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High Speed Dispensing – a High-Throughput Metallization Technology for >21% PERC Type Solar Cells
M. Pospischil, M. Kuchler, M. Klawitter, I. Lacmago, S. Tepner, R. Efinger, M. Linse, D. Witt, S. Gutscher, A. Brand, M. König, L. Wende, F. Clement, D. Biro
Silicon Solar Cell(s), Metallization, Metallisation, Dispensing
Wafer-Based Silicon Solar Cells and Materials Technology
Subtopic: Silicon Solar Cells Improvements and Innovation
Event: 32nd European Photovoltaic Solar Energy Conference and Exhibition
Session: 2CO.2.2
403 - 406
ISBN: 3-936338-41-8
Paper DOI: 10.4229/EUPVSEC20162016-2CO.2.2
0,00 EUR
Document(s): paper


In this study, high speed dispensing with a novel 6” dispensing print head is applied to different screen printing pastes. The novel print head features a homogeneous distribution of Ag-paste from an inlet supply with a diameter of Din = 2mm to an outlet slot with a width of ws = 160 mm. A first printing test followed by geometrical characterization of the dispensed contacts revealed a distribution of the contact finger width of wf = 35±1 μm across the whole wafer (156x156mm²) which demonstrates highest precision of the device. The print head is directly integrated in an inline feasible dispensing platform, developed by ASYS GmbH. Respective nozzle plates can be customized to any desired front side grid regarding nozzle diameter, nozzle pitch and the total number of nozzles n. In the actual version, the print head uses two strokes to print two adjacent contact fingers using 50 nozzles while moving up and down at a speed of up to vy = 700mm/s. In a first solar cell test sequence with the new 6“ print head, a maximum cell efficiency of n = 21.2% on industrially preprocessed Cz-PERC samples was reached which demonstrates a successful launching of the print head. A follow up experiment with an industrial reference paste demonstrated similar results on the same material. Here, for the first time, a nozzle opening of only 35μ allowed for a reduction of the wet paste consumption down to mwet,Ag 50mg for the contact grid (N = 100) which is a reduction of m/m 15% compared to screen printed references. At the same time, more homogeneous contact fingers allow for a reduced grid resistance of RGrid/RGrid = -10%.