Using Reduced Graphene Oxide As Conducting Layer of Plating through Holes of a Printed Circuit Board

Graphene is a popular material because of its unique two-dimensional (2D) structure and intrigued physical and chemical properties. Graphene materials, including single layer and multi-layer graphene sheets, have recently drawn extensive attention due to their outstanding electrical and thermal properties. In the traditional metallization process of through holes of printed circuit boards (PCBs), copper electroless deposition process has been commonly used. It has environmentally unfriendly characteristics because it contains precious metal (i.e., Pd), formaldehyde and chelating agents. In contrast, reduced graphene oxide (rGO) has no these issues and can replace the copper electroless deposition of PCBs because the rGO process for copper metallization is simpler than that of copper electroless deposition. Herein, we used rGO process to replace the copper electroless deposition process in order to achieve a green fabrication process. In this study, the effect of different conditioners for uniform adsorption of graphene oxide (GO) on the sidewalls of through holes of a PCB was investigated. We used different conditioners to chemically modify the substrate surfacefor uniform adsorption of GO. Following the GO adsorption, the adsorbed GO was reduced to rGO on the substrate surface. Then, the rGO-coated sidewall becomes conductive to replace the copper seed layer by electroless deposition. Finally, the rGO-coated through holes were successfully plated in an acidic copper bath with a high throwing power and these through holes could pass thermal shock reliability test.