Laser Processing Method for Precise Cutting Functional Element Layers
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Solution Overview
Problem
Existing laser processing methods face difficulties in accurately cutting targets with functional element layers due to challenges in forming cracks that reach the front surface, leading to inaccurate cutting.
Innovation Solution
A laser processing method involving two stages of pulsed laser light emission, where a first pulsed laser with a shorter pulse width forms a weakened region in the functional element layer, followed by a second pulsed laser with a longer pulse width to create a crack reaching the front surface, allowing for precise cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single pulsed laser is used to cut the target, then the process is simple, but the crack cannot reliably reach the front surface through the functional element layer
Solution Approach 1:
The laser processing is divided into two distinct steps: first forming a weakened region in the functional element layer, then forming a crack in the substrate that propagates through the weakened region to the front surface. This segmentation allows each step to be optimized independently, ensuring reliable crack formation through the functional element layer.
Solution Approach 2:
Before forming the crack, a weakened region is preliminarily formed in the functional element layer by irradiating with a first pulsed laser. This preliminary action reduces the resistance to crack propagation, enabling the subsequent second pulsed laser to reliably form a crack reaching the front surface.
2Manufacturing precision
If the pulse width is long to ensure adequate energy delivery, then the cutting depth is sufficient, but the functional element layer cannot be properly weakened
Solution Approach 1:
Different pulse widths are applied at different locations and stages: a short pulse width is used in the first step to locally weaken the functional element layer without excessive heat accumulation, while a longer pulse width is used in the second step to deliver sufficient energy for crack formation and propagation through the substrate.
3Productivity
If laser energy is concentrated to form a crack, then cutting speed improves, but the functional element layer may be damaged without proper weakening
Solution Approach 1:
The functional element layer is preliminarily weakened by the first pulsed laser before the second pulsed laser forms the crack. This preliminary action ensures that when high-energy laser is applied for crack formation, the functional element layer can be properly traversed without uncontrolled damage, maintaining integrity while enabling fast cutting.
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 method enables accurate cutting of targets by reliably forming a weakened region and utilizing it to create a crack that reaches the front surface, improving the precision and effectiveness of the cutting process.
Implementation Method 1
irradiating the functional element layer with a first pulsed laser light along the line, to form a weakened region in the functional element layer along the line
Implementation Method 2
irradiating the functional element layer with a first pulsed laser light along the line, to form a weakened region
Implementation Method 3
emitting a second pulsed laser light into the target to follow the first pulsed laser light along the line, to form a crack reaching the front surface along the line in the target
Implementation Method 4
emitting a second pulsed laser light into the target to follow the first pulsed laser light along the line, to form a crack
Data Source
AI summary
A laser processing method includes a laser light emitting step of emitting a pulsed laser light along a line from a back surface of a target having a functional element layer on side of a front surface. The laser light emitting step includes: a first step of irradiating the functional element layer with a first pulsed laser light along the line, to form a weakened region in the functional element layer along the line; and a second step of emitting a second pulsed laser light into the target to follow the first pulsed laser light along the line, to form a crack reaching the front surface along the line in the target. The first pulsed laser light has a pulse width that is shorter than a pulse width of the second pulsed laser light.