Multilayer Capacitor Electrode Through-Ports for Crack Resistance
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Solution Overview
Problem
High-voltage multilayered capacitors for electric devices in vehicles are prone to cracking due to piezoelectric phenomena caused by dipoles aligning in a specific direction under an electric field, leading to stress-induced deformation.
Innovation Solution
A multilayered capacitor design with internal electrodes featuring through-portions that extend in the thickness direction, where dielectric layers are integrated to enhance bonding force, reducing piezoelectric behavior and suppressing deformation and cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high-voltage multilayered capacitor is manufactured by laminating dielectric green sheets with internal electrodes, then high capacity and small size are achieved, but cracks may be generated due to piezoelectric phenomenon under high voltage electric field
Solution Approach 1:
The internal electrode is divided into a first internal electrode and a second internal electrode that are not in direct contact. This segmentation breaks the continuous conductive path, reducing the piezoelectric stress concentration and preventing crack propagation through the electrode structure.
Solution Approach 2:
A resin layer is introduced as an intermediary substance between the first and second internal electrodes. This resin layer acts as a stress buffer and electrical insulator, preventing direct stress transmission between electrodes while maintaining electrical connectivity through the capacitor structure.
2Reliability
If dipoles in ferroelectric material are aligned by electric field to achieve high capacity, then capacitance increases, but length contraction in width direction causes deformation
Solution Approach 1:
By segmenting the internal electrode structure into separate first and second electrodes, the patent creates discrete stress zones that prevent continuous deformation propagation. The segmentation allows localized dimensional changes without affecting overall structural integrity.
Solution Approach 2:
The resin layer serves as a compliant intermediary that accommodates dimensional changes caused by piezoelectric contraction. It absorbs the mechanical stress from dipole alignment, preventing transmission of deformation to the overall capacitor structure.
3Reliability
If internal electrodes are directly connected to enhance conductivity, then electrical performance improves, but bonding force between electrodes and dielectric layers decreases leading to cracks
Solution Approach 1:
The resin layer acts as an intermediary bonding medium between internal electrodes and dielectric layers. It provides mechanical adhesion while allowing electrical conductivity to pass through, thereby maintaining both bonding strength and electrical performance simultaneously.
Solution Approach 2:
The capacitor employs a composite structure combining dielectric layers, conductive internal electrodes, and insulating resin material. This composite approach allows each material to perform its optimal function - dielectric for capacitance, metal for conductivity, and resin for mechanical bonding and stress relief.
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 enhanced bonding force between internal electrodes and dielectric layers effectively minimizes cracking and deformation, ensuring structural integrity under high voltage conditions.
Implementation Method 1
dielectric layers are integrated to enhance bonding force
Implementation Method 2
cracking due to piezoelectric phenomena caused by dipoles aligning in a specific direction under an electric field
Data Source
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AI summary
A multilayered capacitor (110) resistant to cracking includes a capacitor body including a dielectric layer (111), and a first internal electrode (121) and a second internal electrode (122) with the dielectric layer interposed therebetween, and an external electrode (131) on one surface of the capacitor body. The first internal electrode (121) has a first through-portion (121a) penetrating the first internal electrode (121), a dielectric of the dielectric layer (111) is disposed in at least a portion of the first through-portion (121a), and the first through-portion (121a) is disposed in a region where the first internal electrode (121) is not overlapped with the second internal electrode (122).