Effect of Copper Powder Modification and Silver Content on Coating Adhesion and Corrosion Resistance of Silver-Coated Copper Powder

Silver-coated copper powder, possessing both excellent electrical conductivity and cost advantages, holds broad application prospects in electronic packaging and conductive materials. This study investigates the surface characteristics of copper powders produced by different methods and the effect of surface modification on electroless silver plating. It also analyses the regulatory role of silver content on coating structure and corrosion resistance. Results indicate varying responses to modifiers among different copper powders: contact angle decreased from 52.9° to 50.3° for physically modified copper powder and from 61.9° to 40.9° for chemically modified copper powder, demonstrating significantly improved surface wettability and enhanced silver layer coverage integrity. As silver content increased from 8 wt% to 15 wt%, the silver layer’s compactness increased, enhancing corrosion resistance. The self-corrosion current densities for physically and chemically modified copper powders decreased from 1.285 × 10−5 and 1.120 × 10−5 A·cm−2 to 4.671 × 10−6 and 5.075 × 10−6 A·cm−2, respectively. At 15 wt% silver content, the emergence of free silver particles on the powder surface led to reduced stability. This study elucidates the synergistic regulation mechanism between the properties of the copper powder matrix and the silver coating content on the silver-coated copper powder structure and its corrosion resistance. It provides experimental evidence for the design and application of high-performance silver-coated copper powders.