Lead free solder interconnections for integrated circuits

摘要

Lead free solder interconnections for integrated circuits. A copper column extends from an input/output terminal of an integrated circuit. A cap layer of material is formed on the input/output terminal of the integrated circuit. A lead free solder connector is formed on the cap layer. A substrate having a metal finish solder pad is aligned with the solder connector. An intermetallic compound is formed at the interface between the cap layer and the lead free solder connector. A solder connection is formed between the input/output terminal of the integrated circuit and the metal finish pad that is less than 0.5 weight percent copper, and the intermetallic compound is substantially free of copper.