Diamond-like carbon coating for effective electrical insulation of Cu and Al wires

Abstract

The physical and mechanical properties, electrical insulation, chemical resistance, and heat resistance of diamond-like carbon (DLC) films fabricated using the radio frequency plasma-enhanced chemical vapor deposition method (RF-PECVD) on Cu (DLC/Cu) and Al (DLC/Al) substrates were evaluated in this study. The electrical insulation testing results showed that the dielectric breakdown voltage of both DLC/Cu and DLC/Al samples was approximately 145 kV/mm. For assessing the heat resistance, the samples were stored at a high temperature of 200 °C for a fixed time duration, and the changes in the insulation voltage resistance were evaluated. Based on the voltage resistance measurement results of the electrical insulation after heat resistance testing, the study confirmed that the DLC film is heat stable for 7 days of heating. In addition, testing confirmed that the DLC coating remained stable with no deterioration when immersed in both acidic and alkaline solutions, thus indicating high chemical resistance. These findings suggest that DLC is suitable for application as a thin and effective electrical insulation coating, and its properties support the realization of small coil lengths with square wires.