Electrical connecting element having nano-twinned copper, method of fabricating the same, and electrical connecting structure comprising the same

Abstract

An electrical connecting element, a method of fabricating the same, and an electrical connecting structure comprising the same are disclosed. The method of fabricating the electrical connecting structure having twinned copper of the present invention comprises steps of: (A) providing a first substrate; (B) forming a nano-twinned copper layer on part of a surface of the first substrate; (C) forming a solder on the nano-twinned copper layer of the first substrate; and (D) reflowing the nano-twinned Cu layer and solder to produce a solder joint, wherein at least part of the solder reacts with the nano-twinned copper layer to produce an intermetallic compound (IMC) layer which comprises a Cu3Sn layer, This invention reduces the voids formation in the interface between the intermetallic compound and the solder, and then enhances the reliability of solder joints.