Electrolytic Capacitor Intermediate Layer for ESR Reduction
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Solution Overview
Problem
Existing electrolytic capacitors with conductive polymeric layers face challenges in reducing equivalent series resistance (ESR) and preventing increased leakage current, despite the use of crosslinking agents.
Innovation Solution
The introduction of an intermediate layer with a cation agent containing cationic groups and an anion agent with specific anionic groups, where the first anionic group is higher in electron-withdrawing property than the second, enhances the formability and covering performance of the second conductive polymeric layer, thereby reducing ESR and leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a crosslinking agent is used to strengthen the conductive polymeric layer, then the strength of the conductive polymeric layer is improved, but the covering performance on the upper portion of the solid electrolytic layer deteriorates
Solution Approach 1:
The conductive polymeric layer is divided into two separate layers: a first conductive polymeric layer formed directly on the solid electrolytic layer, and a second conductive polymeric layer formed on top of the first layer. This segmentation allows each layer to be optimized independently - the first layer provides strong adhesion through crosslinking, while the second layer provides smooth covering performance.
Solution Approach 2:
The first conductive polymeric layer acts as an intermediary between the solid electrolytic layer and the second conductive polymeric layer. It provides a transition interface that enables both the crosslinking agent to strengthen the base layer and the second layer to achieve good covering performance, resolving the contradiction between strength and covering.
2Strength
If the conductive polymeric layer is strengthened using crosslinking agents, then the mechanical strength is improved, but the equivalent series resistance (ESR) increases and leakage current worsens
Solution Approach 1:
By segmenting the conductive polymeric layer into two layers with different compositions and functions, the first layer can be optimized for mechanical strength through crosslinking, while the second layer can be optimized for electrical performance with lower ESR and leakage current, as it is not subjected to crosslinking treatment.
3Device complexity
If a single conductive polymeric layer is used, then the structure is simple, but the performance in terms of ESR, leakage current, and covering is insufficient
Solution Approach 1:
The conductive polymeric layer is segmented into two layers with distinct functions: the first layer provides adhesion and structural support, while the second layer provides optimized electrical performance. This segmentation achieves superior electrical performance and covering without excessive complexity.
Solution Approach 2:
Different regions of the conductive polymeric structure are given different qualities - the first layer near the solid electrolytic layer is designed for strong adhesion and strength, while the second layer at the top surface is designed for low ESR, low leakage current, and smooth covering. This local differentiation optimizes overall 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 decreases ESR and restrains the increase in leakage current, while also protecting the anode body from corrosion, resulting in improved performance and reliability of the electrolytic capacitor.
Implementation Method 1
the intermediate layer comprises a cation agent containing at least one cationic group, and an anion agent containing at least one first anionic group and at least one second anionic group
Data Source
AI summary
Disclosed is an electrolytic capacitor including: an anode body; a dielectric layer formed over the anode body; a first conductive polymeric layer covering at least one portion of the dielectric layer; a second conductive polymeric layer covering at least one portion of the first conductive polymeric layer; and an intermediate layer formed between the first conductive polymeric layer and the second conductive polymeric layer. The intermediate layer includes a cation agent containing at least one cationic group, and an anion agent containing at least one first anionic group and at least one second anionic group, and the first anionic group is higher in electron-withdrawing property than the second anionic group. The anion agent includes a polymer containing the first anionic group and the second anionic group.