AVATAR – Development of a Digital Twin for Printing Forms for Fully Automated Resource-Efficient Optimization of Fine-Line Printing Process Applications

In the age of digitization, the question arises as to how established printing technologies such as the flatbed screen printing process can be transferred into the digital space. Key challenges such as reducing structure widths or maximizing production throughput could be handled more cost-effectively and faster with the help of a digital twin. The outlined project represents an approach to digitizing the flatbed screen printing process and includes the optimization of production parameters using CFD simulation and artificial intelligence, as well as the integration of a feedback loop for live process control and adjustment. The project consortium covers a broad range of the production chain and thus enables optimal collaboration.

As part of the FINALE joint project with the funding code 0324098B, a simulation of screen structures was developed which can be used in flatbed screen printing for the metallization of Si solar cells. This can be used to model arbitrary channel structures and determine the opening area along the channel. Figure 1 shows a summary of the simulation model. The channel structure of a screen was generally modeled mathematically in such a way that a virtual image of this structure can be formed, analyzed and evaluated with respect to the performance expected in the printing process. The degree of opening and its deviation along the channel structure, as well as the shape, area and position of all individual partial opening areas can be determined and placed in the context of printability via flow simulations. The central objective of the research project is the further development of this simulation model in 3-dimensional space up to a digital twin for the design, physical production and subsequent performance of fine-line printing forms, which are used in the flatbed printing process. The design process of a screen consists, among other things, of a complex trade-off between expected resolution and performance in the printing process with respect to the desired printed image, reproducibility of the workpiece in the manufacturing process, scalability of the manufacturing process, manufacturing costs and service life of the workpiece in use. The development of a digital twin that maps all facets of the workpiece can fulfill these complex trade-offs in a way that would not be feasible with the current state of the art. The project will further develop a 3D simulation model for tissue deformation, which can be used to fully replicate squeegee motion in the printing process. Any mechanical stresses and deflections of the fabric can thus be modeled. The digital twin will be able to create virtual clones of screens, evaluate their performance and suggest specific design parameters to the user. Furthermore, it will handle the entire manufacturing planning of the screens and inform the user about complex trade-offs and ecomic trade-offs. The optimized layouts will be output in CAD formats (common to the industry) so that interfaces to manufacturing equipment can be used error-free and efficiently.