Analysis of moisture and time dependent material parameters

Microsystems are used more and more in wide range of different environmental conditions (temperature, moisture, vibration). For development of robustness micro systems are fundamental knowing of reliability relevant material parameters are needed. This paper present some results of experimental methods for obtaining moisture and temperature sensitive parameters of polymers materials used in electronic packaging. Modified DMA, as an advanced measurement method for multifrequency and hygroscopic swell analysis, were used for the determination of moisture dependent parameters for micro and nano scale samples. The water molecules seem to weaken the intermolecular forces for the polymers to prefer the state of entropy elasticity already to lower temperature, and the moisture shows influences on the visco-elastic properties significantly. Modified non-Fickian absorption models provide an insight to the rate of initial (Fickian) moisture diffusion in the voids compared to the secondary non-fickian diffusion, and show a very good agreement with experimental data. In combination with numerical methods new strategies for life time evaluation and fatigue of microelectronic packaging, MEMS and NEMS can be addressed.