Effect of CuSO4 Content in the Plating Bath on the Properties of Composites from Electroless Plating of Ni-Cu-P on Birch Veneer

A wood-based composite was prepared via simple electroless Ni-Cu-P plating on birch veneer for EMI shielding. The effects of CuSO4·5H2O concentration on the metal deposition, elemental composition, phase structure, surface morphology, wettability, surface resistivity, and shielding effectiveness of coatings were investigated. The coatings were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). When the CuSO4·5H2O concentration was increased from 0.6 g/L to 2.2 g/L, the metal deposition was decreased from 79.61 g/m 2 to 66.44 g/m 2 . Elemental composition showed that the copper content in the coating increased significantly, whereas the nickel content was reduced significantly and the phosphorus content was slightly reduced. The crystallinity of coatings increased, and fine-grain structure was observed, with higher copper content. Ni-Cu-P deposition improved the hydrophobic properties when the maximum static contact angle increased from 77.5° to 116.5°. The lowest surface resistivity was 367.5 mΩ/cm 2 , and the EMI shielding effectiveness of Ni-Cu-P-coated veneers was higher than 60 dB in frequencies ranging from 9 kHz to 1.5 GHz.