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http://dx.doi.org/10.5369/JSST.2004.13.4.287

A Capacitive Type Humidity Sensor Using a Polyimide Film for Hermeticity Measurement of Micro Packages  

Kim, Yong-Ho (Department of Mechanical Engineering, Yonsei University)
Kim, Yong-Jun (Department of Mechanical Engineering, Yonsei University)
Kim, Kyung-Il (Department of Chemical Engineering, Yonsei University)
Kim, Joong-Hyun (Department of Chemical Engineering, Yonsei University)
Publication Information
Journal of Sensor Science and Technology / v.13, no.4, 2004 , pp. 287-291 More about this Journal
Abstract
A capacitive type humidity sensor has been fabricated using a polyimide film without hydrophobic elements and its characteristics has been evaluated for hermeticity measurement of micro packages. For a highly sensitive humidity sensor, a polyimide film without hydrophobic elements has been synthesized and used instead of using a commercial one in which 7 group elements such as fluorine or chlorine are included. Sensitivity, stability and hysteresis has been performed to characterize the fabricated sensors. The sensitivity defined as normalized percent capacitance change was 0.3751%RH and hysteresis was 0.77% in the range of 10%RH to 90%RH. Maximum deviation from the average capacitance measured for 120 minutes at 50%RH was 0.25%. The proposed humidity sensor can be used for hermeticity measurement of micro packages.
Keywords
Humidity sensor; polyimide; hermeticity; micro package;
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