Laser-Textured Copper Conductor Surface for Low Contact Resistance

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Solution Overview

Problem

Existing electrical conductors in equipment face challenges in controlling contact resistance, which is intrinsically difficult to determine and manage, leading to potential excessive heating and unreliable connections, necessitating additional coatings like tin, silver, gold, or nickel, which are costly and complex.

Innovation Solution

A method involving laser stripping and texturing of bare copper-based electrical conductors using near-infrared pulsed laser radiation to create a network of craters, reducing contact resistance without additional coatings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional coatings like tin, silver, gold, or nickel are applied to reduce contact resistance, then contact resistance is reduced, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvecontact resistanceVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the additional coating layer entirely and instead extracts/creates a textured surface pattern directly on the base metal surface through laser processing, eliminating the need for separate coating materials and processes while achieving low contact resistance

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/chemical coating deposition process with a laser-based surface texturing process, using optical energy to create the functional surface pattern directly on the conductor surface

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If additional coatings are applied to reduce contact resistance, then contact resistance is reduced, but manufacturing cost increases

Engineering Contradiction:
Improvecontact resistanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses the base metal surface itself as the functional element, eliminating the need for expensive additional coating materials (tin, silver, gold, nickel) and relying on a cost-effective laser processing method

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the surface parameters of the base metal through laser texturing, creating a functional surface pattern that achieves low contact resistance without requiring material composition changes or additional coating layers

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the surface of the conductor is left bare, then manufacturing is simple, but contact resistance is high and connections are unreliable

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcontact resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies surface texturing only to specific contact areas of the conductor, maintaining the simplicity of using bare metal overall while creating localized functional patterns where electrical contact occurs, achieving low contact resistance without complex overall manufacturing

Inventive Principle:
Principle #3Local quality

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 method effectively reduces contact resistance, ensuring reliable electrical connections and compliance with normative heating tests, while eliminating the need for additional coatings, thus being simple, economical, and efficient.

Implementation Method 1

stripping and texturizing at least a portion of the bare electrical conductor using a laser device emitting radiation comprising a wavelength of between approximately 700 nm and approximately 1600 nm

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

emitting radiation comprising a wavelength of between approximately 700 nm and approximately 1600 nm

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentEP4632969A1Method for manufacturing an electrical conductor intended to equip an electrical apparatus
Publication Date: 2025.10.15 LEGRAND FRANCE SA
  • EP4632969A1 patent drawingFigure 1~2
  • EP4632969A1 patent drawingFigure 3~4
  • EP4632969A1 patent drawingFigure 5~6

AI summary

The invention relates to a method for manufacturing an electrical conductor intended to equip electrical equipment, comprising the steps of providing (101) a bare electrical conductor made from copper and of stripping and texturizing (103) at least a portion of the bare electrical conductor using a laser device emitting radiation comprising a wavelength of between approximately 700 nm and approximately 1600 nm.