Electrolytic Capacitor Anode Lead-out Protrusion Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The joint strength between the anode lead-out part and the external electrode in electrolytic capacitors is low, leading to potential air and water ingress, which can deteriorate the solid electrolyte layer and increase equivalent series resistance.
Innovation Solution
The anode lead-out part is designed to protrude from the exterior body, allowing for a secure and tight connection with the external electrode, eliminating the porous part in the joining area and enhancing joint reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the anode lead-out part uses a porous body structure to increase connecting area, then contact resistance decreases, but joint strength with external electrode becomes lower
Solution Approach 1:
The anode lead-out part is divided into two functional regions: a porous body portion for electrical connection and a non-porous core portion for mechanical strength. This segmentation allows each region to fulfill its specific function optimally while working together as a unified structure.
Solution Approach 2:
Different portions of the anode lead-out part are given different structural properties: the porous body portion has high surface area for low contact resistance, while the non-porous core portion has dense structure for high joint strength. This local differentiation resolves the contradiction between electrical performance and mechanical strength.
2Area of stationary object
If the porous part is joined to the external electrode, then connecting area is increased, but air and water can enter through the interface
Solution Approach 1:
The non-porous core portion acts as an intermediary between the porous body and the external electrode. It provides a sealed, non-porous interface for joining to the external electrode, preventing air and water ingress while the porous body maintains electrical connection functionality.
Solution Approach 2:
By separating the porous body from the joining interface through the non-porous core, the structure allows the porous region to provide electrical connection area while the non-porous region provides a hermetic seal against harmful contaminants.
3Reliability
If air enters through the interface between porous part and external electrode, then solid electrolyte layer deteriorates, but equivalent series resistance increases
Solution Approach 1:
The non-porous core portion is designed in advance to prevent air and water from reaching the solid electrolyte layer. This preventive structure cushiones against potential deterioration before it can occur, maintaining long-term reliability and preventing ESR increase.
Data Source
AI summary
An electrolytic capacitor includes a capacitor element, an exterior body that seals the capacitor element, and an external electrode. The capacitor element includes an anode foil, a dielectric layer, and a cathode part. The anode foil includes an anode lead-out part and a cathode forming part. The anode lead-out part has a first end of the anode foil. The cathode forming part has a second end of the anode foil. The dielectric layer is disposed on a surface of the cathode forming part. The cathode part covers at least part of the dielectric layer. The first end in the anode lead-out part protrudes from an end surface of the exterior body. At least part of the first end is in contact with the external electrode.