Patent ID: 7220618

Claim:
A method for forming a redistribution layer in a wafer structure comprising: (a) providing a wafer having a plurality of conductive structures and a first passivation layer thereon, wherein the first passivation layer covers the wafer except conductive surfaces of the conductive structures; (b) forming a second passivation layer over the first passivation layer; (c) selectively removing part of the second passivation layer to form a plurality of grooves corresponding to a predetermined circuit, wherein the grooves extend from an exposed portion of the second passivation layer, which exposes the conductive surfaces of the conductive structures, to another portion of the second passivation layer other than the exposed portion; (d) forming a redistribution layer in the grooves, wherein the redistribution layer does not extend out of the grooves in relation to a top surface of the second passivation layer; and (e) forming a third passivation layer over the second passivation layer and the redistribution layer.