Pattern Drawing Apparatus Positional Shift Detection
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Solution Overview
Problem
Existing pattern drawing apparatuses fail to accurately detect positional shifts relative to designed values during the drawing process, especially due to time lags between worktable movement and laser irradiation timing, which can lead to inaccuracies in higher precision pattern drawing.
Innovation Solution
A pattern drawing system and method that utilize a first image-pickup unit for reading alignment marks and a second image-pickup unit for detecting positional shifts caused by the irradiation light beam, with a positional shift detection unit calculating coordinate differences to correct for these shifts, allowing for high-accuracy movement control between the workpiece and optical head.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single image-pickup unit is used to detect positional shifts, then the device complexity is reduced, but the measurement precision of positional shifts deteriorates due to time lag between worktable movement and laser irradiation
Solution Approach 1:
The detection system is segmented into two separate image-pickup units: a first image-pickup unit that reads the alignment mark before laser irradiation, and a second image-pickup unit that reads the drawn pattern after laser irradiation. This segmentation allows independent timing of each detection function, eliminating the time lag error that would exist in a single unified detection system.
Solution Approach 2:
The first image-pickup unit performs preliminary detection of the alignment mark position before the laser irradiation occurs. This preliminary action captures the worktable position at the exact moment of alignment mark reading, establishing a reference point that eliminates time lag errors by detecting position before the movement-irradiation sequence begins.
2Ease of manufacture
If positional shift detection is performed away from actual drawing operation timing, then the detection process is simplified, but the reliability of positional shift detection deteriorates due to time lag between worktable movement and laser irradiation
Solution Approach 1:
The first image-pickup unit performs preliminary detection of the alignment mark position before the laser irradiation occurs. This preliminary action captures the worktable position at the exact moment of alignment mark reading, establishing a reference point that eliminates time lag errors by detecting position before the movement-irradiation sequence begins.
Solution Approach 2:
The system establishes a feedback loop where the first image-pickup unit detects the alignment mark position, this information is used to control the worktable and optical head movement, then the second image-pickup unit verifies the actual drawn position. This closed-loop feedback ensures detection reliability by continuously monitoring and correcting positional deviations throughout the drawing process.
3Manufacturing precision
If higher precision pattern drawing is required, then the manufacturing precision improves, but the harmful effect of time lag-induced positional shift increases
Solution Approach 1:
The system converts the potentially harmful time lag effect into a beneficial detection opportunity. By using the second image-pickup unit to read the drawn pattern after laser irradiation, the system actually measures the cumulative positional deviation including time lag effects. This measured deviation is then used to correct the drawing position, transforming the time lag error from a harmful uncorrected deviation into a quantifiable and correctable parameter that improves overall drawing precision.
Solution Approach 2:
The system replaces reliance on purely mechanical timing synchronization with an optical detection and computational correction system. Instead of attempting to mechanically eliminate time lag through precise synchronization, the invention uses optical image-pickup units to detect the actual positional deviation caused by time lag and applies computational correction based on the measured coordinate differences, substituting mechanical precision requirements with optical measurement and data processing.
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 detection and correction of positional shifts, improving the accuracy of pattern drawing by accounting for time lag-induced errors and ensuring that patterns are drawn at their intended positions.
Implementation Method 1
a first image-pickup unit for reading the alignment mark and reading an image of a first pattern for detecting a positional shift
Implementation Method 2
a second image-pickup unit for reading the image of the first pattern and reading an image of a second pattern for detecting a positional shift
Implementation Method 3
allows the optical head to draw a pattern on the workpiece
Implementation Method 4
draws a wiring pattern or the like by irradiating a photosensitive material on a substrate
Data Source
AI summary
A pattern drawing apparatus includes a first image-pickup device for reading an alignment mark and reading a first pattern image for detecting a positional shift, a second image-pickup device for reading the first pattern image and reading a second pattern image for detecting a positional shift drawn by an irradiation light beam from the optical head while carrying out a relative movement between the table and the optical head, and a positional shift detection unit for obtaining a first coordinate difference between a center of a visual field of the first image-pickup device and a center of the first pattern based on a read image by the first image-pickup device and obtaining a second coordinate difference between the center of the first pattern and a specific position of the second pattern based on a read image by the second image-pickup device.