Circuit board with twinned CU circuit layer and method for manufacturing the same

Abstract

A circuit board with twinned Cu circuit layer and a method for manufacturing the same are disclosed, wherein the method comprises the following steps: (A) providing a substrate with a first circuit layer formed thereon, wherein the first circuit layer comprises a conductive pad; (B) forming a first dielectric layer on the surface of the substrate; (C) forming plural openings in the first dielectric layer, wherein each opening penetrates through the first dielectric layer and communicates with the conductive pad to expose the conductive pad; (D) forming a Cu seeding layer in the openings; (E) forming a nano-twinned Cu layer in the openings with an electroplating process; and (F) annealing the substrate to transfer the material of the Cu seeding layer into nano-twinned Cu, wherein the nano-twinned Cu layer and the transferred Cu seeding layer are formed into a second circuit layer.