Multilayer Dielectric Composition for Grain-Stable High-Capacitance MLCCs
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Solution Overview
Problem
Existing multilayer ceramic capacitors face issues with grain growth and structural instability in the dielectric layer due to grain size distribution and thickness deviation, leading to reduced electrical characteristics and reliability, particularly in high-capacitance and miniaturized applications.
Innovation Solution
A dielectric composition for multilayer electronic components using a BaTiO3-based base material with additives such as Sm, Gd, and Tb, controlled within specific content ranges, is used to suppress grain growth and stabilize the dielectric layer structure, ensuring uniform grain size and thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If various additives are used to suppress grain growth in the dielectric layer, then electrical characteristics are improved, but structural stability is reduced due to grain size distribution and thickness deviation
Solution Approach 1:
The patent applies parameter changes by precisely controlling the content ratios of multiple rare earth elements (Dy, Sm, Gd, Tb) in the dielectric layer. By adjusting the specific parameters of element composition within defined ranges, the patent achieves optimal balance between grain growth suppression and structural stability, resolving the contradiction between improved electrical characteristics and maintained compositional stability.
Solution Approach 2:
The patent uses composite materials by combining multiple rare earth elements (Dy, Sm, Gd, Tb) in specific proportions within the BaTiO3-based dielectric system. This composite approach allows synergistic effects where each element contributes differently to grain growth control and structural stability, achieving both improved electrical characteristics and enhanced overall stability compared to single-element additives.
2Productivity
If the dielectric layer is miniaturized to increase capacitance, then high-capacitance is achieved, but grain size control and structural uniformity become more difficult
Solution Approach 1:
The patent applies parameter changes by optimizing the content ratios of rare earth elements specifically for miniaturized structures. The defined compositional ranges (Dy: 50-150 ppm, Sm: 25-75 ppm, Gd: 25-75 ppm, Tb: 25-75 ppm) are tailored to control grain growth at reduced scales, enabling precise grain size control even as the dielectric layer is miniaturized to achieve higher capacitance density.
Solution Approach 2:
The patent applies local quality by ensuring uniform distribution of multiple rare earth elements throughout the dielectric layer at controlled concentrations. This creates consistent local properties across the miniaturized structure, maintaining uniform grain size and structural homogeneity even at reduced dimensions, thereby enabling high capacitance while preserving manufacturing precision.
3Volume of stationary object
If sintering temperature is increased to improve densification, then density is improved, but grain growth increases leading to larger grain size
Solution Approach 1:
The patent applies parameter changes by using multiple rare earth elements in specific proportions to modify the sintering behavior of the dielectric material. This compositional adjustment allows effective densification at relatively lower sintering temperatures (1100-1400°C) while simultaneously suppressing excessive grain growth, achieving both high density and controlled grain size through optimized elemental composition.
Solution Approach 2:
The rare earth elements (Dy, Sm, Gd, Tb) act as intermediaries during the sintering process. They mediate between the competing requirements of densification and grain growth control by forming specific microstructures and defect chemical structures that promote particle packing and densification while inhibiting uncontrolled grain boundary migration, thus resolving the contradiction between density improvement and grain size control.
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 results in a dense and uniform dielectric layer with reduced dielectric resistance deviation, enhanced structural stability, and improved reliability, even under external electric field stress, facilitating miniaturization and high capacitance.
Implementation Method 1
suppressing grain growth of a dielectric included in the dielectric layer by adjusting a content of an additive included in one dielectric layer
Implementation Method 2
sintering the laminate at a sintering temperature of 1100° C. to 1400° C. in a reducing atmosphere
Implementation Method 3
forming a body including a dielectric layer and an internal electrode alternately disposed with the dielectric layer by reoxidizing the sintered laminate in an oxidizing atmosphere at a temperature lower than the sintering temperature
Data Source
AI summary
A multilayer electronic component includes a body including a dielectric layer and an internal electrode alternately disposed with the dielectric layer, and an external electrode disposed on the body. The dielectric layer includes a BaTiO3-based base material main ingredient, a sub-ingredient including Dy, and an additive. The additive is one or more of Sm, Gd and Tb, and a content of the additive is 25 mol or more and less than 50 mol relative to 100 mol of Dy. The dielectric layer includes a plurality of dielectric grains. When an average grain size of the plurality of dielectric grains is represented by G, and an average thickness of the dielectric layer is represented by td, 1.75≤td/G≤2.23 is satisfied.