A circuit board or each circuit board of a multi-layer circuit board includes an electrically conductive sheet coated with an insulating top layer covering one surface of the conductive sheet, an insulating bottom layer covering another surface of the conductive sheet and an insulating edge layer covering...http://www.google.com.au/patents/US20050124196?utm_source=gb-gplus-sharePatent US20050124196 - Single or multi-layer printed circuit board with improved via design
