Laser Line Coating Treatment for Substrate Flatness Defects

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The challenge lies in achieving homogeneous heat treatment of large substrates with flatness defects at high speeds in industrial environments, where precise positioning of the substrate relative to the laser focal spot is difficult due to vibrations and size constraints, leading to treatment heterogeneities.

Innovation Solution

A process utilizing pulsed or continuous laser radiation focused into lines with specific beam quality and power density characteristics, allowing for relative displacement speeds of at least 3 meters per minute, ensuring temperature uniformity within 15% variation across the substrate, despite variations in distance from the laser focal spot.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If substrates are moved at high speed on industrial conveyors, then productivity is improved, but manufacturing precision deteriorates due to position variations relative to the laser focal spot

Engineering Contradiction:
Improvesubstrate treatment speedVSAvoidposition accuracy relative to laser focal spot
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the laser beam parameters (wavelength between 400-1500 nm, beam quality factor BPP ≤ 3 mm·mrad, linear power density ≥ 200 W/cm) to create a more tolerant processing system that maintains treatment homogeneity despite position variations at high substrate speeds

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a longer laser line length (at least 20 mm) and broader beam width (mean width at least 30 micrometers) to provide a larger processing margin, ensuring that even with position variations, the entire coating area receives adequate treatment

Inventive Principle:
Principle #16Partial or excessive action

2Adaptability or versatility

If substrates with large flatness defects are treated, then adaptability is improved, but manufacturing precision deteriorates due to treatment heterogeneities

Engineering Contradiction:
Improvetolerance to flatness defectsVSAvoidtreatment homogeneity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent optimizes laser parameters including wavelength (400-1500 nm), beam quality (BPP ≤ 3 mm·mrad), and power density (≥ 200 W/cm) to create a processing system that maintains treatment homogeneity across substrates with flatness variations of ±1 mm

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a more uniform energy distribution across the coating by using extended laser line geometry and controlled beam width, ensuring that all areas of the coating receive comparable treatment energy levels despite substrate flatness variations

Inventive Principle:
Principle #12Equipotentiality

3Manufacturing precision

If mechanical control systems are added to correct position variations, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improvesubstrate position controlVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical position control systems with optimized optical parameters (beam quality, wavelength, power density) that inherently tolerate position variations, eliminating the need for active mechanical correction systems

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 approach ensures remarkably homogeneous treatment results, maintaining temperature consistency and properties like resistivity, emissivity, and photocatalytic activity across the entire substrate surface, even with ±1 mm variations in distance from the focal plane.

Implementation Method 1

a step of heat treatment of said coating using a pulsed or continuous laser radiation focused on said coating in the form of at least one laser line

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

heat treatment of said coating using a pulsed or continuous laser radiation focused on said coating

Methodology Applied
Scientific EffectLaser: Laser

Data Source

PatentUS10597774B2Method for producing a coated substrate
Publication Date: 2020.03.24 SAINT GOBAIN VITRAGE SA

AI summary

The subject of the invention is a process for obtaining a substrate provided on at least one portion of at least one of its sides with a coating, comprising a step of depositing said coating on said substrate, then a step of heat treatment of said coating using a pulsed or continuous laser radiation focused on said coating in the form of at least one laser line, the wavelength of which is within a range extending from 400 to 1500 nm, said heat treatment being such that a relative displacement movement is created between the substrate and the or each laser line, the speed of which is at least 3 meters per minute, the or each laser line having a beam quality factor (BPP) of at most 3 mm·mrad and, measured at the place where the or each laser line is focused on said coating, a linear power density divided by the square root of the duty cycle of at least 200 W/cm, a length of at least 20 mm and a width distribution along the or each line such that the mean width is at least 30 micrometers and the difference between the largest width and the smallest width is at most 15% of the value of the mean width.