APPLICATION OF ION CHROMATOGRAPHY TO FAILURE ANALYSIS OF ELECTRONICS PACKAGING

Ionic contamination is a frequent cause of corrosion failures in electronics packaging. Ionic Cl-, SO4(2-), Na+ and K+ are the species most frequently associated with corrosion and are easily detected by ion chromatography (IC) or other surface analysis techniques (XRF, EDX, etc). This paper will describe a corrosion problem, involving gold-plated copper wires and an automated wire bonding operation, and its solution using IC and Fourier transform infrared (FT-IR) analysis, which showed that the corrosion was caused by ionic NO2- and NO3-, species which are not easily detected by other surface analysis techniques.