Multilayer Ceramic Capacitor Moisture-Proof Layer Design
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Solution Overview
Problem
Multilayer ceramic capacitors (MLCCs) face challenges in moisture resistance reliability and performance degradation due to thinning, particularly in automotive applications where chip cracking and moisture penetration are concerns, necessitating improved methods for high capacitance and mechanical strength.
Innovation Solution
A multilayer electronic component design featuring dielectric layers and alternately laminated internal electrodes with a moisture-proof layer containing rare-earth oxide on at least one surface, enhancing moisture resistance and reliability by preventing moisture penetration and ion migration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional MLCC structure is used, then manufacturing simplicity is maintained, but moisture resistance reliability deteriorates due to moisture penetration and chip cracking
Solution Approach 1:
A moisture-proof layer is formed on the body surface before the component is put into service, preventing moisture penetration from the outset. This preliminary protective action addresses moisture resistance reliability without requiring complex operational controls.
Solution Approach 2:
The moisture-proof layer is formed by incorporating barium oxide and zinc oxide into a glass composition, creating a composite material with enhanced moisture barrier properties. This composite approach improves reliability while maintaining manufacturing simplicity through a single-layer solution.
2Ease of operation
If the component size is reduced for miniaturization, then ease of mounting is improved, but mechanical strength deteriorates leading to chip cracking
Solution Approach 1:
A thin moisture-proof layer (1-10 μm) is applied to the body surface, providing protective function without significantly increasing component size. This thin film approach maintains miniaturization benefits while preventing chip cracking through stress distribution.
Solution Approach 2:
The glass composition parameters are optimized with specific ratios of barium oxide (40-70 wt%) and zinc oxide (30-60 wt%) to achieve both mechanical strength and moisture resistance in a compact structure, resolving the contradiction between miniaturization and strength.
3Reliability
If the dielectric layer thickness is reduced to increase capacitance density, then capacitance performance is improved, but moisture penetration resistance deteriorates
Solution Approach 1:
The protection function is segmented from the dielectric layers by introducing a dedicated moisture-proof layer on the body surface. This allows the dielectric layers to be thinned for high capacitance density while the separate moisture-proof layer provides targeted moisture barrier protection.
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 significantly improves moisture resistance reliability and maintains high capacitance, addressing the issues of chip cracking and performance degradation in MLCCs, especially in automotive applications, by effectively preventing moisture ingress and enhancing mechanical strength.
Implementation Method 1
a moisture-proof layer disposed on at least one surface of anyone of the first, second, fifth, or sixth surface and containing a rare-earth oxide
Data Source
AI summary
A multilayer electronic component includes a body including dielectric layers and first and second internal electrodes alternately laminated with respective dielectric layers interposed therebetween, and first and second surfaces opposing each other in a direction by which the internal electrodes are laminated, third and fourth surfaces connected to the first and second surfaces and opposing each other, and fifth and sixth surfaces connected to the first to fourth surfaces and opposing each other; a moisture-proof layer disposed on at least one surface of anyone of the first, second, fifth, or sixth surface and containing a rare-earth oxide; a first external electrode disposed on the third surface and connected to the first internal electrodes; and a second external electrode disposed on the fourth surface and connected to the second internal electrodes.