Preparation and characterization of silver self-metallization on polyimide

In this work, silver (Ag) self-metallization on a polyimide (PI) film was prepared through autocatalytic plating. PI films were prepared through the solution casting method, followed by etching with potassium hydroxide (KOH) solution, sensitization with tin chloride (SnCl ₂ ), and the use of palladium chloride (PdCl ₂ ) to activate the surface of PI. Energy-dispersive X-ray analysis (EDX) showed the highest peak in the (Ag) region and confirmed the presence of AgNPs. The diffraction peaks at 2θ = 38.2 ^° , 44.5 ^° , 64.6 ^°, and 78.2 ^° represented the 111, 200, 220, and 311 planes of Ag, respectively. The FT–IR analysis for Ag-metalized PI showed that the =C-O-C= stretching absorption bands at 1735 cm ⁻¹ had no changes in position, only a significant difference in peak size at the deposition time increase. The formation of new bands (N–H stretching absorption band and N–C stretching band) assigned at 2325 and 955 cm ⁻¹ indicated strong coordination between N atoms and silver nanoparticles. The C–C stretching and = C–H plane vibration band at 1488 and 1117 cm ⁻¹ are shifted to 1413 and 1112 cm ⁻¹ , indicating the silver nanoparticles' interaction with the polymer backbone. The thermal stability of PI- and Ag-metalized PI films at various deposition times (5, 10, and 15 min) was examined using thermogravimetric analysis (TGA). For PI, T ₀ , T ₅ , T _10, and T _max were observed to be 388°C, 402°C, 414°C, and 515°C, respectively. When the deposition time increased, the thermal stability increased. As a function of the deposition, the thickness and surface morphology of the copper layer on the PI films were characterized using scanning electron microscopy (SEM).