Multilayer Ceramic Component with Mg Segregation Phase
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Solution Overview
Problem
Multilayer ceramic capacitors face challenges in maintaining high capacitance and high-temperature reliability when dielectric layers are made thinner, as reduced grain size decreases specific permittivity and increases dielectric loss, and existing solutions fail to effectively manage internal electrode continuity and segregation phases.
Innovation Solution
A multilayer ceramic component with a dielectric layer composed of a Ba-Ti-O based ceramic composition, including Mg, R, and Si oxides, where a segregation phase containing Mg is formed in electrode missing portions, maintaining high specific permittivity and reliability even when the dielectric layer is thin, by controlling the thickness and coverage of the electrode and dielectric layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the dielectric layer is made thinner to achieve downsizing, then the capacitance density is improved, but the specific permittivity is declined due to decreased grain size
Solution Approach 1:
The patent changes the chemical composition parameters of the dielectric ceramic layer by adding specific amounts of MgO (0.75-2.0 moles), R2O3 (0.4-1.0 mole), and SiO2 (0.4-0.8 mole) per 100 moles of ABO3 compound. This compositional parameter change enables the maintenance of high specific permittivity even when the dielectric layer thickness is reduced to several micrometers or less, thereby resolving the contradiction between thinning the layer for downsizing and maintaining permittivity for capacitance.
2Productivity
If the dielectric layer is made thinner to achieve higher performance, then the integration density is improved, but the high temperature accelerated lifetime is lowered
Solution Approach 1:
The patent modifies the chemical composition parameters by incorporating MgO, R2O3, and SiO2 in specific proportions. This parameter change stabilizes the microstructure and suppresses harmful segregation phases, thereby maintaining high reliability and long accelerated lifetime even when the dielectric layer is thinned to achieve higher integration density.
Solution Approach 2:
The patent creates a composite dielectric ceramic system by combining ABO3 (where A is Ba, Ca, Sr and B is Ti, Zr, Hf) with MgO, R2O3, and SiO2. This composite material approach synergistically combines the high permittivity of ABO3 with the grain growth suppression and stability provided by MgO, R2O3, and SiO2, enabling both thin layer fabrication and high reliability.
3Quantity of substance
If the internal electrode continuity is increased to improve capacitance, then the capacitance is improved, but the sintering distortion and interfacial cracks are increased
Solution Approach 1:
The patent changes the compositional parameters of the dielectric ceramic to include MgO (0.75-2.0 moles), R2O3 (0.4-1.0 mole), and SiO2 (0.4-0.8 mole) per 100 moles of ABO3. This compositional adjustment optimizes the sintering behavior and thermal expansion characteristics, enabling high internal electrode continuity (70-95%) while suppressing sintering distortion and interfacial cracks through improved stress distribution.
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 enhances capacitance, reduces dielectric loss, and extends high-temperature accelerated lifetime by suppressing grain growth and optimizing the segregation phase's position within the component, ensuring favorable properties across varying layer thicknesses.
Implementation Method 1
Mg suppresses grain growth of dielectric particles
Implementation Method 2
specific permittivity is declined
Data Source
AI summary
A multilayer ceramic electronic component comprises an element body obtained by stacking dielectric layers (thickness t1) and electrode layers (thickness t2). The dielectric layer includes a compound expressed by ABO3 (A includes Ba, and may include Ca or Sr; and B includes Ti, and may include Zr or Hf), and includes 0.75 to 2.0 moles of MgO, 0.4 to 1.0 mole of an oxide of Y, Dy, Ho and the like in terms of the oxide, and 0.4 to 0.8 mole of SiO2 per 100 moles of the compound. A segregation phase containing Mg is formed in at least a part of an electrode missing portion. Line coverage of the electrode layer is 60 to 90% and relations of 0.3 μm≦t1≦2.0 and 0.3 μm≦t2<1.0 μm are fulfilled.