JSTS:Journal of Semiconductor Technology and Science

The Institute of Electronics and Information Engineers (대한전자공학회)
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A Highly Sensitive Humidity Sensor Using a Modified Polyimide Film

  • Kim, Yong-Ho (School of Mechanical Engineering, Yonsei University) ;
  • Lee, Joon-Young (School of Mechanical Engineering, Yonsei University) ;
  • Kim, Yong-Jun (School of Mechanical Engineering, Yonsei University) ;
  • Kim, Jung-Hyun (Department of Chemical Engineering, Yonsei University)
  • Published : 2004.06.30
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Abstract

This paper presents the design, fabrication sequence and measurement results of a highly sensitive capacitive-type humidity sensor using a polyimide film without hydrophobic elements. The structure of the humidity sensor is MIM (metalinsulator-metal). For a high sensitivity, a modified aromatic polyimides as a moisture absorbing layer has been synthesized instead of using general polyimides containing hydrophobic elements. The polyimide film was obtained by synthesizing and thermally polymerizing polyamic acid composed of m-pyromellitic dianhydride, phenelenediamine and dimethylacetamide. Characteristics of fabricated sensors which include sensitivity, hysteresis and stability have been measured. The measurement result shows the percent normalized capacitance change of 0.37/%RH over a range from 10 to 90%RH, hysteresis of 0.77% over the same %RH range and maximum drift of 0.25% at 50%RH. The result shows that the developed humidity sensor can be applied to evaluate a hermeticity of various sensors and actuator systems as well as micro packages.

Keywords

References

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