Laser Beveling Hard Dielectric Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laser processing methods for hard dielectric materials like sapphire are inefficient and costly, often resulting in edge defects such as chipping and cracking due to high costs of pulsed lasers and multi-step processes, and require maintenance of UV cutting crystals with short lifespans.
Innovation Solution
A method and system utilizing a quasi-continuous wave laser with parameters such as a wavelength of 1060-1070 nm and coordinated motion to angle the laser beam for beveling and polishing, reducing edge defects by using a second laser beam with shorter wavelength and pulse width for post-cut processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional pulsed lasers are used for cutting hard dielectric materials, then cutting speed and efficiency are improved, but edge defects such as chipping and cracking increase
Solution Approach 1:
The cutting process is divided into two distinct stages: a first laser beam performs the primary cutting operation, and a second laser beam performs post-cut processing to address edge defects. This segmentation allows each laser to be optimized for its specific function, with the second laser specifically targeting edge quality improvement without compromising the overall productivity gained from the first laser's cutting speed.
2Productivity
If UV lasers with short wavelength are used for sapphire cutting, then absorption and cutting efficiency are improved, but laser maintenance complexity and cost increase due to crystal lifespan issues
Solution Approach 1:
The invention uses a second laser beam with different parameters (shorter wavelength and/or shorter pulse width) than the first laser beam. This parameter change allows the second laser to provide sufficient absorption for edge processing without requiring the maintenance-intensive UV laser crystals, thereby reducing device complexity and maintenance costs while still achieving the necessary processing effectiveness.
3Productivity
If high power lasers are used for rapid cutting, then productivity is improved, but heat-affected zone and induced stress concentrations increase
Solution Approach 1:
The second laser beam performs preliminary action by processing the cut edges before the part is fully completed or assembled. This preliminary edge processing removes potential defect sites (chipping and cracking) that would otherwise serve as stress concentration points, thereby preventing future failure while allowing the first laser to maintain high cutting speed for productivity.
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 enables efficient, cost-effective laser cutting and reduces edge defects in hard dielectric materials by using a QCW laser system with optimized parameters and coordinated motion, improving processing speed and yield while minimizing edge imperfections.
Implementation Method 1
generating a laser beam with parameters capable of providing sufficient absorption in the material to modify the material such that edge defects are reduced
Implementation Method 2
Such lasers may be used to emit pulses with high peak power capable of ablating sapphire
Data Source
AI summary
Laser processing of hard dielectric materials may include cutting a part from a hard dielectric material using a continuous wave laser operating in a quasi-continuous wave (QCW) mode to emit consecutive laser light pulses in a wavelength range of about 1060 nm to 1070 nm. Cutting using a QCW laser may be performed with a lower duty cycle (e.g., between about 1% and 15%) and in an inert gas atmosphere such as nitrogen, argon or helium. Laser processing of hard dielectric materials may further include post-cut processing the cut edges of the part cut from the dielectric material, for example, by beveling and/or polishing the edges to reduce edge defects. The post-cut processing may be performed using a laser beam with different laser parameters than the beam used for cutting, for example, by using a shorter wavelength (e.g., 193 nm excimer laser) and/or a shorter pulse width (e.g., picosecond laser).