Development of an Innovative Micro Capacitive Humidity Sensor with Double Polyimide Thin Films and Interlacing Out-of-plane Electrodes

• Main Authors: Yao-Yu Li, 李曜宇
• Other Authors: I-Yu Huang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/97598980248151472689

碩士 === 國立中山大學 === 電機工程學系研究所 === 94 === Polyimide thin films have been widely used in microelectronic and Micro-Electro-Mechanical System applications due to their many excellent characteristics including low dielectric constant, easy processing, good step coverage ability, high heat resistance and chemical resistance. This paper presents the design, fabrication and complete characterization of an innovative capacitive relative humidity (RH) microsensor. The double polyimide thin films adopted in this study function as a capacitance sensing layer and a protecting layer of top electrodes respectively. To improve the humidity sensitivity and responding speed, interlacing out-of-plane electrodes are designed in the RH microsensor. The higher sensitivity ( 1.25 pF/％RH ), optimized sensing linearity ( 99.968％ ) , very low hysteresis ( 0.24 ％RH ), excellent stability ( 1.36 ％RH ) , high accuracy ( ± 1.12 ％RH ) and fast response ( within 1 seconds ) characteristics of the RH microsensor have been demonstrated in this thesis.