Dielectric Material for High DC Bias Multilayer Ceramic Capacitors
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Solution Overview
Problem
Multilayer ceramic capacitors face challenges in achieving high capacitance and reliability while maintaining small size, as miniaturization leads to deterioration in high-temperature withstand voltage and DC bias characteristics, especially under high field DC bias conditions.
Innovation Solution
A dielectric material composed of (Ba1-xCax)(Ti1-yZry)O3, (Ba1-xCax)(Ti1-ySny)O3, or (Ba1-xCax)(Ti1-yHfy)O3 with specific XRD pattern characteristics, including a main component and subcomponents, is used to enhance the dielectric constant and withstand voltage, improving the performance of multilayer ceramic electronic components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the size of multilayer ceramic capacitors is reduced to achieve smaller components, then miniaturization is achieved, but high-temperature withstand voltage characteristics and DC bias characteristics deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the dielectric material by incorporating specific ratios of Ba, Ca, Ti, Zr, Sn, or Hf elements. By adjusting the compositional parameters (represented by variables x, y, z in the formulas), the patent achieves improved DC bias characteristics and high-temperature withstand voltage properties while maintaining miniaturized dimensions. The specific compositional ranges are optimized to balance size reduction with performance maintenance.
Solution Approach 2:
The patent uses composite dielectric materials combining multiple ceramic phases: (Ba1-xCax)(Ti1-yZry)O3, (Ba1-xCax)(Ti1-ySny)O3, or (Ba1-xCax)(Ti1-yHfy)O3 as main components, along with specific subcomponents containing elements like Mn, V, Cr, Fe, Ni, Co, Cu, Zn, Mg, and rare earth elements. This composite approach allows the material to exhibit both the miniaturization capability and the improved reliability characteristics simultaneously.
2Quantity of substance
If the dielectric layer thickness is reduced to increase capacitance density, then higher capacitance is achieved, but product reliability and DC bias characteristics deteriorate
Solution Approach 1:
The patent changes the material parameters rather than just geometric parameters. By optimizing the chemical composition and crystal structure of the dielectric material, the patent enables thinner dielectric layers to maintain adequate breakdown strength and DC bias characteristics. The compositional optimization allows capacitance enhancement through material properties rather than solely through geometric thinning.
Solution Approach 2:
The composite dielectric structure with multiple phases and controlled grain sizes provides both the thin-layer capability for high capacitance density and the structural integrity for reliability. The combination of main component phases and subcomponent phases creates a material that can be processed into thin layers while maintaining the necessary electrical properties.
3Quantity of substance
If a larger number of dielectric and electrode layers are laminated to achieve higher capacitance, then capacitance increases, but manufacturing complexity and DC bias characteristics worsen
Solution Approach 1:
The patent changes the dielectric constant of the material itself through compositional optimization, enabling higher capacitance per layer. This reduces the number of layers required to achieve target capacitance values, thereby simplifying the lamination process and improving DC bias characteristics. The material parameter changes compensate for the reduced layer count.
4Ease of manufacture
If conventional dielectric materials are used in miniaturized structures, then manufacturing is easier, but DC bias dielectric constant and high-temperature withstand voltage characteristics deteriorate
Solution Approach 1:
The patent modifies the compositional parameters of conventional ceramic materials to achieve the desired performance. The base material system ((Ba,Ca)(Ti,Zr/Sn/Hf)O3) is similar to conventional materials, maintaining ease of manufacture, while the specific compositional ratios and additions are optimized to improve DC bias characteristics and high-temperature withstand voltage properties.
Solution Approach 2:
The patent creates composite materials that build upon conventional ceramic formulations. The main component phases are based on well-known perovskite structures that are familiar to manufacturers, while subcomponents and dopants are added to enhance specific properties without fundamentally changing the manufacturing process.
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 dielectric material achieves improved high field DC bias dielectric constant and high-temperature withstand voltage characteristics, satisfying X5R or X7R specifications, thereby enhancing the performance and reliability of multilayer ceramic capacitors.
Implementation Method 1
a dielectric material including a main component represented by (Ba1-xCax)(Ti1-yZry)O3, (Ba1-xCax)(Ti1-ySnym)O3, or (Ba1-xCax)(Ti1-yHfy)O3
Data Source
AI summary
A dielectric material includes a main component represented by (Ba1-xCax)(Ti1-yZry)O3, (Ba1-xCax)(Ti1-ySny)O3, or (Ba1-xCax)(Ti1-yHfy)O3 (0≤x≤1 and 0≤y≤0.05) and a subcomponent. When an angle corresponding to a maximum peak is referred to as θ0 and angles corresponding to a full width at half maximum (FWHM) are respectively referred to as θ1 and θ2 (θ1<θ2) in the peaks of (002) and (200) plane of an x-ray diffraction (XRD) pattern using Cu Kα1 radiation (wavelength Δ=1.5406 Å), (θ2−θ0)/(θ0−θ1) is greater than 0.54 to 1.0 or less.