A method for making a circuit board includes the following steps. At least two substrates are provided, wherein each substrate includes two surfaces, two circuit layers respective formed on the two surfaces and at least a via passing through the two surfaces. A metal layer is formed on the side wall of the via, wherein the metal layer electrically connects two circuit layers on the two surfaces of each substrate to each other. An insulating film is at least formed on the surface of the metal layer by an electrophoretic deposition process. Vias of two substrates are aligned with each other and two substrates are laminated to each other, so as to form a multi-layer substrate. Another metal layer is formed on the insulating film, wherein each metal layer is an independent electrical channel.