Nickel-tin micro bump structures and methods of making the same

摘要

Techniques and mechanisms for providing effective surface level microbuckle connectivity on a package substrate of an integrated circuit. In one embodiment, different metals are variously electroplated to form a microbump that extends through a surface level dielectric of a substrate to a seed layer comprising copper. The microbump includes nickel and tin, with the nickel helping copper to reduce absorption of the seed layer. In another embodiment, the microbump has a mass fraction of tin or a mass fraction of nickel that is different in different regions along a height of the microbump.