Display Glass Laser Cutting for Fast Clean Complex Shapes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for cutting and separating glass substrates, particularly for Thin Film Transistor (TFT) devices, are inefficient in terms of speed, cleanliness, cost, and reliability, with existing laser technologies struggling to achieve high precision and edge strength.
Innovation Solution
A laser cutting process using an ultra-short pulsed laser to create defect lines within the glass substrate, followed by thermal stress induction with a CO2 laser, allowing for precise cutting and separation of complex shapes with minimal debris and high edge strength, capable of cutting speeds exceeding 1 m/sec and achieving edge roughness of less than 0.5 microns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional laser cutting methods are used on glass substrates, then cutting can be performed, but cutting speed is slow and edge quality is poor
Solution Approach 1:
The patent employs periodic pulsed laser action with specific duty cycles (e.g., 10% duty cycle with 10ms pulse width) to create controlled defect lines in the glass substrate. This periodic heating and cooling cycle enables high-speed cutting while maintaining precise edge quality by allowing thermal diffusion during the off-period, preventing excessive melting and maintaining clean cut edges at speeds exceeding 1 m/sec.
2Productivity
If higher laser energy is used to increase cutting speed, then productivity improves, but subsurface damage and edge roughness increase
Solution Approach 1:
The patent applies preliminary low-energy laser pulses to create a network of defect lines throughout the glass substrate before the final cut. These pre-created defects serve as controlled fracture paths that guide the subsequent high-energy cutting pulse, enabling fast separation without generating excessive subsurface damage or edge roughness, as the fracture follows predetermined clean paths.
Solution Approach 2:
The patent dynamically adjusts laser parameters including pulse width (e.g., 10ms), duty cycle (e.g., 10%), and energy density during the cutting process. By optimizing these parameters, the system achieves high cutting speeds while controlling the depth and distribution of subsurface damage, maintaining edge roughness below 0.5 microns through precise parameter management.
3Strength
If multiple processing steps are used to improve edge strength, then edge quality improves, but process complexity and time increase
Solution Approach 1:
The patent combines defect line creation and cutting separation into a single integrated laser processing step. The same pulsed laser system that creates the defect line network also performs the final cut by following the predetermined defect paths, eliminating the need for separate preprocessing and cutting steps. This merged approach achieves high edge strength while reducing process complexity and cycle time.
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 process enables fast, clean, and reliable cutting of glass substrates with improved edge strength and impact resistance, capable of cutting complex shapes and stacks of glass in a single pass, while minimizing subsurface damage and edge roughness.
Implementation Method 1
the laser beam focal line generating an induced absorption within the material, and the induced absorption producing defect lines or a damage track along the laser beam focal line within the workpiece
Implementation Method 2
focusing a pulsed laser beam into a laser beam focal line oriented along the beam propagation direction. The laser beam focal line is also directed into the glass composite workpiece, the laser beam focal line generating an induced absorption within the material
Implementation Method 3
The method involves the utilization of an ultra-short pulse laser and can be followed by a CO 2 laser to create thermal stress
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3A
AI summary
The present invention relates to a laser cutting technology for cutting and separating thin substrates of transparent materials, for example to cutting of display glass compositions mainly used for production of Thin Film Transistors (TFT) devices. The described laser process can be used to make straight cuts, for example at a speed of >0.25 m/sec, to cut sharp radii outer corners (<1 mm), and to create arbitrary curved shapes including forming interior holes and slots. A method of laser processing an alkaline earth boro-aluminosilicate glass composite workpiece includes focusing a pulsed laser beam into a focal line. The pulsed laser produces pulse bursts with 5-20 pulses per pulse burst and pulse burst energy of 300-600 micro Joules per burst. The focal line is directed into the glass composite workpiece, generating induced absorption within the material. The workpiece and the laser beam are translated relative to each other to form a plurality of defect lines along a contour, with adjacent defect lines have a spacing of 5-15 microns.