Diffractive Beam Separation for Low-Spatter Laser Seam Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser processing systems for soldering and welding often result in uneven seam surfaces and frayed edges, particularly in visible areas, due to the spatter-prone nature of the soldering process, which is undesirable for applications like car bodywork.
Innovation Solution
An optical system using a diffractive optical beam-shaping element with a planar phase mask that impresses a primary beam diffuser phase curve to broaden the laser beam and a secondary beam diffuser phase curve to diffract a portion of the beam, creating multiple intensity zones for precise spot shaping and reduced spatter, allowing for smoother seam formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single laser beam is used for soldering, then the process is simple, but the seam surface becomes uneven and spatter increases
Solution Approach 1:
The single laser beam is segmented into multiple intensity zones (primary and secondary zones) using a diffractive optical beam-shaping element. This segmentation allows different regions of the workpiece to receive appropriately tailored energy distribution, reducing spatter and improving seam surface quality while maintaining a relatively simple overall system configuration.
Solution Approach 2:
Different intensity zones are created with distinct energy characteristics - a primary intensity zone for the main soldering area and secondary intensity zones for adjacent regions. This local differentiation of energy distribution optimizes the soldering process in different areas, preventing uneven surfaces and spatter in critical regions.
2Manufacturing precision
If multiple laser beams are used to improve seam quality, then spatter is reduced, but the system complexity increases
Solution Approach 1:
Multiple intensity zones that would traditionally require separate laser beams and optical paths are merged into a single laser beam system using a diffractive optical beam-shaping element. This integration achieves the benefits of multiple beams (reduced spatter, improved seam quality) while avoiding the complexity of multiple independent beam delivery systems.
Solution Approach 2:
A diffractive optical beam-shaping element acts as an intermediary between the single laser beam source and the workpiece. This intermediate optical component transforms the single beam into multiple intensity zones, enabling complex energy distribution patterns without requiring multiple laser sources or complex beam steering mechanisms.
3Measurement precision
If the laser beam is focused to a small spot, then processing precision is high, but spatter increases and seam edges become frayed
Solution Approach 1:
The concentrated laser energy is segmented into multiple intensity zones with different spatial distributions. The primary intensity zone provides focused energy for precise processing, while secondary intensity zones distribute energy more broadly to adjacent areas, preventing the excessive energy concentration that causes spatter and frayed edges.
Solution Approach 2:
The spatial energy distribution parameter of the laser beam is changed from a single concentrated spot to multiple intensity zones with varying intensity levels. This parameter modification allows the central region to maintain high precision while peripheral regions receive reduced energy density, eliminating spatter and fraying without sacrificing processing precision.
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 solution effectively reduces spatter and enhances the smoothness of seam edges and surfaces by generating multiple intensity zones, enabling quieter and more controlled laser processing with improved seam quality.
Implementation Method 1
the phase curve having a primary beam diffuser which diffusely widens the laser beam in the laser beam propagation direction
Implementation Method 2
at least one secondary beam generator, in particular a secondary beam diffuser, which emits at least one secondary beam divides the laser beam (particularly diffusely), in particular diffracts from the laser beam
Implementation Method 3
near-field optics, which are arranged downstream of the beam-shaping element to focus the laser beam in a focus zone, forming the primary intensity zone and the at least one secondary intensity zone
Data Source
Figure 1~2
Figure 3
Figure 4A~4B
AI summary
An optical system (25) for beam splitting of a laser beam (31) for providing a primary intensity zone (49) and at least one secondary intensity zone (55, 57) for workpiece processing comprises a beam shaping element (33) configured to impose a beam-shaping phase profile on the laser beam (31) via a transverse input intensity profile (35), wherein the phase profile forms a primary beam diffuser that diffusely broadens the laser beam (31) in the laser beam propagation direction, and at least one secondary beam generator/diffuser that splits at least one secondary beam from the laser beam (31). Furthermore, the optical system (25) comprises a near-field optic (39) which is arranged downstream of the beam shaping element (33) to focus the laser beam (31) in a focus zone (41) forming the primary intensity zone (49) and the at least one secondary intensity zone (55, 57).