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Study on the effect of moisture and elevated temperature on the fracture properties of visco elastic polymers

: Walter, H.; Shirangi, H.; Dermitzaki, E.; Wunderle, B.; Michel, B.

Materials Technology Laboratory -MTL-, Ottawa:
12th International Conference on Fracture 2009. Proceedings. CD-ROM : Ottawa, Canada, July 12 - 17, 2009
Ottawa: NRCanCANMET, 2009
International Conference on Fracture (ICF) <12, 2009, Ottawa>
Fraunhofer IZM ()

The universal applicability of polymer materials in microelectronics is based on the wide adaptability of their thermo-mechanical as well as fracture characteristics. These materials have strong time and temperature dependent mechanical properties and are sensitive to moisture. In this paper the effects of temperature and moisture on the thermo-mechanical and fracture properties of thermosetting polymers are studied. Moisture induces a reduction in glass transition temperature, changes the elastic stiffness slightly and degrades the fracture toughness of polymer determination. For the Analysis of fracture toughness, miniaturized CT specimens are initially pre-cracked. Strain fields around the crack-tip at the moment of crack-onset are later determined by gray scale correlation technique and mapped to finite-element analysis for the determination of energy release rate, considering the effect of moisture, temperature and visco elasticity. This work provides a unique meth od for the analysis of moisture-induced cracking in encapsulated devices.