The invention provides a multi-layer circuit board sequentially having an insulating substrate, a first electrically conductive pattern arbitrarily formed, an insulating material layer and a second electrically conductive pattern formed by providing an electrically conductive material on a graft polymer...http://www.google.es/patents/US7849593?utm_source=gb-gplus-sharePatente US7849593 - Method of making multi-layer circuit board
