Electroless Ni-P deposition on flexible polyimide substrates with tin-palladium nucleation

The purpose of this study is to report a low-cost electroless deposition (EN) process of Ni-P thin films using a wet-chemical process on flexible polyimide substrate (Kapton ® 300HN DuPont™), comprising surface functionalization with NaOH, nucleation with Sn and Pd, and acceleration with HCl. The pretreatment performed on the polyimide surface was investigated using a contact angle system and Fourier-transform infrared spectroscopy (FTIR). Structural, morphological and electrical characterization of the Ni-P film were performed by X-ray diffraction (XRD), stylus scan profiler, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and four-point probe measurements. The results showed that the pretreatment of the flexible polyimide enables a faster EN process, with lower thermal expenses, delivering a compact, spherical shaped Ni-P film -free of holes, scratches, and flaws, with particle size ranging from 380 to 780 nm.