Electronic Component Electrode Depression for Crack Prevention
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Solution Overview
Problem
Existing electronic components are prone to cracking due to excessive stress caused by the binding force from solder fillets, especially when mounted on deflected electronic devices, as the stress concentrates at the second external electrode region.
Innovation Solution
A configuration with a depression in the conductor part of the second external electrode reduces the solder fillet height and binding force, thereby minimizing stress on the element body, and the positioning of the depression at the center or deviated regions ensures secure bonding while reducing crack occurrence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the second external electrode is bonded to the electronic device by soldering with a large solder fillet, then the bonding strength between the electrode and device is improved, but the stress concentration in the element body increases causing cracks
Solution Approach 1:
The conductor part of the second external electrode is designed with non-uniform thickness, creating a thick region and a thin region. This local variation in geometry allows different parts of the same electrode to provide different functions: the thick region ensures adequate bonding strength while the thin region reduces stress concentration and prevents cracking in the element body.
Solution Approach 2:
The thickness parameter of the conductor part is deliberately varied to optimize performance. By changing the thickness from a uniform value to a gradient distribution (thick at certain regions, thin at others), the electrode achieves both strong bonding capability and reduced stress transmission to the element body, resolving the contradiction between bonding strength and stress concentration.
2Ease of manufacture
If the conductor part has uniform thickness, then the manufacturing process is simplified, but the stress distribution becomes uneven causing cracks in the element body
Solution Approach 1:
Instead of using uniform thickness throughout the conductor part, the design introduces local variations with thick and thin regions. This allows the electrode to have different properties in different areas, enabling it to withstand stress without cracking while still being manufacturable through conventional processes like screen printing or thick film deposition.
3Object-affected harmful factors
If the solder fillet height is reduced, then the binding force from the electronic device is reduced minimizing stress, but the bonding strength may become insufficient
Solution Approach 1:
The conductor part is designed with localized thick and thin regions rather than uniform thickness. The thick region provides adequate bonding strength to maintain electrical connection, while the thin region limits the solder fillet height to reduce binding force and stress on the element body, thus resolving the contradiction between bonding strength and stress reduction.
Solution Approach 2:
Instead of reducing the conductor thickness uniformly (which would compromise bonding), the design applies partial thinning only in specific regions where stress concentration occurs. This partial action approach maintains sufficient bonding strength in critical areas while reducing stress in other areas, achieving the optimal balance.
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 reduced binding force and stress in the element body effectively suppress the occurrence of cracks, while maintaining sufficient bonding strength between the electronic component and the device, thus stabilizing the posture and preventing damage.
Implementation Method 1
the solder wetted on the conductor tends not to be wetted beyond the depression
Data Source
AI summary
An element body includes first and second end surfaces opposing each other in a first direction, first and second side surfaces opposing each other in a second direction, and first and second principal surfaces opposing each other in a third direction. The length of the element body in the second direction is shorter than that of the element body in the first direction, and the length of the element body in the third direction is shorter than that of the element body in the second direction. A pair of first external electrodes is disposed at both ends of the element body in the first direction. A second external electrode is disposed on the element body and positioned between the pair of first external electrodes. The second external electrode includes a first conductor part disposed on the first side surface. A depression is formed in the first conductor part.