In the traditional circuit board metallization process, the electroless plating process is the most common, but it contains precious metals (such as palladium catalyst), formaldehyde and chelating agents which can cause a serious environmental problem. However, the direct reduction process of graphene oxide (GO) does not include the toxic as mentioned above. In additionally, reduced GO (rGO) can be regarded as a direct plating process (i.e., without electroless deposition before copper electroplating) is simpler than electroless plating process and can replace the electroless plating process to achieve a green metallization process.

Although rGO is a good electric conductor, copper is difficult directionally deposited on it due to its p-electron characteristics, which transfers only in X-Y two-dimensions. Therefore, when rGO is electroplated in a copper electroplating solution, the deposited copper crawls initially from the cathodic terminal and then fully cover the rGO-coated substrate if the surface area of the substrate is large.

In this work, we propose an approach to enhance the conductivity of rGO in Z-direction, so that rGO will have three-dimensional conductivity to meet the industrial requirement.