Growth of Al2O3–PTFE composite film at room temperature by aerosol deposition method

To fabricate a ceramic-based substrate for 3-dimensional integration modules with a thick film coating process at room temperature, aerosol deposition method was employed. Al2O3 was chosen as a main coating material for the requirements of low permittivity and dielectric loss. Especially to give a functionality of plasticity, composite film with polytetrafluoroethylene (PTFE) was also studied. The effects of PTFE, which was incorporated in the film, were investigated by the microstructural characterization. It was confirmed that Al2O3–PTFE film with the grain size of 100–200 nm were grown at room temperature using Al2O3–0.5 wt% PTFE mixture powders. Dielectric constant and dielectric loss of Al2O3–PTFE film were 4.5 and 0.005 at 1 MHz, respectively.