BaTiO3 Dielectric Composition for MLCC Oxygen Vacancy Suppression
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Solution Overview
Problem
High-capacitance multilayer ceramic capacitors face reliability issues due to oxygen vacancy generation during sintering under reduction atmospheres, leading to decreased insulator resistance and deteriorated temperature coefficient of capacitance (TCC) characteristics, especially when thinning dielectric layers or increasing voltage.
Innovation Solution
A dielectric composition comprising BaTiO3 with specific accessory ingredients such as transition metals (V, Nb, Ta), Si oxides, Group 2 elements (Ca, Sr, Ba), and additional elements like Mg, Mn, Cr, Fe, Co, Y, and rare earth elements, optimized to maintain reduction resistance and improve TCC characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If sintering is performed under reduction atmosphere to form high-capacitance MLCC with BaTiO3 and nickel, then capacitance is improved, but oxygen vacancy generation occurs leading to decreased reliability and insulator resistance
Solution Approach 1:
The patent introduces rare earth elements (Dy, Y, Ho) as intermediary substances that mediate between the reduction atmosphere and the BaTiO3 dielectric material. These elements suppress oxygen vacancy generation by stabilizing the crystal structure during sintering, thereby maintaining insulator resistance while allowing high capacitance to be achieved through the reduction atmosphere process.
Solution Approach 2:
The patent changes the chemical composition parameters of the dielectric material by adding specific amounts of rare earth elements and transition metals. This compositional modification alters the sintering behavior and electrical properties, enabling the material to maintain high insulator resistance even when processed under reduction atmosphere for high capacitance.
2Power
If dielectric layer is thinned to achieve higher capacitance, then capacitance is improved, but reliability deteriorates due to increased susceptibility to oxygen vacancy effects
Solution Approach 1:
The patent modifies the compositional parameters of the dielectric material by incorporating rare earth elements and transition metals in specific ratios. This enables the use of thinner dielectric layers while maintaining reliability, as the modified composition suppresses oxygen vacancy generation even at reduced thicknesses.
Solution Approach 2:
The patent creates a composite dielectric material system combining BaTiO3 with rare earth elements and transition metals. This composite structure provides both the high capacitance needed for thin dielectric layers and the oxygen vacancy suppression needed for high-temperature reliability.
3Power
If voltage is increased to achieve higher power output, then power is improved, but TCC characteristics deteriorate due to enhanced oxygen vacancy generation
Solution Approach 1:
The patent adjusts the compositional parameters by adding transition metals and rare earth elements that stabilize the dielectric material against voltage-induced oxygen release. This allows higher operating voltages to be applied without significant TCC deterioration, as the modified composition resists oxygen vacancy generation under electrical stress.
4Reliability
If rare earth elements are added to suppress oxygen vacancy, then insulator resistance is improved, but permittivity and TCC characteristics deteriorate
Solution Approach 1:
The patent optimizes the concentration parameters of rare earth elements and transition metals to achieve a balance between insulator resistance and permittivity. By controlling the exact amounts of each additive, the patent maintains high dielectric constant while suppressing oxygen vacancy generation.
Solution Approach 2:
The patent creates a multi-component composite system where rare earth elements and transition metals work synergistically. The rare earth elements suppress oxygen vacancies while transition metals help maintain permittivity, achieving both high insulator resistance and high capacitance through the composite effect.
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 enhances high-temperature reliability and TCC characteristics, effectively preventing oxygen vacancy generation and maintaining capacitance performance even under severe conditions.
Implementation Method 1
a method of adding a rare earth element, for example, Dy, Y, Ho, and the like, to suppress the generation of an oxygen vacancy and decrease mobility of the oxygen vacancy
Implementation Method 2
adding a transition metal to suppress generation of the electrons to thereby exhibit dielectric characteristics
Implementation Method 3
The body as described above should be sintered under a reduction atmosphere
Data Source
AI summary
A dielectric composition contains: a base material powder containing BamTiO3 (0.995≤m≤1.010); a first accessory ingredient containing at least one element corresponding to a transition metal in Group 5 of the periodic table in a total content of 0.3 to 1.2 moles; a second accessory ingredient containing one of ions, oxides, carbides, and hydrates of Si in a content of 0.6 to 4.5 moles; a third accessory ingredient containing at least one element in Period 4 or higher; and a fourth accessory ingredient containing at least one element in Period 3, wherein 0.70×B≤C+D≤1.50×B and 0.20≤D/(C+D)≤0.80, in which B is a total content of the second accessory ingredient, C is a total content of the third accessory ingredient, and D is a total content of the fourth accessory ingredient.