Low-Height Multilayer Ceramic Capacitor Flexure Strength
Solution Overview
Problem
Low-height multilayer ceramic capacitors exhibit lower flexure strength compared to laminated ceramic capacitors, leading to functional issues such as capacity reduction due to thermal shock, which is a concern for reducing the thickness of circuit boards and mobile devices.
Innovation Solution
A low-height multilayer ceramic capacitor design with a dielectric chip of roughly rectangular shape, featuring external electrodes with a wraparound part that covers both sides, where the thickness of the protective dielectric layers is less than the wraparound part, enhancing flexure strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the height of the multilayer ceramic capacitor is reduced to make it wider, then the thickness of circuit boards and mobile devices can be reduced, but the flexure strength decreases leading to capacity reduction under thermal shock
Solution Approach 1:
The patent applies local quality by making the protective dielectric layers have different thickness characteristics compared to the wraparound parts. Specifically, the protective dielectric layers are designed with thickness t11c that is less than the thickness t12b of the wraparound parts, creating a localized thickness difference that optimizes both the low-height requirement and flexure strength. This local differentiation allows the capacitor to maintain low profile while resisting flexure-induced capacity reduction.
2Strength
If the wraparound part thickness is increased to improve flexure strength, then the capacitor can resist thermal shock better, but the overall height increases
Solution Approach 1:
The patent applies parameter changes by establishing a specific thickness relationship between the protective dielectric layers and wraparound parts. The condition t11c < t12b creates an optimized parameter configuration where the wraparound parts provide sufficient flexure strength while the protective dielectric layers maintain a low overall profile. This parameter optimization allows the capacitor to achieve both low height and high flexure strength simultaneously.
Data Source
AI summary
A low-height multilayer ceramic capacitor offering excellent flexure strength meets the condition “t11c<t12b,” where t11c represents the thickness of each protective dielectric layer provided on respective top and bottom sides of a dielectric chip, and t12b represents the thickness of a wraparound part of each external electrode provided at least part of both top and bottom faces of the dielectric chip.