Multi-Laser Cutting Hard Dielectric Materials
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Solution Overview
Problem
Conventional methods for laser processing of 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 crystals with short lifespans.
Innovation Solution
A multi-laser system using a continuous wave laser operating in a quasi-continuous wave mode at a wavelength of 1060-1070 nm for cutting, followed by a second laser for beveling and polishing to reduce edge defects, with post-cut processing to minimize stress concentrations and improve edge quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pulsed lasers (UV, picosecond, nanosecond) are used for cutting hard dielectric materials, then cutting efficiency and absorption are improved, but equipment cost and process complexity increase
Solution Approach 1:
The patent divides the processing into two separate steps performed by different lasers: first, a UV laser performs the cutting operation, then a second laser (visible or IR wavelength) performs post-cut processing to remove edge defects. This segmentation allows each laser to be optimized for its specific function, maintaining high cutting efficiency while reducing the complexity and cost associated with using only expensive pulsed lasers for the entire process.
Solution Approach 2:
The patent changes the wavelength parameter by using a second laser with visible or IR wavelength (500-1500 nm) after the UV cutting laser. This parameter change enables post-processing that removes edge defects without requiring the same high-cost pulsed laser equipment, thereby reducing overall device complexity and cost while maintaining productivity.
2Productivity
If high power lasers are used for efficient cutting, then cutting speed is improved, but edge defects (chipping, cracking) increase
Solution Approach 1:
The patent segments the processing into cutting and edge refinement stages. The first laser (UV) operates at high power for fast cutting, accepting some edge defects. The second laser (visible/IR) then performs post-processing to remove these defects. This segmentation allows high cutting speed to be maintained while edge quality is improved in a separate step.
Solution Approach 2:
The patent converts the harmful effect of high-power laser-induced edge defects into a beneficial process feature. Instead of avoiding high power, the method uses it intentionally for fast cutting, then employs a second laser to remove the resulting defects. The harmful edge defects become a temporary intermediate state that is subsequently eliminated, enabling both high speed and high quality.
3Use of energy by moving object
If UV lasers with crystals are used for cutting, then absorption in sapphire is improved, but maintenance cost and operational reliability worsen
Solution Approach 1:
The patent uses a UV laser for cutting (which may have limited crystal lifespan) but replaces it with a second laser operating at visible or IR wavelengths for post-processing. These alternative wavelength lasers can use different gain media with longer operational lifetimes and lower maintenance requirements. The expensive UV laser is used only for the cutting step, while the more reliable second laser handles the post-processing, overall improving system reliability and reducing maintenance costs.
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 system enables efficient, cost-effective laser cutting and post-processing of hard dielectric materials with reduced edge defects, improving production yields and reducing maintenance costs by using a continuous wave laser for cutting and a separate laser for edge refinement.
Implementation Method 1
cutting at least one part from a hard dielectric material using at least a first laser beam, wherein the first laser beam is emitted from a continuous wave laser operating in a quasi-continuous wave ('QCW') mode
Implementation Method 2
absorbed in sapphire... lasers operating in a wavelength range between about 157 and about 355 nm
Implementation Method 3
post-cut processing cut edges of the at least one part using at least a second laser beam to bevel and/or polish the cut edges
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).