PREPARATION AND CHARACTERIZATION OF NANOSIZED GRAPHITE BASED THICK FILM FOR FLEXIBLE ELECTRONICS

Abstract

This paper presents results of study on graphite thick film paste using linseed oil as organic binder and nanosized graphite powder. First, graphite powder is milled for 1 hour to obtain nanosized powder. Next, graphite nanopowder is mixed with organic vehicle which consists of linseed oil, m-xylene and α-terpineol. Samples are prepared to study the morphology and electrical properties of the paste when subjected to different firing temperature, and also adhesion to flexible kapton film. Paste samples were screen printed onto kapton film as substrate, dried and fired at different temperatures of 300°C and 400°C respectively. Microscopic images of the samples were observed to determine good dispersion of the active powder with the organic vehicle. Based on the results, the paste with linseed oil as organic vehicle showed good adhesion to the substrate with low firing temperature at 300°C, but has high resistivity thus not having a good conductivity. Thick film with firing temperature 400°C has good morphology and conductivity, therefore higher temperature gives good result in terms of electrical properties. Longer firing holding time also helped to improve the conductivity of the graphite thick film.