Screen Printing Device Optical Axis Calibration
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Solution Overview
Problem
Current screen printing devices with two imaging optical axes face challenges in achieving high precision substrate positioning due to errors in optical axis alignment and movement, leading to positional deviations and complex calibration processes, making it difficult to accurately match pattern holes with print areas on substrates of varying shapes and sizes.
Innovation Solution
A screen printing device and method that includes an imaging unit with two imaging optical axes, which uses optical axis calibration and surface correction data to accurately align the imaging axes, correcting for positional errors caused by the movement mechanism, allowing for precise substrate positioning by detecting and correcting relative positions between the imaging axes and movement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single imaging unit with two imaging optical axes is used to image both substrate and mask plate, then the device complexity is reduced and only one travel unit is needed, but positioning precision deteriorates due to optical axis alignment errors and movement errors
Solution Approach 1:
The patent performs optical axis calibration before actual positioning operations. By pre-determining the relative positions of imaging optical axes and creating correction data tables, the system eliminates the need for complex real-time adjustments, thereby maintaining high positioning precision while using a simplified single-unit imaging structure
Solution Approach 2:
The patent implements a feedback mechanism where position detection results are continuously used to correct and update the correction data tables. This feedback loop compensates for optical axis deviations and movement errors, allowing the simplified imaging unit to achieve precise positioning through iterative refinement
2Measurement precision
If calibration processing is performed to obtain position reference data, then positioning precision is improved, but the operation complexity and time consumption increase
Solution Approach 1:
The patent performs all necessary calibration measurements and creates correction data tables during initial setup before actual production operations. This preliminary calibration action stores correction information that can be quickly retrieved and applied during normal operation, eliminating the need for complex real-time calibration procedures
Solution Approach 2:
The patent creates a digital copy of the correction data in the form of lookup tables that store pre-calculated position corrections. During actual positioning operations, the system simply retrieves and applies the appropriate correction values from these tables, transforming a complex real-time calculation problem into a simple data retrieval operation
3Adaptability or versatility
If the imaging unit is moved horizontally to image different positions, then the adaptability to different substrate positions is improved, but positioning precision deteriorates due to local position errors in the moving mechanism
Solution Approach 1:
The patent performs preliminary movement calibration to determine the actual positions of the imaging unit at various horizontal locations. By pre-measuring deviations from expected positions and storing them in correction data tables, the system compensates for mechanical positioning errors during actual operation, maintaining precision across the entire imaging range
Solution Approach 2:
The patent creates location-specific correction data for different horizontal positions of the imaging unit. Each position has its own correction values stored in the lookup tables, allowing the system to apply localized corrections tailored to the specific position being imaged, thereby maintaining high precision across the entire field of view
Data Source
AI summary
Prior to a mark imaging process executed for the purpose of detecting a position of recognition marks for positioning the substrate and the mask, an optical axis calibration processing process of detecting a horizontal relative position between imaging optical axes, and a surface correction data creation processing process of detecting a local positional deviation of the imaging optical axes, which is caused by the travel of the imaging unit, are executed. Before starting production, a production pre-start precision evaluation process for evaluating a substrate positioning precision is executed by using a verification substrate and a verification mask, and after starting the production, a production post-start precision evaluation process for evaluating a substrate positioning precision after starting the production is executed by using a commercial production substrate and a commercial production mask.