Solid Electrolytic Capacitor Lead Welding Without Electrolyte Damage

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Solution Overview

Problem

Existing methods for laser-welding an anode lead to an anode lead frame in solid electrolytic capacitors often damage the organic electrolyte layer, leading to degradation in capacitor characteristics.

Innovation Solution

A manufacturing method where the anode lead is laser-welded to the anode lead frame by positioning the laser beam to radiate from above and rearward of the standing portion, minimizing exposure and energy required for welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the anode lead is laser-welded to the anode lead frame using conventional methods, then welding can be achieved, but the organic electrolyte layer is damaged and capacitor characteristics are degraded

Engineering Contradiction:

Improvecapacitor characteristicsVSAvoidlaser beam damage to organic electrolyte layer

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A light reflection layer is introduced as an intermediary component between the organic electrolyte layer and the laser beam. This layer reflects the laser beam away from the organic electrolyte layer, preventing damage while allowing the welding process to proceed. The light reflection layer serves as a protective mediator that enables the welding operation without transmitting harmful laser energy to the sensitive organic electrolyte material.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the anode lead frame is positioned with sufficient space for conventional laser welding, then welding can be performed, but volumetric efficiency is reduced

Engineering Contradiction:

Improvevolumetric efficiencyVSAvoidlaser welding accessibility

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The laser beam is directed from an overhead position (in the up-down direction) rather than from the front or side. This dimensional change in approach allows the laser to access the welding area from above, enabling compact positioning of the anode lead frame in the front-rear direction while still providing adequate laser access for welding. The radiation point is positioned above and rearward of the standing portion, utilizing vertical space to achieve both compactness and weldability.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Strength

If high laser energy is used to ensure secure welding, then welding strength is improved, but the risk of damaging the organic electrolyte layer increases

Engineering Contradiction:

Improvewelding strengthVSAvoidlaser beam damage to organic electrolyte layer

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The light reflection layer acts as a mediator that allows high laser energy to be used for welding without damaging the organic electrolyte layer. By reflecting the laser beam, this intermediary layer enables the use of higher energy levels that produce stronger welds while protecting the sensitive organic electrolyte material from direct laser exposure and thermal damage.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 method enhances volumetric efficiency, reduces the risk of capacitor degradation, and allows for the production of solid electrolytic capacitors with superior characteristics, including a smaller size and improved electrical connectivity.

Implementation Method 1

the standing portion and the front end of the anode lead are welded to each other by radiating a laser beam toward the predetermined region of the standing portion from a radiation point which is located above the standing portion in an up-down direction perpendicular to the front-rear direction and is located rearward of the standing portion

Methodology Applied

Scientific EffectLaser beam welding: Laser Beam Welding

Data Source

PatentUS20250191854A1Solid electrolytic capacitor and manufacturing method thereof

Publication Date: 2025.06.12 TOKIN CORP

AI summary

A solid electrolytic capacitor can be manufactured by a manufacturing method comprising a facing step and a welding step. The solid electrolytic capacitor comprises an anode body, an anode lead and an anode lead frame. The anode lead extends forward from a front surface of the anode body in a front-rear direction. The anode lead frame has a standing portion. In the facing step, a predetermined region on a rear surface of the standing portion and a front end of the anode lead are faced to each other. In the welding step, the standing portion and the front end of the anode lead are welded to each other by radiating a laser beam toward the predetermined region of the standing portion from a radiation point which is located above the standing portion in an up-down direction perpendicular to the front-rear direction and is located rearward of the standing portion.