| 摘要 |
PURPOSE:To manufacture dielectric powder giving a dense thick film porcelain capacitor almost free from defects by dropping a water-isopropyl alcohol mixed soln. into a soln. of specified 3 kinds of metallic alkoxides in isopropyl alcohol. CONSTITUTION:Isopropyl alcohol is added to 48.0-49.92mol% barium dialkoxide, 44.0-49.78mol% titanium tetraalkoxide and 0.3-8mol% niobium pentaalkoxide by an amount >=5 times the total amount of the alkoxides by weight, and they are stirred at 40-85 deg.C to dissolve the alkoxides. The resulting soln. is kept at 40-85 deg.C, a water-isopropyl alcohol mixed soln. having 1:10-2:1 weight ratio is dropped into said soln. under stirring, and Nb doped BaTiO3 is precipitated by aging at 40-85 deg.C. The precipitate is separated by filtration, dried, and heated to 400-1,000 deg.C to obtain dielectric powder having >=1,800 dielectric constant at room temp. and giving a small-sized thick film porcelain capacitor of large capacity. The dielectric strength of the capacitor is >=150V when the film thickness is regulated to 10mum. |
