Patent ID: 8227333

Claim:
A method of forming a ball limiting metallurgy (BLM) structure on a semiconductor chip, said method comprising: wet etching a first metal layer through a first patterned resist to remove a first annular section of said first metal layer, said first annular section, which is removed, extending outwardly away from a first circumferential edge of said first metal layer of said BLM structure and toward an edge of said semiconductor chip; stripping said first patterned photoresist; forming a second patterned photoresist on said semiconductor chip, except on a portion of said first annular section, which is adjacent to said first circumferential edge, and except on a portion of said first metal layer that is adjacent to said first circumferential edge; electroplating a second metal layer on said semiconductor chip, such that said second metal layer fills said portion of said removed first annular section, which is adjacent to said first circumferential edge, and covers said portion of said first metal layer; performing one of: forming a solder bump on said second metal layer and subsequently stripping said second patterned photoresist; and stripping said second patterned photoresist and subsequently forming a solder bump on said second metal layer; and wet etching said semiconductor chip, using said solder bump as a mask, to remove portions of said first metal layer from areas of said semiconductor chip surrounding said BLM structure.