SiC Ingot Laser Slicing via Internal Separation Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Slicing SiC ingots using a laser results in a rough surface, leading to poor work efficiency due to the need for frequent mirror-finishing and increased kerf loss, unlike slicing silicon or glass ingots which produce a mirror-finished surface.
Innovation Solution
An SiC ingot slicing method involving initial separation layer formation, repetition of focal point movement, and separation using external force, where a laser beam at a transmitting wavelength forms separation layers inside the ingot, reducing kerf loss and improving surface finish.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a laser beam is used to slice an SiC ingot, then the kerf loss is reduced compared to wire saw slicing, but the sliced cross-section becomes a rough surface requiring frequent mirror-finishing
Solution Approach 1:
The slicing process is divided into multiple passes, with each pass creating a separation layer at a different depth position. The focal point is sequentially moved to different depth positions to form multiple separation layers, allowing the ingot to be separated into multiple plates in one setup rather than requiring repeated end-face machining
Solution Approach 2:
Separation layers are formed in advance at predetermined depth positions before the actual separation step. By pre-forming these layers throughout the ingot depth, the system eliminates the need for repeated mirror-finishing operations that would otherwise be required after each slicing pass
2Loss of substance
If the focal point is positioned inside the SiC ingot to reduce kerf loss, then material waste is minimized, but the resulting surface is rough rather than mirror-finished
Solution Approach 1:
The invention transitions from two-dimensional surface machining to three-dimensional internal layer formation. Instead of machining the end face surface, the laser forms separation layers inside the ingot volume by positioning the focal point at various depth positions, thereby eliminating surface roughness issues while maintaining precise kerf control
3Reliability
If repeated laser machining and slicing steps are conducted to acquire SiC plates, then separation layers can be formed, but the work efficiency deteriorates due to frequent mirror-finishing requirements
Solution Approach 1:
The laser forms separation layers continuously at multiple depth positions in sequence without interrupting the slicing process. By moving the focal point systematically through different depths and forming separation layers in each pass, the system maintains continuous productive action while eliminating the need for intermediate mirror-finishing operations
Solution Approach 2:
Multiple functions are merged into a single integrated process: separation layer formation, ingot separation, and plate acquisition are combined in one continuous operation. The external force application step simultaneously separates all plates along the pre-formed separation layers, eliminating the need for repeated machining and finishing cycles
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 enhances cutting efficiency by minimizing the need for mirror-finishing and reducing kerf loss, allowing for more efficient production of SiC plates with improved surface quality.
Implementation Method 1
a laser beam at a wavelength that transmits through the SiC ingot to enter the SiC ingot from an end face thereof, thus forming a focal point inside the SiC ingot
Implementation Method 2
a laser beam at a wavelength that transmits through the SiC ingot to enter the SiC ingot from an end face thereof, thus forming a focal point inside the SiC ingot
Implementation Method 3
scanning the focal point in a planar manner along a scheduled separation plane parallel to the end face, thus forming a separation layer at a depth corresponding to the scheduled separation plane
Implementation Method 4
scanning the focal point in a planar manner along a scheduled separation plane parallel to the end face, thus forming a separation layer at a depth corresponding to the scheduled separation plane
Implementation Method 5
The separation step applies, after the repetition step, an external force to the plurality of separation layers formed by the repetition step, thus separating the SiC plates starting from the separation layers
Data Source
AI summary
Disclosed herein is an SiC ingot slicing method including: an initial separation layer formation step for scanning a focal point of a laser beam parallel to an end face of the SiC ingot along a scheduled separation plane, and forming a separation layer at a position at a distance from the end face; a repetition step for sequentially moving, after the initial separation layer formation step, the focal point by the distance equal to the thickness of an SiC plate from the separation layer toward the end face, scanning the focal point parallel to the end face, repeating the formation of the separation layer, and forming the plurality of separation layers; and a separation step for applying an external force to the plurality of separation layers formed by the repetition step, peeling off the SiC plates starting from the separation layers, and acquiring the plurality of SiC plates.