PURPOSE: To obtain a slide rheostat of long sliding life by a method wherein it is arranged on an insulated substrate composed of a thin film intermetallic compound having specific Vickers hardness, surface roughness and resistivity.
CONSTITUTION: The slide rheostat 9 on a glass substrate 8 is an intermetallic compound having a Cr-Au-O composition, and the slide rheostat 9 is formed by a two-element simultaneous sputtering method in which O2-containing Ar gas is introduced into a device using Cr and Au as a sputtering target. This thin film intermetallic compound has the Vickers hardness of 1000 or higher, surface roughness of 1.6Rmax and resistivity of 1×10-1 to 1×10-4 Ω/cm. After electrodes 10 and 11 have been formed on both ends of the slide rheostat 9 which is formed as above, a lead wire is soldered to the electrodes 10 and 11. As a result, a slide rheostat, having a long sliding life, can be obtained.
UCHIDA KIMIO
YORINAGA MUNEO
MASE SHUNJI
NIPPON SOKEN