Adhesion of HIPIMS-Deposited Gold to a Polyimide Substrate

Gold is the preferred material for conductive structures in neural implants. The hitherto employed process applies adhesive layers to avoid delamination of gold structures from a polymeric substrate. The possibility to deposit gold without the use of adhesive layers is offered by the high-power impulse magnetron sputtering (HIPIMS) process. In this work, it is shown that it is possible to utilize the HIPIMS process to deposit gold onto polyimide while having enough adhesion between these two layers to omit the use of an adhesive layer. A scratch test was performed to demonstrate the adherence between the layers.