Roll To Roll Manufacturing of Flexible Electronic Devices

Abstract

Flexible electronics may be bent, flexed and rolled to an extent and still be expected to maintain their functionality. The focus of this thesis is on efficient manufacture of electronic devices in flexible form using roll to roll (RTR) method of continuous manufacturing which is expected to significantly improve productivity and efficiency and reduce manufacturing costs. A comprehensive study of the literature was undertaken to understand the various processes involved in the manufacture of flexible electronics such as organic light emitting diodes (OLEDs) and solar cells, and an investigative study was carried out to highlight those processes and methods that are suitable for RTR manufacture of flexible electronic devices. Design of three web lines for RTR manufacturing of different stages of flexible electronic devices was investigated. Based on a comprehensive study of the various processes involved in manufacturing of flexible electronic devices, OLEDs and polymer solar cells in particular, web handling strategies and parameters were determined for continuous processing of flexible electronic devices using several web lines. The drag force on the web material was calculated based on the crosswise laminar movement of the fluid in the liquid bath through which the web is transported. Simulations were conducted to regulate tension and velocity of the web using the governing equations for web tension and velocity. The web process lines designed in this thesis for OLEDs and solar cells can be modified to manufacture other flexible electronic devices using RTR methods. A model for web tension for lamination of two webs was investigated. This model was used for studying the tension behavior during simultaneous lamination of barrier materials to both sides of a solar cell substrate material.