Distortion of knotless printing screens in solar cell mass-production

Advanced solar cell technologies may need precision print-on-print or alignment-specific metallization to improve energy efficiency and quality. This study examines knotless printing screens in two tests to determine which factors affect their alignment and behavior during metallization.

In the first experiment, we collected samples printed with knotless screens across their entire lifetime in mass manufacturing at the factory. To track screen expansion trends, we examined and analyzed these samples using a high-precision microscope and automated measurement equipment.

In the second experiment, we examined how snap-off distance and squeegee length affect end-to-end finger pattern extension in the second. We isolated and analyzed these parameters’ effects on screen expansion and finger alignment precision in this experiment. Higher snap-off distances cause more printed image displacement, while longer squeegees reduce expansion effects, especially at higher snap-off values.

Systematic measurements revealed a progressive increase in screen expansion, from +10 μm after 10,000 prints to +20 μm by the end of its lifetime (30,000–70,000 prints). The study sets guidelines for the use of knotless screens for precise print-on-print alignment in advanced technologies such as Cu-TOPCon cells and Advanced TOPCon solar cells with patterned p-type or n-type poly-Si fingers [1] [2] [3]. Large-scale solar cell manufacturing requires optimized print and screen parameters to increase metallization alignment precision. This study gives industry guidance.