Research on Surface Treatment and Interfacial Bonding Technology of Copper–Polymer Direct Molding Process

To realize the connection of copper and Polyphenylene sulfide (PPS) by metal–polymer direct molding, this paper combined anodic oxidation and chemical corrosion to treat the surface of copper, and carried out the injection molding experiment. An orthogonal experimental arrangement was used to identify the optimal electrolyte and etching solution for preparing a microstructure on a copper surface. The bonding and fracture mechanisms of the copper–polymer assembly were investigated through injection molding experiment and SEM technology. The results revealed that the phosphoric acid concentration had the most significant effect on the microstructure quality and etching solution containing 20% phosphoric acid produced a uniform microstructure with 25.77% porosity and 5.52 MPa bonding strength. Meanwhile, SEM images of the interface from bonding to fracture in the copper–polymer assembly indicated a well-filled polymer in the microstructure with a mainly cohesive fracture mode.