Progress in Fine Line Metallization: A Statistical Approach to Optimize Laser Processing During Screen Production

Currently, the majority of screens manufactured for the screen-printed metallization of industrial-grade solar cells are structured using laser processing. This study aims to enhance the scientific understanding of the interaction between the laser and the screen during the structuring process by investigating the effects of key laser parameters, including laser power, line-to-line pitch, number of passes, and scanning speed, on the quality of screen openings. From the conducted parameter variation tests, a statistical model is developed using the R software to predict screen opening widths. The model focuses on identifying key laser parameters that significantly influence the screen opening width and aims to provide accurate predictions. By establishing a robust predictive model, this work seeks to minimize the need for extensive laser parameter variations conducted on screens and to select optimal laser parameters. The model indicates that laser power and scanning speed exert the greatest influence on screen opening widths. The predicted results demonstrate an accuracy within 1 μm when compared to experimental findings, thereby validating the model's predictive capabilities. Subsequently, the optimal laser parameters are used to structure two screens with the same mesh configuration and which are then used to print on M10-sized tunnel oxide passivating contact substrates with a silver paste. The results are compared with an industry-standard reference screen with similar screen specifications. The mean shading width of the printed contacts from both screens are measured to be 22 and 21 μm, which is comparable with the 20 μm shading width printed from the industry standard screen.