Electrolytic Capacitor Lead Structure for Lower ESR Sealing

Solution Overview

Problem

Existing methods for manufacturing electrolytic capacitors struggle to sufficiently reduce the equivalent series resistance (ESR) due to the need for long internal leads to prevent interference with sealing plates and joint devices, which increases resistance.

Innovation Solution

The method involves connecting a foil-shaped internal lead to an electrode foil, then connecting a rod-shaped external lead to the internal lead, and inserting the external lead into a sealing plate, allowing for a shorter internal lead and reduced resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If long internal leads are used to prevent interference with sealing plates and joint devices, then the reliability of connection is improved, but the equivalent series resistance (ESR) increases

Engineering Contradiction:

Improveconnection reliabilityVSAvoidequivalent series resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The internal lead is divided into two separate components: a foil-shaped first internal lead connected to the electrode foil, and a rod-shaped first external lead connected to the first internal lead. This segmentation allows the foil-shaped lead to be short (reducing ESR) while the rod-shaped external lead handles the connection to the sealing plate (ensuring reliability and preventing interference).

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The rod-shaped first external lead acts as an intermediary component between the foil-shaped first internal lead and the sealing plate. This intermediary structure allows the foil-shaped lead to remain short for low ESR while the rod-shaped external lead provides the necessary length and rigidity for reliable connection and interference prevention.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of energy

If short internal leads are used to reduce ESR, then the equivalent series resistance decreases, but the risk of interference with sealing plates and joint devices increases

Engineering Contradiction:

Improveequivalent series resistanceVSAvoidconnection reliability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The internal lead is divided into two separate components: a foil-shaped first internal lead connected to the electrode foil, and a rod-shaped first external lead connected to the first internal lead. This segmentation allows the foil-shaped lead to be short (reducing ESR) while the rod-shaped external lead handles the connection to the sealing plate (ensuring reliability and preventing interference).

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The rod-shaped first external lead acts as an intermediary component between the foil-shaped first internal lead and the sealing plate. This intermediary structure allows the foil-shaped lead to remain short for low ESR while the rod-shaped external lead provides the necessary length and rigidity for reliable connection and interference prevention.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If a single long internal lead is used to connect electrode to sealing plate, then the device complexity is reduced, but the equivalent series resistance increases

Engineering Contradiction:

Improvelead structure complexityVSAvoidequivalent series resistance

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The internal lead is divided into two separate components: a foil-shaped first internal lead connected to the electrode foil, and a rod-shaped first external lead connected to the first internal lead. Although this increases structural complexity, it significantly reduces ESR by allowing the foil-shaped lead to be short while the rod-shaped external lead handles the connection function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the lead structure have different properties optimized for their specific functions: the foil-shaped first internal lead has low resistance and flexibility for connection to the electrode foil, while the rod-shaped first external lead has high rigidity and appropriate length for connection to the sealing plate and interference prevention.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12308180B2Electrolytic capacitor and method for producing same

Publication Date: 2025.05.20 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A method for manufacturing an electrolytic capacitor includes a first connection step, a second connection step, a first insertion step, a housing step, and a sealing step. In the first connection step, a first internal lead having a foil shape is connected to a first electrode foil. In the second connection step, after the first connection step, a first external lead having a rod shape is connected to the first internal lead to obtain the first electrode. In the first insertion step, the first external lead is inserted into an insertion port of a sealing plate after the second connection step. In the housing step, the first electrode is housed in a container after the first insertion step. In the sealing step, an opening of the container is closed with the sealing plate after the housing step.