Stacked Solid Electrolytic Capacitor Cathode Structure for Lower ESR
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid electrolytic capacitors have low capacitance storage efficiency and high ESR (Equivalent Series Resistance) values, necessitating a reduction in ESR to enhance performance.
Innovation Solution
The design incorporates a stacked unit of capacitor units with a cathode lead terminal having a side wall portion electrically connected to the cathode foil, using a conductive paste without silver, and featuring a carbon layer with a resin or binder, along with a dielectric layer and conductive polymer in the solid electrolyte, to reduce ESR and manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solid electrolytic capacitor structure is used, then manufacturing process is simple, but ESR value is high and capacitance storage efficiency is low
Solution Approach 1:
The capacitor is divided into multiple capacitor units stacked together, with each unit having its own cathode portion and cathode foil. This segmentation allows for optimized current distribution and reduced ESR while maintaining manageable manufacturing complexity through modular assembly
Solution Approach 2:
The cathode lead terminal extends in the width direction to form side wall portions that face the side surfaces of capacitor units. This dimensional extension creates additional electrical connection paths without significantly increasing overall device complexity, thereby reducing ESR through parallel conduction paths
2Reliability
If silver paste is used for electrical connection, then electrical conductivity is high, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive silver paste with carbon-based conductive paste containing carbon particles and resin. This substitution significantly reduces material costs while maintaining adequate electrical conductivity for the application, accepting that the conductive paste may have slightly lower conductivity than silver but compensating through increased application area
Solution Approach 2:
The cathode lead terminal is designed with extended side wall portions that increase the surface area for paste application. This parameter change allows the use of less conductive carbon-based paste to achieve the same overall conductivity by distributing the current across a larger area, thereby reducing material costs
3Device complexity
If cathode lead terminal is simplified, then device complexity is reduced, but electrical connection area decreases
Solution Approach 1:
The cathode lead terminal is designed with side wall portions that extend in the width direction to face the side surfaces of capacitor units. This dimensional extension increases the electrical connection area without adding complex three-dimensional structures, maintaining manufacturing simplicity while improving electrical connection
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 reduces the ESR of the solid electrolytic capacitor while lowering manufacturing costs by eliminating the need for silver paste and optimizing the conductive path, resulting in improved performance and cost-effectiveness.
Implementation Method 1
a cathode foil connected to the cathode portion via a first conductive paste; and a cathode lead terminal electrically connected to the cathode portion
Implementation Method 2
a capacitor element including an anode portion and a cathode portion, and a solid electrolyte layer that is a cathode
Data Source
AI summary
A disclosed solid electrolytic capacitor includes: a stacked unit constituted by a stack of a plurality of capacitor units each having a capacitor element including an anode portion and a cathode portion, and a cathode foil connected to the cathode portion via a first conductive paste; and a cathode lead terminal electrically connected to the cathode portion. The cathode lead terminal has at least one side wall portion facing a side surface of the cathode portion and electrically connected to the cathode foil. This makes it possible to reduce the ESR of the solid electrolytic capacitor.