What should a designer use as an "overspray zone" for conformal coating? I would like to keep components and vias away from areas that will NOT be coated. I don't know why 3mm sticks in my mind, but I can't find anything in IPC-CC-830 about it (including the new Working Draft) I also downloaded the new Conformal Coat ebook from 007 and can't find it there, either!