BaTiO3 Core-Shell Dielectric Ceramic for High-Temperature Reliability
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Solution Overview
Problem
Laminated ceramic capacitors using BaTiO3 based dielectric materials face reliability issues under high temperature or high electric field conditions, as existing core-shell structures with certain accessory constituents do not adequately maintain performance.
Innovation Solution
A dielectric ceramic with a sintered body of BaTiO3 based ceramic grains featuring a core-shell structure where rare-earth elements and other accessory constituents are concentrated from the grain boundary towards the core, with optional substitution of Ba with Ca and Ti with Zr, enhancing the reliability of the ceramic layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a core-shell structure with accessory constituents in surface layer parts is adopted to balance temperature characteristics and reliability, then temperature characteristics are improved, but life characteristics decrease under high temperature or high electric field intensity
Solution Approach 1:
The patent refines the local quality principle by specifying that the shell part contains acceptor elements and Mg with controlled concentrations, while the core part has a different composition. This precise local differentiation allows the shell to stabilize temperature characteristics while the core maintains structural integrity under high temperature and electric field stress, thus improving both temperature characteristics and life characteristics.
Solution Approach 2:
The patent applies parameter changes by controlling the concentration of accessory constituents in the shell part and the specific composition of the core part. By adjusting these parameters (composition ratios, concentration gradients), the material achieves optimal balance between temperature stability and resistance to degradation under high temperature and electric field conditions, thereby improving life characteristics while maintaining temperature characteristics.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The dielectric ceramic achieves improved reliability and life characteristics by maintaining high relative permittivity and extending mean time to failure under high temperature and electric field conditions, ensuring stable performance in laminated ceramic capacitors.
Implementation Method 1
maintaining high relative permittivity
Implementation Method 2
a sintered body including BaTiO3 based ceramic grains as main phase grains
Data Source
AI summary
A dielectric ceramic that includes a sintered body of BaTiO3 based ceramic grains, in which the ceramic grains each include a shell part as a surface layer part and a core part inside the shell part. The ceramic grains contain, as accessory constituents, R (R, which is a rare-earth element, is at least one selected from the group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Y) and M (M is at least one selected from the group consisting of Mg, Mn, Ni, Co, Fe, Cr, Cu, Al, Mo, W, and V). R and M are present in the shell part of the ceramic grain, and concentrations of R and M contained in the shell part are increased from a grain boundary toward the core part.