Core-Dual Shell MLCC Dielectric for TCC and High-Temperature Life

The patent applies local quality by creating a core-shell structure where the dielectric grain has different compositions in different regions. The core contains BaTiO3 with specific dopants, while the shell contains a different ratio of rare earth elements and other oxides. This allows the inner core to provide insulation resistance through rare earth element addition, while the outer shell composition is optimized for high-temperature stability and TCC characteristics, thus resolving the contradiction between insulation resistance and high-temperature lifespan.

The patent uses composite materials by combining multiple oxide components (BaTiO3, SrTiO3, PbZr1-xTixO3, and rare earth element oxides) in a core-shell structure. The composite nature allows different regions to contribute different properties: the core provides insulation through rare earth element suppression of oxygen vacancies, while the shell provides thermal stability and capacitance temperature coefficient control through its specific composite composition, thereby achieving both improved insulation resistance and high-temperature lifespan.

The patent applies local quality by designing the core-shell structure where the core region is optimized for high permittivity at room temperature through specific dopant combinations, while the shell region is optimized for thermal stability. The core contains BaTiO3 with dopants that enhance permittivity, while the shell contains a controlled composition of SrTiO3, PbZr1-xTixO3, and rare earth elements that provide thermal stability, thus resolving the contradiction between room temperature capacitance performance and high-temperature stability.

The patent uses composite materials to achieve both high permittivity and thermal stability. The core-shell structure combines materials with different properties: the core uses BaTiO3-based composition for high permittivity, while the shell uses a composite of SrTiO3, PbZr1-xTixO3, and rare earth element oxides for thermal stability. This composite approach allows the capacitor to achieve excellent room temperature capacitance while maintaining stability at high temperatures.

The patent applies preliminary anti-action by pre-doping the dielectric grains with rare earth elements before sintering. This preliminary action creates a composition that is resistant to oxygen vacancy generation during the subsequent reducing atmosphere sintering process. The rare earth elements are incorporated into the dielectric grain structure in advance, so when the reducing atmosphere sintering occurs and oxygen is released, the rare earth elements suppress oxygen vacancy formation, thus preventing insulation resistance deterioration while still allowing multilayer structure formation.

The patent applies preliminary action by preparing the dielectric grain composition with specific rare earth element content and core-shell structure before the sintering process. This preliminary preparation ensures that when the multilayer structure is formed through reducing atmosphere sintering, the oxygen vacancies are already suppressed by the pre-positioned rare earth elements, thus achieving both easy manufacture of multilayer structure and maintenance of insulation resistance.