In order to improve the surface performance of PCB epoxy resin board for sensor, sodium hypophosphate system was used for vacuum evaporation copper plating on its surface. Sodium benzenesulfonate SBS and polyethylenimine PEI were selected as additives to analyze their influence on the performance of copper plating layer, and the suitable additives for vacuum evaporation copper plating process were obtained. Results showed that the optimal content of PEI was 16～28 mg/L, that of SBS was 54～62 mg/L, and the vacuum evaporation copper plating temperature was 40～50 ℃ under the condition of continuous deposition of copper for 0.5 h at 65 ℃, based on the deposition rate and plate color. Copper was precipitated from the plating solution at approximately 20 min, and the vacuum evaporation copper plating solution with combined additives had the longest duration and showed the optimal stability. With additives, the coating had better microstructure and particle size became finer, and the number of holes decreased significantly, resulting in a denser structure and a smoother grain shape. The coating prepared by the combined additive had smaller porosity and better performance than that prepared by the single additive.
