Comparative analysis of gold-coated silver and conventional gold wire for semiconductor wire bonding: material properties and corrosion susceptibility in microelectronics

Purpose This research aims to provide a comprehensive material-level comparison of gold-coated silver (ACA) wire and conventional gold (Au) wire, specifically for use in semiconductor packaging applications, exploring ACA as a potential low-cost alternative to enhance the cost-effectiveness and competitive positioning within the packaging market. This study introduces and validates a novel and practical evaluation framework for material selection, designed to enable informed, early-stage package development. Design/methodology/approach The methodology used surface characterization, corrosion resistance evaluation and the determination of key material properties. Surface morphology and elemental distribution of the ACA wire (18.1 µm diameter) has a uniform Au layer (approximately 110nm thickness) were examined using scanning electron microscope. Corrosion resistance was assessed through potentiodynamic polarization curve analysis in a 3.5 Wt.% NaCl solution, a widely accepted standard. In addition, the study involved precise measurements of electrical resistivity, tensile properties and wire hardness to provide a complete comparative profile of both wire types. Findings The comparative analysis conducted through the proposed framework, revealed distinct differences in material properties between ACA and Au wires. ACA wire exhibited a 12.5% reduction in hardness, a 22.5% reduction in breaking load and a 21.0% reduction in electrical resistivity when compared to Au wire. Furthermore, potentiodynamic polarization curve analysis indicated a higher corrosion current density (icorr) for ACA wire (12.473 nA/cm2) compared to Au wire (2.546 nA/cm2), suggesting a lower corrosion resistance. Originality/value This research provides a comprehensive material-level assessment, and the analysis, tailored to the targeted application, contributes a novel framework for material selection. This framework enables informed early-stage package development and can potentially reduce development time and costs for the microelectronic packaging industry. The experimental results, while aligning with existing literature, also serve to validate the effectiveness of our proposed evaluation methodology.