Sputtering Process Assessment of ITO Film for Multiple Quality Characteristics With One-Sided and Two-Sided Specifications

Abstract

Abstract The evolution of technology has increased the demand for convenient and user-friendly human–machine interfaces. This demand has driven the rapid development of the touch panel industry. Functioning as a conductive medium, indium tin oxide (ITO) film is a key factor in the quality of touch screens or panels. Because the sputtering process of ITO film includes both STB- and NTB-type quality characteristics, the analysis methodology proposed in the past cannot represent distinct influences or provide the production department with sufficient reference for improvements. Therefore, the purpose of this paper is to apply the bilateral index Cpm, which fully reflects process loss and yield, to develop an effective assessment model for the sputtering process with one-sided and two-sided specifications. Traditionally, Cpm can only be used to measure the capability of processes with two-sided specifications. We used the variable transformation method to develop the multi-process capability analysis chart. This chart is capable of measuring process precision and accuracy in relation to both types of quality characteristics. When process capability falls short of required standards, manufacturers can investigate the reasons according to the position of each quality characteristic on the chart. These data provide an important point of reference for proposing improvements to the sputtering process to enhance the quality of ITO film products and increase the competitive advantage and productivity of manufacturers.