Application of the Self-Made Flexible Three-in-One Microsen-Sor to the Laboratory Oven for Immediate Micro-Monitoring of the Roll-to-Roll Process of Polarizing Films

Abstract

The main purpose of this study is to carry out the immediate micro-monitoring of the roll-to-roll (R2R) process of polarizing films. Therefore, a self-made flexible three-in-one (temperature, humidity, and flow) microsensor is developed. The temperature and flow sensing area are 585 μm × 450 μm, the humidity sensing area is 1065 μm × 1035 μm, and the minimum line width is 15 μm. The micro-electro-mechanical systems (MEMS) technology was applied to integrate temperature, humidity, and flow sensors on a 50 µm thick polyimide substrate. A 100 Å thick chromium (Chrome, Cr) section form the adhesion layer. A 1000 Å thick gold section forms the sensing layer. A self-made flexible three-in-one microsensor set up in a laboratory oven for immediate micro-monitoring of the R2R process of the polarizing film. Since it is not advisable to set up signal lines in a clean room, the analog signals of the sensor should be transmitted via wireless means. Thus, a monitoring module should be connected to the back end of the self-made flexible three-in-one microsensor to receive the analog signals of the sensor, convert them into digital signals, send them out in the form of wireless signals, and store the data on the server-side. Through these measures, both the R2R process and yield can be improved. Therefore, the focus of this study is the environmental monitoring of drying process ovens. However, commercially available all-in-one sensors cannot handle the temperature of high-temperature factory ovens, and commercial flow sensors are rarely used in high-temperature applications. Some are also expensive and cannot be widely distributed, so this study intends to develop an integrated sensor to measure the internal environment of the drying oven.