Flat Anode Lead-Out Wire Structure for Solid Electrolytic Capacitors

Solution Overview

Problem

The existing solid electrolytic capacitors with cylindrical anode lead-out wires face issues such as welding failures and reduced manufacturing yield due to bending of the wires during insertion into anode body powder.

Innovation Solution

A solid electrolytic capacitor design featuring an anode lead-out wire with a flat cross-section and recesses on its surface, along with linear protrusions, which improves the wire's stability and prevent bending during manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a cylindrical anode lead-out wire is used, then the wire structure is simple and easy to manufacture, but welding failures occur when the wire and lead frame are welded together

Engineering Contradiction:

Improvewire structure simplicityVSAvoidwelding reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies asymmetry by changing the wire cross-section from a symmetric cylindrical shape to an asymmetric flat shape with a recess on one surface and a protrusion on the other. This asymmetric geometry creates a flat welding surface that improves contact with the lead frame, thereby enhancing welding reliability while maintaining manufacturing simplicity through the extrusion process

Inventive Principle:

Principle #4Asymmetry

2Volume of moving object

If the anode lead-out wire is thinned while maintaining cylindrical structure, then the thickness of the solid electrolytic capacitor is reduced, but the wire bends when inserted into anode body powder

Engineering Contradiction:

Improvecapacitor thicknessVSAvoidwire straightness

Core Design Contradiction:

Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The asymmetric flat cross-section with recess and protrusion provides structural rigidity that prevents bending during insertion into anode body powder, even when the wire is thinned to reduce capacitor thickness. The geometry creates resistance to deformation while maintaining the reduced thickness requirement

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The recess and protrusion are pre-formed during the wire extrusion process before the wire is inserted into the anode body powder. This preliminary structural preparation ensures the wire maintains its straightness and stability during subsequent assembly operations

Inventive Principle:

Principle #10Preliminary action

3Volume of moving object

If the anode lead-out wire is flattened to reduce capacitor thickness, then the capacitor thickness is reduced, but manufacturing yield is degraded due to wire bending

Engineering Contradiction:

Improvecapacitor thicknessVSAvoidmanufacturing yield

Core Design Contradiction:

Volume of moving objectVSProductivity

Solution Approach 1:

The asymmetric flat cross-section with recess and protrusion provides structural rigidity that prevents bending during insertion into anode body powder, even when the wire is thinned to reduce capacitor thickness. The geometry creates resistance to deformation while maintaining the reduced thickness requirement

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The recess and protrusion are pre-formed during the wire extrusion process before the wire is inserted into the anode body powder. This preliminary structural preparation ensures the wire maintains its straightness and stability during subsequent assembly operations

Inventive Principle:

Principle #10Preliminary action

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 proposed design enhances manufacturing yield by preventing welding failures and anode lead-out wire bending, resulting in improved electrical connections and reduced equivalent series resistance (ESR).

Implementation Method 1

forming an anode lead-out wire having a flat cross section by holding the wire by first and second rollers that are disposed so as to be opposed to each other

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

A protrusion provided in a central part, a third linear part that is extended outward from one side of the protrusion, and a fourth linear part that is extended outward from another side of the protrusion are provided in at least one of the first and second rollers. In at least one of an upper surface and a lower surface of the anode lead-out wire formed in the first process, a recess is formed in a central part, and a first linear part that is extended outward from one side of the recess is formed

Methodology Applied

Scientific EffectDeformation: Deformation

Data Source

PatentUS12340953B2Solid electrolytic capacitor and method for manufacturing solid electrolytic capacitor with improved anode lead-out wire

Publication Date: 2025.06.24 TOKIN CORP

AI summary

A solid electrolytic capacitor capable of improving manufacturing yield is provided. A solid electrolytic capacitor according to one aspect of the present disclosure includes an anode lead-out wire and a capacitor element in which the anode lead-out wire is embedded. The cross section of at least a part of the anode lead-out wire in a direction in which the anode lead-out wire is extended has a flat shape, and a recess provided in a central part, a first linear part that is extended outward from one side of the recess, and a second linear part that is extended outward from another side of the recess are formed in at least one of an upper surface and a lower surface of the anode lead-out wire having the flat shape.