Core-Shell Dielectric Grains for High-Constant Multilayer Capacitors
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Solution Overview
Problem
The limited availability of barium titanate powder and manufacturing technology hinders the development of high-performance multilayered capacitors, particularly for automotive and industrial applications, which require high reliability and miniaturization, and there is a need for improved dielectric constants in these capacitors.
Innovation Solution
A multilayered capacitor design with a core-shell structure dielectric grain composition, controlled Ba/Ti mole ratio, and specific area ratios, incorporating secondary components like dysprosium and manganese, enhances the dielectric constant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If barium titanate powder is used as the primary dielectric material, then the dielectric constant can be improved, but the limited availability of powder and manufacturing technology constrains further development
Solution Approach 1:
The patent employs a core-shell structure where the core contains barium titanate as the primary component and the shell contains secondary components (at least one of dysprosium, manganese, or vanadium) combined with barium titanate. This composite approach allows the capacitor to achieve high dielectric constant performance while using available manufacturing technologies, as the shell structure provides additional functionality and stability without requiring entirely new manufacturing processes.
2Reliability
If the Ba/Ti mole ratio in the core is controlled within 0.9975 to 1.0055, then the dielectric constant is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies a controlled Ba/Ti mole ratio range of 0.9975 to 1.0055 in the core, which represents an optimization of the stoichiometric parameters. This parameter control ensures high dielectric constant performance while maintaining feasibility for manufacturing. The relatively wide tolerance range (±0.0055 from stoichiometric 1:1) balances performance requirements with manufacturing capabilities.
Solution Approach 2:
The core-shell composite structure allows the core to focus on achieving high dielectric constant through controlled Ba/Ti ratio, while the shell provides additional functionality. This division of functional responsibilities enables the core to operate at optimized parameters without requiring extremely tight manufacturing tolerances across the entire material system.
3Reliability
If the shell area ratio is controlled within 30% to 50%, then the dielectric performance is optimized, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies the shell area ratio should be controlled within 30% to 50% of the total grain area. This parameter optimization balances dielectric performance with manufacturing feasibility. The moderate shell thickness ensures sufficient functionality while avoiding excessive complexity in the manufacturing process that would be required for very thin or very thick shells.
4Reliability
If secondary components (dysprosium, manganese, vanadium) are added to the shell, then the dielectric constant is improved, but the device complexity increases
Solution Approach 1:
The patent introduces a core-shell composite structure where the shell contains secondary components (at least one of dysprosium, manganese, or vanadium) combined with barium titanate. This composite approach enhances dielectric performance by incorporating multiple functional elements while maintaining a relatively simple overall architecture. The secondary components in the shell provide additional dielectric functionality without fundamentally complicating the basic capacitor structure.
Solution Approach 2:
The patent applies different material compositions to different regions: the core contains primarily barium titanate with controlled Ba/Ti ratio, while the shell contains barium titanate combined with secondary components. This local differentiation optimizes performance in each region - the core provides high dielectric constant while the shell provides additional functionality and stability - without requiring complex structures throughout the entire material system.
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 design achieves a significant improvement in dielectric constant, ensuring high reliability and performance under varying temperature and humidity conditions, addressing the limitations of existing capacitors.
Implementation Method 1
the dielectric layer may include a plurality of dielectric grains containing barium titanate as a primary component
Data Source
AI summary
Provided is a multilayered capacitor, including a capacitor body including a dielectric layer and an internal electrode, and an external electrode disposed outside the capacitor body, wherein the dielectric layer includes a plurality of dielectric grains containing barium titanate as a primary component, at least one of the plurality of dielectric grains has a core-shell structure, the average mole ratio of barium to titanium (Ba/Ti mole ratio) in the core of the dielectric grain is 0.9975 to 1.0055, and the average number of cores per unit area (1 μm×1 μm) in the dielectric layer is 25 to 35.