The Effect of Current Density on Zinc Whisker Growth

Abstract:

Zinc whiskers threaten the safety of electronic components due to their electrical conductivity. Factors that control zinc whisker growth are still unknown. The aim of this study was to investigate the effect of current density (1.5, 2.25 and 3.0 A/dm2) on the formation of zinc whiskers, and to relate this to the microstructure of the deposit. Scanning Electron Microscopy (SEM) analyses show that the surface morphologies of deposits became rougher when current density increased; however, nodule density increased from 25/mm2 to 53/mm2 when current density increased from 1.5 to 2.25 A/dm2, and it decreased to 24/mm2 when current density increased to 3.0 A/dm2. X-ray diffraction analyses (XRD) show that the preferred orientation of deposits remain when current densities increased from 1.5 to 2.25 A/dm2, while it changed to when current density increased to 3.0 A/dm2. Results show that zinc coatings electroplated at 2.25 A/dm2 may have greater risk of whisker growth then that electroplated at 1.5 or 3.0 A/dm2.

• Periodical: Advanced Materials Research (Volumes 562-564)
• Pages: 129-133
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.562-564.129
• Online since: August 2012
• Authors: Wen Cui
• Keywords: Coating Surface Morphology, Current Density, Grain Orientation, Zinc Whisker

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