Core-Dual Shell Dielectric Grains for MLCC Oxygen Vacancy Control
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Solution Overview
Problem
Multilayer ceramic capacitors face challenges in maintaining reliability, high-temperature lifespan characteristics, and temperature coefficient of capacitance (TCC) characteristics, especially when layers are thinned for higher capacitance or under high voltage conditions, due to issues with oxygen vacancies and electron mobility.
Innovation Solution
A ceramic electronic component with a core-dual shell structure in the dielectric layer, where the dual shell includes different types of rare earth elements with controlled concentrations, acts as a barrier to prevent electron flow and enhance reliability, comprising a core and dual shells with specific concentration ratios of rare earth elements in the first and second shells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If layers are thinned to increase capacitance, then capacitance is improved, but reliability deteriorates due to oxygen vacancies and electron mobility issues
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the shell region has different compositional characteristics than the core. The shell is enriched with rare earth elements (R1 and R2) that specifically address electron mobility and oxygen vacancy issues at grain boundaries, while the core maintains the primary dielectric properties. This localized compositional differentiation allows the thinned layers to maintain high capacitance while the shell region provides enhanced reliability by blocking electron flow and stabilizing the dielectric structure.
Solution Approach 2:
The patent employs composite materials by combining multiple rare earth elements (R1 and R2) in specific concentration ratios within the shell region. The dual-element composition creates synergistic effects where R1 and R2 work together to suppress oxygen vacancy formation and reduce electron mobility more effectively than single-element additions. This composite approach in the shell region enables the thinned capacitor layers to achieve both high capacitance and improved reliability.
2Reliability
If rare earth element is added to suppress oxygen vacancies, then reliability is improved, but high-temperature lifespan characteristics deteriorate
Solution Approach 1:
The patent applies parameter changes by precisely controlling the concentrations of two different rare earth elements (R1 and R2) in the shell region. The specific concentration ratio (0.01 ≤ R2S1/R1S1 ≤ 0.5 and 0.5 ≤ R2S2/R1S1 ≤ 3.0) optimizes the balance between suppressing oxygen vacancies for improved reliability and maintaining high-temperature stability. This controlled compositional parameter in the shell region allows the material to exhibit both improved reliability and enhanced high-temperature lifespan characteristics.
3Reliability
If rare earth element is added to remove electrons, then insulation resistance is improved, but temperature coefficient of capacitance characteristic deteriorates
Solution Approach 1:
The patent applies local quality by concentrating the rare earth elements (R1 and R2) specifically in the shell region rather than uniformly throughout the entire grain structure. This localized placement in the shell allows the rare earth elements to effectively remove excess electrons and improve insulation resistance at the grain boundaries, while the core region maintains its original compositional stability. This spatial differentiation preserves the temperature coefficient of capacitance characteristics while improving insulation resistance.
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 core-dual shell structure effectively improves high-temperature lifespan characteristics and TCC characteristics by controlling the concentration of rare earth elements, enhancing the reliability and insulation resistance of the ceramic electronic component.
Implementation Method 1
a rare earth element such as Dy, Y, Ho, or the like is added to suppress the generation of the oxygen vacancies, to reduce mobility of oxygen vacancies, and to remove electrons generated by the addition of a transition metal
Implementation Method 2
a rare earth element such as Dy, Y, Ho, or the like is added to suppress the generation of the oxygen vacancies, to reduce mobility of oxygen vacancies
Data Source
AI summary
A ceramic electronic component includes a body, including a dielectric layer and an internal electrode. The dielectric layer includes a plurality of dielectric grains, and at least one of the plurality of dielectric grains has a core-dual shell structure having a core and a dual shell. The dual shell includes a first shell, surrounding at least a portion of the core, and a second shell, surrounding at least a portion of the first shell. The dual shell includes different types of rare earth elements R1 and R2, and R2S1/R1S1 is 0.01 or less and R2S2/R1S1 is 0.5 to 3.0, where R1S1 and R1S2 denote concentrations of R1 included in the first shell and the second shell, respectively, and R2S1 and R2S2 denote concentrations of R2 included in the first shell and the second shell, respectively.