MLCC Fresnoite Phase Grain Control
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Solution Overview
Problem
Multi-layer ceramic capacitors face challenges in achieving a high dielectric constant and thin layers while maintaining insulation reliability, as reducing grain size to achieve thinner layers leads to a decrease in dielectric constant, and adding MgTiO3 suppresses grain growth but does not provide sufficient dielectric constant.
Innovation Solution
Incorporating a fresnoite phase with an average grain size of 1 μm or less in the dielectric layers or at the internal electrode interface, composed of barium titanate and silicon compounds, with controlled magnesium oxide and rare earth oxide additives to enhance dielectric constant and insulation properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the grain size is reduced to achieve thinner layers, then the layer thickness decreases, but the dielectric constant per grain drops due to the sizing effect
Solution Approach 1:
The patent changes the chemical composition parameters of the dielectric material by adding specific secondary constituents (MgTiO3, SiO2, B2O3, Al2O3) to the barium titanate base material. This compositional parameter change allows the material to maintain high dielectric constant even when grain size is reduced for thinner layers, resolving the contradiction between layer thickness and dielectric constant.
Solution Approach 2:
The patent creates a composite dielectric material by combining barium titanate with multiple secondary constituents (MgTiO3, SiO2, B2O3, Al2O3) in specific ratios. This composite structure enables the material to achieve both thin layer thickness and high dielectric constant, as the secondary constituents compensate for the dielectric constant reduction caused by grain size reduction.
2Length of stationary object
If MgTiO3 is added to suppress grain growth and enable thinner layers, then layer thickness decreases, but the dielectric constant is insufficient
Solution Approach 1:
The patent creates a composite dielectric material by combining barium titanate with multiple secondary constituents (MgTiO3, SiO2, B2O3, Al2O3) in specific ratios. This composite structure enables the material to achieve both thin layer thickness and high dielectric constant, as the secondary constituents compensate for the dielectric constant reduction caused by grain size reduction.
Solution Approach 2:
The patent changes the chemical composition parameters of the dielectric material by adding specific secondary constituents (MgTiO3, SiO2, B2O3, Al2O3) to the barium titanate base material. This compositional parameter change allows the material to maintain high dielectric constant even when grain size is reduced for thinner layers, resolving the contradiction between layer thickness and dielectric constant.
3Reliability
If the number of dielectric layers is increased to achieve larger capacity, then the capacitance increases, but the manufacturing complexity increases
Solution Approach 1:
The patent changes the chemical composition parameters of the dielectric material by adding specific secondary constituents (MgTiO3, SiO2, B2O3, Al2O3) to the barium titanate base material. This compositional parameter change allows the material to maintain high dielectric constant even when grain size is reduced for thinner layers, resolving the contradiction between layer thickness and dielectric constant.
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 approach results in a multi-layer ceramic capacitor with a high dielectric constant and excellent insulation reliability, allowing for thinner layers without compromising other characteristics, and provides superior cost performance and long life.
Implementation Method 1
a fresnoite phase having an average grain size of 1 μm or less is present in the dielectric layers
Implementation Method 2
the method of producing desired segregation and thus controlling the solid solution states of added elements is employed to improve the dielectric constant
Implementation Method 3
The capacity of a multi-layer ceramic capacitor is directly proportional to the dielectric constant of the material used for the dielectric layers
Data Source
AI summary
A multi-layer ceramic capacitor has a laminate of dielectric layers and internal electrode layers laminated alternately with one another, as well as cover layers formed as the outermost layers at the top and bottom of the laminate in the laminating direction, wherein the dielectric layers are constituted by a sintered compact containing a barium titanate and a silicon compound, and a fresnoite phase having an average grain size of 1 μm or less is present in the dielectric layers.