Electroless Plating Of Cu-Ni-P Alloy Film For EMI Shielding On Epoxy Resin Surface

An electromagnetic interference (EMI) shielding film was prepared in this thesis by using electroless plating of Cu-Ni-P alloy on the surface of epoxy resin plastic packaging. The results show that the method of electroless plating of Cu-Ni-P alloy film possess simple process technics, carrying out easily, excellent properties of film, good stability and long periods of plating bath, and the Cu-Ni-P film can fit the require of EMI shielding commendably.The optimized processes of electroless Cu-Ni-P film plating were got in this study. First the raw materials are innocuous, non-contaminative to environment by using sodium hypHospHite instead of traditional formaldehyde as reducer. Formaldehyde is volatilizable and has the danger of causing cancer, however, sodium hypHospHite is not volatilizable. Furthermore, the localization with nickel as main component in most Cu-Ni-P alloy was changed. This method can get the film with varied copper and nickel element content by changing the adding proportion of copper and nickel ions of plating bath according to different purpose and demand. Thus the aim of the copper and nickel element content proportion to vary continuously was realized.The Cu-Ni-P films have different properties, such as electrical conductivity, magnetic conductivity, anti-eroding capability and crystal style of film, prepared in different component of plating bath. The films with most copper content have high electrical conductivity, low magnetic conductivity and anti-eroding capability, and the films belong to crystal structure. When the nickel content increases, the electrical conductivity of film become decrease, the magnetic conductivity and anti-eroding capability become increase, and the film change to be uncrystallized structure gradually. According to the results of experiments, the anti-eroding capability of Cu-Ni-P film is better than that of pure Ni-P film. The reason is that the adding of copper changed the crystal configuration of Ni-P alloy.The EMI shielding effectiveness (SE) of films was calculated by formula and measured using flange coax method separately, and compared each other. It is show that the EMI shielding effectiveness of Cu-Ni-P alloy films obtained in this study is satisfied whenever at the theory or the fact measuring.