Hostname: page-component-76fb5796d-22dnz Total loading time: 0 Render date: 2024-04-27T00:32:53.664Z Has data issue: false hasContentIssue false
  • English
  • Français

Mechanical and Piezoresistive Properties of Graphite-Filled Polyimide Thin Films

Published online by Cambridge University Press:  15 February 2011

A. Bruno Frazier ,
M. R. Khan  and
Mark G. Allen
A. Bruno Frazier
Affiliation:
Georgia Institute of Technology, School of Electrical Engineering, Atlanta, Georgia 30332-0250
M. R. Khan
Affiliation:
Georgia Institute of Technology, School of Electrical Engineering, Atlanta, Georgia 30332-0250
Mark G. Allen
Affiliation:
Georgia Institute of Technology, School of Electrical Engineering, Atlanta, Georgia 30332-0250
Get access

Abstract

The piezoresistive effect of materials is used as the basis for many types of microsensors. Polyimide, a material widely used in microelectronic fabrication, may be made to exhibit this effect by addition of small graphite particles to form a composite material. Polyimide / graphite based piezoresistive films have the advantage of being spin-castable, plasma-processable, highly chemically resistant, and thermally stable up to 400 °C in nitrogen atmospheres. In this work, piezoresistive polyimide films are formed by addition of various amounts (loadings) of graphite particles one micron in diameter or less to DuPont PI-2555 polyimide. Thin films of these materials are spin-cast on silicon wafers, and an in-situ load-deflection measurement technique is used to evaluate the following film properties: piezoresistive coefficient as a function of both strain and graphite loading; Young's modulus as a function of graphite loading; and residual film stress as a function of graphite loading. The observed piezoresistive coefficient is a strong function of graphite loading, with good piezoresistive properties exhibited in the loading range of 15–25 wt% graphite.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 276: Symposia U/Y – Smart Materials Fabrication and Materials for Micro-Electro-Mechanical Systems , 1992 , 295
Copyright
Copyright © Materials Research Society 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Taylor, L.T. and St. Clair, A.K., ‘Mechanical and Spectroscopic Properties of Metal Containing Polyimides’, Polyimides: Synthesis. Characterization. and Applications, Vol.2, Plenum Press, 1982, pp. 617–646.Google Scholar
2. Taylor, L.T., ‘Synthesis and Properties of Metal Containing Polyimide Films’, Recent Advances In Polyimide Science and Technology, Proceedings of the Second International Conference on Polyimides, 1985, pp. 428–437.Google Scholar
3. Rancourt, J.D., Boggess, R.K. and Taylor, L.T., ‘Electrical Properties of Polyimide Containing Surface Cobalt Oxide’, Recent Advances In Polyimide Science and Technology, Proceedings of the Second International Conference on Polyimides, 1985, pp. 438–452.Google Scholar
4. Madeleine, D.G. and Taylor, L.T., ‘Thermal and Ultraviolet Treatment of Gold Containing Polyimide XU-218’, Recent Advances In Polyimide Science and Technology, Proceedings of the Second International Conference on Polyimides, 1985, pp. 453–462.Google Scholar
5. Boggess, R.K. and Taylor, L.T., ‘Polyimide Films Doped with Silver Nitrate’, Recent Advances In Polyimide Science and Technology, Proceedings of the Second International Conference on Polyimides, 1985, pp. 463–470.Google Scholar
6. Stoakley, D.M. and St. Clair, A.K., ‘Lanthanide-Containing Polyimides’, Recent Advances In Polyimide Science and Technology, Proceedings of the Second International Conference on Polyimides, 1985, pp. 471–479.Google Scholar
7. Timenshenko, S., Theory of Plates and Shells, (McGraw-Hill, New York, 1940), Chapter 1.Google Scholar
8. Allen, M.G., Mehregany, M., Howe, R.T. and Senturia, S.D., ‘Microfabricated Structures for the In Situ Measurement of Residual Stress, Young' Modulus, and Ultimate Strain of Thin Films’, Applied Physics Letters, 51, 1987, pp. 241–243.CrossRefGoogle Scholar
9. Tabata, O., Kawahata, K., Sugiyama, S. and Igarashi, I., ‘Mechanical Property Measurements of Thin Films Using Load-Deflection of Composite Rectangular Membranes’, Sensors and Actuators, 20, 1989, pp. 135–141.CrossRefGoogle Scholar
10. Bokov, Y.S., Soviet Microelectronics, 14, 1985, pp. 210–215.Google Scholar
11. Clark, L.D., and Edell, D.F., “KOH: H2O Etching of (110) Si, (111) Si, SiO2 and Ta: An Experimental Study’, IEEE Micro Robots and Teleoperators Workshop, Hyannis, MA, 1987.Google Scholar