere from trim it off to bonding it back down to roughening the surface 
up and doing a formal bandage.  If the intended application is short lived, 
even polyimide tape might be acceptable (Kapton, low esd, etc).

I would be much more concerned about how demasking could have torn a rigid 
flex board in the first place.   That is very scary or some very strong 
masking tape.

Phil

At 04:01 PM 5/21/2007 -0500, Steve Gregory wrote:
>Hi All!
>
>I got a rigid-flex assembly here that has multi-layer flex in it, and it
>had a layer of the flex get torn while de-masking it after conformal
>coating. I have a picture of the tear here:
>
>http://www.stevezeva.homestead.com/files/Flex_Tear.jpg
>
>As you see, the tear is on the edge and away from any conductors. The
>assembly isn't going to be continuously flexed back and forth, it is
>going to be formed in a fixture and remain that way and installed into
>the upper-level assembly where it will stay in the formed position.
>
>Should I do anything with it other than maybe carefully trim it off?
>Will any repair actually do anything as far as reliability is concerned?
>For that matter, has the tear compromised the reliability of the flex in
>that area? There's been suggestions of some sort of epoxy repair, but I
>don't think that it will buy you anything as far as reliability is
>concerned.
>
>What do you think I should do?
>
>Steve Gregory
>
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