MLCC Dielectric Composition for Moisture-Resistant Insulation

The patent applies local quality by creating a core-shell structure where the dielectric grain has a distinct core region and shell region with different compositions. The shell region contains secondary phases (including Zr and Y) that are concentrated at the grain boundaries, while the core region maintains a different composition. This localized distribution allows the secondary phases to provide high-temperature and moisture resistance at the grain boundaries without forming continuous conductive paths through the entire dielectric layer, thus resolving the contradiction between reliability improvement and conductive path formation.

The patent introduces an intermediary approach by using a specific shell layer composition that acts as a barrier between the internal electrode and the harmful effects of secondary phases. The shell region, with its controlled composition and structure, mediates the interaction between secondary phases and the electrode, preventing direct contact that would lead to conductive path formation while still allowing the secondary phases to provide their protective effects at the grain boundaries.

The patent implements local quality by concentrating secondary phases specifically at the grain boundaries in the shell region, rather than having them uniformly distributed or directly contacting the internal electrode. This localized positioning ensures that secondary phases provide high-temperature reliability enhancement at the grain boundaries while the core-shell structure prevents them from forming conductive paths with the electrode, thus maintaining insulation resistance.

The patent uses composite materials by creating a dielectric layer with a core-shell structure composed of different material compositions. The core region and shell region have distinct compositions, with the shell region containing secondary phases (Zr and Y) that provide high-temperature stability. This composite structure allows the material to simultaneously achieve high-temperature reliability and maintain insulation resistance by separating the functional roles of different regions.