Graphene-Oxide-Assisted\nElectroless Cu Plating on\na Glass Substrate

In recent years, the advancement of high-frequency communication\nsystems, particularly 5G and future 6G technologies, has increased\nthe need for substrates that minimize signal loss and electromagnetic\ninterference. Glass substrates are highly desirable for these applications\ndue to their low dielectric constant and excellent surface smoothness.\nHowever, conventional electroless Cu plating methods struggle to achieve\nstrong adhesion between Cu and the smooth, low-polarity surface of\nglass, making this an important challenge to address. To overcome\nthis issue, this study presents a novel electroless Cu plating method\nthat employs graphene oxide (GO) as an intermediary layer on amino-functionalized\nglass substrates. During a preheating process at 150 °C, the\nGO layer forms covalent C–N bonds with the amino-modified glass,\nsignificantly enhancing adhesion while preserving the surface smoothness\nrequired for high-frequency applications (<i>R</i><sub>a</sub> = 6.6 nm). This GO-based approach eliminates the need for traditional\nsurface roughening techniques. Additionally, by incorporating silver\nnanoparticles (Ag NPs) as a catalyst, this method provides a cost-effective\nalternative to conventional palladium-based processes for Cu electroless\nplating. The resulting Cu film exhibits excellent adhesion, as confirmed\nby tape peel tests and a low volume resistivity of 2.4 μΩ·cm,\nmaking it well-suited for applications that require minimal signal\nloss at high frequencies.This innovative technique not only enhances\nthe adhesion of the conductive layer but also maintains the surface\nsmoothness crucial for high-frequency signal transmission, positioning\nit as a promising solution for the fabrication of advanced substrates\nin next-generation communication technologies.