Solid Electrolytic Capacitor Conductive Polymer Coating Delamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solid electrolytic capacitors face challenges in achieving good mechanical robustness and electrical performance due to difficulties in forming a thick solid electrolyte layer, which often delaminates during encapsulation, and the complexity and cost associated with using polymeric dispersions like poly(3,4-dioxythiophene) doped with polymeric anions.
Innovation Solution
A solid electrolytic capacitor is developed with a conductive coating comprising nanoparticles formed from poly(3,4-ethylenedioxythiophene) quaternary onium salt, which is highly soluble in water, eliminating the need for additional dopants and simplifying the formation process, and is applied as a nanodispersion over the solid electrolyte.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick solid electrolyte layer is formed to achieve good mechanical robustness and electrical performance, then mechanical robustness and electrical performance are improved, but the electrolyte layer delaminates during encapsulation
Solution Approach 1:
The patent uses a composite structure consisting of a solid electrolyte layer and a conductive polymer coating layer. The conductive polymer coating is formed by polymerizing a monomer in the presence of the solid electrolyte, creating a bonded interface between the two layers. This composite structure prevents delamination while maintaining mechanical robustness and electrical performance.
2Reliability
If polymeric dispersion with polymeric anion dopant is used to form conductive coating, then electrical performance is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and eliminates the need for polymeric anion dopants from the conventional formulation. Instead of using complex doped polymeric dispersions, the invention uses a simple conductive polymer coating formed by in-situ polymerization of a monomer on the solid electrolyte surface, removing the harmful or unnecessary dopant components while maintaining electrical performance.
Solution Approach 2:
The conductive polymer coating is formed through self-service polymerization where the monomer polymerizes in the presence of the solid electrolyte to form a coating that is inherently bonded to the substrate. This self-forming process eliminates the need for additional dopants and simplifies the formulation while achieving the desired electrical performance.
3Reliability
If polymeric dispersion with polymeric anion dopant is used to form conductive coating, then electrical performance is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive polymeric anion dopants with a cost-effective monomer that polymerizes in-situ to form the conductive coating. The simple monomer formulation and direct polymerization process reduce material costs and manufacturing complexity while achieving the required electrical performance.
4Reliability
If conventional conductive polymer coating is applied, then electrical performance is improved, but adhesion to solid electrolyte is poor causing delamination
Solution Approach 1:
The conductive polymer coating is formed by preliminary polymerization of a monomer in the direct presence of the solid electrolyte surface. This in-situ formation creates strong interfacial bonding between the coating and substrate before any encapsulation or mechanical stress is applied, preventing subsequent delamination while maintaining electrical 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
The use of poly(3,4-ethylenedioxythiophene) quaternary onium salt nanoparticles enhances mechanical robustness and electrical performance by improving adhesion and reducing equivalent series resistance and leakage current, while being cost-effective and easily dispersible in aqueous mediums.
Implementation Method 1
a conductive coating that overlies the solid electrolyte and includes nanoparticles formed from a poly(3,4-ethylenedioxythiophene) quaternary onium salt
Implementation Method 2
enhances mechanical robustness and electrical performance by improving adhesion
Data Source
AI summary
A solid electrolytic capacitor a solid electrolytic capacitor that includes an anode body, a dielectric overlying the anode body, and a solid electrolyte overlying the dielectric is provided. The capacitor also comprises a conductive polymer coating that overlies the solid electrolyte and includes nanoparticles formed from a poly(3,4-ethylenedioxythiophene) quaternary onium salt.