Alloy Electroplating and Young’s Modulus Characterization of AuCu Alloy Microcantilevers

Abstract

This paper reports fabrication of AuCu alloy microcantilevers by alloy electroplating with a non-cyanide electrolyte and evaluation of the Young’s modulus by a resonance frequency method. Length of the microcantilever is ranged from 50 ∼ 1000 μm, and the width is from 10 ∼ 20 μm. Effects of the applied current density (CD) on the composition, morphology, Vickers hardness, and Young’s modulus of the AuCu alloy microcantilever are studied. The copper content increases from 0.8 ∼ 10.1 wt% when the CD increased from 0.01 ∼0.6 A dm−2. The alloy electroplated at 0.6 A dm−2 shows the highest Vickers hardness at 379 HV. Young’s moduli of the AuCu alloy microcantilevers are varied in a range from 70.4 ± 4.2 ∼ 80.0 ± 1.9 GPa when the copper content varied from 1.38 ∼ 4.03 wt%.