BaTiO3 Dielectric Composition for Nickel Electrode MLCCs
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Solution Overview
Problem
Multilayer ceramic capacitors face challenges with dielectric materials that reduce to semiconductors under sintering, leading to decreased insulation resistance and high manufacturing costs due to the use of noble metals, and issues with high-temperature reliability when using magnesium oxide additives.
Innovation Solution
A dielectric ceramic composition comprising a base material powder of BaTiO3 with specific accessory ingredients such as oxides and glass compounds, which allows for high dielectric constant and high-temperature reliability, enabling sintering at low temperatures under a reducing atmosphere using nickel internal electrodes without magnesium oxide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If base metal (nickel) is used as internal electrode material to reduce cost, then manufacturing cost is reduced, but internal electrodes are oxidized during sintering under air atmosphere
Solution Approach 1:
The patent applies a reducing atmosphere (inert environment) during the sintering process to prevent oxidation of the nickel-based internal electrodes. This allows the use of cost-effective base metals while maintaining their electrical conductivity and preventing harmful oxidation reactions that would occur in air atmosphere.
2Manufacturing precision
If magnesium oxide additive is used to suppress non-uniform grain growth, then grain uniformity is improved, but high-temperature reliability deteriorates due to solid-solubilization
Solution Approach 1:
The patent removes magnesium oxide from the dielectric material composition to eliminate the problem of solid-solubilization that causes high-temperature reliability deterioration. Instead, other additives or compositional adjustments are used to achieve the desired grain uniformity without the harmful effects of MgO.
3Reliability
If noble metal (palladium) is used as internal electrode material to prevent oxidation, then oxidation resistance is improved, but manufacturing cost increases significantly
Solution Approach 1:
The patent uses inexpensive base metals like nickel as internal electrode material, accepting that they require protective sintering conditions (reducing atmosphere) rather than relying on expensive noble metals. This approach reduces manufacturing cost while maintaining functionality through process 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 composition achieves high capacitance with excellent reliability and economical efficiency, maintaining insulation resistance and preventing high-temperature degradation, even without magnesium oxide, while using nickel internal electrodes.
Implementation Method 1
A dielectric ceramic composition comprising a base material powder of BaTiO3 with specific accessory ingredients such as oxides and glass compounds, which allows for high dielectric constant and high-temperature reliability, enabling sintering at low temperatures under a reducing atmosphere
Data Source
AI summary
A dielectric ceramic composition includes: a base material powder BamTiO3 (0.995≦m≦1.010); 0.2 to 2.0 moles of a first accessory ingredient, an oxide or carbide containing at least one of Ba and Ca, based on 100 moles of the base material powder; a second accessory ingredient, an oxide containing Si or a glass compound containing Si; 0.2 to 1.5 moles of a third accessory ingredient, an oxide containing at least one of Sc, Y, La, Ac, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, based on 100 moles of the base material powder; and 0.05 to 0.80 mole of a fourth accessory ingredient, an oxide containing at least one of Cr, Mo, W, Mn, Fe, Co, and Ni, based on 100 moles of the base material powder, a content ratio of the first accessory ingredient to the second accessory ingredient being 0.5 to 1.7.