A New Reliable, Corrosion Resistant Gold-Palladium Coated Copper Wire Material

In this paper, we present studies for the new gold-palladium coated copper wire "EX1R" with focus to application in the automotive industry. This wire material was developed to prevent halide induced interface corrosion and also sulfur induced pitting corrosion. The copper base material was alloyed with special elements to systematically adjust the intermetallic compound formed at the interface to the pad metallization and to define the microstructure of the copper base material to prevent sulfur induced corrosion. We show results of high resolution analyses (Scanning Electron Microscopy, Transmission Electron Microscopy, nanospot-EDS-mapping, electron-beam diffraction) for the characterization of the intermetallic compounds formed between bond wire and die metallization of different wire types in comparison to the new APC wire "EX1R". Also the running corrosion mechanisms at the interconnection area will be investigated in detail. The results show that the newly developed gold-palladium coated copper wire "EX1R" shows a much higher reliability, robustness and stability especially for harsh environments with regard to halide induced corrosion.