Multilayer Ceramic Capacitor Composition for Thin-Layer Insulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multilayer ceramic capacitors face challenges with insufficient insulation and reliability under high electric field strength, particularly in thinner dielectric layers, which are not reliably receiving an applied voltage.
Innovation Solution
The multilayer ceramic capacitor includes dielectric layers made of a perovskite compound with Ba and Ti, partially substituted with Ca and Zr, and internal electrodes containing Sn, which diffuse to the dielectric layers during firing, enhancing insulation and reliability by adjusting the Sn content at the interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the dielectric layer thickness is reduced to increase capacitance, then the capacitance increases, but the insulation resistance decreases and reliability deteriorates
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the crystal grain core and shell have different compositions and properties. The shell region has higher insulation resistance than the core, compensating for the reduced thickness effect. This local differentiation allows thin dielectric layers to maintain high insulation resistance while achieving high capacitance.
Solution Approach 2:
The patent uses composite materials by combining multiple elements (Ba, Ti, Ca, Zr, Sn) in specific ratios within the perovskite structure. The composite nature of the dielectric material, with intentional compositional gradients from core to shell, enables simultaneous achievement of high capacitance and high insulation resistance in thin layers.
2Quantity of substance
If the dielectric layer thickness is reduced to increase capacitance, then the capacitance increases, but the breakdown voltage decreases
Solution Approach 1:
The core-shell structure creates local quality differences where the shell has enhanced insulation properties compared to the core. This local enhancement in the shell region provides additional resistance to electrical breakdown, allowing thin dielectric layers to withstand high voltages while maintaining high capacitance.
Solution Approach 2:
The patent employs beforehand cushioning by pre-forming the core-shell structure with the shell acting as a protective layer. This shell structure serves as a cushion against electrical breakdown before it occurs, enabling the thin dielectric layer to withstand high breakdown voltages while achieving high capacitance.
3Reliability
If Sn content is increased to improve insulation resistance, then the insulation resistance increases, but the manufacturing complexity increases
Solution Approach 1:
The patent merges the functions of insulation enhancement and manufacturing simplicity by incorporating Sn into the perovskite dielectric material itself rather than applying it as a separate coating or treatment. This integration allows Sn to diffuse during the standard firing process, improving insulation resistance without adding significant manufacturing complexity.
Solution Approach 2:
The patent uses parameter changes by controlling the Sn content within a specific range (0.1-5.0 atomic%) and optimizing the firing conditions. By adjusting these parameters, the patent achieves high insulation resistance while keeping the manufacturing process manageable and avoiding excessive complexity.
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 capacitor achieves improved insulation and reliability by ensuring a sum of resistance values greater than or equal to 1 MΩ, resulting in higher breakdown voltage and longer time-to-failure, thus enhancing its performance under high electric field strength.
Implementation Method 1
internal electrodes containing Sn, which diffuse to the dielectric layers during firing, enhancing insulation and reliability
Data Source
AI summary
A multilayer ceramic capacitor includes a stack and a plurality of external electrodes. The stack includes a plurality of dielectric layers stacked on one another and a plurality of internal electrodes located along interfaces between the plurality of dielectric layers. The plurality of external electrodes is located on outer surfaces of the stack and electrically connected to the plurality of internal electrodes. The plurality of dielectric layers contains, as a main component, a perovskite compound containing Ba and Ti. Ba is partially optionally substituted with Ca, and Ti is partially optionally substituted with Zr. A sum of resistance values of the main component and other components in the plurality of dielectric layers measured with an alternating current impedance method is greater than or equal to 1 MΩ.