1989 年 38 巻 9 号 p. 485-492
Copper is widely used to make cables, printed circuit boards and various structural components. However, copper tends to form thin film of oxide or sulfide on its surface, presenting tarnished appearance or undesired effects such as lowering of electrical characteristics. The present study elucidates the growth mechanism of such film through analysis of the influence of temperature, humidity, contaminating substance, surface treatment and impurity gases (SO2, HCl, H2S) on the growth speed of the film. It was found out that the long-established cathodic reduction technique was the simplest and yet considerably accurate analyzing method.