Surface Topography and Microstructure of Copper Plating Machined with Single-Crystal Diamond Tool

This study investigates the surface characteristics of copper plating machined with a single-crystal diamond tool. The surface topographies of the machined samples were evaluated using WLI and AFM. PSD analysis showed that copper plating is smoother than oxygen-free copper at spatial frequencies below 2 × 10⁴ mm⁻¹. Although the PSD of copper plating was the highest above 2 × 10⁴ mm⁻¹ due to its sand-like texture, this did not significantly affect its RMS roughness. Microstructural analysis using EBSD and XRD revealed that the copper-plated surface consists of fine crystalline grains, likely responsible for the observed texture. These results indicate that copper plating can be smoothly machined and is suitable for use in optical components.