Electrical connection method capable of reducing module packaging loss

Abstract

The invention discloses an electrical connection method capable of reducing module packaging loss. Aluminum paste is printed on the back of a screen printing plate, then presintering and sintering are carried out to form an all aluminum back field, and then tin or an alloy of tin is welded as an electrode by adopting an ultrasonic welding technology at the position, corresponding to a positive electrode, on the surface of the back field. Due to the fact that the technology of printing the back silver electrode in a traditional scheme is omitted, the all aluminum back field is formed, and the tin or the alloy of tin is adopted and welded, so that the effects of reducing the cost and enhancing the power can be reached.

Description

technical field [0001] The invention belongs to the technical field of solar energy, and in particular relates to a manufacturing process of a solar cell. Background technique [0002] There are electrical loss and optical loss in the packaging of photovoltaic modules. The optical loss is mainly caused by three aspects: the light transmittance of the glass and the packaging film (EVA, PVB, POE, etc.), the light reflectivity of the back plate, and the optical path matching. The loss is composed of battery resistance loss, ribbon and bus bar resistance loss, contact resistance loss (solder ribbon and battery), junction box resistance loss, and line loss. The existing solutions do not perform well in terms of contact loss between the battery and the ribbon (or interconnection strip). The current general technical solutions have the following three characteristics: [0003] 1. High-purity silver paste is used for the front electrode of the battery, and low-purity silver paste i...

AI Technical Summary

Problems solved by technology

[0007] 1. The silver electrode on the back surface of the battery is in direct contact with the body of the silicon material, which destroys the integrity of the aluminum back surface field (Al-BSF) of the battery and limits the open circuit voltage Voc of the battery;

[0008] 2. The electrode on the back surface of the battery is made of precious metal silver, and the cost is relatively high, which limits the cost reduction space of the battery sheet;

[0009] 3. The electrical connection between the ribbon and the back electrode mainly considers mechanical factors (to ensure long-term reliability), and lacks sufficient consideration for the collection function of the back current