MLCC Dielectric Grain Structure for Electrode Reliability
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Solution Overview
Problem
Existing multilayer ceramic capacitors face challenges in achieving high reliability due to deterioration of internal electrodes under electric fields, particularly when dielectric materials and internal electrodes are thinned for miniaturization and high capacitance, and sintering processes with small dielectric powder particles result in insufficient additive diffusion, leading to reliability issues.
Innovation Solution
A multilayer electronic component with dielectric grains having a core-interface shell-shell structure, incorporating additives like silicon and other metals to enhance reliability, and a tetragonal structure to improve dielectric characteristics, while reducing sintering temperature and preventing oxygen vacancy formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thickness of dielectric materials and internal electrodes is decreased to achieve miniaturization and high capacitance, then the size is reduced and capacitance is increased, but the internal electrode deteriorates under electric field resulting in worsened reliability
Solution Approach 1:
The patent applies local quality by creating a core-interface shell-shell structure where different regions of the dielectric grain have different compositions and functions. The core region contains one type of additive while the interface shell region contains another type, allowing each region to perform its specific function: the core maintains dielectric properties while the interface shell prevents internal electrode deterioration.
Solution Approach 2:
The interface shell region acts as an intermediary between the core dielectric grain and the internal electrode. This intermediate layer facilitates controlled diffusion of additives to the grain boundary while preventing direct contact between harmful electric fields and the internal electrode, thus protecting the electrode without compromising the overall dielectric performance.
2Reliability
If high-temperature shortening sintering is applied to prevent deterioration of internal electrodes, then reliability is improved, but time of additive diffusion into dielectric composition lattice is insufficient resulting in worsened reliability
Solution Approach 1:
The patent changes the chemical composition parameters of the dielectric material by incorporating specific additives (Bi2O3, TiO2, SiO2, Al2O3, Fe2O3, MnO2, ZnO, Nb2O5, Ta2O5, or SrZrO3) in controlled amounts. These compositional changes enable the sintering process to achieve proper additive diffusion and grain boundary formation at reduced temperatures and shorter times while maintaining or improving reliability.
Solution Approach 2:
The desired additive composition and distribution are prepared in advance during the green sheet formation stage, before sintering. This preliminary arrangement of additives ensures that during the shortened high-temperature sintering process, the additives are already positioned optimally for diffusion, eliminating the need for prolonged sintering time to achieve proper distribution.
3Reliability
If additive elements are added to dielectric composition to improve reliability, then internal electrode deterioration is prevented, but sintering stability decreases making it difficult to achieve target reliability level
Solution Approach 1:
The patent uses composite materials by combining multiple oxide components (Bi2O3, TiO2, SiO2, Al2O3, Fe2O3, MnO2, ZnO, Nb2O5, Ta2O5, or SrZrO3) in specific proportions with the base dielectric material. This composite approach creates a synergistic effect where each component contributes specific properties: some enhance reliability by preventing electrode deterioration, while others maintain sintering stability, thus resolving the contradiction between improved reliability and reduced sintering stability.
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 solution enhances the reliability and dielectric performance of multilayer capacitors by improving grain boundary resistance and reducing sintering temperature, thereby maintaining high dielectric constant and preventing electrode deterioration.
Implementation Method 1
time of additive diffusion into a lattice of a dielectric composition is insufficient
Implementation Method 2
high-temperature shortening sintering maintaining process time to be short at a high temperature during a sintering process
Data Source
AI summary
A multilayer electronic component including a dielectric layer is provided. The dielectric layer includes a plurality of dielectric grains, and at least one of the plurality of dielectric grains has a core-interface shell-shell structure. The dielectric grain having the core-interface shell-shell structure includes a perovskite (BaTiO3)-based base main component, a first subcomponent including silicon (Si), and a second subcomponent including at least one selected from the group consisting of manganese (Mn), vanadium (V), chromium (Cr), iron (Fe), nickel (Ni), cobalt (Co), copper (Cu), zinc (Zn), and tin (Sn). An average content of the first subcomponent is highest in the first interface shell region, and an average content of the second subcomponent is highest in the second interface shell region.