Hi, We have a PCB that turns out to require 2500VAC test for 60 seconds and we had some flash over on pads to vias. We also have a planar ferrite transformer with primary windings on one side. Does anyone know of a screen on insulation material that can be used to increase flash over voltages? I would like to get a 2 or 3 mils of material. My other option is to have a laser cut layer of isolation but that could leave air paths under the material. Any other ideas welcome. Thanks, Bob K.