Highly-Sensitive Capacitive Touch Sensor Integrated on Thin Film Encapsulated Active-Matrix OLED for Ultra-Thin Display

Abstract: Ultra thin and highly sensitive input/output devices consisting of capacitive touch sensor (Cap-TSP) integrated on thin film encapsulated AMOLED are achieved. The optimal structure of capacitive touch sensors without an electrical noise, assembled on a thin-film-encapsulated AMOLED display, is obtained by investigating the internal electrical field distribution and capacitance change based on a Q3D Extractor model. An electrostatic simulation can verify malfunction- free electrical signals for 4-inch diagonal sized capacitive touch sensors on AMOLED with a 100μm-thick optically clear adhesive (OCA, εr=1.4) layer. Prototype OLED platform with capacitive touch sensors exhibits an overall thickness of 1.2mm, the thinnest among commercially available OLED platforms.