HIGH-PERFORMANCE MULTILAYER CAPACITOR DIELECTRICS FROM CHEMICALLY PREPARED POWDERS

Advantages of chemically prepared powders for electronic ceramics have been demonstrated for a number of multilayer capacitor (MLC) dielectr ics. A cost-efficient precipitation process was developed to produce u ndoped or doped crystalline barium titanate powder with a narrow parti cle size distribution close to 0.5 mum. More complex compositions, e.g ., barium-neodymium titanate, were amorphous as precipitated but could be crystallized by calcination below 1000-degrees-C. Additional compo sitional modifications, to adjust electrical properties or to lower si ntering temperature, were accomplished by doping the surface of the po wder particles using a solution coating process. Exceptional fired den sities and electrical performance were obtained.