Electrostatic Workpiece Holding for Precise Laser Welding

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Solution Overview

Problem

Current methods for holding and contacting parts during laser machining or welding, especially for flexible or soft materials, face challenges in maintaining precise positioning without damaging the parts, as traditional clamping methods can compromise the quality of the process due to compression issues and inhomogeneous pressure distribution.

Innovation Solution

A system utilizing electrostatic charges to hold parts in position relative to an electrically conductive support, allowing for precise and contactless machining or welding by generating opposite charges on the part surfaces, which attract the part to the conductive support, ensuring good contact and retention without mechanical compression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional mechanical clamping methods are used to hold parts during laser machining or welding, then parts can be securely positioned, but the parts may be damaged or deformed due to compression and inhomogeneous pressure distribution

Engineering Contradiction:
Improvesecure positioningVSAvoiddamage to parts
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical clamping system with an electrostatic field-based holding system. Instead of using physical clamps that apply compressive force to hold parts during laser machining or welding, the invention uses electrostatic attraction between a charged support surface and oppositely charged parts to achieve secure positioning without mechanical contact or compression, thereby eliminating damage to the parts.

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

Solution Approach 2:

The patent introduces an electrostatic field as an intermediary between the support surface and the parts. Rather than direct mechanical contact, the electrostatic field acts as a mediator that transmits the holding force without physical compression, allowing parts to be securely positioned while avoiding the harmful effects of mechanical clamping.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If transparent compression devices are used to maintain contact between parts, then good contact is achieved, but accurate control of laser power and precise positioning of the laser beam are hindered

Engineering Contradiction:
Improvecontact between partsVSAvoidlaser beam positioning
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent uses an electrostatic field as an intermediary to maintain contact between parts during laser processing. Instead of using transparent compression devices that physically intervene between the laser beam and the workpiece, the electrostatic field provides the necessary holding force without obstructing the laser path, thereby preserving both contact stability and measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical compression system with an electrostatic field-based system. This substitution eliminates the physical barrier that transparent compression devices create in the laser path, allowing for accurate laser power control and precise beam positioning while still maintaining good contact between parts through electrostatic attraction.

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

3Reliability

If piston systems are used to apply pressure for holding parts, then parts can be secured in position, but the weld quality is negatively impacted

Engineering Contradiction:
Improvepositioning stabilityVSAvoidweld quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces the piston-based mechanical pressure system with an electrostatic field-based holding system. Instead of using pistons that apply compressive force to secure parts, the invention uses electrostatic attraction to achieve positioning stability without the inhomogeneous pressure distribution that degrades weld quality, thereby maintaining both reliability and manufacturing precision.

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

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 enables precise and quality laser machining or welding over the entire surface of parts, including flexible materials, with improved contact uniformity and reduced risk of damage, particularly suitable for microfluidics and curved surfaces, by using electrostatic attraction to maintain parts in position during the process.

Implementation Method 1

a first electrostatic charge generating device for generating electrostatic charges on said upper surface of part; an electrically conductive support for forming on the lower surface of part electrostatic charges of opposite signs to those generated by said electrostatic charge generating device

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentEP3823816B1System and method for holding a workpiece in position for laser machining and/or welding thereof
Publication Date: 2024.02.14 LASER ENG APPL
  • EP3823816B1 patent drawingFigure 1~2
  • EP3823816B1 patent drawingFigure 3~4
  • EP3823816B1 patent drawingFigure 5~6

AI summary

A system (100) for holding a workpiece (5) in position and exposing it to laser radiation, such that: - said workpiece (5) comprises a bottom surface (51) and a top surface (52) that are electrically insulated from each other; - said system (100) comprising: o an electrostatic charge generating device (9) for generating electrostatic charges on said top surface (52); o an electrically conductive support (80) for forming, on the bottom surface (51), electrostatic charges of opposite sign to those generated on said top surface (52); o a laser device (20) for machining or welding (5); said electrostatic charge generating device (9) being arranged to be activated before or during the laser machining or welding, such that said workpiece (5) is held in position relative to said electrically conductive support (80) during the machining or welding thereof.