Laser Processing Calibration Through Multi-Directional Focal Mapping
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Solution Overview
Problem
Existing material processing systems face inaccuracies in focal position and directional dependencies of energy beams, leading to undesired material modifications due to insufficient energy density and beam shape issues, which are not adequately addressed by conventional characterization methods.
Innovation Solution
A method involving multi-directional movement patterns of an energy beam through a sample to form test patterns at varying calibration distances, accounting for directional dependencies and focal position accuracy, using an adjustable beam redirection element and imaging system to calibrate the laser processing system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional focal position characterization methods are used, then the calibration process is simple, but the focal position accuracy is insufficient leading to undesired material modifications
Solution Approach 1:
The patent transitions from conventional single-point or single-plane focal characterization to a multi-dimensional approach by characterizing focal positions at multiple different orientations and locations within the processing volume. This multi-dimensional characterization captures the complex spatial variations of the energy beam, enabling accurate compensation for focal drift and orientation-dependent effects, thereby resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The system performs preliminary characterization of the energy beam's focal positions at multiple orientations and locations before actual material processing. This pre-characterization data is stored and used to compensate for focal drift during processing, allowing the system to maintain high focal position accuracy without requiring complex real-time measurement equipment during operation.
2Adaptability or versatility
If beam direction is fixed, then the characterization process is straightforward, but directional dependencies of beam geometry are not accounted for
Solution Approach 1:
The patent employs dynamic beam redirection using adjustable mirrors or galvanometer scanners to direct the energy beam at multiple different orientations and angles during characterization. This dynamic approach allows the system to map focal positions across various directions and orientations, capturing the directional dependencies of beam geometry while maintaining control through software-based movement patterns rather than physical reconfiguration.
Solution Approach 2:
The characterization system is designed to handle multiple characterization tasks using the same hardware infrastructure. The adjustable beam redirection elements serve both for directing the beam during material processing and for steering the beam through multiple orientations during characterization, eliminating the need for separate dedicated characterization equipment and reducing overall system complexity.
3Measurement precision
If single-point focal measurement is used, then the measurement process is quick, but the energy density distribution and beam shape variations are not captured
Solution Approach 1:
The characterization process is segmented into multiple discrete measurement points distributed throughout the processing volume at different orientations and locations. By systematically measuring focal positions at these segmented points and interpolating between them, the system builds a comprehensive three-dimensional map of energy density distribution and beam shape variations without requiring continuous real-time measurement, thus achieving high precision while managing characterization 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
Provides a comprehensive characterization and calibration of the laser processing system, ensuring accurate material modification by accounting for beam shape and energy density variations, thereby improving the precision of material processing.
Implementation Method 1
directing an energy beam through a plurality of portions of a sample to form a plurality of test patterns in the sample
Implementation Method 2
detecting a level of modification in the sample caused by the energy beam at the plurality of test patterns
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
A method of characterizing a laser processing system (140) includes directing an energy beam (170) through a plurality of portions of a sample (318) by adjusting an orientation of an adjustable laser redirection element (162) of an optical system (160) in accordance with a predetermined movement pattern to form a plurality of test patterns (320) in the sample at each portion. The optical system (160) comprises an imaging system (380) having an expected focal position. In the movement pattern, the energy beam (170) is directed in a plurality of different directions in the sample in the formation of each test pattern. At least two of the plurality of test patterns (320) are formed at different calibration distances from an expected focal position of the optical system (160). An accuracy of the expected focal position is determined by detecting a level of modification in the sample (318) caused by the energy beam (170) at the plurality of test patterns (320).