Hironori Hatono

Application of BaTiO3 Film Deposited by Aerosol Deposition to Decoupling Capacitor

By using aerosol deposition, BaTiO3 films of more than 0.5 µm thickness were fabricated at room temperature on metal substrates. The dielectric constant of the films was 80 and their tan δ was 0.02 at 1 MHz. The change in the temperature characteristics of the capacitance of the films was rectilinear from room temperature to 180 °C. The films were fabricated on the substrates with Ra values of 0.011 and 0.048 µm. The breakdown voltages of the films were measured: the maximum value was 220 V/µm. The volume resistivities of thin films depended on film thickness. They stabilized at a value of 1012 Ωcm when the film thickness was 5 µm or more. These electric properties are considered to depend on film density. We manufactured a noise-cutting probe with a decoupling capacitor as an inspection apparatus for microwave devices in trial production using the BaTiO3 films fabricated by aerosol deposition. The contact probe had a 0.3 mm diameter, a 5 mm length, and a 6-µm-thick BaTiO3 film on the outer surface. Its capacitance was 0.5 nF. Its withstand voltage was 700 V. These values are sufficient for this application.

Thickness and surface structure of a ceramic layer created on three indirect resin composites with aerosol deposition.

PURPOSE Aerosol deposition is a technology for coating ceramics with impact consolidation at room temperature. The aim of the present study was to investigate the thickness and the microstructure of the aluminium oxide layer on different three dental resin composite materials created by means of aerosol deposition. METHODS Disk-shaped specimens were fabricated with three resin composites (Estenia C&B, Targis, and Gradia). The specimens were ground flat, and then subjected to aerosol deposition using aluminium oxide submicron particles without inducing a localized temperature rise. The average thickness (AVH) and maximum thickness (Hmax) of the aluminium oxide layer deposited on the resin composite material were measured using a profilometer. Data were analyzed by ANOVA and post hoc Tukey compromise test at α=0.05. The specimen surfaces were also observed using a scanning electron microscope. RESULTS The aluminium oxide layer formed on Estenia C&B (AVH 8.1 μm, Hmax 9.1 μm) and Targis (AVH 7.7 μm, Hmax 8.9 μm) were significantly thicker than that on Gradia (AVH 4.2 μm, Hmax 5.4 μm). The micrograph showed that the aluminium oxide layer on Estenia C&B was similar to that on Targis. However, the aerosol deposition area of Gradia was seen relatively rough and partly caved. CONCLUSIONS The type of resin composite affected the microstructure of the deposited aluminium oxide layer. The highly filled light- and heat-cured resin composites are advantageous as a target material rather than the lower filled light-cured resin composite.