Authors: M L Huang F F Huang J L Pan T X Zhang
Publish Date: 2014/08/21
Volume: 25, Issue: 11, Pages: 4933-4942
Abstract
The optimal electroplating parameters for a pulsecurrent coelectroplating system of Au–Sn deposits in a noncyanide electrolyte were investigated using experimental strategies including fractional factorial design FFD and central composite design CCD coupled with the response surface methodology pH value ethylene diamine tetraacetic acid EDTA concentration catechol concentration and metallic ions molar ratio ie Au/Sn were identified as the key factors affecting the composition of Au–Sn deposits in the FFD study A reliable model between the response variable and the key factors of pH value EDTA concentration and catechol concentration was established for the composition control of Au–Sn alloys in the CCD study The standard deviation of the response variable tin content was set at the minimum level to determine the optimal coelectroplating parameters for the predicted composition value of Au–Sn deposits Pair T test was conducted to validate both predicted and observed composition values under the optimal electroplating parameters and the composition of Au–Sn deposits can be precisely controlled based on the established model Scanning electron microscope observation and Xray diffractometer analysis revealed that the morphology and crystalline of the Au–Sn deposits were compositiondependent
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