WITHSTAND VOLTAGE TESTING METHOD FOR INSULATOR

PURPOSE:To provide the withstand voltage testing method capable of easily testing all insulators applied with high voltage and capable of simply performing a post-treatment. CONSTITUTION:Voltage is applied to a substrate 5 to inspect its insulation property in the withstand voltage testing method of an insulator. Voltage is applied for testing while the substrate 5 is dipped in an inactive fluorine liquid 4. Perfluorocarbon (with the structural formula of CnF2n+2 having a high insulation property and the boiling point within the range of 40-200 deg.C is used for the inactive liquid 4. When perfluorocarbon is used for the inactive liquid 4, a test can be performed at the voltage higher than the expected load voltage to the substrate 5, and the reliability on the test result is sharply improved. The perfluorocarbon stuck to the substrate 5 can be easily removed by the withstand voltage test, the post-treatment is simple, and all insulators can be easily tested.