Metallization of Polymer Substrates for Flexible Electronics

In this thesis the metallization of different polymers and several issues related to it is studied. The main emphasis is on resistivity, effects of different kinds of process and operation conditions are characterized. The electrical properties of sputtered and evaporated metals on polymers are compared. Metal film patterning with the help of a shadow mask is studied. The effects of temperature, substrate bending and mechanical strain to thin film resistance are characterized. Also the influence of substrate surface nanopatterns is tested. Finally adhesion between different metals and polymers is determined.

Characterizations done show that in general the electrical properties of metal thin films on polymer substrates are worse than on conventional substrate materials such as SiO2. According to measurements resistivities of sputtered films on polymers are much lower than the ones of evaporated films. The presence of a shadow mask is stated to disturb the deposition process and to have a declining effect on electrical properties. The effect of elevated temperatures is characterized to be similar than in the case of conventional substrate materials. The resistances of metal patterns on planar substrates are stated to increase substantially under mechanical strain. The improving effect of substrate surface nanopatterns on this phenomenon is characterized. The positive effect of nanopatterns on adhesion is also stated.