Preparation of ultra-thin silver coatings by laser-induced chemical deposition: Deposition mechanism and regulation of optical characteristics

Abstract

The localized silver-plating process typically involves three stages: pre-plated silver, mask silver plating, and de-plated silver. Among these, the design and fabrication of profiling fixtures required for the mask silver plating process have become increasingly challenging. In this study, laser-induced chemical deposition (LICD) technology was introduced to replace conventional mask profiling fixtures in the mask silver plating process, and the effects of laser parameters on the optical characteristics of silver coatings were investigated. Under a single pulse energy of 100 μJ, an experimental study was conducted to systematically examine the chemical deposition of silver coatings induced by varying pulse widths. The results revealed that laser irradiation remelts the pre-plated silver substrate, a critical condition for the formation of fog silver coatings. In contrast, bright silver coatings are formed under different conditions. The fog silver coatings produced by LICD exhibited superior thickness, roughness, and corrosion resistance, while the bright silver coatings featured smaller grain sizes and enhanced brightness characteristic of silver. This mechanistic analysis of the optical properties of silver coatings provides a theoretical foundation for optimizing LICD and tailoring the functional properties of the coatings.