Ceramic Chip Electrode Structure for Thermal Stress Peel Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-layer ceramic electronic components face peeling issues due to stress concentration from thermal expansion and contraction, even with conductive resin layers having high flexibility, when mounted on substrates that undergo significant temperature changes.
Innovation Solution
The design incorporates a conductive resin layer with first and second convex portions on the main-surface-covering portion of the external electrodes, which swell toward the center and are apart from each other, distributing stress effectively and enhancing adhesion to the ceramic body, while a laminated structure with a plating layer ensures direct contact and reduced stress propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conductive resin layer with high flexibility is used in the external electrode, then the flexibility and stress absorption capability is improved, but the external electrode still peels off from the ceramic body when subjected to large temperature changes and stress concentration
Solution Approach 1:
The patent applies local quality by creating convex portions with different shapes and properties at specific locations on the main surface of the external electrode. These convex portions have different radii of curvature and heights, providing localized stress distribution capabilities rather than uniform properties across the entire surface. This allows the electrode to adapt to local stress concentrations while maintaining overall adhesion to the ceramic body.
Solution Approach 2:
The patent segments the main surface of the external electrode into multiple convex portions instead of having a single flat or uniformly curved surface. By dividing the surface into discrete convex regions with different geometries, the stress from temperature changes is distributed across multiple localized areas rather than concentrating at single points, preventing peel-off while maintaining flexibility.
2Temperature
If the substrate undergoes large temperature changes, then the thermal expansion and contraction capability is improved, but stress concentration occurs causing the external electrode to peel off from the ceramic body
Solution Approach 1:
The patent changes the geometric parameters of the external electrode surface by introducing convex portions with varying radii of curvature and heights. This parameter variation allows the electrode to accommodate thermal expansion and contraction more effectively by distributing the resulting stresses across multiple locations with different compliance characteristics, preventing stress concentration that would lead to peel-off.
3Ease of manufacture
If the main-surface-covering portion is made flat and continuous, then the manufacturing simplicity is improved, but the stress distribution capability is reduced leading to peel-off under thermal stress
Solution Approach 1:
Rather than making the entire main-surface-covering portion complex, the patent introduces localized convex portions with specific geometric properties at strategic locations. This approach maintains relative manufacturing simplicity while providing localized stress distribution capabilities, balancing ease of manufacture with stress management performance.
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
This configuration effectively prevents peeling of the external electrodes from the ceramic body by distributing stress and enhancing adhesion, ensuring reliable mounting even under severe temperature changes.
Implementation Method 1
such a stress can be distributed to the first convex portion and the second convex portion. Therefore, the main-surface-covering portion can be prevented from peeling off from the ceramic body due to the concentration of stress.
Implementation Method 2
enhancing adhesion to the ceramic body
Implementation Method 3
a laminated structure with a plating layer ensures direct contact and reduced stress propagation
Data Source
AI summary
A multi-layer ceramic electronic component includes a ceramic body and a pair of external electrodes. The ceramic body includes a pair of main surfaces perpendicular to a first axis, a pair of end surfaces perpendicular to a second axis, a pair of side surfaces perpendicular to a third axis, and internal electrodes drawn to the end surfaces, and has a substantially rectangular parallelepiped shape. The external electrodes each include an end-surface-covering portion that covers one of the end surfaces, and a main-surface-covering portion that is formed to be continuous from the end-surface-covering portion and covers a part of the main surface. The main-surface-covering portion includes a conductive resin layer, and first and second convex portions formed on the basis of a shape of the conductive resin layer, each swelling toward the center in the direction of the second axis, and disposed apart from each other in the third axis direction.