Multilayer Ceramic Component BaTiO3 Grain Control
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Solution Overview
Problem
The miniaturization of multilayer ceramic electronic components leads to thinner dielectric sheets, which affects the size and dispersion of crystal grains, resulting in deteriorated withstand voltage and reliability characteristics due to non-uniform microstructures and concentrated electric fields.
Innovation Solution
The multilayer ceramic electronic component adjusts the molar ratio of barium (Ba) to titanium (Ti) in the inner and outer regions of the cover and active portions to control the size and dispersion of crystal grains, ensuring a consistent ratio of 1.00 ≤ XA/XB ≤ 1.04, thereby improving the uniformity of microstructures and enhancing withstand voltage characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the dielectric sheet is thinned to achieve miniaturization and high capacitance, then the capacitance increases and the component size decreases, but the crystal grain sizes become non-uniform and the withstand voltage characteristics deteriorate
Solution Approach 1:
The patent applies local quality by differentiating the composition between the inner region (contacting internal electrode) and outer region (not contacting) of the cover portion. The inner region has a controlled Ba/Ti molar ratio (1.02-1.06) to promote uniform crystal grain growth and prevent electric field concentration, while the outer region has a standard ratio. This localized compositional adjustment resolves the contradiction by maintaining high capacitance through thin dielectric sheets while improving withstand voltage through uniform microstructure in the critical inner region.
Solution Approach 2:
The patent changes the chemical composition parameter (Ba/Ti molar ratio) in specific regions to control crystal grain morphology. By adjusting the Ba/Ti ratio in the inner region of the cover portion, the patent achieves uniform crystal grain sizes and reduces size dispersion, thereby improving withstand voltage characteristics while maintaining the thinned dielectric sheet structure for high capacitance.
2Quantity of substance
If the sizes of crystal grains in the dielectric layer are increased to achieve high capacitance and high resistance, then the capacitance increases, but the size dispersion increases causing non-uniform microstructures and concentrated electric fields
Solution Approach 1:
The patent applies local quality by creating a composition gradient between the inner and outer regions of the cover portion. The inner region (contacting the internal electrode) contains barium titanate with a controlled Ba/Ti molar ratio of 1.02-1.06, which promotes uniform crystal grain growth. The outer region maintains a standard Ba/Ti ratio. This localized compositional control ensures uniform microstructure where it is most critical, preventing electric field concentration while maintaining overall capacitance.
Solution Approach 2:
The patent changes the Ba/Ti molar ratio parameter in the inner region of the cover portion to control crystal grain size distribution. By optimizing this compositional parameter, the patent achieves uniform crystal grain sizes (reducing size dispersion) in the inner region, thereby improving microstructure uniformity while maintaining high capacitance through the thinned dielectric structure.
Data Source
AI summary
A multilayer ceramic electronic component includes: a ceramic body including an active portion having dielectric layers and first and second internal electrodes and first and second cover portions disposed on opposite surfaces of the active portion in a stacking direction, respectively; wherein when a region of the cover portion in contact with the first or second internal electrode is an inner region of the cover portion and a region of the active portion in contact with the inner region of the cover portion is an outer region of the active portion, 1.00<XA/XB≤1.04 in which XA/XB is a ratio of a molar ratio (XA) of barium (Ba) to titanium (Ti) in the inner region of the cover portion to a molar ratio (XB) of barium (Ba) to titanium (Ti) in the outer region of the active portion.