Multi-Laser Cutting of Hard Dielectrics With Edge Polishing
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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 useful life.
Innovation Solution
A multi-laser system using a continuous wave laser operating in quasi-continuous wave mode at a wavelength of 1060-1070 nm for cutting, followed by post-cut processing with a second laser for beveling and polishing to reduce edge defects, employing a motion stage and control system for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pulsed lasers are used for cutting hard dielectric materials, then cutting efficiency is improved, but equipment cost and maintenance cost increase
Solution Approach 1:
The patent changes the laser operating parameters from pulsed mode to quasi-continuous wave mode, and from UV wavelength to infrared wavelength (1060-1070 nm). This parameter change allows the use of less expensive continuous wave laser sources while maintaining cutting effectiveness on hard dielectric materials, thereby resolving the contradiction between cutting efficiency and equipment cost.
2Manufacturing precision
If UV lasers are used for cutting, then cutting precision is improved, but maintenance complexity increases due to crystal degradation
Solution Approach 1:
The patent replaces expensive UV laser crystals with shorter-lived, less expensive infrared laser sources. The infrared laser wavelength (1060-1070 nm) avoids the crystal degradation issues inherent in UV lasers, eliminating maintenance complexity while maintaining adequate cutting precision through optimized quasi-continuous wave operation parameters.
3Productivity
If high power lasers are used for cutting, then cutting speed is improved, but edge defects such as chipping and cracking increase
Solution Approach 1:
The patent employs periodic pulsed operation within a quasi-continuous wave framework, where laser power is delivered in controlled pulses rather than continuous high power. This periodic action allows sufficient cutting speed while providing cooling intervals that prevent thermal damage and edge defects, thus resolving the contradiction between cutting speed and edge quality.
Solution Approach 2:
The system dynamically adjusts laser power, pulse duration, and repetition rate during the cutting process. By optimizing these dynamic parameters, the system achieves high cutting speeds while maintaining edge quality, preventing chipping and cracking that would occur with static high power settings.
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 efficient, cost-effective laser cutting 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 post-processing.
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 mode
Implementation Method 2
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).