Residual Stress in Thin-Film Parylene-C
Caltech Micromachining Laboratory
Project Abstract
This paper reports the influence of thermal annealing on the residual stress in
parylene-c thin-films on silicon. Although recently others have used the diaphragm
bulge testing method to measure the residual stress in parylene, this is the first
extensive study of residual stress in parylene using the load-deflection method and
rotating tip strain gages. This paper supports the hypothesis that stress is relaxed
in parylene-c films at elevated temperatures (>100 °C) and that thermal stress accounts
for 90% of the residual stress in films that have undergone annealing at these elevated
temperatures. It was found that this held true up to 180 °C which is above the glass
transition temperature of the material.
Involved Personnel
Theodore A. Harder, Tze-Jung Yao, Qing He, Chi-Yuan Shih and Yu-Chong Tai
Related Publications
W. Xuan-Qi, et al., "A Parylene micro check valve," MEMS 99, pp.177-82. Piscataway, NJ, USA., 1999.