Correlations between processing parameters and surface finish of activated polymer samples coated by plasma polymerization in an industrial device (L2-60148)

Project Leader: Dr Žiga Gosar (Elvez)

Investigator: Assoc. Prof. Dr Rok Zaplotnik (Jozef Stefan Institute)

The correlations between the processing parameters and the surface finish of products treated in an industrial device with a volume of about 5 m³ will be presented. The correlations will enable upgrading the device to meet Industry 4.0 standards. The commercial device is suitable for surface activation of products and deposition of various coatings. Of particular interest is the deposition of polydimethylsiloxane-like films deposited by plasma polymerization. The device is currently used in the mass production of components for automotive and other industries, but the quality of the deposited films varies from batch to batch, supposedly due to unpredictable variations in plasma parameters. The device is not equipped with sensors of plasma parameters or deposition rates. We shall develop custom-designed sensors or modify commercial sensors to suit our specific applications. We shall install numerous sensors in the industrial device and perform systematic measurements of the temporal and spatial variations of the following plasma parameters: the density of charged particles, the electron temperature, the space-to-floating potentials, the fluxes of radicals, and the types of molecular fragments that are formed upon partial dissociation of hexamethyldisiloxane precursor. The correlations between the adjustable parameters (the gases and partial pressures in the processing chamber, the discharge voltage, and power) and the plasma parameters will be presented in figures and published in scientific papers. The deposition rates and the quality of the deposited films (composition, structure, morphology, adhesion) will be determined using thin-film thickness sensors and instruments for surface and thin-film characterization (XPS, ToF-SIMS, AFM, SEM). Correlations between the quality of deposited films and plasma parameters will be drawn and published as scientific papers. The scientific papers will represent the first report worldwide on the correlations in plasmas sustained at an extremely low power density of about 1 W per liter. The experimental results will enable the development of a feedback loop to self-adjust the processing parameters to keep them within the optimal range as identified from the correlations. The modified production device will meet Industry 4.0 requirements. The innovative solution for making the device smart will be protected by a patent application.