Study of Color Change Characteristics of Plasma Indicators by Vacuum Ultraviolet Light from Excimer Lamps

We examined the color change characteristics of two types of “Plasma Indicators” (referred to as Indicators hereinafter) irradiated by vacuum ultraviolet (VUV) light from excimer lamps. We found that the colors of both Indicators change in accordance with the sensitivity of the VUV irradiation dose when the oxygen concentration is constant. We concluded that an appropriate Indicator must be selected according to the required VUV irradiation dose of each excimer lamp application. Moreover, we demonstrated that both Indicators were useful, and the reproducibility of VUV irradiation was confirmed only under the same VUV irradiation conditions. Copyright © The Japan Institute of Electronics Packaging.