Enhancement of mechanical strength in Au films electroplated with supercritical carbon dioxide

Abstract

The effects of grain refinement and enhancement in the micro-mechanical strength were observed in the Au film fabricated by electroplating with a supercritical CO 2 contained electrolyte (EP-SCE). The ultra-fine grained Au film was achieved when a current density of 5 mA/cm 2 and a pressure of 10 MPa were applied. High carbon content was also observed in the film, which contributed to the grain refinement effect and expected to stabilize the ultra-fine grain structure. Micro-mechanical properties of the Au films were evaluated by micro-compression tests for the applications as the components in micro-electronic devices. Dimensions of the fabricated Au micro-pillar were 10×10×20 μm 3. The 0.2% yield strength and the compressive flow stress of the Au micro-pillar reached 520 MPa and 800 MPa, respectively. The micro-pillar fabricated from the EP-SCE Au film exhibited a much higher mechanical strength than that from the conventional electroplated Au film.

Electrochemical Approaches for the Recovery of Metals from Electronic Waste: A Critical Review

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“…Unlike SCFED conducted in a single SCF phase, SCFEP was normally studied in emulsified SCFs consisting of an aqueous electrolyte and a SCF. With the aid of a small amount of surfactant, Au film [129], Co film [130], Co-Ni alloy coating [131], Cu-Ni alloy coating [132], and Ni-SiC nanocomposites [131] were fabricated in emulsified ScCO 2 baths, and they all displayed smaller grain sizes, smoother surfaces, and enhanced mechanical properties. Furthermore, the use of ultrasound was reported to replace the role of the surfactant in electroplating processes, and the resulting Cu film [133], Ni coating [134], Ni-Co alloy coating [135], and Ni-Co-P alloy film [136] all exhibited superior tribological and anti-corrosive properties to those same materials that had been fabricated using either a regular ScCO 2 or a conventional method.…”

Effective Young’s Modulus of Complex Three Dimensional Multilayered Ti/Au Micro-Cantilevers Fabricated by Electrodeposition and the Temperature Dependency

“…From the Euler-Bernoulli beam theory [16], structural stability of a cantilever can be improved by using materials having high Young's modulus. The Young's modulus of gold is 78.5 GPa [8], which is much lower than that of copper (128 GPa) and silicon (165 GPa) [9]. Copper and silicon are materials commonly used in electronic components.…”

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Nanoscale Hierarchical Structure of Twins in Nanograins Embedded with Twins and the Strengthening Effect

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