Laser Beam Divergence Correction for Substrate Self-Breaking
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Solution Overview
Problem
Conventional laser-based scribing methods for semiconductor and LED substrates face issues such as fine dust generation, uneven surfaces, substrate cracking, and difficulty in forming precise cuts due to divergence angle deviations, leading to increased processing time and costs.
Innovation Solution
A target object processing method and apparatus that corrects the divergence angle of a laser beam to form a precise spot within the substrate, using a beam shaping module and condensing lens, allowing for self-breaking with a phase transformation area as the starting point, thereby reducing dust generation and improving cut surface quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a laser beam is used for scribing or cutting a substrate, then the substrate can be separated into chips, but fine dust is generated which has a bad influence on element characteristics
Solution Approach 1:
The patent utilizes phase transition of the substrate material through controlled laser heating. The laser beam heats the substrate to a specific temperature range that induces phase transition (such as crystalline to amorphous transformation), creating a weakened zone that facilitates clean separation without generating fine dust. This phase transition approach replaces conventional mechanical or thermal field methods that produce dust.
2Manufacturing precision
If a scribing line is formed on the surface of the substrate by laser beam, then the substrate can be cut, but substrate particles melted by heat adhere to the periphery of the scribing line and cause uneven surfaces and unexpected cracking
Solution Approach 1:
The patent precisely controls laser beam parameters including power, pulse duration, and scanning speed to maintain the substrate temperature within a specific range during scribing. By adjusting these parameters, the laser creates a phase-transformed zone without excessive melting. The controlled parameter changes ensure that material transforms phase rather than melts and adheres, preventing surface unevenness and cracking.
Solution Approach 2:
The laser scribing process performs preliminary action by creating a phase-transformed weakened zone along the intended cut line before actual separation occurs. This preliminary phase transformation prepares the substrate for clean separation by creating a predetermined path of reduced strength, preventing unexpected cracking during subsequent cutting operations.
3Ease of operation
If conventional laser beam transfer system is used, then laser beams can be irradiated to the substrate, but divergence angle deviations make it difficult to form a precise spot within the substrate
Solution Approach 1:
The patent introduces an optical compensating system as an intermediary between the laser beam source and the substrate. This intermediary system includes optical elements that compensate for divergence angle deviations, correcting the beam path and focusing characteristics. The compensating optical system acts as a mediator that transforms divergent beams into precisely focused spots at the intended locations within the substrate.
4Productivity
If a separate cutting process is performed after scribing, then the substrate can be separated, but a considerable external force is needed which increases processing time and costs
Solution Approach 1:
The patent merges the scribing and cutting processes into a single integrated operation. By controlling the laser beam parameters and scanning pattern, the phase transformation zone created during scribing automatically serves as the separation path. The merged process eliminates the need for separate cutting operations and reduces the external force required, as the phase-transformed zone provides a natural separation path that requires minimal additional energy or time.
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 enables precise cutting with minimal external force, reduces substrate cracking, and enhances integration density of stacked portions on a single wafer, maintaining element characteristics and improving light luminance.
Implementation Method 1
generating a laser beam from a laser beam source
Implementation Method 2
correcting a divergence angle of the generated laser beam
Implementation Method 3
forming a spot by condensing the corrected laser beam to the inside of the target object
Implementation Method 4
a phase transformation area is formed within the target object by the spot
Data Source
AI summary
There is provided a target object processing method capable of self-breaking a target object with a laser beam. The target object processing method includes: generating a laser beam from a laser beam source; correcting a divergence angle of the generated laser beam; and forming a spot by condensing the corrected laser beam to the inside of the target object. A shape or a size of the spot is adjusted by correcting the divergence angle of the laser beam, a phase transformation area is formed within the target object by the spot, and the target object is subject to self-breaking with the phase transformation area as the starting point.