Optimization of fine line screen printing using in-depth screen mesh analysis

Screen pattern simulation for an improved front‐side Ag‐electrode metallization of Si‐solar cells

“…Afterwards, the shape and exact size of all polygons are calculated, creating a full mathematical description of any screen opening defined by its wire diameter d, the mesh count MC (or wire-to-wire distance d 0 ), the screen opening width w n , and the screen angle φ (illustrated in Figure 2). 22 The simulation approach was experimentally verified in both previous publications. Table 1 shows the range and increment of the sweep for the screen parameters and the alignment on the screen perpendicular to the screen opening direction.…”

“…In this study, we utilize the simulation approach first published by Ney et al 22 and then extended by Tepner et al 19 to perform a complete F I G U R E 1 Evolution of published results for the achieved finger width for solar cell metallization since 2005. The figure has been slightly adapted from Lorenz et al 3 and novel results since the original publication are added (see figure legend for details).…”

“…3 Additionally, the prediction trend line of the ITRPV 3rd and 10th edition has been added [Colour figure can be viewed at wileyonlinelibrary.com] F I G U R E 2 This SEM image presents a typical screen opening channel. Its geometric architecture is defined by the dimension of the underlying mesh with the wire diameter d and the wire-to-wire distance d 0 , the screen opening width w n , the channel length l, and finally the angle between emulsion edge and mesh φ (commonly referred to as the screen angle φ) 22 screen pattern analysis on different screen openings to derive conclusions about their expected screen printing performance for solar cell metallization. The simulation approach is based on a mathematical model that calculates all intersection points between an arbitrary quadratic grid and a rectangle with the width w n and the length l, which is placed at an angle φ on that grid.…”

“…3,[19][20][21] In order to establish a comprehensive understanding of the significance of the presented screen parameters, Ney et al published a method to model the screen opening based on those parameters. 22 Later, Tepner et al expanded this simulation model to derive specific conclusions by simulating and studying the dependency of the wire crossings on such screen parameters. 19 They were able to show that the state-of-the-art method of describing a screen channel by the established parameter open area OA % is not sufficient when fine-line screen printing below 30 μm is desired.…”

“…Therefore, they introduced a new parameter σ OA , describing the average deviation of OA % across the screen opening length. 22 In this study, we will elaborate on these results by running a full simulation of different screen architectures and then perform solar cell metallization experiments for five different screen architectures at four different screen opening widths w n . Afterwards, the simulation results are directly correlated to the printing performance to create a complete understanding of how changes to the screen architecture are influencing fine-line screen printing.…”