Core-Shell Dielectric Particles for High Voltage Capacitors
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Solution Overview
Problem
Multilayer ceramic capacitors exhibit insufficient characteristics under high electric field intensity, particularly in terms of specific permittivity and insulation resistance, which affects their capacity and reliability when used at high voltages.
Innovation Solution
A dielectric ceramic composition comprising a perovskite type compound with specific molecular ratios, rare earth element oxides, and a sintering agent, where the rare earth elements are uniformly diffused throughout the dielectric particles, maintaining good specific permittivity and enhancing insulation resistance and high-temperature accelerated lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the electric field intensity is increased for high voltage application, then the voltage rating capability is improved, but the specific permittivity and insulation resistance decrease
Solution Approach 1:
The patent applies local quality by creating a concentration gradient of sub components specifically at the shell part of the dielectric particle, with maximum concentration near the particle boundary. This localized modification allows the particle boundary region to have enhanced properties that maintain insulation resistance and specific permittivity even under high electric field intensity, while the core region maintains the base dielectric properties.
Solution Approach 2:
The patent uses composite materials by creating a core-shell structure dielectric particle where the core consists of the base perovskite compound and the shell contains a concentration gradient of sub components. This composite structure combines the advantages of both regions: the core provides the fundamental dielectric properties while the shell with concentrated sub components at the boundary provides enhanced stability and resistance under high electric field conditions.
2Stress or pressure
If the electric field intensity is increased for high voltage application, then the voltage rating capability is improved, but the reliability under used environment decreases
Solution Approach 1:
The patent applies local quality by creating a concentration gradient of sub components specifically at the shell part of the dielectric particle, with maximum concentration near the particle boundary. This localized modification allows the particle boundary region to have enhanced properties that maintain insulation resistance and specific permittivity even under high electric field intensity, while the core region maintains the base dielectric properties.
Solution Approach 2:
The patent uses composite materials by creating a core-shell structure dielectric particle where the core consists of the base perovskite compound and the shell contains a concentration gradient of sub components. This composite structure combines the advantages of both regions: the core provides the fundamental dielectric properties while the shell with concentrated sub components at the boundary provides enhanced stability and resistance under high electric field conditions.
3Reliability
If the concentration of rare earth element R is increased to improve insulation resistance, then the insulation resistance improves, but the manufacturing precision of uniform concentration distribution becomes more difficult
Solution Approach 1:
The patent applies segmentation by dividing the dielectric particle into core and shell regions, with the sub components (rare earth element R) primarily located in the shell part rather than being uniformly distributed throughout. This segmentation allows the sub components to be concentrated where they are most needed (near the particle boundary) while avoiding the manufacturing difficulties of achieving uniform distribution throughout the entire particle.
Solution Approach 2:
The patent applies local quality by creating a concentration gradient of sub components specifically at the shell part of the dielectric particle, with maximum concentration near the particle boundary. This localized modification allows the particle boundary region to have enhanced properties that maintain insulation resistance and specific permittivity even under high electric field intensity, while the core region maintains the base dielectric properties.
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 composition achieves improved insulation resistance and high-temperature accelerated lifetime, maintaining effective performance even under high electric field intensities, thereby enhancing the reliability and capacity of multilayer ceramic capacitors.
Implementation Method 1
said dielectric particle comprises a complete solid solution particle wherein the rare earth element R is solid dissolved to entire dielectric particle
Implementation Method 2
when the rare earth element concentration (atom %) is measured at a part excluding an area 20 nm or less from the particle boundary of said complete solid solution particle, then a standard deviation and an average value of a measured values satisfies (standard deviation/average value)≤0.25
Data Source
AI summary
A dielectric ceramic composition having good characteristic even under high electric field intensity, and particularly good IR characteristic and high temperature accelerated lifetime. The present invention is a dielectric ceramic composition comprising,a main component comprising a perovskite type compound shown by a compositional formula (Ba1-x-ySrxCay)m(Ti1-zZrz)O3,a first sub component comprising oxides of a rare earth element,a second sub component as a sintering agent, whereinsaid dielectric ceramic composition is a complete solid solution particle wherein the rare earth element is solid dissolved to entire dielectric particle, or a core-shell particle having high ratio of the diffusion phase, and comprises the dielectric particle having 5 to 20 atom % of the average concentration of the rare earth element in the diffusion phase, and having uniform concentration distribution of the rare earth element in the diffusion phase.