Abstract: The electroplating Ni/Au process plays a significant role in the electronics manufacturing industry, but the insufficient adhesion of the Ni/Au plating layer severely affects product quality. This study found that the absence of a “micro-etching” process in existing techniques leads to inadequate surface microstructure of the substrate, resulting in insufficient adhesion strength of the electroplated film layer. To address this issue, this research proposes introducing a “micro-etching” process before electroplating, which optimizes the substrate surface microstructure through chemical reactions, significantly improving the root mean square roughness (Rq) and average roughness (Ra) of the copper layer. Experimental results indicate that the adhesion test pass rate increased from 67% to 100% after implementing the micro-etching process, and its effectiveness was validated in actual production. The findings demonstrate that enhancing the substrate surface microstructure is critical to improving the adhesion of the Ni/Au plating layer, providing an effective solution to enhance the reliability of the Ni/Au electroplating process on thick-film and thin-film hybrid substrates.