Silane modification of semi-curing epoxy surface: High interfacial adhesion for conductive coatings

Weak interfacial bonding between epoxy resin and plated metallic layer limits the development of epoxy resin in electronic devices and multilayer circuits. In this work, we propose a surface silane graft strategy by utilizing the active epoxy groups of semi-curing epoxy resin, which can replace the alkali washing and coarsening steps before metallization and achieve higher interfacial adhesion strength to the metallic layer. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the chemical composition of the surface after the modification process. The effects of modification time and concentration of 3-mercaptopropyltriethoxysilane (MPTES) solution on the adhesion strength were studied by 180° peeling test. When the modification time reached 20 min or the concentration of MPTES solution was above 8 %, the adhesive strength was stable at 16 N/cm, showing a strong adhesive effect on the silver layer. This research may have positive implications for improving interfacial bonding between metal and polymer surfaces.