A fracture mechanics approach for quantifying slow crack growth in thin polyimide films and assessing their structural integrity and life expectancy is presented. The methodology and techniques developed in this investigation may also be applied to other polymeric materials. A test protocol for studying slow crack growth is described. Room temperature fracture tests were performed and an analysis model was developed and validated to analyze the fracture tests. Correlations between the rate of crack growth and the crack driving force as measured by the stress intensity factor were made and contrasted for Kapton 100HN, 300H and 500HN polyimide films. The crack growth rate was found to depend very strongly upon the stress intensity factor. The practical implication of this finding is that the fracture of these polyimide films may be approximated as being controlled by a critical value of the stress intensity factor.

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