Laser Ablation of Brittle-Hard Material for Deep Crack-Free Removal
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Solution Overview
Problem
Conventional methods for processing thin glass substrates using laser radiation result in limited removal depth and introduce cracks or damage, limiting the achievement of high removal rates without additional stresses or cracks in brittle materials.
Innovation Solution
Setting the laser beam radius to a small value to achieve a flank angle close to 90 degrees, exceeding the material-specific critical angle, thereby increasing the removal depth significantly and minimizing damage by avoiding the introduction of cracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser radiation is used to remove brittle hard material, then removal rate and removal depth can be increased, but cracks and damage are introduced into the material
Solution Approach 1:
The patent applies parameter changes by optimizing the laser beam radius to a specific small value and controlling the flank angle to be close to 90 degrees. This parameter optimization allows achieving high removal depths (at least twice that of conventional methods) while preventing crack formation and material damage, thus resolving the contradiction between productivity improvement and harmful factor prevention
2Area of stationary object
If a larger beam radius is used, then wider material removal is achieved, but the flank angle decreases below the critical angle limiting removal depth
Solution Approach 1:
The patent resolves this contradiction by changing the beam radius parameter to a small value, which enables the flank angle to exceed the material-specific critical angle wmax. This parameter change allows achieving both adequate removal width and significantly increased removal depth (at least a factor of 2 greater than conventional methods), eliminating the trade-off between width and depth
3Ease of manufacture
If conventional mechanical processing is used on thin glass panes, then material can be removed, but microcracks and chips are introduced requiring additional post-processing
Solution Approach 1:
The patent replaces mechanical processing methods with laser radiation processing. By using laser radiation with a small beam radius and controlling the flank angle to be close to 90 degrees, the process achieves clean material removal without introducing microcracks or chips that would require subsequent grinding or etching, thus eliminating the need for post-processing while maintaining manufacturing capability
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 method achieves a removal depth at least twice that of conventional methods while preventing additional cracks, ensuring high removal rates without material damage.
Implementation Method 1
Method for removing, for example cutting, scoring, drilling, brittle hard material by means of laser radiation
Data Source
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AI summary
The invention relates to a method for removing brittle-hard material by means of laser radiation, wherein a removal depression having a flank angle w of the flanks of the removal depression forms in the material as a result of the removal, wherein the flank angle w is defined as the angle between the surface normal on a flank of the removal depression and the surface normal on the unremoved surface of the material, wherein the flank angle w exceeds a material-specific limit angle wmax during the removal. The beam radius of the laser radiation, at the entrance of the removal depression, is set to be small enough that the flank angle w attains almost 90 angular degrees and the achievable removal depth becomes greater at least by a factor of 2 than for a larger beam radius for which the flank angle is less that the material-specific limit angle wmax.