Title:	"Project FINALE" - Screen and Screen Printing Process Development for Ultra-Fine-Line Contacts below 20µm Finger Width
Author(s):	F. Clement, M. Linse, S. Tepner, N. Wengenmeyr, L. Ney, K. Krieg, A. Lorenz, M. Pospischil, S. Bechmann, K. Oehrle, S. Steckemetz, R. Preu
Keywords:	Printing, Si Solar Cell, Metallization, Production Technology
Topic:	Silicon Materials and Cells
Subtopic:	Manufacturing & Production of Si Cells
Event:	36th European Photovoltaic Solar Energy Conference and Exhibition
Session:	2DO.5.1
Pages:	255 - 258
ISBN:	3-936338-60-4
Paper DOI:	10.4229/EUPVSEC20192019-2DO.5.1
Price:	0,00 EUR
Document(s):	paper, presentation

Abstract/Summary:

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Within this work, a new model of the screen printing process is set up in order to improve the understanding of the screen printing process with focus on the interaction between -paste and -screen. First results show that wall slip behavior of the paste can be significantly improved by adapting the screen chemistry, enabling a lower finger resistances and reduced finger widths. A mean contact finger width of wf = 26 µm combined with a mean finger resistance of RFinger = 99 /m shows the high potential of the newly developed screen chemistry using single-step screen printing. Screen openings of wch = 16µm and printed finger widths of wf = 17µm can be realized on textured Si wafers with ARC. Moreover, finger resistance values far below RFinger = 1000 /m are reached for nominal finger widths down to wf = 18µm. This proves the high potential of the single step screen printing process on the way to ultra-fine line contacts in combination with multi-busbar cell layouts. PERC-type Cz-Si solar cells fabricated with a 5 busbar cell layout and a nominal screen opening of wn = 24µm achieve efficiencies up to max = 22.1%. First multi-busbar solar cells with a 18µm nominal screen opening demonstrate a significant Ag reduction.