Thin film coating of silver on fibers by roll to roll inverted cylindrical magnetron sputtering

Abstract

There is a huge demand in functional textile product by the advent of nanotechnology and thin film technology. Antistatic and antibacterial textile materials are highly required in medical centers, clean rooms, military basis and electronic device manufacturers. Moreover, these materials are increasingly studied in many scientific committees by several method. Functional textile fabrics can be produced by surface finishing or adding conductive fibers. Many methods are employed to obtain conductive fiber but Physical Vapor Deposition (PVD) offer better homogeneity and high efficiency when compared to Chemical Vapor Deposition (CVD) methods. Magnetron sputtering is the industrial scale thin film production technique among PVD methods. However, mainly used planar magnetron sputtering systems do not enable samples to be coated all sides of cylindrical surface of a fiber so that an inverted cylindrical magnetron (ICM) sputtering system was designed for this research. ICM system was optimized and operated to deposit silver thin film on all sides of PA fibers which have diameters 85 and 150 um. A continuous roll to roll mechanism was mounted to system that enables to metalize fibers at high speed continuously. Conductive fibers are proposed to be produced at industrial scale. XRD, SEM and optical microscopy characterizations are employed on silver thin film coated polyamide fibers. In order to obtain thin film thickness of fibers, they are investigated by three different methods which can be calculating from i) bulk resistivity formula by using measured resistance, ii) deposited silver mass by using density of silver and iii) system calibration sample which is basically sending a glass lamella with same sputtering parameters and measuring sputtered thin film on it. These all results were compared to find optimum thickness. These conductive fibers woven in synthetic fabrics to promote them antistatic and shielding property. Antistatic and adhesion analysis of these fabrics are investigated and surface resistance and shielding property of fabrics were studied. All in all, these fabrics will be used as technical textile which is presumed to satisfy demands.