Sharp features in planes and E-fields

Hi All,

I was wondering if anyone has any experience with sharp features in
a plane (say power plane) and intensified E-field in the pre-preg as a
result?

In the case of a uniform power plane on a layer adjacent to a
ground layer, we would get a simple v/d relationship for the E-field
between the two planes. This is the field intensity that the pre-preg
must tolerate without breaking down. If the board carries high voltage
say 100VDC and the plane to plane separation is 2 mils, we will have
50v/mil. Howerver, if the power plane has pointed features, we may
have a much more intense field.

Does anyone have experience with measuring this field or
characterizing it?

Thanks,
Eldho.