Pulse plating of matt tin: effect on properties

The present work investigates the effects of pulse plating on the microstructure of matt tin coatings derived from a proprietary acidic methanesulphonate bath. The objective was to analyze how varying duty cycles and pulse frequencies affect current efficiency, surface roughness, grain size, and grain orientation of tin deposits. Using a systematic experimental approach, the study measured these parameters under different pulse plating conditions. The results revealed that while the overall impact of pulse plating on microstructure was limited, significant trends were observed. Specifically, the average grain size increased with rising duty cycle but decreased with higher pulse frequency. The fundamental columnar structure of the deposits was largely unchanged by pulsed current deposition. In terms of orientation, pulse plated deposits displayed a strong (110) texture that weakened with diminished duty cycle or frequency. Notably, surface morphology improved with pulse plating; a reduction in surface roughness was noted as duty cycle or frequency decreased. This study highlights the nuanced effects of pulse plating in electrodeposition, providing insights into optimizing the microstructural characteristics of tin coatings.