Patent ID: 7323780

Claim:
A method for forming an electrical structure, comprising: providing a substrate comprising a first electrically conductive pad and a second electrically conductive pad formed within a volumetric portion of the substrate and a first dielectric layer over a surface of said substrate, a surface of said first electrically conductive pad, and a surface of said second electrically conductive pad; forming a first via and a second via in said first dielectric layer, said first via located over a portion of said surface of said first electrically conductive pad, said second via located over a portion of said surface of said second electrically conductive pad; forming a metallic layer over a surface of said first dielectric layer and within said first via and said second via; forming a second dielectric layer over a surface of said metallic layer; removing a first portion, a second portion, and a third portion of said second dielectric layer, said first portion removed from over and within said first via, said second portion removed from over and within said second via, and said third portion removed from between said first via and said second via; forming a ball limiting metallization layer within said first via and said second via, over a portion of said surface of said metallic layer, and over a surface of said second dielectric layer that remains after said removing said first portion, said second portion, and said third portion of said second dielectric layer; forming a photoresist layer over a surface of said ball limiting metallization layer; forming a first opening in said photoresist layer by removing a first portion of said photoresist layer located within and over said first via and extending laterally over and parallel to a portion of said surface of said ball limiting metallization layer; forming a second opening in said photoresist layer by removing a second portion of said photoresist layer located within and over said second via and extending laterally over and parallel to a portion of said surface of said ball limiting metallization layer; and forming a first solder structure within said first opening and a second solder structure within said second opening.