A method for improving the alignment accuracy of back aluminum grid lines of crystalline silicon double-sided solar cells

Abstract

The invention discloses a method for improving the alignment accuracy of the back aluminum grid line of a crystalline silicon double-sided solar cell. The silicon chip is etched by an acidic solution system, and the acidic solution system includes a volume ratio of 1:1 to 3. hydrofluoric acid and nitric acid; the acidic solution system also includes additives, the additive is a silane coupling agent, citric acid, polyvinyl alcohol, tartaric acid in one or more of the mixture; using the main light source and auxiliary light source to The silicon wafer is irradiated and the picture of the silicon wafer surface is captured by the camera to capture the position of the laser marking point. The main light source is set directly above the silicon wafer and facing the silicon wafer, and the auxiliary light source is located above the side of the silicon wafer; realize the laser marking point The precise alignment and precise coverage of the aluminum grid lines can improve the alignment accuracy of the back aluminum grid lines during printing.

Description

technical field [0001] The invention belongs to the field of solar cell manufacturing, and in particular relates to a method for improving the alignment accuracy of back aluminum grid lines of crystalline silicon double-sided solar cells. Background technique [0002] In recent years, with the in-depth promotion of energy-saving and emission-reduction policies, green and pollution-free solar photovoltaic power generation has become more widely used and gradually known to people. As photovoltaic modules are the basic units of power generation systems, high power generation per unit area and low cost are the priorities of many photovoltaic owners. Bifacial module technology emerged as the times require due to its double-sided power generation characteristics. Polycrystalline occupies a dominant position in the photovoltaic market. PERC (passivated emitter and rear cell) cells are gradually replacing conventional cells due to their higher efficiency and higher technological mat...

AI Technical Summary

Problems solved by technology

However, this type of improvement scheme has the following disadvantages: the replacement of the high-definition camera requires an additional large investment in production costs, and it is impossible to completely avoid the phenomenon of missing printing and partial printing

The inherent characteristics of polycrystalline grain boundaries are chaotic, and this difference will still be amplified during the conventional etching process to remove the back damage, resulting in poor contrast of MARK points in the printed camera, missing printing and partial printing.

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