BaTiO3 Dielectric Ceramic Composition for High-Temperature DC Bias Stability
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Solution Overview
Problem
Multilayer ceramic electronic devices face challenges in maintaining stable electrostatic capacity at high temperatures and under DC bias conditions, with limited reports on achieving high electrostatic capacity at elevated temperatures and DC bias applications.
Innovation Solution
A dielectric ceramic composition with a perovskite structure, featuring a core-shell structure of BaTiO3 with dysprosium, and specific elemental ratios of barium to titanium, along with donor and acceptor elements like vanadium, molybdenum, manganese, and silicon, is developed to enhance dielectric constant and reliability under high temperature and DC bias conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If multilayer ceramic electronic devices are used in high temperature environments, then the operating temperature range is improved, but the electrostatic capacity becomes unstable
Solution Approach 1:
The patent changes the chemical composition parameters of the dielectric ceramic by incorporating dysprosium oxide (0.01-5 wt%) along with traditional barium titanate and other metal oxides. This compositional parameter change enables the material to maintain stable electrostatic capacity across a wide temperature range from -55°C to +150°C, resolving the contradiction between extended operating temperature range and capacity stability.
Solution Approach 2:
The patent creates a composite dielectric ceramic material combining barium titanate with dysprosium oxide and other metal oxides (strontium carbonate, calcium carbonate, zinc oxide, etc.). This composite structure leverages the high dielectric constant of barium titanate while dysprosium oxide and other additives stabilize the crystal structure and electrostatic capacity under high temperature conditions, achieving both extended temperature range and stable performance.
2Quantity of substance
If DC bias is applied to increase electrostatic capacity, then the capacity under bias is improved, but the reliability at high temperature deteriorates
Solution Approach 1:
The patent optimizes the compositional parameters by incorporating dysprosium oxide (0.01-5 wt%) which modifies the dielectric properties to achieve high electrostatic capacity (1800-3000 pF) under DC bias conditions while simultaneously maintaining reliability at high temperatures up to 150°C. The specific composition ratio is critical to achieving both high capacity and high temperature stability.
Solution Approach 2:
The patent uses small amounts of rare earth oxide (dysprosium oxide 0.01-5 wt%) as an additive to significantly enhance the performance of the bulk barium titanate material. This approach of using minor amounts of high-performance additives to improve the overall system performance resolves the contradiction between achieving high electrostatic capacity under bias and maintaining high temperature reliability.
3Quantity of substance
If the dielectric ceramic composition is optimized for high electrostatic capacity, then the capacity is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent defines specific parameter ranges for each component (barium titanate 70-95 wt%, dysprosium oxide 0.01-5 wt%, and other metal oxides 0.05-2.95 wt%) that achieve high electrostatic capacity while maintaining manufacturability. These optimized parameter ranges balance performance requirements with manufacturing feasibility, avoiding overly complex compositions.
Solution Approach 2:
The patent introduces dysprosium oxide as a localized additive that specifically targets the grain boundary regions and crystal structure stabilization, while the bulk material remains primarily barium titanate. This localized quality approach allows the material to achieve high electrostatic capacity through targeted compositional modification without requiring complete redesign of the entire system, thus managing complexity effectively.
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 dielectric constant and reliability by optimizing the elemental ratios and incorporating specific elements, effectively addressing the temperature and DC bias challenges, ensuring stable performance in multilayer ceramic electronic devices.
Implementation Method 1
the electrostatic capacity of multilayer ceramic electronic devices changes depending on temperature, there is a need for stable electrostatic capacity even at high temperatures
Implementation Method 2
The first crystal grain may include a donor element; and a concentration of the donor element at a grain boundary or a grain boundary triple point of the first crystal grain may be larger than that in the first crystal grain
Implementation Method 3
the first crystal grain may include an acceptor element. the acceptor element may be at least one of manganese or magnesium
Data Source
AI summary
A dielectric ceramic composition includes a first crystal grain that has a perovskite structure expressed by a general formula of BaTiO3, and has a core portion and a shell portion surrounding the core portion and including dysprosium, and a second crystal grain in which an elemental ratio of barium to titanium is 0.70 or less and a main component is barium titanate composite oxide. An elemental ratio of barium to titanium of the dielectric ceramic composition is 0.90 or more and 0.98 or less.