Non-Axisymmetric Laser Beam Shaping for Clean Glass Separation

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Solution Overview

Problem

Current methods for cutting and separating glass substrates are inefficient, lacking speed, cleanliness, cost-effectiveness, and reliability, necessitating the development of alternative techniques for precise and repeatable separation.

Innovation Solution

A method involving laser processing using a pulsed laser beam with a non-axisymmetric beam cross-section, directed through an aspheric optical element and decohering optical elements, to induce absorption and create defects in the glass substrate, enabling controlled separation by forming a contour line that defines the separation path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional laser cutting methods are used on glass substrates, then the cutting process can be performed, but the process is slow, produces debris, and causes subsurface damage

Engineering Contradiction:

Improvecutting speedVSAvoiddebris and subsurface damage

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the fundamental parameters of laser processing by using ultrashort pulse durations (femtosecond to picosecond range) and high peak powers to create clean fractures through nonlinear optical absorption, eliminating debris and subsurface damage while increasing cutting speed

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic pulsed laser action with specific pulse repetition rates to accumulate damage along a contour line, enabling continuous and clean separation of glass substrates without generating harmful byproducts

Inventive Principle:

Principle #19Periodic action

2Reliability

If conventional cutting methods are used, then separation can be achieved, but the process lacks repeatability and reliability

Engineering Contradiction:

Improveseparation repeatabilityVSAvoidprocessing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent incorporates feedback mechanisms through precise control of laser parameters (pulse energy, repetition rate, focal position) and real-time monitoring to ensure repeatable and reliable separation outcomes while maintaining high processing efficiency

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces conventional mechanical cutting methods with laser-based nonlinear optical processing, achieving superior repeatability and reliability through precise optical field control while dramatically improving processing efficiency

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If high energy laser beams are used to increase cutting speed, then productivity improves, but the risk of damage and debris increases

Engineering Contradiction:

Improvecutting speedVSAvoiddamage and debris

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent uses periodic ultrashort laser pulses with optimized repetition rates to deliver high energy over time while allowing heat dissipation between pulses, achieving fast cutting without generating debris or causing thermal damage

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent exploits phase transitions in the glass material through nonlinear optical absorption during ultrashort pulse interaction, creating clean fracture surfaces through controlled structural changes without melting or vaporization that would produce debris

Inventive Principle:

Principle #36Phase transitions

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 allows for faster, cleaner, and more reliable separation of glass substrates with minimal debris and subsurface damage, preserving the integrity and strength of the workpiece.

Implementation Method 1

directing a pulsed laser beam oriented along a beam pathway and output by a beam source through an aspheric optical element positioned offset in a radial direction from the beam pathway and into the transparent workpiece such that the portion of the pulsed laser beam directed into the transparent workpiece generates an induced absorption within the transparent workpiece

Methodology Applied

Scientific EffectInduced absorption: Absorption (EM radiation)

Data Source

PatentUS11130701B2Apparatuses and methods for laser processing transparent workpieces using non-axisymmetric beam spots

Publication Date: 2021.09.28 4JET MICROTECH GMBH & CO KG

AI summary

A method for laser processing a transparent workpiece includes forming a contour line that includes defects, by directing a pulsed laser beam output by a beam source through an aspheric optical element positioned offset in a radial direction from the beam pathway and into the transparent workpiece such that the portion of the pulsed laser beam directed into the transparent workpiece generates an induced absorption within the transparent workpiece that produces a defect within the transparent workpiece. The portion of the pulsed laser beam directed into the transparent workpiece includes a wavelength λ, an effective spot size wo,eff, and a non-axisymmetric beam cross section having a minimum Rayleigh range ZRx,min in an x-direction and a minimum Rayleigh range ZRy,min in a y-direction. Further, the smaller of ZRx,min and ZRy,min is greater thanFD=π⁢⁢w0,eff2λ,where FD is a dimensionless divergence factor comprising a value of 10 or greater.