Autotuned Screen Printing Alignment for Solar Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing screen printing processes for solar cells face challenges with mis-alignment of patterns on substrates due to positioning errors, leading to poor device performance and increased manufacturing costs, necessitating an improved method for controlling substrate positioning and increasing throughput.
Innovation Solution
An automated deposition process that utilizes alignment marks on substrates, optical inspection systems, and a system controller to accurately position and orient substrates, calculating offsets to ensure precise alignment and improve the alignment of subsequent layers, thereby enhancing the accuracy and efficiency of the screen printing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If manual calibration of substrate positioning is used, then positioning accuracy can be adjusted for different substrate batches, but the process becomes time-consuming and requires frequent adjustments
Solution Approach 1:
The system uses alignment marks printed on the substrate itself to automatically determine positioning and orientation. The substrate effectively calibrates itself by providing reference features that the optical inspection system detects, eliminating the need for manual calibration operations while maintaining high positioning accuracy across different substrate batches
Solution Approach 2:
The optical inspection system detects the actual position and orientation of alignment marks on the substrate, feeds this information back to the system controller, which then calculates correction values. This closed-loop feedback mechanism automatically adjusts positioning for each substrate without manual intervention, resolving the contradiction between precision and time loss
2Productivity
If automated substrate positioning is used, then throughput increases, but mis-alignment errors due to positioning errors still occur
Solution Approach 1:
Alignment marks are printed on the substrate before the screen printing process. These pre-established reference features enable the optical inspection system to detect and calculate positioning offsets in advance, allowing the system to compensate for automation-induced alignment errors while maintaining high throughput
Solution Approach 2:
The system replaces manual mechanical positioning adjustments with an optical detection and computational correction system. The optical inspection system captures images of alignment marks, and the system controller calculates precise correction values based on detected positional deviations, substituting mechanical calibration with optical-mechanical integration that maintains both speed and precision
3Manufacturing precision
If frequent manual adjustment of substrate positioning is performed, then alignment accuracy is maintained, but device yield decreases due to production interruptions
Solution Approach 1:
The substrate provides its own alignment reference through pre-printed alignment marks. The system automatically detects these marks and adjusts positioning without requiring operator intervention, maintaining alignment accuracy while keeping production continuous and maximizing device yield
Solution Approach 2:
The system implements continuous automatic feedback control where the optical inspection system monitors alignment mark positions, the controller calculates correction values, and the positioning system applies adjustments in real-time. This automated feedback loop maintains alignment accuracy without production interruptions, resolving the contradiction between precision and yield
Data Source
AI summary
Embodiments of the invention generally provide apparatus and methods of screen printing a pattern on a substrate. In one embodiment, a patterned layer is printed onto a surface of a substrate along with a plurality of alignment marks. The locations of the alignment marks are measured with respect to a feature of the substrate to determine the actual location of the patterned layer. The actual location is compared with the expected location to determine the positional error of the patterned layer placement on the substrate. This information is used to adjust the placement of a patterned layer onto subsequently processed substrates.