Wire bonding substrate and fabrication thereof

A method for forming a wire bonding substrate is disclosed. A substrate comprising a first surface and a second surface is provided. A through hole is formed in the substrate. A conductive layer is formed on the first surface, the second surface and the sidewall in the through hole. The conductive layer on the first surface of the substrate is patterned to form at least a first conductive pad, and the conductive layer on the second surface of the substrate is patterned to form at least a second conductive pad. An insulating layer is deposited on the first surface and the second surface of the substrate, and the insulating layer covers the first and second conductive pad. Next, the insulating layer is recessed to expose top surfaces of the first conductive pad and the second conductive pad. Current is applied from the second conductive pad through the conductive layer in the through hole to the first conductive pad to electroplating a first metal layer on the first conductive pad.