Front pattern structure of solar cell suitable for step-by-step printing and solar cell

Abstract

The invention discloses a front pattern structure of a solar cell suitable for step-by-step printing. The front pattern structure is designed on the front side of the solar cell; the front pattern structure comprises a first printing pattern and a second printing pattern; the first printing pattern comprises a plurality of main grid lines arranged in parallel; each main grid line comprises end welding pad points located at the end of the main grid line, internal welding pad points distributed between the two end welding pad points at intervals, connecting lines connected between the end welding pad points and the internal welding pad points or between the two internal welding pad points, and first connecting grids arranged on the welding pad points and the connecting lines, the extension direction of the first connecting grids is perpendicular to the extension direction of the connecting lines; the second printing pattern comprises a hollow part corresponding to the end welding pad points and a plurality of parallel auxiliary grid lines; and the first connecting grids are used for connecting the main grid lines and the auxiliary grid lines.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic modules, and in particular relates to a step-by-step printed front pattern structure of a solar cell and a solar cell including the front pattern structure. Background technique [0002] Solar photovoltaic power generation, due to its cleanliness, safety, convenience and high efficiency, has become an industry that is widely concerned and focused on development all over the world. With the continuous innovation of technology, the conversion efficiency of solar cells is also increasing rapidly, so cost reduction and efficiency increase have become the top priority of solar energy companies. [0003] The existing printing methods of solar cells can be divided into single printing, step printing and double printing. Compared with traditional single printing, step printing has the advantages of reducing unit consumption cost, improving conversion rate, and enhancing front electrode pulling force,...

AI Technical Summary

Problems solved by technology

[0005] However, in the front pattern structure of the existing solar cells, on the one hand, since the printed part of the main grid uses non-burn-through front silver paste, especially the U-shaped hollow part of the main grid, which is printed integrally with the main grid, Offset is easy to occur, and because the use of non-burn-through front silver paste cannot form a good Ag-Si alloy layer with the silicon substrate, the contact resistance becomes larger and the current transmission capability becomes weaker, resulting in blackening under EL detection ; On the other hand, in the front pattern structure of the existing solar cells, although there has been a tapered connection grid at the junction of the main grid and the auxiliary grid to improve the electrical connection between the main grid line and the auxiliary grid line, it is guaranteed Current transmission, but in some cases where the printing accuracy is not enough or the equipment is old, it is still possible to electrically connect the main grid line and the auxiliary grid line only by adding a tapered connection grid

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