Laser-Cut Boroaluminosilicate Glass Edges Without Burrs
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 separation techniques often resulting in burrs and requiring additional grinding or polishing to remove melted material.
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 of complex shapes and high-speed separation with minimal debris and subsurface damage, achieving edge strengths and impact resistance superior to conventional methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional laser separation techniques are used to cut glass substrates, then cutting speed can be increased, but burrs and melted material are generated requiring additional grinding or polishing
Solution Approach 1:
The patent changes the laser processing parameters by using ultra-short pulse durations (picosecond or femtosecond range) instead of conventional continuous or long-pulse laser modes. This parameter change enables cold ablation of glass material, removing it without melting, thus achieving high cutting speed while maintaining clean edges without burrs that require additional polishing
Solution Approach 2:
The patent utilizes phase transition control by maintaining the glass material in a solid state during removal through ultra-short pulse laser ablation. The extremely short pulse duration prevents thermal diffusion that would cause melting, allowing direct sublimation or fracture of glass bonds, thereby eliminating the molten phase that creates burrs and surface defects
2Manufacturing precision
If additional grinding or polishing is performed to remove melted material, then edge quality is improved, but process complexity and time increase
Solution Approach 1:
The patent extracts the harmful melting step from the conventional glass cutting process by using ultra-short pulse laser parameters that prevent thermal diffusion. This eliminates the need for subsequent grinding or polishing operations, simplifying the overall process while maintaining high edge quality
Solution Approach 2:
The ultra-short pulse laser process is self-sufficient in producing clean cuts without requiring additional secondary processing steps. The laser parameters are configured to automatically prevent burr formation and melted material generation, making the process self-cleaning and eliminating the need for separate grinding or polishing equipment
3Productivity
If conventional cutting methods are used, then process simplicity is maintained, but cutting speed and reliability are insufficient
Solution Approach 1:
The patent employs periodic ultra-short pulse laser bursts to cut glass substrates at high speeds. The pulsed nature of the laser allows for rapid successive ablation events that maintain high cutting speed while the brief pulse duration prevents thermal accumulation that would complicate the process with melting and burr formation
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
Enables fast, clean, and reliable cutting of glass substrates with improved edge quality and strength, capable of producing complex shapes like circular memory disks without burrs, and efficiently separating glass stacks in a single pass, enhancing process efficiency and product reliability.
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
followed by a CO 2 laser to create thermal stress, sometimes coupled with high pressure air flow, for fully automated separation
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3A
AI summary
The present invention relates to an alkaline earth boro-aluminosilicate glass article having an edge having a plurality of defect lines extending at least 250 microns, each defect line having a diameter less than or equal to about 1 micron, separated by a distance of 5 microns to 15 microns. This may be obtained by a laser cutting process which includes focusing a pulsed laser beam into a focal line. The focal line is directed into the glass 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.