Aspect ratios smaller than 1:5 are never a problem in Fr-4 boards. For
thicker boards you can increase the copper thickness in the hole.
Remark: Because of the higher expansion rate of the acrylic adhesive
there are other rules for rigid flex boards.

You can find some more information on our webpage (technologies).
http://www.dyconex.com

Regards
F.Steiner, Dyconex



VOLPE, RAY wrote:
>
> Would there be any problem with using an .028 via hole in a .09thk , FR4
> material double sided PCB ?
> Reliability issues ? Thermal Stress?
>
> Thanks in advance, Ray
>
>

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