Electrolytic Capacitor Electrolyte for Low-ESR Dielectric Coverage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in achieving high capacitance in electrolytic capacitors lies in the difficulty of polymer dopants, such as polystyrenesulfonic acid, to penetrate fine recesses of the dielectric layer due to their high molecular weight, which limits the coverage and conductivity, thereby increasing the equivalent series resistance (ESR).
Innovation Solution
The use of a liquid mixture containing a conjugated polymer and a polymer dopant with an anionic group, where the amount of metal ions is less than 1 equivalent relative to the anionic group, facilitates better impregnation and coverage of the dielectric layer, reducing ESR and enhancing capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a polymer dopant with high molecular weight (e.g., polystyrenesulfonic acid) is used to improve conductivity and suppress ESR, then the ESR is reduced, but the dopant cannot penetrate fine recesses of the dielectric layer, limiting capacitance
Solution Approach 1:
The polymer dopant is segmented into smaller molecular weight components that can penetrate fine recesses while maintaining conductivity functionality. This segmentation allows the dopant to access previously unreachable areas of the dielectric layer, increasing overall coverage without sacrificing the ESR suppression capability.
Solution Approach 2:
The invention merges the benefits of high molecular weight polymer dopants (ESR suppression) with low molecular weight dopants (penetration capability) by using a combination or gradient structure. This allows both functions to coexist: the conductive network is established throughout the dielectric layer while maintaining low energy loss.
2Reliability
If a polymer dopant with high molecular weight is used to improve conductivity, then the ESR is suppressed low, but the impregnation into fine recesses of the dielectric layer is difficult, limiting capacitance
Solution Approach 1:
The molecular weight parameter of the polymer dopant is changed or optimized to a specific range that balances conductivity and impregnation capability. By adjusting this critical parameter, the dopant achieves both sufficient conductivity for low ESR and adequate mobility to penetrate fine recesses during the manufacturing process.
Solution Approach 2:
An intermediary substance or process is introduced to facilitate the impregnation of polymer dopant into fine recesses. This intermediary may be a solvent, surfactant, or processing condition that temporarily reduces viscosity or surface tension, enabling the dopant to penetrate deeply before固化, thereby improving manufacturing effectiveness without compromising final conductivity.
3Quantity of substance
If the coverage of dielectric layer with conductive polymer is improved to achieve higher capacitance, then more fine recesses need to be penetrated, but high molecular weight polymer dopants cannot reach these areas
Solution Approach 1:
The polymer dopant structure is segmented into smaller units or lower molecular weight variants that can physically penetrate fine recesses. This segmentation maintains the essential conductive properties while enabling access to deep dielectric structures, thereby achieving high coverage without sacrificing penetration strength.
Solution Approach 2:
The approach transitions from relying solely on molecular size to achieving penetration through alternative dimensions such as optimizing concentration gradients, using multi-stage impregnation processes, or creating porous structures that facilitate dopant distribution. This dimensional change in the impregnation strategy enables high coverage while maintaining effective penetration capability.
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 approach results in an electrolytic capacitor with improved capacitance and suppressed ESR, as the appropriate amount of metal ions in the liquid mixture allows for better permeation and increased conductivity, leading to a lower tan δ and higher capacitance values.
Implementation Method 1
The solid electrolyte layer usually includes a conductive polymer containing a conjugated polymer and a dopant
Implementation Method 2
the electrolyte contains a conjugated polymer, a polymer dopant having an anionic group, and a metal ion
Data Source
AI summary
An electrolytic capacitor includes a capacitor element. The capacitor element includes an anode body having a dielectric layer at a surface of the anode body, and an electrolyte covering part of the dielectric layer. The electrolyte contains a conjugated polymer, a polymer dopant having an anionic group, and a metal ion. The amount of the metal ion is less than 1 equivalent, relative to 1 equivalent of the anionic group.