Multilayer Capacitor Side Composition for Void-Free Electrode Interfaces
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Solution Overview
Problem
Multilayer capacitors with exposed internal electrodes in the width direction face challenges in achieving high reliability due to voids at the interface with side portions, leading to reduced breakdown voltage and moisture resistance, which is critical for electronic devices in harsh environments.
Innovation Solution
Incorporating zirconium (Zr) and magnesium (Mg) into the side and cover portions of the capacitor body, with Zr content up to 1 mol% and Mg content between 10-30 mol% compared to BaTiO3, to form an oxide layer that mitigates electric field concentration and enhances insulation properties, thereby improving reliability and capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If internal electrodes are exposed in the width direction of the capacitor body to increase area, then capacitance is improved, but voids form at the interface with side portions causing reduced reliability
Solution Approach 1:
The patent applies local quality by modifying the composition of side portions and cover portions to include Zr (0.1-5 wt%) and Mg (1-10 wt%). This local compositional change creates an oxide layer specifically at the interface regions where voids typically form, improving reliability without affecting the overall capacitance-enhancing exposed electrode structure.
Solution Approach 2:
The patent uses composite materials by combining multiple oxides (BaTiO3, PbZr1-xTixO3, PbMg1/3Nb2/3O3, PbTiO3, Pb1-xLaxZr1-yTiyO3) in the side and cover portions. This composite approach creates a synergistic effect where the combined materials form a robust oxide layer that prevents void formation while maintaining the electrical performance needed for high capacitance.
2Manufacturing precision
If side portions are attached to cover exposed internal electrodes, then electrode coverage is improved, but interface voids reduce breakdown voltage
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition parameters of the side portions and cover portions, specifically adding Zr (0.1-5 wt%) and Mg (1-10 wt%). This compositional parameter change alters the sintering behavior and oxide formation characteristics, creating a denser interface structure with higher breakdown voltage while maintaining proper electrode coverage.
3Reliability
If side portions and cover portions include Zr and Mg, then insulation resistance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the functions of side portions and cover portions by applying the same compositional modification (adding Zr and Mg) to both components. This unified approach simplifies the manufacturing process compared to treating different components separately, while still achieving improved insulation resistance and reliability across all interface regions.
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 use of Zr and Mg in the side and cover portions increases the breakdown voltage, improves insulation resistance, and enhances the reliability of multilayer capacitors by reducing voids and increasing sintering density, while maintaining capacitance characteristics.
Implementation Method 1
Incorporating zirconium (Zr) and magnesium (Mg) into the side and cover portions of the capacitor body, with Zr content up to 1 mol% and Mg content between 10-30 mol% compared to BaTiO3, to form an oxide layer that mitigates electric field concentration and enhances insulation properties
Implementation Method 2
a capacitor body formed of a ceramic material, an internal electrode disposed inside the capacitor body, and an external electrode installed on a surface of the capacitor body to be connected to the internal electrode
Data Source
AI summary
A multilayer capacitor includes: a capacitor body including first and second internal electrodes alternately stacked with a dielectric layer interposed therebetween, and having first to six surfaces, the first internal electrode being exposed through the third, fifth, and sixth surfaces, the second internal electrode being exposed through the fourth, fifth, and sixth surfaces; first and second side portions disposed on the fifth and sixth surfaces of the capacitor body; and first and second external electrodes. The capacitor body includes upper and lower cover portions disposed on an upper surface of an uppermost internal electrode and a lower surfaces of a lowermost internal electrode, respectively, in a stacking direction of the first and second internal electrodes. The first and second side portions and the upper and lower cover portions include zirconium (Zr).