Rationally design of substrate surface topography toward the improvement of Cu-plated coating adhesion

Electroless plating is a promising method to achieve material surface metallization, low rupture work of plated coating and complex production processes have become important factors that restrict its progress. In this study, a facile method combined with primer modification (mixture of SiO₂ particle and resin) and electroless deposition to fabricate a high-adhesion Cu-plated coating is demonstrated. Results showed that poly(ethylene terephthalate) (PET) modified with primer could absorb Ag⁺ through the coordination effect because hydrophilic groups (–OH and –NH₂) were possibly used as a bridge for chemisorbing of rare metal ions (Ag⁺) through ion exchange, which acted as a catalyst for the deposition of Cu coating on its surface. More importantly, introducing SiO₂ particles in the primer can improve surface roughness, which is enhanced from 0.643 to 0.829 μm of modified coating, result in the improvement of substrate/deposited coating contact area, which would facilitate the enhancement of the adhesion behavior of plated coating. The deposition of bead-like structure Cu coating on primer-modified PET surface with a higher average roughness value possessed excellent electrical property, adhesion and crystallization. The resistivity of the copper patterns is approximately 9.81 × 10⁻⁶ Ω·cm. It is promising to integrate this kind of metal material with excellent performance in future flexible devices.