Formulation and characterization of UV-light-curable electrically conductive pastes

Abstract UV-light-curable electrically conductive pastes have been formulated from granular silver particles and flake-shaped silver and epoxyacrylate, ethylene glycol and photo-initiator in this study. These conductive pastes were analyzed using photo-DSC, TGA and conductivity metry for reaction rate during photo-polymerization process, thermal resistance and conductivity, respectively. It is shown that (1) the rate of photo-polymerization can be regulated by varying the exposure dose and time depending on the particle size and particle loading; (2) the resistance of the paste containing 60 wt% silver with mean particle size from 0.6 to 1.5 μm is reduced to 5.63 × 10−7 Ωcm; and (3) with granular-shaped silver with 0.6 to 3.5 μm in diameter the decomposition temperature of electrically conductive paste is 424°C, while the temperature of thermal decomposition is 397°C for the same solid content of flake shape silver with length 0.5 to 5 μm, after photo-polymerization using a radiation dose of 500 mJ/cm2. Keywords: FORMULATIONCHARACTERIZATIONDISPERSIONGRANULAR SHAPEFLAKE SHAPESILVERUV LIGHTPHOTO-DSCELECTRICALLY CONDUCTIVE PASTE