Rhodium is an extremely rare and expensive precious metal belonging to the platinum group. It is known as a silvery-white metal with excellent corrosion resistance, wear resistance, high hardness, and high catalytic activity. In manufacturing, it is primarily used for surface treatment to leverage these properties. Typical processing methods include electroplating, electroless plating, sputtering, and vapor deposition, with thin-film formation technologies being central. Its main applications are diverse, including three-way catalysts for automotive exhaust gas purification, wear resistance and low contact resistance in electronic component contacts and connectors, anti-tarnish plating for jewelry, chemical reaction catalysts, and high-reflectivity mirrors. Due to its rarity and high functionality, precise and advanced processing technologies are required.