Four-section back electrode back electric field screen printing plate

Abstract

The invention discloses a four-section back electrode back electric field screen printing plate, which comprises a back electrode of a five-main-grid four-section structure and a back electric field of the five-main-grid four-section structure, and the back electric field correspondingly overprints and covers the back electrode. The back electrode corresponds to the front main grid in position andis divided into four sections by the electrode, and the length of each section is 11 +/-3mm. The length of the back electrode is reduced; the width of the back electrode is increased, and the overlapping area of the back electrode and the back electric field is increased; on the basis of not increasing the consumption of the back silver, the silver-aluminum overlapping area of a junction area isincreased, the conductivity of the back electrode is better improved, ohmic contact of the back silver and the back aluminum is greatly improved, Rs is greatly reduced, longitudinal silicon exposure design is added for a short plate and the back electrode at the welding starting position of an assembly series welding machine, assembly pseudo soldering corresponding to the assembly can be improved,and the assembly tension and the fragment rate are improved.

Description

technical field [0001] The invention relates to the technical field of solar energy, and more specifically relates to a four-segment back electrode back electric field screen. Background technique [0002] At present, the materials printed on the back of solar cells include aluminum paste and silver paste. The function of aluminum paste is to passivate the P area on the back of the solar cell, form the back electric field of the BSF layer, collect electrons, absorb the long wave passing through the cell, and at the same time passivate On the surface, the Uoc and Isc of the battery sheet are improved; the back electrode is used for conduction and welding, and silver paste is the material for making the back electrode, but silver is relatively high in cost. In the prior art, the back electrode and back electric field pattern of silicon solar cells are conventionally designed as four segments, and the electrode length is relatively long, generally between 16-20mm. Considering t...

AI Technical Summary

Problems solved by technology

[0003] However, this kind of screen has the following disadvantages: the overlapping area of ​​the back electrode and the back electric field is too small, and the silver-aluminum ohmic contact is not good enough, resulting in low efficiency; the saturation contact between the back electrode and the back electric field is very easy to be used for component welding. Debris caused by solder joints

The above unreasonable design eventually makes solar cells not only increase the cost, but also have low conversion efficiency

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