Improvement of Adhesiveness of Cu Films on a PTFE Surface Irradiated with Low-Angle N⁺ Ion Beam

Abstract

As mobile devices become more sophisticated, their components are required to adapt to high-frequency signals. Therefor kinds of printed wiring board materials are limited, and PTFE (polytetrafluoroethylene) becomes one of candidates by improving its low adhesion characteristic. In this study, the adhesion between PTFE and Cu thin films was investigated by varying an N⁺-ion beam fluence irradiated to PTFE. The irradiation condition of an N⁺-ion beam was controlled under an acceleration voltage of 5 kV - 10 kV at an incident angle of 60°. The main focus of this study was to investigate the surface shape and chemical state of the irradiated PTFE surface, which affected to adhesiveness of PTFE. The surface smoothness was temporarily improved by increasing an irradiation fluence, and also the mechanical properties were improved by increase of the surface C-C bonding at an acceleration voltage of 5 kV. As for adhesiveness, the relationship between Cu thin films and the irradiated PTFE surface was discussed from the ion implantation simulation.