Laser Beam Processing Machine with Dynamic Focal Point Adjustment
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Solution Overview
Problem
Existing laser beam processing machines face challenges in precisely processing plate-like workpieces with uneven thickness, as they struggle to maintain a consistent focal point due to undulations in the workpiece surface, leading to inefficient processing and reduced productivity.
Innovation Solution
A laser beam processing machine equipped with a focal point position adjusting mechanism, utilizing a detection laser beam and dichroic half mirror system, which allows for real-time adjustment of the processing laser beam's focal point based on height position detection, ensuring precise alignment with the workpiece surface despite unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a cutting blade with thickness of about 20 μm is used to cut the workpiece, then the workpiece can be divided along the dividing lines, but the area ratio of the dividing lines to the wafer becomes 14%, thereby reducing productivity
Solution Approach 1:
The patent replaces the mechanical cutting blade system with a laser beam processing system. The laser beam processes the workpiece without physical contact, eliminating the need for a thick cutting blade and the associated 14% area ratio loss, thereby improving productivity while maintaining cutting capability.
2Productivity
If the focal point position is not adjusted according to the unevenness of the workpiece surface, then the processing speed is maintained, but the deteriorated layers cannot be formed to a predetermined depth uniformly, leading to imprecise processing
Solution Approach 1:
The patent implements a dynamic focal point position adjusting mechanism that responds in real-time to the detected unevenness of the workpiece surface. The focal point position is continuously adjusted according to the actual surface height, ensuring uniform deteriorated layer formation and precise processing while maintaining high processing speed through automated real-time control.
Solution Approach 2:
The patent employs a feedback control system where the height position detection means detects the unevenness of the workpiece surface, and this detection signal is fed back to the focal point position adjusting means. The control means processes this feedback information and adjusts the focal point position accordingly, ensuring precise processing while maintaining high productivity through automated real-time adjustment.
3Manufacturing precision
If a height position detection means and focal point position adjusting means are introduced to follow the unevenness of the workpiece, then processing precision is improved, but the device complexity increases
Solution Approach 1:
The patent integrates multiple functions into unified components. The height position detection means not only detects surface height but also provides feedback for focal point positioning. The focal point position adjusting means serves both to maintain processing precision and to compensate for surface unevenness. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in device complexity while achieving high processing precision.
4Manufacturing precision
If the focal point position adjusting means is controlled based on a height position signal detected by the height position detection means, then processing precision is improved, but there is a slight time lag, making it difficult to adjust the position of the focal point precisely
Solution Approach 1:
The patent implements continuous height position detection and continuous focal point position adjustment based on the detected unevenness. The height position detection means continuously monitors the workpiece surface, and the focal point position adjusting means continuously adjusts the focal point position in real-time without interruption or delay. This continuous operation eliminates time lag and achieves precise focal point positioning throughout the processing operation.
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
Enables precise laser processing at the desired position on non-uniform workpieces, improving productivity by maintaining consistent processing quality and reducing time lag in focal point adjustment.
Implementation Method 1
a detection laser beam oscillation means for oscillating a detection laser beam having a wavelength different from the wavelength of the processing laser beam
Implementation Method 2
a dichroic half mirror which is interposed between the processing laser beam oscillation means and the focal point position adjusting means, allows the processing laser beam oscillated from the processing laser beam oscillation means to pass through and deflects a detection laser beam oscillated from the detection laser beam oscillation means
Implementation Method 3
a band pass filter which allows only reflected light corresponding to the wavelength of the detection laser beam to pass through
Implementation Method 4
a processing laser beam oscillation means for oscillating a processing laser beam and a condenser for converging the processing laser beam oscillated by the processing laser beam oscillation means
Implementation Method 5
a condenser for converging the processing laser beam oscillated by the processing laser beam oscillation means
Implementation Method 6
a focal point position adjusting means which is interposed between the processing laser beam oscillation means and the condenser and shifts the position of the focal point of the processing laser beam converged by the condenser
Data Source
AI summary
A laser beam processing machine comprising a laser beam application means for applying a laser beam to the top surface of the workpiece held on the chuck table, the laser beam application means comprising a processing laser beam oscillation means for oscillating a processing laser beam and a condenser for converging the processing laser beam oscillated by the processing laser beam oscillation means, wherein the laser beam processing machine further comprises a focal point position adjusting means for adjusting the position of the focal point of the processing laser beam converged by the condenser, a height position detection means for applying a detection laser beam to the workpiece through the focal point position adjusting means to detect the height position of the top surface of the workpiece based on its reflected light, and a control means for controlling the focal point position adjusting means based on the detection value of the height position detection means.