Abstract: An aluminum substrate is drilled to form a first through hole, and is then laminated with copper foils on upper and lower surfaces of the aluminum substrate via a binder. Due to the pressure of the lamination, the binder is partially forced to flow into and fill the first through hole, and the binder is then solidified. Concentric with the first through hole, a second through hole having a smaller aperture than the first through hole is drilled. By a non-electrical and electrical plating method, a copper conductive layer is formed on the side wall of the second through hole to complete the through hole wire. Because of the isolation effect of the binder, the aluminum substrate is not electrically connected to the copper foils and the copper conductive layer.