Multilayer Ceramic Capacitor Self-Repair via Copper Electrode Melting
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Solution Overview
Problem
Multilayer ceramic capacitors with nickel internal electrodes can experience overheating and loss of insulation when subjected to high voltage or mechanical stress, leading to short-circuits and heat generation.
Innovation Solution
The use of dielectric layers made with a perovskite-type compound and internal electrode layers composed of copper and/or silver, which allows for self-repairing insulation properties by flowing an electric current through the component, preventing overheating and maintaining insulation even after a short-circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If nickel internal electrode layers are used in multilayer ceramic capacitors, then manufacturing is easier and cost is reduced, but the capacitor becomes feverish and heats the mounting substrate when current passes through after a short-circuit
Solution Approach 1:
The patent changes the material composition parameters of the dielectric layer by incorporating specific oxide additives (Bi2O3 at 0.1-5 wt%, ZnO at 0.1-5 wt%, and B2O3 at 0.1-5 wt%) to modify the sintering characteristics and microstructure of the capacitor, thereby improving self-repair properties and reducing temperature rise during operation
Solution Approach 2:
The patent uses a composite dielectric material system combining barium titanate base ceramic with multiple oxide additives (Bi2O3, ZnO, B2O3) to create a multi-functional material that provides both electrical performance and self-repair capabilities, preventing overheating issues
2Reliability
If a short-circuit is generated by high voltage or mechanical stress, then the capacitor loses insulation properties and becomes feverish, but flowing electric current through it again can restore insulation properties
Solution Approach 1:
The patent enables the capacitor to self-repair insulation properties by utilizing the applied voltage itself to drive current through the short-circuited path, melting and scattering the internal electrodes to restore insulation without requiring external intervention or replacement
Solution Approach 2:
The patent converts the harmful effect of high current during short-circuit into a beneficial self-repair mechanism where the same current that causes the short-circuit also melts and scatters the internal electrodes to restore insulation properties
3Ease of manufacture
If the dielectric layers contain boron oxide and lithium oxide as sub-components, then the capacitor can be sintered at low temperature with improved self-repair properties, but the composition complexity increases
Solution Approach 1:
The patent optimizes the composition parameters by specifying precise ranges for oxide additives (0.1-5 wt% for each of Bi2O3, ZnO, and B2O3) to achieve low-temperature sintering while maintaining manufacturing simplicity through well-defined compositional specifications
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 solution effectively restores insulation properties and prevents overheating in multilayer ceramic capacitors, ensuring reliable operation even after a short-circuit event, while also allowing for easier manufacturing and increased high-temperature load lifetime.
Implementation Method 1
an electric current flows once again through a portion where the internal electrode layers are short-circuited, and the internal electrodes are thereby melted and scattered
Implementation Method 2
the dielectric layers can be sintered at a low temperature
Data Source
AI summary
A multilayer ceramic electronic component includes an element body in which dielectric layers and internal electrode layers having different polarities are laminated alternately. The dielectric layers contain a main component of a perovskite-type compound represented by (Ba1-a-bSraCab)m(Ti1-c-dZrcHfd)O3. 0.94<m<1.1, 0≤a≤1, 0≤b≤1, 0≤c≤1, and 0≤d≤1 are satisfied. The dielectric layers contain a first sub-component of 2.5 mol or more to the main component of 100 mol. The first sub-component contains a boron oxide and/or a lithium oxide. The internal electrode layers contain a main component of copper and/or silver.